Progress in Solar Energy Technologies and Applications 9781119555681, 111955568X

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Progress in Solar Energy Technologies and Applications

Scrivener Publishing 100 Cummings Center, Suite 541J Beverly, MA 01915-6106

Publishers at Scrivener Martin Scrivener ([email protected]) Phillip Carmical ([email protected])

Progress in Solar Energy Technologies and Applications

Edited by

Umakanta Sahoo

This edition first published 2019 by John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, USA and Scrivener Publishing LLC, 100 Cummings Center, Suite 541J, Beverly, MA 01915, USA © 2019 Scrivener Publishing LLC For more information about Scrivener publications please visit www.scrivenerpublishing.com. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions. Wiley Global Headquarters 111 River Street, Hoboken, NJ 07030, USA For details of our global editorial offices, customer services, and more information about Wiley prod-ucts visit us at www.wiley.com. Limit of Liability/Disclaimer of Warranty While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials, or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Library of Congress Cataloging-in-Publication Data ISBN 978-1-119-55560-5 Cover image: Solar Panel City - Ssuaphoto | Dreamstime.com Cover design by Kris Hackerott Set in size of 11pt and Minion Pro by Manila Typesetting Company, Makati, Philippines Printed in the USA 10 9 8 7 6 5 4 3 2 1

Contents About the Editor

xi

Contributors

xii

1 Reliability Testing of PV Module in the Outdoor Condition Birinchi Bora, O.S. Sastry, Som Mondal and B. Prasad 1.1 Introduction 1.2 Indoor Testing of Reliability of PV Module 1.3 Basics of Measurement Methods used to Identify Failures in the PV Module in the Field after Installation 1.3.1 Visual Inspection 1.3.2 I-V Tracer 1.3.3 Temperature Coefficient 1.3.4 Series Resistance 1.3.5 Curve Correction Factor 1.3.6 Dark I-V 1.3.7 Degradation Analysis 1.3.8 IR Thermography 1.3.9 Insulation Resistance Tester 1.3.10 EL Camera 1.3.11 Interconnect Breakage Tester 1.3.12 Current, Voltage and Continuity Checking 1.3.13 Environmental Parameter Checking 1.4 Quantification of Reliability 1.5 Procedure for Performance and Reliability Testing of PV Module in Outdoor Conditions 1.5.1 Selection Procedure of PV Modules for Testing in the Field 1.5.2 Testing Report Format of Performance Guarantee Test 1.6 Conclusion Abbreviation References

1 1 4 7 8 11 13 15 16 17 18 19 22 23 25 25 25 26 33 33 33 35 35 36

v

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Contents

2 Solar Energy Technologies and Water Potential for Distillation: A Pre-Feasibility Investigation for Rajasthan, India Nikhil Gakkhar, Manoj Kumar Soni and Sanjeev Jakhar 2.1 Introduction 2.2 Solar Assisted Technologies for Water Purification 2.3 Resource Availability in Rajasthan, India, for Solar Distillation 2.3.1 Availability of Solar Irradiance 2.3.2 Land Availability in Rajasthan 2.3.3 Water Availability from Various Sources 2.3.3.1 Surface Water Resources of Rajasthan 2.3.3.2 Rainfall 2.3.3.3 Domestic Wastewater 2.3.3.4 Groundwater 2.4 Estimation of Solar Potential and Water Availability 2.4.1 Solar PV Potential 2.4.2 Solar CSP Potential 2.4.3 Water Potential Estimation for Distillation 2.5 Choice of Distillation Technology 2.5.1 PV-Assisted RO Plants 2.5.2 CSP-Assisted MSF Plants 2.6 Conclusion Nomenclature References 3 Design Analysis of Solar Photovoltaic Power Plants for Northern and Southern Regions of India Sanjay Kumar 3.1 Introduction 3.1.1 Solar Power in India 3.2 Site Selection 3.2.1 Geography 3.2.2 Specification of Locations 3.2.3 Location Dedicated for Power Plant Setup 3.2.4 Load Profile of INA 3.3 Technology 3.3.1 Solar PV Systems 3.3.2 Major Components 3.3.2.1 Module 3.3.2.2 Inverters 3.3.2.3 Auxiliary Components 3.4 BOM for 3MW Power Plant

39 40 41 45 47 47 51 51 54 54 58 58 59 60 61 65 65 71 75 77 77 83 83 88 90 90 100 100 116 124 124 125 126 127 128 134

Contents 3.5 Quality, Testing and Standard Certification 3.6.1 Modules selection 3.6.1.1 Installation of Module 3.6.2 Inverter Selection 3.7 Financial Analysis 3.8 Plant Layout with Electrical and Civil Engineering Aspects 3.8.1 Land Requirement 3.8.2 Plant Layout 3.8.3 Civil Works 3.8.4 Module Mounting Structures 3.8.5 Operation and Maintenance 3.9 Monitoring System 3.9.1 SCADA 3.9.2 Control and Instrumentation System 3.10 Environmental Aspects 3.10.1 State Pollution Control Board Clearances 3.11 Project Management 3.11.1 Project Contracting 3.11.2 Quality Management 3.11.3 Construction Management 3.11.4 Health, Safety and Environment 3.11.5 Commissioning and Testing 3.11.6 Operation and Maintenance (O & M) 3.11.7 Training 3.12 Solar Business Models for Megawatt-Scale Projects in India 3.12.1 Power Purchase Agreement (PPA) Model 3.12.2 Captive Model 3.12.3 REC Model 3.12.4 REC Formalities and Procedures 3.12.5 Business Models under the REC Mechanism 3.12.6 Risk Factors of REC 3.13 Concepts toward Net Zero Energy Solar Building 3.14 Strategy Implementation 3.15 Conclusion Abbreviations References 4 Cold Storage with Backup Thermal Energy Storage System K. Sahoo, B. Bandhyopadhyay, S. Mukhopadhyay, U. Sahoo, T. S. Kumar, V. Yadav and Y. Singh 4.1 Introduction 4.1.1 Recommended Condition for Fruits and Vegetables

vii 140 146 147 148 150 151 151 151 152 152 152 153 153 154 155 156 156 156 157 157 158 159 160 161 161 161 161 162 163 165 166 167 168 176 177 179 181

181 183

viii

Contents 4.2

4.3

4.4 4.5

4.6 4.7 4.8 4.9 4.10 4.11

4.12

4.1.2 Incompatibility Solar Energy Scenario 4.2.1 Overview of Solar Radiation 4.2.1.1 Basic Principles 4.2.1.2 Diffuse and Direct Solar Radiation 4.2.1.3 Global Solar Radiation Refrigeration Technology Overview 4.3.1 Brier Introduction of Refrigeration 4.3.2 Carnot Cycle 4.3.3 Reverse Carnot Cycle 4.3.4 Air Refrigeration Cycle 4.3.5 Vapour Compression Refrigeration System 4.3.6 Actual Vapour Compression Refrigeration System Literature Review Designing of Solar PV Cold Storage 4.5.1 Determining the Size of Cold Room 4.5.2 Cooling Load Calculation 4.5.2.1 Transmission Load 4.5.2.2 Heat Transmission through Door 4.5.2.3 Equipment Load 4.5.2.4 Product Heat Load 4.5.2.5 Heat of Respiration 4.5.2.6 Human Occupancy Load 4.5.2.7 Cooling Load Due to Thermal Energy Storage 4.5.3 Cooling Load Summary for 10 MT Storage Capacities 4.5.4 Solar Photovoltaic Plant Design 4.5.4.1 Photovoltaic Module Design 4.5.4.2 Inverter Sizing 4.5.4.3 Battery Sizing 4.5.4.4 Solar Charge Controller Sizing Design of Cold Room Mechanical System Designing of Thermal Energy Storage System (TES) Battery Storage Refrigerant Specification of Cold Storage and Thermal Energy Storage System Design of Solar Thermal Based Cold Storage 4.11.1 Technology Selection 4.11.2 Energy and Collector Area Required from Solar Thermal Technology Economic Analysis 4.12.1 Net Present Value (NPV)

183 184 187 187 188 188 190 190 191 192 193 194 195 195 196 197 197 197 198 199 199 199 200 200 200 202 202 202 203 203 203 206 208 208 209 210 211 212 213 213

Contents 4.12.2 Internal Rate of Return (IRR) 4.12.3 Payback Period 4.13 Economic Analysis of Solar PV Cold Storage 4.13.1 NPV and IRR Calculation of Solar PV Cold Storage 4.13.2 Payback Period of Solar PV Cold Storage 4.14 Economic Analysis of Solar Thermal System Based Cold Storage 4.14.1 NPV and IRR Calculation 4.14.2 Payback Period of Solar Thermal Cold Storage 4.15 Conclusion References 5 Development of Parabolic Trough Collector Based Power and Ejector Refrigeration System Using Eco-Friendly Refrigerants D.K. Gupta, R. Kumar and N. Kumar 5.1 Introduction 5.2 Literature Review 5.3 Solar Operated Ejector Cooling and Power Cycle 5.3.1 Working of Proposed Cycle 5.3.2 First and Second Law Analysis of Proposed Cycle 5.4 Ejector Cooling and Power Cycle with Various Ecofriendly Refrigerants 5.4.1 System Description 5.4.2 Properties of Refrigerants 5.4.3 Thermodynamic Analysis 5.4.4 Parameters considered for Operation of Proposed System 5.5 Ejector Organic Rankine Cycle Integrated with a Triple Pressure Level Vapour Absorption System 5.5.1 Working of Proposed System 5.5.2 Energy and Exergy Analysis of the Proposed System 5.6 Combined Organic Rankine Cycle with Double Ejector 5.6.1 Working of Proposed Cycle 5.6.2 First and Second Law Analysis of Proposed Cycle 5.7 Result and Discussions 5.8 Conclusion Nomenclatures Greek symbols Subscript References

ix 214 214 215 215 221 223 223 229 231 231 233 234 236 244 245 247 250 250 251 251 253 253 253 258 261 262 264 267 297 298 299 300 300

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Contents

6 Unlocking the Design of Stand-Alone and Grid-Connected Rooftop Solar PV Systems Tanmay Bishnoi 6.1 Introduction 6.2 Stand-Alone Solar PV System 6.2.1 Types of Stand-Alone PV System Configurations 6.2.2 Design Methodology 6.2.3 Detailed Steps for Designing a Solar PV System 6.2.4 Stand-Alone Solar PV System Design and Safety Standards 6.3 Grid-Connected Solar PV System 6.3.1 Step by Step Procedure for Designing a Rooftop Grid-Connected Solar PV System 6.3.2 Grid-Tied Solar PV System Standards 6.3.3 Performance Analysis of a Solar PV System 6.4 Costing Analysis for a Solar PV System 6.5 Conclusion References Index

309 310 312 312 313 314 330 330 331 333 334 337 359 360 363

About the Editor Umakanta Sahoo, Ph.D., is Research Scientist at the National Institute of Solar Energy, India. He has 8 years of research experience in the field of Solar and Biomass Energy. He has published many research papers in International Journals and two books in the field of solar, biomass energy, polygeneration system and six books in the field of Mechanical Engineering. His research interest areas are Energy, Exergy, Hybrid Solar-Biomass power in Co(Poly-) Generation Process, Solar Photovoltaic Thermal System, Primary Energy Saving, Waste heat utilization for industrial processes, Organic Rankine Cycle, Cooling with Process Heat, Desalination, Energy Storage, Solar Thermal Technologies Characterization, Solar Radiation and Biomass Resources Assessments. He has conducted numerous trainings on designing, operation and maintenance of solar energy systems.

xi

Contributors Birinchi Bora National Institute of Solar Energy, Gurugram, Haryana India O.S. Sastry National Institute of Solar Energy, Gurugram, Haryana India Som Mondal TERI School of Advanced Studies, New Delhi, India B. Prasad TERI School of Advanced Studies, New Delhi, India Nikhil Gakkhar Sardar Swaran Singh National Institute of Bio Energy, Kapurthala Manoj Kumar Soni Department of Mechanical Engineering, Birla Institute of Technology & Science, Pilani, Rajasthan Sanjeev Jakhar Mechanical Engineering Department, Mody University of Science and Technology, Lakshmangarh, Rajasthan Sanjay Kumar National Institute of Solar Energy, Gurugram-122003, India K.Sahoo Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India B. Bandhyopadhyay Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India S. Mukhopadhyay Indian Institute of Engineering Science and Technology, Shibpur, West Bengal, India U. Sahoo National Institute of Solar Energy, Gurugram, Haryana India T. S. Kumar National Institute of Solar Energy, Gurugram, Haryana India V. Yadav National Institute of Solar Energy, Gurugram, Haryana India Y. Singh National Institute of Solar Energy, Gurugram, Haryana India D.K. Gupta Mechanical Engineering Department, IPEC, Ghaziabad, Uttar Pradesh, India R. Kumar Department of Mechanical Engineering, Delhi Technological University, New Delhi, India N. Kumar Department of Mechanical Engineering, Delhi Technological University, New Delhi, India Tanmay Bishnoi Skill Council for Green Jobs, New Delhi, India

xiii

1 Reliability Testing of PV Module in the Outdoor Condition Birinchi Bora*1, O.S. Sastry1, Som Mondal2 and B. Prasad2 1

National Institute of Solar Energy, Gurugram, India TERI School of Advanced Studies, New Delhi, India

2

Abstract This chapter describes the procedure of reliability testing of PV modules. Applicable standards for both indoor and outdoor conditions are explained. Required equipment for the inspection of the PV module in the outdoor condition, its scope and procedures, are described in this chapter. Procedures to quantify the reliability of different failure modes are also explained. A test report format is described in the chapter for reporting the reliability of PV module. Keywords: PV module, reliability, indoor test, outdoor test, temperature coefficient, I-V tracer, degradation, breakage tester

1.1 Introduction People’s energy requirements are increasing day by day. For meeting their energy requirements, most people are using conventional energy sources. However, due to limited and unsustainable conventional sources of energy generation, the popularity of solar photovoltaic is increasing as one of the cleanest and best energy sources. As per Global status report 2018 (REN21), renewable energy covers 26.5% of the total estimated global energy consumption. In global energy consumption, the contribution of solar PV technology is only 1.9% [1]. In recent years, PV power plant installation in developing countries has been increasing because of its decentralized applications. It has been observed that in India, the total target of PV power plant installation is very high, up to 100 GW by 2022 [2]. Most of the developed and developing countries of the world are *Corresponding author: [email protected] Umakanta Sahoo (ed.) Progress in Solar Energy Technologies and Applications, (1–38) © 2019 Scrivener Publishing LLC

1

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Progress in Solar Energy Technologies and Applications

increasing their target to use solar PV as an energy source [3]. So, the competition in the solar PV power market is increasing day by day. People are cutting costs in the power plant installation to reduce the payback period. The cost of installation of a PV power plant is going down, but at the same time, the component used for the power plant must be reliable. The reliability of a power plant is nothing but getting optimum output with safety during its operating lifetime [4]. The reliability of the components of the PV power plant needs to be tested before its installation in the field [5]. Testing standards for reliability testing of components of PV power plant are available from different international organizations like the International Electro-technical Commission (IEC), IEEE, UL, TUV, etc. In the case of a tropical country like India, the module gets a fail in the field because of the harsh environment, although the module qualifies in the test, according to IEC 61215/IEC 61646. A survey conducted by National Institute of Solar Energy, India and Indian Institute of Technology Bombay, India, has reported that the degradation rate of C-Si in the field is more than 2% per year in the case of a good module. However, the degradation rate is very high in the case of bad modules [6–8]. To ensure the performance guarantee during its lifetime the reliability of the power plant needs to be maintained. Sometimes the PV module needs to be replaced in the power plant after some time of operations if reliability issues arise. The reliability checking of the module after installation is a requirement to ensure the performance guarantee. There are three different types of a PV power plant in terms of its design configurations, viz., off-grid, on-grid and hybrid power plant. An off-grid power plant consists of a PV module, inverter, battery, and no feeding electricity to the grid; An on-grid PV power plant consists of a PV module, inverter and feeding electricity directly to the grid; a hybrid PV power plant consists of a PV module, inverter, battery and feeds electricity to the grid and also has off-grid use. A typical list of the bill of material (BOM) of 1 MWp on-grid PV power plant is given in Table 1.1. The list will give the reader a glimpse about the requirements of different components for the installation of the PV power plant. For the inspection of the PV power plant, it is necessary to know about the technical specifications of the components used. The AC and DC components used for the power plant and the details about the weather sensors required to be used are also given in Table 1.1. The failure mode of a PV module is defined as the defects that (i) produce non-reversible degradation of power output and (ii) creates a safety issue. There are some defects that do not affect the performance and safety of PV module; such are known as benign defects [9–11]. A PV module failure is relevant for the warranty when it occurs under conditions the module normally experiences. There are two types of reliability testing of PV module: before installation and after installation. Before installation, PV modules are usually tested in indoor conditions. After installation of the PV module in

Reliability Testing of PV Module in the Outdoor Condition 3 Table 1.1 BOM of 1 MWp Grid-Tied SPV Power Plant. Sl. No.

Description

Approximate Quantity

Unit

1

Solar PV Module

1000

kWp

2

1000 kW Grid Tied 3- Phase Central Inverter

1

Nos.

3

Mounting structure for ground

1000

kWp

4

DC String Fuse (1000V, 20A)

300

Nos.

5

DC Isolator [(1500V, 100A) + (1500V, 160A)]

1+12

Nos.

6

DC Surge Protector Device

13

Nos.

7

DC Combiner Box [(12 In 1 Out) + (6 In - 1 Out)]

12 + 1

Nos.

8

DC cable [(Single core, 6mm2), (Single core, 70mm2)]

1100+1700

Meter

9

1.25 MVA, 400V/33kV Transformer and compact substation

1

Nos.

10

AC wire for Inverter to transformer (Single core, 400mm2 Al)

32

Meter

11

AC wire Transformer to meter (4 core, 120 mm2 Al)

400

Meter

12

Vacuum circuit breaker 33kV

1

Nos.

13

Lightning arrestors

4

Nos.

14

Earthing strip earth pit

14

Nos.

15

Energy meter

1

Set

16

Monitoring system

1

Set

17

Pressure sensor

1

Set

18

Rain gauge

1

Set

19

Humidity sensor

1

Set

20

Wind sensor

1

Set

21

Pyranometer

1

Set

21

Temperature sensor

3

Set

4

Progress in Solar Energy Technologies and Applications

the field, indoor testing is a tedious job and it is not economically feasible for a large type of installation. To check the reliability of a PV module in the field, outdoor testing with proper procedure needs to be adopted. The power plant owner can check the power plant during its warranty period for claiming warranty. Usually, a PV module degrades more than any other components of a PV power plant in the field. The technologies of all other components are more matured than PV modules. In this chapter basically, the reliability study of PV module in the outdoor condition will be analyzed in detail.

1.2 Indoor Testing of Reliability of PV Module For the testing of the qualification or reliability of PV module, there are different standards available for indoor testing. The International Electrotechnical Commission (IEC) prepares and publishes international standards for all electrical, electronic and related technologies including PV modules. For indoor testing of reliability of PV modules before installation in the field some of the following IEC standards can be used: A. IEC 61215: 2016 There are two main sections under this category: I. IEC 61215-1: 2016 Terrestrial photovoltaic (PV) modules Design qualification and type approval - Part 1: Test requirements [12] This standard depicts the test requirements to test the design qualification requirements and type approval of terrestrial module for long-term operation in the field. It is applicable to all terrestrial flat-plate modules such as crystalline silicon and thin-film module types. It has four parts: a)

b)

c)

IEC 61215-1-1:2016 Terrestrial photovoltaic (PV) modules Design qualification and type approval - Part 1-1: Special requirements for testing of crystalline silicon photovoltaic (PV) modules [13]. IEC 61215-1-2:2016 Terrestrial photovoltaic (PV) modules Design qualification and type approval - Part 1-2: Special requirements for testing of thin-film Cadmium Telluride (CdTe) based photovoltaic (PV) modules [14]. IEC 61215-1-3:2016 Terrestrial photovoltaic (PV) modules Design qualification and type approval - Part 1-3: Special requirements for testing of thin-film amorphous silicon-based photovoltaic (PV) modules [15].

Reliability Testing of PV Module in the Outdoor Condition 5 d)

IEC 61215-1-4:2016 Terrestrial photovoltaic (PV) modules Design qualification and type approval - Part 1-4: Special requirements for testing of thin-film Cu(In,GA)(S,Se)2 based photovoltaic (PV) modules [16]. All four parts are related to different technologies of PV modules. The main aim of these testing standards of the PV module is to determine the electrical and thermal characteristics of the module and check its capability of withstanding the climatic stress of the field for its useful lifetime. In general, the useful lifetime of the PV module is around 25 years and it depends on the warranty period provided by the manufacturer. To ensure the warranty claim by the manufacturer, these standards can be used to test the PV modules.

II. IEC 61215-2:2016 Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 2: Test procedures [17] This standard depicts the test procedure to test the design qualification requirements and type approval of terrestrial module for long-term operation in the field. It is applicable to all terrestrial flat-plate modules such as crystalline silicon and thin-film module types. B. IEC 61730:2016 There are two main sections under this category: I. IEC 61730-1:2016 Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction [18] This standard depicts the fundamental construction requirements for photovoltaic modules in order to provide safe electrical and mechanical operations in the field. This standard is applied to all terrestrial flat-plate module such as crystalline silicon and thin-film modules. It includes checking for the prevention of electric shock, fire hazards and personal injury due to mechanical and environmental stress. II. IEC 61730-2:2016 Photovoltaic (PV) module safety qualification - Part 2: Requirements for testing [19] This standard is depicting the testing sequence for all terrestrial flat-plate photovoltaic modules such as crystalline silicon and thin film. Test categories include general inspection, electrical shock hazard, fire hazard, mechanical stress, and environmental stress to find out the potential breakdown of internal and external components of PV modules.

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Progress in Solar Energy Technologies and Applications C. IEC TS 62804-1:2015 Photovoltaic (PV) modules - Test methods for the detection of potential-induced degradation - Part 1: Crystalline silicon [20] This standard depicts the test methods of detection of potential induced degradation (PID) of crystalline silicon module. The reliability of a PV module due to climatic and high-voltage stress can be checked using this standard. It has been observed in the field that PID is likely in the module installed in a hot and humid climate with high-system voltage. This is not a full standard until now. However, in some parts of the world people have modified the testing conditions of this standard for PID testing as per their local conditions. D. IEC 61701:2011 Salt mist corrosion testing of photovoltaic (PV) modules [21] This standard depicts the test methods to determine the resistance of different PV modules to corrosion from salt mist containing Cl- (NaCl, MgCl2, etc.). This Standard can be applied to both flat-plate PV modules and concentrator PV modules and assemblies. The testing sequence includes a cycle of salt fog exposure followed by humidity storage under controlled temperature and relative humidity conditions. E. IEC 62716:2013 Photovoltaic (PV) modules - Ammonia corrosion testing [22] This standard depicts the test methods to determine the resistance of different PV modules to corrosion from ammonia (NH3). It is used to evaluate possible faults caused in PV modules when operating under wet atmospheres having a high concentration of dissolved ammonia. F. IEC 62759-1:2015 Photovoltaic (PV) modules - Transportation testing - Part 1: Transportation and shipping of module package units [23] This standard describes the methods for the simulation of transportation of complete package units of modules and combined subsequent environmental impacts. The requirement of this test is more for the countries where the road conditions are not good for the transportation of the PV module.

Reliability Testing of PV Module in the Outdoor Condition 7 G. IEC TS 62782:2016 Photovoltaic (PV) modules - Cyclic (dynamic) mechanical load testing [24] This technical specification describes a test method for performing a cyclic (dynamic) mechanical load test in which the module is supported at the design support points and a uniform load normal to the module surface is cycled in negative and positive directions. This test is used to check the mechanical stress due to wind over the module. The requirement of this test is more in the areas where wind speed is very high.

1.3 Basics of Measurement Methods used to Identify Failures in the PV Module in the Field after Installation Table 1.2 shows the different methods used to detect different failure mode and a list of equipment required for this purpose. The details about all these methods are explained below:

Table 1.2 List of equipment used for inspection of PV power plant. Method

Equipment required

Visual inspection

A trained eye, sufficient light, digital camera

I-V curve testing

I-V curve tracer

Thermography

IR camera, DC power supply

Electroluminescence

EL camera, DC power supply

Insulation testing

Insulation resistance tester

Inspection of disconnection in interconnection of cells

Interconnect breakage tester

Current, voltage and continuity checking

Ammeter, Voltmeter or multi-meter

Environmental parameter checking

Weather station

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Progress in Solar Energy Technologies and Applications

1.3.1 Visual Inspection Visual inspection of the PV module is required to perform at more than 1000 lux. Visual inspection is done in terms of IEC 61215 -1: 2016 [13–16]. Table 1.3 shows the different failure modes of the PV module for different components. In this chapter, the only procedure for visual inspection of the module installed in the field is explained. The defects in different components affect the performance and safety issues in the field. A. Inspection procedure: The following procedure can be followed for the visual inspection of the used module in the field. 1. Identify and differentiate the different product types/sizes to be inspected in the power plant. 2. Select the sample size in the power plant. It is good to check all the modules in the power plant but it may increase the Table 1.3 List of visual defects in different PV components [13]. PV module component

Defect

Front of PV module, encapsulant

Bubbles, delamination, yellowing, browning, burn marks

Glass or front cover

Broken, cracked, or torn external surfaces.

PV Cells

Broken cell, cracked cell, discolored antireflection, snail trails

Cell metallization

Burned, oxidized

Frame

Bend, broken, scratched, misaligned

Back of module

Delaminated, bubbles, yellowing, scratches, burn marks, exposure of electrical parts

Junction box

Loose, oxidation, corrosion

Wires – connectors

Detachment, brittle, exposed electrical parts

Diode

Broken, burn marks

Module marking, nameplate

Not attached, information unreadable

Interconnection of cell/ string, joints or terminal

Broken, corroded, short-circuited live parts

Reliability Testing of PV Module in the Outdoor Condition 9 amount of work. So, some people decide to choose 5% of the total number of modules in the power plant. 3. The inspector should complete a checklist of defects for each module and other components of the power plant. The checklist should be prepared with an indication of defect presence and percentage of severity. 4. Depending on the requirements, photos need to be taken. 5. The inspector should review the results and find out the level of severity for the particular defects. Figure 1.1 shows the browning of encapsulant after a long term of operation. The browning of encapsulant happens due to humidity and UV exposure to the module. Browning of encapsulant can lower the short circuit current of the PV module. This also corresponds to an increase in leakage current in the module. Figure 1.2 shows the corrosion of metal contacts; this

Figure 1.1 Browning of C-si module.

Figure 1.2 Corrosion of metal contacts.

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Progress in Solar Energy Technologies and Applications

Figure 1.3 Corrosion of grid lines.

will lead to an increase in series resistance. Figure 1.3 shows the corrosion of grid lines of the PV module; this will also increase the series resistance in the PV module. Figure 1.4 shows the delamination of encapsulant over the cell. This happens due to long-term outdoor exposure of UV and humidity in the field. Figure 1.5 shows the burn marks in the backsheet of the PV module. This is a safety issue and its occurrence may be due to a hot spot. Figure 1.6 shows the crack in the front glass of the PV module; this is a safety issue. This may reduce the transmissivity in the PV module. B. Acceptance or rejection criteria As per IEC 61215, the module can be rejected if some major visual defects are found in the module as mentioned in the above Table 1.3.

Figure 1.4 Delamination of solar cell.

Reliability Testing of PV Module in the Outdoor Condition 11

Figure 1.5 Burn marks on the backsheet.

Figure 1.6 Glass breakage of PV module.

1.3.2

I-V Tracer

An I-V tracer is used to trace the current-voltage characteristics of a PV module under lighted conditions. In an I-V tracer, the current is measured against a variable load point of resistance. For measuring the performance of the PV module, the voltage measuring a range of I-V tracer should be from 10 Volt to 1000 Volt. The voltage range should be high so that the same tracer can also be used to measure the performance of the module in the series. The measuring current range for the instrument should be more than 10 Ampere. The uncertainty level of the equipment should be less than 1%. I-V tracer should have the facility to measure the irradiance and module temperature as well. Usually, for measuring the temperature, Pt100 or Pt1000 sensors are used because of its accuracy and temperature measuring range. The irradiance sensor should be solar cell based; this can reduce mismatch in the in-plane irradiance and effective irradiance for tested module technology.

Progress in Solar Energy Technologies and Applications

12

Trace current-voltage characteristics of the PV module at a constant irradiance and temperature covering the range of interest of testing condition. For the estimation of performance at desired irradiance and temperature level, procedure 1 of IEC 60891-1 is used here. The formulae are as follows [25]:

I2

I1 I SC

G2 1 G1

* (T2 T1 )

(1.1)

V2 = V1 – RS (I2 – I1) – k * I2 * (T2 – T1) + β * (T2 – T1)

(1.2)

Where, I2, V2 = Target current and voltage, I1, V1 = Measured current and voltage, G2, T2 = Target irradiance and temperature, G1, T1 = Measured irradiance and temperature, α = temperature coefficient Isc (A/°C), β = temperature coefficient Voc (V/°C), Rs = series resistance (Ω), κ = curve correction factor (Ω/°C). Figure 1.7 shows the current-voltage and power-voltage of a PV module. It is the measured current against the change in load resistance. At 4 300 3.6 270

Translated I-V curve to STC

3.2

240 2.8 Current in A

180

2

150

I-V curve as measured

1.6

120

1.2

90

0.8

P-V Curved

60

0.4 0 0

30 8

16

24

32

40 48 Voltage in V

Figure 1.7 I-V and P-V curve of a PV module.

56

64

72

0 80

Power in W

210 2.4

Reliability Testing of PV Module in the Outdoor Condition 13 zero voltage, the corresponding current is known as short circuit current and at infinity resistance when current is zero, the corresponding voltage is known as open circuit voltage. The current and voltage corresponding to maximum power is known as the current and voltage at the maximum power point.

1.3.3 Temperature Coefficient The temperature coefficient of the PV module in outdoor condition can be estimated by measuring I-V data at fixed irradiance and variable temperature. The facility is required to cool the module with respect to the ambient temperature of the site. Short circuit current, open circuit voltage, and maximum power need to be plotted against the module temperature at fixed irradiance. The slope of the electrical parameter with respect to temperature is the temperature co-efficient of the particular electrical parameter. The percentage of temperature coefficient is estimated by dividing the slope by electrical parameters at STC [25]. Figure 1.8 shows the performance of the PV module at different irradiance conditions and at the same irradiance range. Figure 1.9 shows the procedure for estimation of temperature coefficients of different technologies, normalized short circuit current, open circuit voltage, and power are plotted against the temperature. A linear fitting is done for each parameter individually. Table 1.4 shows the typical temperature coefficients of different module technologies. It has been observed from the table that the power temperature co-efficient of thin-film technologies are low as compared to other technologies. 10

Current (A)

8 Module temperature (°C) 20 25 35 50

6

4

2

0 0

10

20 30 Voltage (V)

40

50

Figure 1.8 I-V curve of PV module at different module temperature and at 1000 W/m2.

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Pmax (W)

15 300

20

25

30

35

40

45

50

55

60

Linear fit

288 276

Slope: –1.063

264

Voltage (V)

47.5

Linear fit

45.6 43.7 Slope: –0.135 41.8

Isc (A)

8.47

Linear fit Slope: 0.0039

8.36 8.25 8.14 15

20

25

30 35 40 45 50 Module temperature (°C)

55

60

Figure 1.9 Change in Isc, Voc and Pmax at different temperature.

Table 1.4 Typical temperature co-efficient of different module technologies. Technology

Power

Current

Voltage

Mono-crystalline silicon

-0.45 %/°C

0.04 %/°C

-0.37 %/°C

Multi-crystalline silicon

- 0.485 %/ °C

+0.053 %/ °C

-0.36%/°C

Amorphous silicon

-0.35%/°C

0.056%/°C

-0.39%/°C

CdTe / CdS

-0.32%/°C

0.04%/°C

-0.28%/°C

HIT (Hetero-junction with thin interfacial layer)

-0.30%/°C

0.03%/°C

-0.25%/°C

Sun power (Maxeon©)

-0.37%/°C

0.04%/°C

-0.34%/°C

CIGS

-0.26%/°C

0.004%/°C

-0.24%/°C

Micro-morph

-0.24%/°C

0.07%/°C

-0.3%/°C

Reliability Testing of PV Module in the Outdoor Condition 15

1.3.4 Series Resistance As per IEC 60891 [25], for estimation of series resistance, two I-V curves at different irradiance but with a constant temperature and spectrum is required. For this, a mesh is used for having different irradiance at the same instant of time without any change in spectrum and module temperature. In procedure 1 of IEC 60891 method the current and voltage needs to find out through the I-V characteristics and uses the equation below;

Ir Im Isc

Gr 1 Gm

(Tr Tm)

Vr = Vm – Rs (Ir – Im) – κIr (Tr – Tm) + β(Tr – Tm)

(1.3)

(1.4)

where Ir is the rated current, Im is the measured current, Isc is the short circuit current, Rs is the series resistance, Vr is the rated voltage, Vm is the measured voltage, k is the curve correction factor and α is the temperature coefficient of the module. The translational procedure 1of IEC 60891 can be mathematically formulated as below:

I2

I1 I sc

G2 1 G1

(1.5)

V2 = V1 – Rs × (I2 – I1)

(1.6)

P = V2 × I2

(1.7)

where I1 and V1 are the pair of measured points on the I-V characteristics, I2 and V2 are the pair of points of the resulting corrected characteristic, G1 is the irradiance measured with the reference; G2 is the irradiance at the reference or other desired conditions. For the calculation of series resistance, I-V curve at lower radiation with constant module temperature is translated into higher radiation data with same module temperature. Since I-V curves are at the same temperature, the temperature coefficient will not play any role. Change RS in steps of 10 mΩ in the positive or negative direction. The deviation of maximum output power values of the transposed I-V characteristics needs to be determined and the proper “Rs” will be found if the Pmax deviation is within ± 0.5 % or better. Figure 1.10 shows the I-V curve of a PV module at different irradiance. Figure 1.11 shows the transparent mesh, which can be used to test the module

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Progress in Solar Energy Technologies and Applications 10

Current (A)

8

6

4

600 W/m2 800 W/m2 1000 W/m2

2

0 0

10

20 30 Voltage (V)

40

50

Figure 1.10 I-V curve at different irradiance and at fixed temperature.

Figure 1.11 Light transparent mesh used in outdoor condition.

at different irradiance and at the same temperature. The gap between the mesh and module should be more than 4 inches to avoid the shadow.

1.3.5 Curve Correction Factor Trace current-voltage characteristics of the PV module at a constant irradiance and at different temperatures covering the range of interest of irradiance condition as mentioned in Figure 1.8. During the I-V measurements, irradiance shall not differ by more than ±1 %. Translate the I-V curve of all the temperature data to the lowest module temperature data by using

Reliability Testing of PV Module in the Outdoor Condition 17 Table 1.5 Typical value of curve correction factor of different PV module technology at 1000 W/m2. Technology

κ (Ω/K)

CIGS

0.069

CdTe / CdS

0.382

Micro-morph

0.07

Multi-crystalline

0.025

HIT

0.014

Sun power (Maxeon©)

0.042

κ = 0 Ω/K in the translational equation. Starting from 0 mΩ/K, κ needs to change in steps of 1 mΩ/K in the positive or negative direction. The proper value of κ has been determined, if the deviation of maximum output power values of the transposed I-V characteristics coincide within 0.5 % or better [25]. Table 1.5 shows the typical value of curve correction factor for different technologies. These values depend on irradiance and are basically technology specific.

1.3.6 Dark I-V It is used to measure the internal resistances of PV modules. The power supply should be bipolar to trace the I-V in both +Ve and –Ve side of the module. The current measurement accuracy should be highly accurate in the μA range also. Data logging of current against applied voltage should be automatic. In order to calculate the dark I-V parameters of the module, we converted the dark I-V of the module into the dark I-V of an equivalent solar cell by dividing the voltage (at each I-V data point) by the number of (series) cells in the module. The ideality factor n of the equivalent solar cell diode is calculated from the slope obtained by drawing a tangent at the maximum power point voltage Vmp [8].

Slope = q/nkT

(1.8)

Figure 1.12 shows a dark I-V of a PV module. The dark I-V depends on the temperature of the module. Figure 1.13 shows a curve between ln(I) versus applied voltage of a PV module. The measurement is done at 25°C.

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Progress in Solar Energy Technologies and Applications 7 6

Current (A)

5 4 3 2 1 0 16

18

20

22

24

26

28

30

32

0.26

0.28

0.30

Voltage (V)

Figure 1.12 Dark I-V curve of PV module.

2 1

In (I)

0 –1 –2 –3 –4 0.14

0.16

0.18

0.20

0.22 0.24 Voltage (V)

Figure 1.13 ln(I) vs. Voltage plot.

1.3.7 Degradation Analysis The degradation of PV module can be estimated by using instant power, PR and energy. The power can be measured in an indoor lab at STC or in outdoor condition. The instant power degradation can be estimated nameplate data or from initial measured data. For the degradation estimation of longterm exposure, the degradation of PV module can be estimated in terms of

Reliability Testing of PV Module in the Outdoor Condition 19 Table 1.6 Typical degradation rate and efficiency of different PV module technologies reported in the literature [26]. Technology

Efficiency

Annual degradation reported

Mono-C- Si

15-20%

0.5-2.0%

Poly Si

13-15%

0.5-2.0%

CdTe

9-11%

1-2%

CIGS

9-11%

1-2%

Amorphous Silicon

5-8%

1.5-2.5%

Sunpower

22%

0.32%

HIT

18.5%

0.36%

performance ratio of the known time period. However, the degradation rate can also be estimated from STC translated power data or for a fixed irradiance and temperature conditions against the time of long-term exposure. The linearity of degradation rate for a time period of the PV module can be studied from the time-line series of degradation. Degradation rate can be estimated by using the following equations:

Percentage  of  degradation

( Initial   Pmax Final   Pmax )  100% (1.9) Initial   Pmax    Year  of  exposure

Table 1.6 shows the typical degradation rate and efficiency of PV module reported in the literature. It has been observed in the table that Sunpower module has the highest efficiency. The degradation is high in the case of Amorphous technology. However, the degradation rate of the PV module mainly depends on the operating conditions. In the case of India and other tropical countries, the degradation rates of PV modules are high [6–8].

1.3.8 IR Thermography IR thermography is used for field diagnostics to detect abnormal heat signatures in PV modules. It is a non-destructive technique to find out defects in the PV module. For precise defect detection in the PV module, thermography imaging is performed under illumination at short circuit, open-circuit, and at the maximum power point. However, at indoor lab condition thermography can be done by using DC power supply to bias the PV module.

20

Progress in Solar Energy Technologies and Applications Procedure: 1. Identify the module of the PV power plant to do the IR thermography. 2. Clean the module based on the requirement. Sometimes people want to find the soiling effect on the module also. In that case, cleaning is not required. 3. Prior to IR scan verify that the PV string is in working condition. 4. The distance between the camera and the module should not exceed 3 meters. For best results, position the camera as perpendicular as possible to the object being measured. 5. Thermography can be done at three different conditions under illumination – at power plant working condition, at open circuit condition and short circuit condition of individual module. 6. Set the mode of the camera to Autoscaling. 7. Check the hot spot and heat signatures created in the module.

In the case of IR inspection of PV module in outdoor condition, the conditions of irradiance and ambient temperature changes with time. It will vary the module temperature between the images. It is necessary to translate the measured module temperature to reference conditions to do the comparisons between the images. The following relation can be used to normalize the temperatures to the reference conditions of 40°C and 1000 W/m2 [27, 28].

Tnormalized

40  

 (Tmeasured    Tambient   )   1000 Irradiance

(1.10)

where, Tnormalized = translated (normalized) temperature Tmeasured = module temperature (obtained from IR image) Tambient = ambient temperature measured at the site Further, Module ΔT = Tmaxcell,norm – Tmodule,norm

(1.11)

where, Tmaxcell,norm = Normalized maximum cell temperature of the module Tmodule,norm = Normalized module temperature of the module

Reliability Testing of PV Module in the Outdoor Condition 21 The module ΔT represents the extent of mismatch between the temperatures in different cells of the module. Usually, it is considered that modules with normalized ModuleΔT above 10°C as modules with “Hot Cells”. Table 1.7 shows the description of the IR image of the PV module and possible failure reasons. Figure 1.14 shows an IR image of a PV module in indoor conditions. Table 1.7 Description of IR image pattern as per possible failure reasons [10]. Description of image pattern

Possible failure reasons

One module cooler than others in a string

Module is open circuited - not connected to the system

One row (sub-string) is warmer than other rows in parallel strings

Short circuited or open sub-string - Bypass diode short circuited, or - Internal short circuited

Single cells are warmer, not any pattern

Module is short circuited or bypass diodes get short circuited or wrong connection in the string

Single cells are warmer, lower parts and close to frame hotter than upper and middle parts.

Potential induced degradation (PID) and/or polarization

One cell clearly warmer than the others

- Shadowing effects - Defected or delaminated cell

Part of a cell is warmer

Broken cell - Disconnected string interconnect

Pointed heating in a cell

Partly shadowed, e.g., bird dropping, soiling, object

Sub-string part remarkably hotter than others when equally shaded

Open-circuited bypass diode

Figure 1.14 IR image of a module with localized hot spot.

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1.3.9 Insulation Resistance Tester An insulation resistance tester (IRT) is used to measure the quality of insulating material in the PV module. The tester should have the facility to apply constant DC voltage and measure the current up to nano-ampere also. The IRT applies a voltage to the circuit under test and measures return current to determine the insulation resistance and reliability. Insulation resistance is the dielectric property of the PV module defined as the amount of Insulation provided in between Solar Cells and metallic frame. Figure 1.15 shows different factors that affect the insulation resistance of the PV module. A. Procedure: 1. Identify the module of the PV power plant to check the insulation resistance. 2. Short the positive and negative output terminal of the module and connect the positive terminal of the insulation tester to it and the other terminal to the frame of the module. 3. Increase the voltage applied by the tester at a rate not exceeding 500 V/s to a maximum equal to 1000 V plus twice the maximum system voltage (IEC 61215-1). Maintain the voltage at this level for 1 min. 4. Reduce the applied voltage to zero and short-circuit the terminals of the test equipment to discharge the voltage build-up in the module. 5. Increase the voltage applied by the test equipment at a rate not exceeding 500 V/s to 500 V or the maximum system voltage for the module, whichever is greater. Maintain the voltage at this level for 2 min. Then determine the insulation resistance.

Temperature

Irradiance

Insulation resistance of PV module

Figure 1.15 Factors affecting insulation resistance.

Voltage

Relative humidity

Reliability Testing of PV Module in the Outdoor Condition 23 6. For wet leakage testing also, the same procedure can be applied. At the time of testing the module needs to be getting wet with water. For this purpose spraying water or a wet cloth to cover the module can be used. B. Acceptance or rejected criteria: As per IEC 61215, the tested module should fulfill the following criteria 1. No dielectric breakdown or surface tracking. 2. For modules with an area of less than 0.1 m2, the insulation resistance shall not be less than 400 MΩ. 3. For modules with an area larger than 0.1 m2 the measured insulation resistance times, the area of the module shall not be less than 40 MΩ·m2.

1.3.10

EL Camera

The electro-luminescence camera is used to detect the defects in the solar cell of a PV module. An electro-luminescence camera has a silicon CCD sensor and it can capture the light signal in the wavelength range more than 950 nm emitted by the DC-biased PV module. The PV test module is supplied by a dc current to stimulate radiative recombination in the solar cells. EL imaging is done in a dark environment because the amount of infrared radiation emitted by the solar module is low as compared to the radiation emitted by the background lighting. It can detect the micro-crack and series resistance in a PV module. A. Procedure: 1. Identify the PV module for taking of the EL image in the power plant. 2. Clean the module and connect the DC power supply to bias the module. 3. The EL imaging in the PV power plant needs to be done at dark condition. So, it is better to take the image at night or irradiance less than 100 W/m2. 4. The distance between the camera and the module should not exceed 3 meters. For best results, position the camera as perpendicular as possible to the object being measured. 5. Bias the module with 0.3 or/and equal to short circuit current and take the EL image at optimum exposure time.

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B. Defects: There are different types of defects that can be detected through the EL image: 1. Cracks in a solar cell of a module with no influence in current flow 2. Cracks in solar cell of a module with influence in current flow to the interconnect ribbon 3. Cracks in solar cell of a module that isolated the cell parts from the cell interconnect 4. Crack line in the solar cell across the cell 5. Finger failure or interruptions in some parts of solar cell 6. Finger failure or interruptions in the solar cell across cracks 7. Soldering defects in the busbar and fingers 8. Corrosion over cell due to humidity 9. Shunt fault in a solar cell or due to cell interconnect 10. Single cells are darker, lower parts and close to frame darker than upper and middle parts of a module in an image taken at 1/10 of short circuit current. This type of image found in a module that is prone to PID. 11. Repetitive induced solar cracks in a different module 12. X-crack in module 13. Dark in a whole string of a module due to shunted by pass diode or break in current flow. Figure 1.16 shows an EL image of the PV module. The image is taken by applying short circuit current of the module at STC. The module has cracked cells and distribution of current is not uniform in the module.

Figure 1.16 EL image of a PV module with defected cells.

Reliability Testing of PV Module in the Outdoor Condition 25

1.3.11

Interconnect Breakage Tester

Interconnect breakage tester is used to detect interconnect failures in between cells of the PV module. It consists of 2 units – the transmitter and the receiver. The receiver unit shows the health of the interconnect connections through flashes of LEDs on a scale of 0 to 10; with no flash meaning, complete failure of the associated interconnect ribbon. Interconnect breakage can be tested using the Togami Cell Line Checker. A. Procedure: 1. Identify the module to check the interconnect breakage. 2. The transmitter needs to connect to the output terminal of the PV module. 3. The receiver is swept on the front side of the module over the interconnect ribbons. 4. Flashes on LEDs show the health of the interconnect connections. B. Acceptance/reject criteria: If there is no flash in the receiver, it shows the breakage on interconnect ribbon. The module can be rejected if the degradation is high as compared warranty.

1.3.12

Current, Voltage and Continuity Checking

For the checking of instant current and voltage ammeter and voltmeter can be used. For checking the open circuit voltage of the PV module, the intensity of solar light should be more than 700 W/m2. For short circuit current testing of PV module DC clamp meter can be used. For continuity testing of bypass diode multi-meter can be used.

1.3.13

Environmental Parameter Checking

For the checking of environmental parameters of the test site, weather station with the following components can be used. I. Pyranometer II. Air temperature sensor III. Relative humidity sensor IV. Wind speed and wind direction

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Progress in Solar Energy Technologies and Applications

Data from these sensors can be used to analyze the performance data of the PV power plant to find out the reliability of the module.

1.4 Quantification of Reliability For the estimation of reliability of PV module and to find out the severe failure mode in the field 29, IEC 60812:2018 standard can be used [29]. This standard explains the failure modes and effects analysis (FMEA), including the failure modes, effects, and criticality analysis (FMECA) variant, is planned, performed, documented and maintained. Reliability of the PV module can be analyzed by using the Risk Priority Number (RPN) related to defects. RPN related to performance defects are referred to as performance RPN and for failure defects of the PV module related to safety issues are referred to as safety RPN. The RPN is calculated using the following equation:

RPN = S × O X D

(1.12)

A.1. Severity In this study, severity ranking is done by performance analysis with different defects for individual PV power plant. Benign defects for each power plant are separated from performance and safety defects by analyzing the follow-up defects. The severity of a failure mode is determined using the safety and performance degradation of the PV modules, ranked from 1 to 5, where 1 indicates the observed degradation mode that has no effect on performance and 5 indicates a major effect on both power and safety. Severity ranking of defects in a PV module is analyzed based on the performance of the PV module into the different bin, viz. power, short circuit current, fill factor, open circuit voltage, shunt resistance, and series resistance. The distribution of degradation rates for each defect from each bin is analyzed for different power plants. The relation between the Pmax degradation with the change in short circuit current, fill factor, open circuit voltage, shunt resistance, and series resistance for different defects need to be estimated. The comparisons of median degradation of each I-V parameters must be studied for each defect. The average degradation rate for each defect is arranged and grouped into different categories. The scale is discrete and not continuous because correlating specific degradation modes to certain power losses varies with operating conditions. For each defect observed in a power plant, a ranking is given for a group of average degradation values. For safety failure mode, the ranking is done based on the severity of safety and average

Reliability Testing of PV Module in the Outdoor Condition 27 degradation rate for the defect. However, it is very much necessary to provide high ranking for a defect in the risk of electric shock and fire. The methods follow for giving a ranking of safety and performance defects are adopted from Kuitche et al. [9]. A.2. Detection Ranking of detection D of each failure mode is done based on the criteria of detection with the monitoring system itself, or with a visual inspection, or with sophisticated laboratory tools. The ranking 1 is given if the monitoring system, i.e., field control mechanism, detects the failure mode in the scheduled/regular maintenance or event-triggered inspections. The detection technique of failure modes is ranked with the accelerated stress tests designed to induce known field failure modes, as reported [4, 9, 11]. Basically, the number goes higher as different techniques are needed to detect the failure mode. In this study, the detection rating corresponds to the criteria of detection with monitoring system/procedure used during the survey. The inspection of the power plant is done by visual inspection and with sophisticated tools such as EL camera, I-V tracer, IR camera, insulation tester, cell line checker, and digital camera. In this study, the lower ranking is given for the detection of defects with a visual inspection; middle ranking is given for the detection of defects which can be identified only with indirect calculation procedure, and a high ranking is given for the defects identified only by using sophisticated tools. Although in this study the detection ranking is given to each defect, the RPN is estimated by normalizing all the detection rank to 1 as all the defects are detected in the field only. A.3. Occurrence In this study, occurrence ranking is done based on defects observed during the survey in a power plant. The frequency of occurrence of each failure mode has been estimated for each defect in a power plant and the number of module failures per thousand per year has been calculated. The cumulative number of module failures for each defect per thousand per year (CNF) is calculated using the following formula [9]:

CNF / 1000

(cumulative % defects ) / 10 cumulative operating time

systems system

(% defects) / 10

(operating time)

(1.13)

The ranking is achieved by making a discrete group of CNF/1000 for different defects and distribute the ranking from 1 to 5. The ranking is high with a high occurrence.

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Progress in Solar Energy Technologies and Applications

The failure modes/defects are observed in PV modules after long-term exposure in the field conditions. Mani et al. have reported that 86 defects of PV modules are used and the details are given in Tables 1.7 and 1.8. Table 1.7 shows 25 defects related to safety failures of the PV module. Table 1.8 shows 61 defects related to performance failure modes of the PV module. The failure mode is divided into two parts: safety and performance issues. Tables 1.9 and 1.10 show the severity and detection of different failure modes as per safety and performance issues [7, 8]. The rank is given by considering the degradation of the PV module with respect to different failure modes.

Table 1.7 Defects of PV module related to safety failures. Glass

Frame

Junction box

Front glass crack Front glass shattered Rear glass crack Rear glass shattered

Frame grounding severe corrosion Frame grounding minor corrosion Frame joint separation Frame cracking

Junction box crack Junction box burn Junction box loose Junction box lid fell off Junction box lid crack Junction box sealing will leak

Backsheet

Wire

Cell

Backsheet peeling Backsheet delamination Backsheet burn Backsheet crack/cut under cell Backsheet crack/cut between cell

Wires burnt Wires animal bite/marks Wire insulation cracked

Hotspot above 20°C String interconnect arc tracks

Reliability Testing of PV Module in the Outdoor Condition 29 Table 1.8 Defects of PV module related to performance failure. Glass

Frame

Junction box

Front glass lightly soiled Front glass heavily soiled Front glass crazing Front glass chip Front glass milky discoloration Rear glass crazing Rear glass chip

Major corrosion of frame Minor corrosion of frame Frame bent Frame degraded Frame oozed Frame adhesive missing

Lid loose Box warped Box weathered Adhesive loose Adhesive fell off Wire attachments loose Wire attachments fell off Wire attachments arced

Cell

Encapsulant

Back sheet

Cell discoloration Cell burn Mark Cell crack Cell moisture penetration Cell worm mark Cell foreign particle embedded Cell Interconnect discoloration Gridline discoloration Gridline blossoming Busbar discoloration Busbar corrosion Busbar burn marks Busbar misaligned Cell Interconnect ribbon discoloration Cell Interconnect ribbon corrosion Cell Interconnect ribbon burn mark Cell Interconnect ribbon break String Interconnect discoloration String Interconnect corrosion String Interconnect burn mark String Interconnect break Hotspot less than 20°C

Encapsulant delamination over the cell Encapsulant delamination under the cell Encapsulant delamination over the junction box Encapsulant delamination near interconnect or fingers Encapsulant discoloration (yellowing/ browning)

Backsheet wavy Backsheet discoloration Backsheet bubble

(Continued)

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Progress in Solar Energy Technologies and Applications

Table 1.8 Defects of PV module related to performance failure. (Continued) Edge seal

Wires

Others

Edge seal delamination Edge seal moisture penentration Edge seal discoloration Edge seal squeezed / pinched out

Wires pliable degraded Wires embrittled Wires corroded Wires soiled

Solder bond fatigue/ failure Module mismatch

Table 1.9 Severity and Detection ranking of Failure mode with safety issues [7, 8]. Failure mode

Severity

Detection

Front glass crack

5

3

Front glass shattered

5

3

Frame grounding severe corrosion

5

2

Frame joint separation

5

1

Frame cracking

5

1

Junction box crack

5

2

Junction box burn

5

2

Junction box loose

5

2

Junction box lid fell off

5

1

Junction box lid crack

5

1

Junction box sealing will leak

5

2

Wires burnt

5

2

Wires animal bite/marks

5

1

Backsheet peeling

5

5

Backsheet delamination

5

5

Backsheet crack/cut under cell

5

5

Backsheet crack/cut between cell

5

5

Insulation resistance

5

5

Severity

1

1

2

1

1

1

1

2

3

2

2

2

1

2

Failure mode

Front glass crazing

Front glass chip

Front glass milky discoloration

Major corrosion of frame

Minor corrosion of frame

Frame bent

Frame degraded

Frame oozed

Junction box loose

Junction box weathered

Junction box warped

Junction box adhesive

Junction box lid loose

Junction box wire attachment loose

1

1

2

2

2

2

1

1

1

1

1

3

3

3

Detection

Hot spot

String arc

String breakage

String burn

String corrosion

String dark discolored

String light discolored

Cell snail trails

Foreign particles

Moisture in cell

Cell breakage

Cell burn

Cell obvious

Cell dark discolored

Failure mode

Table 1.10 Typical values of severity and detection ranking of Failure mode with performance issues [7, 8].

2

3

3

3

3

3

3

1

1

1

1

1

3

3

Severity

(Continued)

3

3

3

3

3

3

3

1

1

1

1

2

5

5

Detection

Reliability Testing of PV Module in the Outdoor Condition 31

Severity

3

3

3

3

3

3

3

2

2

1

5

Failure mode

Fingers discolored

Busbars light discolored

Busbars dark discolored

Busbars obvious

Busbars diffuse

Busbars misalignment

Cell light discolored

Edge seal moisture ingression

Wires pliable degraded

Wires embrittled

Solder bond fatigue/failure

4

2

2

2

5

3

3

3

3

3

3

Detection

Wires soiled

Wires corroded

Cracks in back sheet

Bubbles in back sheet

Back sheet chalking

Back sheet discoloration

Encapsulant discoloration

Encapsulant delamination near junction box

Encapsulant delamination inter connect

Encapsulant delamination edge

Encapsulant delamination corner

Failure mode

1

1

3

3

3

3

3

1

1

1

1

Severity

Table 1.10 Typical values of severity and detection ranking of Failure mode with performance issues [7, 8]. (Continued)

1

2

5

5

5

5

5

1

1

1

1

Detection

32 Progress in Solar Energy Technologies and Applications

Reliability Testing of PV Module in the Outdoor Condition 33

1.5 Procedure for Performance and Reliability Testing of PV Module in Outdoor Conditions The objectives of performance and reliability testing of the PV module in outdoor condition are: I. Identification of defects in the PV module in terms of type and frequency. II. Determination of degradation rate of PV module with respect to initial rating.

1.5.1 Selection Procedure of PV Modules for Testing in the Field The following procedure may be used to choose the sample for testing the performance and reliability of PV module I. Checking the complete performance data of power plant logged through SCADA (provided by the client) or by measuring the current of each combiner box II. Choosing 3% of total combiner box (CB) III. Checking the performance of the total string from 3% of CB IV. Checking module wise performance of 3% of String from CB

1.5.2 Testing Report Format of Performance Guarantee Test The report should include the following details: I. A title of the report II. Name and address of the test laboratory and location of the test site III. Name and address of the power plant IV. Name and address of the power plant owner V. Description and identification of the power plant tested VI. Characterization and condition of the power plant VII. Date of inspection VIII. Reference to the sampling procedure IX. Procedure followed for testing of the power plant X. Any deviation from the reference procedure XI. Major equipment used XII. Test results of observation of visual inspection a. Broken, cracked, or torn external surfaces. b. Bent or misaligned external surfaces, including superstrates, substrates, frames and junction boxes to the

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Progress in Solar Energy Technologies and Applications extent that the operation of the PV module would be impaired. c. Bubbles or delaminations forming a continuous path between the electric circuit and the edge of the module. d. If mechanical integrity depends on lamination or other means of adhesion, the sum of the area of all bubbles shall not exceed 1% of the total module area. e. Evidence of any molten or burned encapsulant, backsheet, front sheet, diode or active PV component. XIII. Results of Thermal imaging a. Information about mean temperature and hot spot temperature b. Loose cable connections c. Hot by pass diode XIV. Results of I-V Test of Statistically Selected Strings a. Name plate data of the string: Isc, Voc, Pmax, FF, Vmp, Imp b. STC translated data of the string: Isc, Voc, Pmax, FF, Vmp, Imp XV. I-V Test of Statistically Selected modules (good, worst and mid-range string) a. Name plate data of the PV module: Isc, Voc, Pmax, FF, Vmp, Imp b. STC translated data of the PV module: Isc, Voc, Pmax, FF, Vmp, Imp XVI. Results of insulation and wet leakage testing of statistically selected modules a. Resistance and leakage current data of dry insulation test b. Resistance and leakage current data of wet insulation test XVII. PR data a. Month-wise PR estimation of the already yearly stored data. XVIII. A statement of the estimated uncertainty of the calibration or test result XIX. A statement as to whether the measured degradation rate agrees with the manufacturer’s rated within the test laboratories measurement uncertainty XX. A signature and title, or equivalent identification of the person(s) accepting responsibility for the content of the certificate or report, and the date of issue;

Reliability Testing of PV Module in the Outdoor Condition 35 XXI. A statement that the certificate or report shall not be reproduced except in full, without the written approval of the laboratory.

1.6 Conclusion In this chapter, the procedure for reliability analysis of the PV module is explained. This chapter will be useful for analyzing the reliability of the PV module in outdoor conditions and issuing a report about it. The quantification of the reliability of the PV module after long-term operation in the field can also be done using the procedure from the chapter.

Abbreviation ISO IEC PID STC NOCT Isc Voc FF Im Vm Pmax IR image EL image RPN I-V curve P-V curve FMECA °C PV C-Si A-Si CdTe CIGS

International Organization for Standardization International Electro technical Commission Potential Induced Degradation Standard Test Conditions: Cell temp 25±2°C, irradiance 1000 W/m2 and spectrum AM I.5 Normal Operating Cell Temperature Short circuit current Open circuit voltage Fill factor Current at maximum power point Voltage at maximum power point Power at maximum power point Infra-red image Electroluminescence image Risk priority number Current-voltage curve Power-voltage curve Failure modes, effects and criticality analysis Degree centigrade Photovoltaic Crystalline silicon Amorphous silicon Cadmium telluride Copper Indium Gallium Selenide

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References 1. Renewables 2018 global status report, http://www.ren21.net/gsr-2018, 2018. 2. https://mnre.gov.in/ 3. Electrification with renewables electrification with renewables driving the transformation of energy services, https://www.irena.org, 2019. 4. O.S. Sastry et al., "RPN analysis of field exposed mono crystalline silicon PV modules under composite climate of India," 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), New Orleans, LA, 2015, pp. 1–3, doi: 10.1109/ PVSC.2015.7356128 5. J.H., Wohlgemuth, "Reliability testing of PV modules," Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC), Waikoloa, HI, 1994, pp. 889–892 vol. 1. doi: 10.1109/WCPEC.1994.520104 6. All-India Survey of Photovoltaic Module Reliability: https://nise.res.in, 2013. 7. All-India Survey of Photovoltaic Module Reliability: https://nise.res.in, 2014. 8. All-India Survey of Photovoltaic Module Reliability: https://nise.res.in, 2016. 9. J. M. Kuitche, R. Pan, and G. TamizhMani, (Main) "Investigation of Dominant Failure Mode(s) for Field-aged Crystalline Silicon PV Modules under Desert Climatic Conditions,” in IEEE Journal of Photovoltaics, vol. 4, no. 3, pp. 814826, May 2014. doi: 10.1109/JPHOTOV.2014.2308720 10. Review of Failures of Photovoltaic Modules, http://www.iea-pvps.org, 2014. 11. K. Yedidi, J. Mallineni, B. Knisely, S. Tatapudi, J. Kuitche, Tamizh- Mani, "Failure and degradationmodes and rates of pv modules in a hot-dry climate: Results after 16 years of field exposure," Proc. IEEE Photovoltaic Spec. Conf., Jun. 2014, pp. 3245–3247. 12. IEC 61215-1: 2016, Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1: Test requirement, https://webstore.iec.ch 13. IEC 61215-1-1:2016, Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1-1: Special requirements for testing of crystaline silicon photovoltaic (PV) modules, https://webstore.iec.ch 14. IEC 61215-1-2:2016, Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1-2: Special requirements for testing of thin-film Cadmium Telluride (CdTe) based photovoltaic (PV) modules, https://webstore.iec.ch 15. IEC 61215-1-3:2016, Terrestrial photovoltaic (PV) modules - Design qualification amd type approval - Part 1-3: Special requirements for testing of thin-film amorphous silicon based photovoltaic (PV) modules, https://webstore.iec.ch 16. IEC 61215-1-4:2016, Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1-4: Special requirements for testing of thin-film Cu(In,GA)(S,Se)2 based photovoltaic (PV) modules, https://webstore.iec.ch 17. IEC 61215-2:2016, Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 2: Test procedures, https://webstore.iec.ch

Reliability Testing of PV Module in the Outdoor Condition 37 18. IEC 61730-1:2016, Photovoltaic (PV) module safety qualification - Part 1: Requirements for construction, https://webstore.iec.ch 19. IEC 61730-2:2016, Photovoltaic (PV) module safety qualification - Part2: Requirememnts for testing, https://webstore.iec.ch. 20. IEC TS 62804-1:2015, Photovoltaic (PV) modules - Test methods for the detection of potencial-induced degradation - Part 1: Crystalline silicon, https://web store.iec.ch 21. IEC 61701:2011, Salt mist corrosion testing of photovoltaic (PV) modules, https://webstore.iec.ch 22. IEC 62716:2013, Photovoltaic (PV) modules - Ammonia corrosion testing, https://webstore.iec.ch 23. IEC 62759-1:2015, Photovoltaic (PV) modules - Transportation testing - Part 1: Transportation and shipping of module package units, https://webstore.iec. ch 24. IEC TS 62782:2016, Photovoltaic (PV) modules - Cylic (dynamic) mechanical load testing, https://webstore.iec.ch 25. IEC 60891:2009, Photovoltaic devices - Procedures for temperature and irradiance corrections to measured I-V characteristics, https://webstore.iec.ch 26. Jordan, D.C. and Kurtz, S.R., Photovoltaic Degradation Rates—an Analytical Review, Prog. Photovolt: Res. Appl., 21:12–29. doi:. 10.1002/pip.1182, 2013. 27. R. Moreton, E. Lorenzo, J. Leloux, J.M. Carrillo, "Dealing in Practice with Hot Spots,” in 29th European Photovoltaic Solar Energy Conference and Exhibition, Amsterdam, pp. 2722–2727, 2014. 28. J. Oh and G. TamizhMani, "Temperature Testing and Analysis of PV modules per ANSI/UL 1703 and IEC 61730 standards," in 35th IEEE Photovoltaic Specialist Conference, Honolulu, pp. 984–988, 2010. 29. IEC 60812:2018, Failure modes and effects analysis (FMEA and FMECA), https://webstore.iec.ch

2 Solar Energy Technologies and Water Potential for Distillation: A Pre-Feasibility Investigation for Rajasthan, India Nikhil Gakkhar1*, Manoj Kumar Soni2 and Sanjeev Jakhar3 1

N Gakkhar, Sardar Swaran Singh National Institute of Bio Energy, Kapurthala 2 MK Soni, Department of Mechanical Engineering, Birla Institute of Technology & Science, Pilani, Rajasthan 3 S Jakhar, Mechanical Engineering Department, Mody University of Science and Technology, Lakshmangarh, Rajasthan

Abstract Among all the renewable energy sources, solar energy is an abundant energy source which provides more than 4000 trillion kWh of insolation per day across the earth. This solar energy can be harnessed by using direct or indirect conversion technologies into electrical energy. One of the commercially proven technologies for direct conversion into electricity is solar photovoltaic (PV) technology, which uses solar cells. The indirect conversion technology for power generation includes concentrated solar power (CSP) in which thermal energy is converted into electrical energy using turbo generator systems. Apart from power generation, the solar energy is also used for distillation/desalination of water. Rajasthan is an arid and semi-arid state and has very high potential for harnessing solar energy. The present chapter discusses the electrical power generation potential and water distillation potential using solar energy for the state of Rajasthan, India. The SPV potential is estimated by considering mono-crystalline silicon cells, polycrystalline silicon cells and thin-film solar cells. While for CSP it is estimated using linear Fresnel reflector, parabolic trough collector and central receiver technologies. For the estimation of water distillation potential for each district, various parameters like water availability from various sources, total dissolve solid content in the water, incident solar radiation, etc., are taken. The case study discusses the water distillation potential of reverse osmosis (RO) technology coupled with SPV or multi-stage flash (MSF) distillation technology coupled with CSP as their energy source. This study may be helpful for policy and decision makers for setting up solar power generation and distillation technologies within the state. *Corresponding author: [email protected] Umakanta Sahoo (ed.) Progress in Solar Energy Technologies and Applications, (39–82) © 2019 Scrivener Publishing LLC

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Keywords: Solar energy, resource assessment, global horizontal iradiance, water source, PV potential, CSP potential, water potential, distillation, reverse osmosis, MSF distillation system

2.1 Introduction Energy plays a quite important role in the growth of human civilization. In earlier times the energy from the sun, fossil fuels, oil, etc., was used to meet basic necessities of life like cooking of food, heating of space, etc. With the onset of industrialization, the concept of energy changed from basic necessities to comfort level including energy requirement for locomotive, heating and cooling of space, running of machines, etc. This requirement of energy has increased over the decades, which is evident from the fact that the world primary energy supply has been increased from 6,101 Mtoe in 1973 to 13,763 Mtoe in 2016 [1]. In order to fulfill the electricity demand, worldwide electricity generation has also been increased, from 6131 TWh in 1973 to 25,551 TWh in 2017 [2]. The fossil fuel sources contribute more than 65% of the world’s electricity, while renewables produce close to 25% of total electricity generation [3]. In India itself, total installed capacity for electricity generation is 344.00 GW as of March 2018, out of which 222.90 GW is from fossil fuelbased power plants [4]. Renewable energy sources have gathered considerable attention from governments, utilities and researchers in order to provide clean sources of energy and to reduce emissions and other environmental concerns associated with fossil fuel-based power generation. During 2008, the total installation of renewable power generation capacity in the world was 1057 GW which rose to 2179 GW in 2017, due to widespread promotion of renewable energy across the world by various agencies. According to the International Renewable Energy Agency, with 74.08 GW, India ranks sixth in the world in the total installed renewable power generation capacity [5]. In the Indian context, it is envisaged to increase renewable based electricity generation to 175 GW by 2022. This includes 100 GW from solar power, 60 GW from wind power, 10 GW from bio-power and 5 GW from small hydro power. As of December 2018, the total installed capacity using of renewable energy sources included 35.28 GW from wind power, 21.87 GW from solar power, 9.94 GW from bio-power and 4.52 GW from small hydro power [6]. Water is an essential aspect for the development of human civilization. It is one of the most abundant resources on earth, covering three fourths of the planet’s surface. About 97% of the earth’s water is in the oceans, which is not potable. The remaining 3% (about 36 million km3 of volume) is fresh water contained in the poles (in the form of ice), groundwater, lakes and rivers, which is used for human and animal needs. Nearly 70% of the world’s

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41

fresh water is frozen in glaciers, permanent snow cover, ice and permafrost [7]. Around 30% of all fresh water is underground, most of it in deep, hardto-reach aquifers. Lakes and rivers together contain just a little more than 0.25% of all fresh water. With increase in population, the demand for fresh water is increasing, which is causing depletion of freshwater resources. Rapid urbanization and industrialization also lead to shrinking of lakes and pollution of water resources. Thus the availability of fresh water for human and animal consumption is significant in the coming years. Lack of fresh water for necessities affects the development and quality of life especially in rural regions of the developing countries. According to a World Water Council report, by the year 2050, per capita availability of freshwater supply for the world would fall from current 6600 cubic meters to 4800 cubic meters [8]. In India the per capita freshwater availability has dropped from 5177 cubic meters in 1951 to about 1545 cubic meters in 2011 and is expected to further come down to 1341 cubic meters in 2025 and 1140 cubic meters in 2050 [9]. India’s rapidly rising population and changing lifestyles also account for the increase in demand for fresh water. Even today many parts of India face a huge water scarcity because of unplanned mechanism and pollution created by human activities. Lack of availability of drinkable water is a major issue in many parts of India, especially in arid regions of Rajasthan and Gujarat. In arid areas, potable water is very scarce and the establishment of human habitat in these areas strongly depends on drinking water resources. Thus, there is an urgent need to make the groundwater potable to meet the current demand. With recent developments in technology, there is a need to create a sustainable ecosystem to harness energy from renewable sources and use it not only for power requirement but also for water distillation. India, being a tropical country, is blessed with plenty of sunshine. The average daily solar radiation varies between 4 to 7 kWh/m2 for different parts of the country. The country has on an average 250–300 clear sunny days a year and in some regions, it goes up to 325 sunny days a year. The western part of the country, which includes state of Rajasthan, a major part of which is an arid and semi-arid region with a high total dissolve solid (TDS) level in groundwater. The state also receives the very highest annual global radiation in the country, which makes the tremendous potential for power generation using solar energy. This solar potential could also be harnessed for water purification technologies in these regions.

2.2 Solar Assisted Technologies for Water Purification Most of the water available in the world is in the ocean, which is not drinkable. So to make it suitable for human consumption, many conventional and

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non-conventional techniques have been used. The most commonly used technique for water purification is distillation/desalination† which uses thermal energy for operation. In this thermal energy can also be used, where water is heated up using thermal energy (heat source). It is evaporated and condensed back to get water free from impurities. The heat source may be solar energy, or any other conventional fossil fuels as well as renewable energy sources like biomass, biofuels, etc. Besides these, non-thermal distillation technologies like Membrane distillation (MD), Reverse Osmosis (RO) and Electro-dialysis (ED) uses electrical power to convert raw water into fresh water. In such systems, the direct electricity is used either to drive high-pressure pumps or to ionize salts and TDS contained in the water. The type of water purification technology deployed depends on the amount of TDS level in the water. The permissible limit of TDS in fresh water is just 500 ppm. In the case of brackish water (TDS 10000) the energy varies from 7–10 kWh/m3 [88]. The average electrical consumption of 7 kWh/m3 is taken for the analysis, with plant capacity of 6 MLD. During the analysis, it is assumed that the power generation from the PV will be utilized for RO plant. Thus the regions having potential energy generation less than the threshold energy requirement of RO plants are eliminated. Further, the raw water from the rainwater harvesting technology and river water is taken as feed for the RO system. For a plant of capacity 6 MLD, with electrical consumption of 7 kWh/ m3, the power requirement will be 42 MWh/d. The areas having threshold radiation more than 1800 kW/m2/d and may generate the daily electrical power of 1.75 MW are chosen. The water availability for RO plant using raw water from rainwater harvesting and surface water resources is shown in Table 2.8. The availability of water resource determined the feasibility of RO plants. From Table 2.8, it is observed that PV power generation potential is highest in the western part of the state. This is due to the fact that this region receives enormous solar insolation throughout the year. The maximum PV potential, irrespective of technology used, is obtained in Jaisalmer district, followed by Bikaner and Jodhpur. Hanumangarh districts have the minimum power potential in all the three technologies. The total potential of the entire state using m-Si, p-Si and TF technology is 1077.44 GW, 811.36 GW and 728.99 GW, respectively. In terms of water availability for RO, Pali district has the maximum raw water potential of 27.93 MLD from surface resources and rainfall and thus is suitable for such systems. Sikar district (1.81 MLD) has minimum potential of water supply, even below the threshold requirement of RO plant due to the absence of any surface resources in the district. The power potential and water availability potential for the state for m-Si, p-Si and TF technologies are mapped graphically using GIS in Fig. 2.5. It is clear from Fig. 2.5(a) that Hanumangarh district, although it has sufficient water availability for RO plant of capacity 6 MLD or more, lacks

Table 2.7 Technical features of a typical distillation technology [87]. Distillation technology

MSF

RO

Typical average capacity (MLD)

25

6

Maximum average capacity (MLD)

50

10

Thermal energy consumption (kWh/m3)

80

–

Electric energy consumption (kWh/m3)

4

5

Total equivalent electric energy consumption (kWh/m3)

15

5

GHI (kWh/m /day)

5.14

4.91

5.17

5.03

5.15

4.89

5.11

4.94

5.07

5.15

4.91

4.97

4.95

Location

Ajmer

Alwar*

Banswara

Baran

Barmer

Bharatpur*

Bhilwara

Bikaner

Bundi

Chittorgarh

Churu*

Dausa

Dhaulpur

2

7.65

4.28

9.39

22.30

7.31

120.95

45.09

6.10

59.75

10.17

6.81

9.07

31.54

m-Si

5.76

3.23

7.07

16.79

5.51

91.08

33.95

4.59

44.99

7.66

5.13

6.83

23.75

p-Si

5.18

2.90

6.35

15.09

4.95

81.83

30.50

4.13

40.43

6.88

4.61

6.14

21.34

TF

Potential of PV (GWh/yr)

8.73

4.20

6.83

14.97

5.60

9.72

14.63

6.97

13.64

4.96

6.19

6.47

10.14

(Continued)

Water availability potential for RO (MLD)

Table 2.8 Power generation potential for different PV technologies along with water availability potential for RO.

Solar Energy Technologies and Distillation 67

GHI (kWh/m /day)

5.25

5.30

4.89

5.20

5.17

5.24

5.08

4.91

5.23

4.95

5.07

5.20

5.19

Location

Dungarpur

Ganganagar

Hanumangarh*

Jaipur

Jaisalmer

Jalore

Jhalawar

Jhunjhunu*

Jodhpur

Karauli

Kota

Nagaur

Pali

2

38.93

25.15

8.47

6.54

85.87

6.82

18.10

20.80

332.12

20.79

4.88

22.26

18.36

m-Si

29.32

18.94

6.38

4.92

64.67

5.13

13.63

15.66

250.10

15.65

3.67

16.77

13.83

p-Si

26.34

17.01

5.73

4.42

58.10

4.61

12.25

14.07

224.71

14.06

3.30

15.06

12.42

TF

Potential of PV (GWh/yr)

27.93

8.91

18.99

5.49

17.23

2.19

4.79

10.37

4.78

15.83

9.57

8.14

6.80

(Continued)

Water availability potential for RO (MLD)

Table 2.8 Power generation potential for different PV technologies along with water availability potential for RO. (Continued)

68 Progress in Solar Energy Technologies and Applications

GHI (kWh/m /day)

5.15

5.19

5.03

5.03

5.15

5.04

–

Location

Rajsamand

Sawaimadhopur

Sikar

Sirohi

Tonk

Udaipur

Total

2

1077.44

52.11

11.57

20.77

9.42

6.64

27.43

m-Si

811.36

39.24

8.71

15.64

7.09

5.00

20.65

p-Si

728.99

35.26

7.83

14.05

6.37

4.49

18.56

TF

Potential of PV (GWh/yr)

332.58

20.49

16.96

14.78

1.81

16.84

7.63

Water availability potential for RO (MLD)

Table 2.8 Power generation potential for different PV technologies along with water availability potential for RO. (Continued)

Solar Energy Technologies and Distillation 69

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Progress in Solar Energy Technologies and Applications N

Legend PV potential using p-Si (GW) 100

> 100

(b) N

Legend CSP potential Water potential using PTC for MSF (MLD) (GW) < 25 < 5.70 5.70 - 25 25 - 50

25 - 50 50 - 75

50 - 75

75 - 100

75 - 100 > 100

> 100

(c)

Figure 2.6 Available water potential for RO operated plant in Rajasthan using power from (a) linear Fresnel concentrator (LFR) (b) parabolic trough collector (PTC) (c) central receiver (CR).

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position for maximum availability of water supply to have MSF solar plants using any of CSP technology due of the presence of Sambhar Lake in the district. For RO-based distillation units, Pali district, followed by Udaipur, has the highest water availability potential. It is observed that Dausa district is the only one which lacks adequate water supply to have RO plant with m-Si technology having capacity more than 6 MLD. Hanumangarh has minimum wasteland for solar power and thus lacks sufficient power generation potential although it has sufficient water availability for RO plants. The estimated potential for power generation and corresponding feasibility of having PV-based RO or CSP-based MSF plants are mapped using GIS tool. The analysis and the results of the study may be useful for the decision makers and policy makers for using PV or CSP for power generation and using the same for distillation units to provide drinking water supply in the state.

Nomenclature CSP CR DNI DWW GHI GW LFR MLD MSF PTC PV RO RW TDS

Concentrating solar power Central receiver systems Direct normal irradiance Domestic wastewater Global horizontal irradiance Groundwater Linear Fresnel reflector Million liter per day Multi-stage flash Parabolic trough collector Photovoltaic Reverse osmosis Rainwater Total dissolved solids

References 1. IEA, World Energy Outlook 2016 - Excerpt - Water-Energy Nexus, A report by International Energy Agency (OECD/IEA), Paris, France 2017. 2. BP, BP Statistical Review of World Energy, A report by BP p.l.c, Pureprint Group Limited, London, UK, 2018. 3. IEA, Key World Energy Statistics, A report by International Energy Agency (OECD/IEA), Paris, France, 2017. 4. Central Electricity Authority India, Power Sector March-2018, A report by Ministry of Power, Govt. of India, New Delhi, 2018.

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5. IRENA, Renewable Energy Prospects for India, a working paper based on REmap, The International Renewable Energy Agency, Abu Dhabi, 2017 6. Ministry of New and Renewable Energy, 2016, [Online]. Available: http:// mnre.gov.in/. 7. Abusharkh, A.G., Giwa, A., Hasan, S.W., Wind and geothermal energy in desalination: A short review on progress and sustainable commercial processes. Ind. Eng. Manag., 04, 04, 175, 2015. 8. Cosgrove, W.J. and Rijsberman, F.R., World Water Vision: Making Water Everybody’s Business, Routledge, Paris, France, 2014. 9. Verma, S. and Phansalkar, S.J., India’s Water Future 2050: Potential Deviations from ‘Business-as-Usual,’. Int. J. Rural Manag., 3, 1, 149–179, 2007. 10. Kalogirou, S., Use of parabolic trough solar energy collectors for sea-water desalination. Appl. Energy, 60, 2, 65–88, 1998. 11. Sampathkumar, K., Arjunan, T.V., Pitchandi, P., Senthilkumar, P., Active solar distillation - A detailed review. Renew. Sustain. Energy Rev., 14, 6, 1503–1526, 2010. 12. Tiwari, G.N. and Sinha, S., Parametric studies of active regenerative solar still. Energy Convers. Manag., 34, 3, 209–218, 1993. 13. Dev, R. and Tiwari, G.N., Characteristic equation of a hybrid (PV-T) active solar still. Desalination, 254, 1–3, 126–137, 2010. 14. Tleimat, B.W. and Howe, E.D., Nocturnal production of solar distillers. Sol. Energy, 10, 2, 61–66, 1966. 15. Sinha, S., Kumar, S., Tiwari, G.N., Active solar distillation system - An investment alternative to a solar hot water system. Energy Convers. Manag., 35, 7, 583–588, 1994. 16. Hanson, A., Zachritz, W., Stevens, K., Mimbela, L., Polka, R., Cisneros, L., Distillate water quality of a single-basin solar still: Laboratory and field studies. Sol. Energy, 76, 5, 635–645, 2004. 17. Al-Hayeka, I. and Badran, O.O., The effect of using different designs of solar stills on water distillation. Desalination, 169, 2, 121–127, 2004. 18. Tiwari, G. and Tiwari, A.K., Solar distillation practice for water desalination systems, Anshan Pub, Delhi, India, 2008. 19. Rajaseenivasan, T. and Kalidasa Murugavel, K., Theoretical and experimental investigation on double basin double slope solar still. Desalination, 319, 25–32, 2013. 20. Tabrizi, F.F., Dashtban, M., Moghaddam, H., Experimental investigation of a weir-type cascade solar still with built-in latent heat thermal energy storage system. Desalination, 260, 1–3, 248–253, 2010. 21. El-Sebaii, A.A., Al-Ghamdi, A.A., Al-Hazmi, F.S., Faidah, A.S., Thermal performance of a single basin solar still with PCM as a storage medium. Appl. Energy, 86, 7–8, 1187–1195, 2009. 22. Dashtban, M. and Tabrizi, F.F., Thermal analysis of a weir-type cascade solar still integrated with PCM storage. Desalination, 279, 1–3, 415–422, 2011. 23. Mahkamov, K. and Akhatov, J.S., Experimental study of the performance of multieffect solar thermal water desalination system. Appl. Sol. Energy, 44, 1, 31–34, 2008.

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24. Singh, S., Bhatnagar, V., Tiwari, G., Design parameters for concentrator assisted solar distillation system. Energy Convers. Manag., 37, 2, 247–252, 1996. 25. Abdel-Rehim, Z.S. and Lasheen, A., Experimental and theoretical study of a solar desalination system located in Cairo, Egypt. Desalination, 217, 1–3, 52–64, 2007. 26. Radhwan, A.M., Transient performance of a stepped solar still with built-in latent heat thermal energy storage. Desalination, 171, 61–76, 2004. 27. Voropoulos, K., Mathioulakis, E., Belessiotis, V., Experimental investigation of the behavior of a solar still coupled with hot water storage tank. Desalination, 156, 1–3, 315–322, 2003. 28. Tiwari, G.N. and Kumar, A., Nocturnal water production by tubular solar stills using waste heat to preheat brine. Desalination, 69, 3, 309–318, 1988. 29. Ummadisingu, A. and Soni, M.S., Concentrating solar power–technology, potential and policy in India. Renew. Sustain. Energy Rev., 15, 9, 5169–5175, 2011. 30. Price, H., A Parabolic Trough Solar Power Plant Simulation Model, National Renewable Energy Laboratory, Golden, CO, USA, 2003. 31. Stine, W.B. and Harrigan, R.W., Solar energy fundamentals and design, John Wiley and Sons, Inc., New York, NY, 1985. 32. Winston, R., Principles of solar concentrators of a novel design. Sol. Energy, 16, 2, 89–95, 1974. 33. Duffie, J.A. and Beckman, W.A., Solar energy thermal processes, University of Wisconsin-Madison, Solar Energy Laboratory, Madison, WI, 1974. 34. G.F. Drew, Parabolic solar concentrator employing flat plate collector. US Patent 4,038,964, 1977. 35. Meinel, A.B. and Meinel, M.P., Applied solar energy: An introduction, AddisonWesley Series in Physics, USA, 1976. 36. Moustafa, S.M.A., Brusewitz, G.H., Farmer, D.M., Direct use of solar energy for water desalination. Sol. Energy, 22, 2, 141–148, 1979. 37. W.S. Kennedy, Parabolic trough solar energy collector assembly. US Patent 4,135,493, 1979. 38. Kalogirou, S., Parabolic Trough Collector System for Low Temperature Steam Generation: Design and Performance Characteristics. Appl. Energy, 55, I, 1–19, 1996. 39. Kalogirou, S.A., Lloyd, S., Ward, J., Eleftheriou, P., Design and performance characteristics of a parabolic-trough solar-collector system. Appl. Energy, 47, 4, 341–354, 1994. 40. Scrivani, A., El Asmar, T., Bardi, U., Solar trough concentration for fresh water production and waste water treatment. Desalination, 206, 1–3, 485–493, 2007. 41. Ali, M.T., Fath, H.E.S., Armstrong, P.R., A comprehensive techno-economical review of indirect solar desalination. Renew. Sustain. Energy Rev., 15, 8, 4187– 4199, 2011. 42. Fath, H.E.S. and Ghazy, A., Solar desalination using humidificationdehumidification technology. Desalination, 142, 119–133, 2002. 43. Gangadharan, А.С., Narayanan, T.V., Bryes, R.W., Sommer, E.W., Design optimization of a small scale solar desalination plant. Colloq. Int. du Cent. Natl. la Rech. Sci., 306, 205, 1980.

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44. Al-Mutaz, I.S. and Al-Ahmed, M.I., Evaluation of solar powered desalination processes. Desalination, 73, 181–190, 1989. 45. Garcia-rodriguez, L., Seawater desalination driven by renewable energies: A review. Desalination, 143, 2, 103–113, 2002. 46. Garcia-rodriguez, L., Palmero-marrero, A.I., Gbmez-camacho, C., Comparison of solar thermal technologies for applications in seawater desalination. Desalination, 142, 135–142, 2002. 47. García-Rodríguez, L. and Gómez-Camacho, C., Design parameter selection for a distillation system coupled to a solar parabolic trough collector. Desalination, 122, 2, 195–204, 1999. 48. Trieb, F. and Müller-Steinhagen, H., Concentrating solar power for seawater desalination in the Middle East and North Africa. Desalination, 220, 1–3, 165– 183, 2008. 49. Trieb, F. and El Noraschy, H., Concentrating Solar Power for Seawater Desalination. Twelfth International Water Technology Conference, 2008. 50. García-Rodríguez, L. and Gómez-Camacho, C., Thermoeconomic analysis of a solar parabolic trough collector distillation plant. Desalination, 122, 2, 215– 224, 1999. 51. García-Rodríguez, L., Renewable energy applications in desalination: State of the art. Sol. Energy, 75, 5, 381–393, 2003. 52. Jakhar, S., Misra, R., Bansal, V., Soni, M.S., Thermal performance investigation of earth air tunnel heat exchanger coupled with a solar air heating duct for northwestern India. Energy Build, 87, 360–369, 2015. 53. Pandey, S., Success in Scaling-up Solar Energy in Rajasthan, India. [Online]. Available: http://re.indiaenvironmentportal.org.in/files/file/Success in Scaling-up Solar Energy in Rajasthan, India.pdf. 54. Gakkhar, N. and Soni, M.S., Techno-economic parametric assessment of CSP power generations technologies in India, in Energy Procedia, 54, 152–160, 2014. 55. Jakhar, S., Soni, M.S., Gakkhar, N., Performance Analysis of Photovoltaic Panels with Earth Water Heat Exchanger Cooling. MATEC Web Conf., 55, 02006, 0–5, 2016. 56. “Rajasthan Map”, in: Government of Rajasthan., [Online]. Available: http:// plan.rajasthan.gov.in/content/industries/rajasthan-foundation/about-rajasthan/ rajasthan-maps.html. 57. Hooda, S.M., Water Assessment - Potential for Private Intervention, Delhi, India, 2013. 58. Purohit, I. and Purohit, P., Techno-economic evaluation of concentrating solar power generation in India. Energy Policy, 38, 6, 3015–3029, 2010. 59. Dawson, L. and Schlyter, P., Less is more: Strategic scale site suitability for concentrated solar thermal power in Western Australia. Energy Policy, 47, 91–101, 2012. 60. The National Aeronautics and Space Administration, NASA Surface meteorology and Solar Energy, [Online]. Available: https://www.nasa.gov/. 61. Department of Land Resources, Wasteland Atlas, [Online]. Available: http:// www.dolr.nic.in/WastelandsAtlas2011/Wastelands_Atlas_2011.pdf.

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62. Purohit, I., Purohit, P., Shekhar, S., Evaluating the potential of concentrating solar  power generation in Northwestern India. Energy Policy, 62, 157–175, 2013. 63. Sharma, C., Sharma, A.K., Mullick, S.C., Kandpal, T.C., Assessment of solar thermal power generation potential in India. Renew. Sustain. Energy Rev., 42, 902–912, 2015. 64. State Water Resources Planning Department, Monsson Report 2014, A report by State Water Resources Planning Department, Govt of Rajastahn, Jaipur, India, 2014. 65. Department of Water Resources, Monsoon 2014, [Online]. Available: http:// water.rajasthan.gov.in/content/water/en/imtikota/Dataroom/rainfall/monsoonrainfall.html. 66. Ministry of Water Resources, Report of the Ground Water Resource Estimation Committee: Ground Water Resource Estimation Methodology, p. 113, 2009. 67. Surface and Ground Water Availability: Study on planning of water resources of rajasthan, 2014. [Online]. Available: http://water. rajasthan.gov.in/content/ water/en/rrbwrpadepartment.html. 68. Study on planning of water resources of rajasthan: Water Supply and Demand by Districts Part C – Water Supply and Demand Balance 2014. 2014. [Online]. Available: http://water.rajasthan.gov.in/content/dam/water/state-water-resources-planning-department/tahaldata/Report 4.3 Final _Ia.pdf. 69. Ground Water Year Book - India 2011–12, in: Central Ground Water Board, Ministry of Water Resources, 2012. [Online]. Available: http://cgwb.gov.in/documents/Ground Water Year Book - 2011–12.pdf. 70. Sharma, A., Goswamee, B., Kumar, R., Agarwal, A., Remuneration of Rain Water Harvesting in Shekahwati Region, Rajasthan. Int. J. Eng. Res. Technol., 1, 7, 1–5, 2012. 71. Suthar, S., Garg, V.K., Jangir, S., Kaur, S., Goswami, N., Singh, S., Fluoride contamination in drinking water in rural habitations of northern Rajasthan, India. Environ. Monit. Assess., 145, 1–3, 1–6, 2008. 72. Mitharwal, S., Yadav, R.D., Angasaria, R.C., Water Quality Analysis in Pilani of Jhunjhunu Distict (Rajasthan) - The Place of Birla’s Origin. Rasayan J. Chem., 2, 4, 920–923, 2009. 73. Lin, G.-F., Advances in Geosciences: Hydrological Science (HS), vol. 23, World Scientific, Singapore, 2011. 74. Government of Rajasthan, “Comprehensive full scale integrated Water Resources plan for the State as a whole.” [Online]. Available: http://waterresources.rajasthan.gov.in/SPWRR/chapter/chapters.htm. 75. Shah, A. et al., Recent progress on microcrystalline solar cells. Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE, pp. 569–574, 1997. 76. Bossert, R.H., Tool, C.J.J., Van Roosmalen, J.A.M., Wentink, C.H.M., De Vaan, M.J.M., Thin-film solar cells: Technology Evaluation and Perspectives, Report number DV 1.1.170, Netherlands Energy Research Foundation – ECN, Netherlands, 2000.

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77. Green, M.A., Solar cells: Operating principles, technology, and system applications, p. 288, Prentice-Hall, Inc., Englewood Cliffs, NJ, 1982. 78. De Wolf, S., Descoeudres, A., Holman, Z.C., Ballif, C., High-efficiency silicon heterojunction solar cells: A review. Green, 2, 1, 7–24, 2012. 79. Bergmann, R.B., Crystalline Si thin-film solar cells: A review. Appl. Phys. A, 69, 2, 187–194, 1999. 80. Hoogwijk, M.M., On the global and regional potential of renewable energy sources, Doctoral dissertation, Universiteit Utrecht, Netherlands, 2004. 81. Mahtta, R., Joshi, P.K., Jindal, A.K., Solar power potential mapping in India using remote sensing inputs and environmental parameters. Renew. Energy., 71, 255–262, 2014. 82. Soni, M.S. and Gakkhar, N., Techno-economic parametric assessment of solar power in India: A survey. Renew. Sustain. Energy Rev., 40, 326–334, 2014. 83. Trieb, F., Schillings, C., Sullivan, M.O., Pregger, T., Hoyer-klick, C., Global Potential of Concentrating Solar Power, in: SolarPACES 2009, 2009. 84. Gupta, S., Demystifying’Tradition’: The Politics of Rainwater Harvesting in Rural Rajasthan, India. Water Altern., 4, 3, 347–364, 2011. 85. Glendenning, C.J. and Vervoort, R.W., Hydrological impacts of rainwater harvesting (RWH) in a case study catchment: The Arvari River, Rajasthan, India: Part 2. Catchment-scale impacts. Agric. Water Manag., 98, 4, 715–730, 2011. 86. Alanis-Noyola, A., Prasanna, A., Rannou, T., Rojas-solórzano, L., PreFeasibility Analysis of a Desalination Plant Powered by Renewable Energy in Thira, Greece. Int. Conf. Renew. Energies power Qual., 2012. 87. Fiorenza, G., Sharma, V.K., Braccio, G., Techno-economic evaluation of a solar powered water desalination plant. Energy Convers. Manag., 44, 14, 2217–2240, 2003. 88. Husain, A., Integrated power and desalination plants, Encyclopedia of Life Support Systems (EOLSS) Publishers, Oxford, UK, 2003. 89. Spiegler, K.S. (ed.), Principles of desalination, Academic Press, NY, USA, 2012. 90. Sharma, C., Sharma, A.K., Mullick, S.C., Kandpal, T.C., Assessment of solar thermal power generation potential in India. Renew. Sustain. Energy Rev., 42, 902–912, 2015.

3 Design Analysis of Solar Photovoltaic Power Plants for Northern and Southern Regions of India Sanjay Kumar

*

National Institute of Solar Energy, Gwal Pahari, Gurugram, Hryana, India

Abstract Solar Energy has several advantages to save the environment and to meet our energy needs from the natural perennial source i.e. the SUN. This chapter deals with the solar energy potential in India and to design solar power plants based on radiation data. It explains how solar power plant is designed. To design solar power plant, first, feasibility studies have to be carried out which consists of site/space analysis, shadow analysis, technology assessment, solar resource assessment for project site, Simulation and energy yield estimation, capacity sizing, implementation schedule, cost estimate and financial modelling analysis for cost-benefit analysis, implementation methodology and scheduling, quality testing against set national/international standards, field analysis and performance measurement of the power plants in northern and southern regions of India. These plants are used to generate green and clean energy to save the environment by reducing harmful gases like CO2 emitted by the fossil fuels and savings of plants/woods. Different quality aspects for its design, installation, testing and commission with SCADA monitoring system have been incorporated for its control and trouble-shooting for its smooth functioning and operation. Keywords: SPV technology, SPV power plant, quality, standard, financial analysis, environmental aspects, monitoring of SPV plant, O&M of spv plant, business model, power purchase agreement

3.1 Introduction India faces formidable challenges in meeting its energy needs and providing adequate energy of desired quality in various forms to users in a Email: [email protected] Umakanta Sahoo (ed.) Progress in Solar Energy Technologies and Applications, (83–180) © 2019 Scrivener Publishing LLC

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sustainable manner and at reasonable cost. India’s per capita power consumption is among the lowest in the world. China has a per capita consumption of 4200kWh, with developed nations averaging around 10,000kWh per capita. The per capita consumption of electricity in India is way below that in other countries. The overall energy storage during 2014-15 was about 3.6% and peak demand shortage was 4.7%. It is expected these shortages are further reduced with the addition of new power plants especially renewable energy projects such as wind and solar. Renewable energy has the advantage of excess availability with free of cost adding to zero percent of emission of pollution. The slight drawbacks of high investment on installation can be compensated with good government policies and subsides. India was the first country in the world to set up a Ministry of Non-Conventional Energy Resources, in the early 1980s. The mission of the ministry is to bring in energy security, increase the share of clean power, increase energy availability and access, improve energy affordability, and maximize energy equity. As of 30th April, 2016, India’s cumulative grid interactive or grid tied renewable energy capacity (excluding large hydro) reached about 42.85 GW, surpassing the installed capacity of large-scale hydroelectric power in India for the first time in Indian history. Of the renewable power, 63% came from wind, while solar contributed nearly 16%. Large hydro installed capacity was 42.78 GW as of 30th April, 2016, and is administered separately by the Ministry of Power and not included in MNRE targets. From 2015 onwards the MNRE began laying down actionable plans for the renewable energy sector under its ambit to make a quantum jump, building on strong foundations already established in the country. MNRE renewable electricity targets have been upscale to grow from just under 43 GW in April 2016 to 175 GW by the year 2022, including 100 GW from solar power, 60 GW from wind power, 10 GW from bio power and 5 GW from small hydro power. The ambitious targets would see India quickly becoming one of the leading green energy producers in the world and surpassing numerous developed countries. The government intends to achieve 40% cumulative electric power capacity from non-fossil fuel sources by 2030. Ministry of New and Renewable Energy initiated Jawaharlal Nehru National Solar Mission in 2011. The objective of the Jawaharlal Nehru National Solar Mission (JNNSM) is to establish India as a global leader in solar energy. The Mission has set a target of 20,000 MW and stipulates implementation and achievement of the target in 3 phases (first phase up to 2012-13, second phase from 2013 to 2017 and the third phase from 2017 to 2022) for various components, including grid connected solar power. In January 2015, the Indian government significantly expanded its solar plans, targeting US$100 billion of investment and 100 GW of solar capacity, including 40 GW directly from rooftop solar by 2022.

Haryana

Himachal Pradesh

Jammu & Kashmir

Jharkhand

9

10

11

Chhatisgarh

5

8

Bihar

4

Goa

Assam

3

Gujarat

Arunachal Pradesh

2

6

Andhra Pradesh

1

7

STATES/Uts

S.No.

4.05

179.03

860.61

73.50

45.70

0.05

76.00

70.70

34.11

107.100

5965.87

4076.45

(MW)

(MW)

162.11

Wind Power

Small Hydro Power

121.40

65.30

228.00

113.00

378.20

(MW)

BM Power/ Bagasse Cogen. (Grid Interactive)

4.30

7.20

84.26

12.00

2.50

8.20

98.98

(MW)

BM Cogen. (Non-Bagasse/ Captive Power)

Bio Power

23.16

(MW)

Waste to Energy

Table 3.1 Statewide installed capacity of Grid Interactive Renewable Power in India.

4.30

7.20

205.66

77.30

230.50

121.20

500.34

(MW)

Bio Power Total

19.05

8.49

0.00

130.80

1836.3

0.95

215.83

138.93

10.67

1.27

2840.77

(MW)

Ground Mounted

13.36

5.89

4.50

88.79

166.73

0.74

15.52

3.52

7.98

4.12

48.52

(MW)

RoofTop

Solar Power

32.41

14.38

4.50

219.59

2003.03

1.69

231.35

142.45

18.65

5.39

2889.29

(MW)

Total

(Continued)

40.76

193.41

872.31

498.75

8091.90

1.74

537.85

334.5

52.76

112.49

7628.19

(MW)

Total Capacity

Design Analysis of Solar Photovoltaic Power Plants 85

Tamil Nadu

Tripura

26

23

Telangana

Sikkim

22

24

Rajasthan

21

25

Odisha

Punjab

20

Nagaland

Manipur

16

19

Maharashtra

15

Meghalaya

Madhya Pradesh

14

Mizoram

Kerala

13

17

Kamataka

12

18

STATES/Uts

S.No.

16.01

90.87

123.05

52.11

23.85

173.55

64.625

30.67

36.47

31.03

5.45

375.570

95.91

222.02

128.10

8764.34

4299.72

4794.13

2519.890

52.50

4682.80

(MW)

(MW)

1230.73

Wind Power

Small Hydro Power

158.10

941.00

119.30

194.00

50.40

2499.70

93.00

1783.60

(MW)

BM Power/ Bagasse Cogen. (Grid Interactive)

1.00

56.48

2.00

123.10

8.82

13.80

16.40

12.35

0.72

15.20

(MW)

BM Cogen. (Non-Bagasse/ Captive Power)

Bio Power

18.50

6.40

9.25

12.59

15.40

1.00

(MW)

Waste to Energy

177.60

1003.88

121.30

326.35

59.22

13.80

2528.69

120.75

0.72

1799.80

(MW)

Bio Power Total (MW)

5.00

3519.27

2098.27

0.00

3045.69

828.1

383.56

0.00

0.10

0.00

0.00

1447.30

1619.22

100.00

5175.06

0.09

64.34

135.07

0.01

96.2

77.52

6.71

1.00

0.40

0.12

3.23

172.26

30.67

38.49

153.75

(MW)

RoofTop

Solar Power

Ground Mounted

Table 3.1 Statewide installed capacity of Grid Interactive Renewable Power in India. (Continued)

5.09

3583.61

2233.34

0.01

3141.89

905.62

390.27

1.00

0.50

0.12

3.23

1619.56

1649.89

138.49

5328.81

(MW)

Total

(Continued)

21.10

3980.18

12124.61

52.12

7586.76

1405.52

514.12

31.67

36.97

44.95

8.68

9317.95

4386.44

413.73

13042.14

(MW)

Total Capacity

86 Progress in Solar Energy Technologies and Applications

35288.100

4528.045

Total (MW)

MW = Megawatt

4.30

Others

Daman & Diu

33

Pondicherry

Dadar & Nagar Havek

32

37

Chandigarh

31

5.25

36

Andaman & Nicobar

30

98.50

Delhi

West Bengal

29

25.10

214.320

Lakshwadeep

Uttarakhand

(MW)

(MW)

35

Uttar Pradesh

27

28

Wind Power

Small Hydro Power

34

STATES/Uts

S.No.

9075.50

300.00

73.00

1957.50

(MW)

BM Power/ Bagasse Cogen. (Grid Interactive)

704.74

19.92

57.50

160.01

(MW)

BM Cogen. (Non-Bagasse/ Captive Power)

Bio Power

138.30

52.00

(MW)

Waste to Energy

9918.54

52.00

319.92

130.50

2117.51

(MW)

Bio Power Total

24582.23

0.03

0.75

8.96

10.15

2.49

6.34

5.10

50.00

239.78

834.00

(MW)

1443.74

1.77

0.00

115.25

4.32

2.97

26.06

1.46

19.56

64.49

68.33

(MW)

RoofTop

Solar Power

Ground Mounted

Table 3.1 Statewide installed capacity of Grid Interactive Renewable Power in India. (Continued)

26025.97

1.80

0.75

124.21

14.47

5.46

32.40

6.56

69.56

304.27

902.33

(MW)

Total

75760.66

4.30

1.80

0.75

176.21

14.47

5.46

32.40

11.81

487.98

649.09

3044.94

(MW)

Total Capacity

Design Analysis of Solar Photovoltaic Power Plants 87

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88

• Phase 1 Up to 2013 • Phase 2 Up to 2017 • Phase 3 Up to 2022

1100MW 10000MW 20000MW (now 1,00,000 MW)

3.1.1 Solar Power in India India is blessed with about 300 clear, sunny days in a year; the theoretically calculated solar energy incidence on India’s land area is about 5000 trillion kilowatt-hours (kWh) per year (or 5 EWh/yr). The solar energy available in a year exceeds the possible energy output of all fossil fuel energy reserves in India. The daily average solar power plant generation capacity over India is 0.20 kWh per m2 of used land area, which is equivalent to about 1400–1800 peak (rated) capacity operating hours in a year with the available commercially proven technologies. As of 30 September 2016, the country’s solar grid has a cumulative capacity of 8,626 MW (8.63 GW). It has been estimated that India’s total rooftop potential is 42.83 GWp and wasteland potential is 706.15GWp which when used complete, makes India an energy surplus country. National Institute of Solar Energy has released a solar potential map, where each state’s capacity is estimated. It can be seen from the map that Kerala belongs to the range of 6 GWp capacities. This is due to the direct radiation (DNI) received from the sun, which is 4.5 to 5 kWh/m2/ day and Global radiation (GHI) is 5 to 5.5 kWh/ m2/day. Figure 3.3 & Figure 3.4 show the India map of direct radiation (DNI) and Global radiation (GHI).

Solar Capacity added in 2014-15(MW) 250

228.85 205

200 168.75

150 100

126.77 81

80 61.25

54.12

50

46.22

42.16 5

2.5

2.26

0.5

M

Figure 3.1 Solar Capacity (MW) added in 2014-2015.

Or iss Ch a ha tti sg ar h

Ra ja st ad ha hy n aP ra de sh Pu An nj dh ab ra Pr ad es h Gu ja ra M t ah ar as ht ra Te la ng an a Ta m il N ad u Ka rn at Ut ak a ta rP ra de sh Tr ip ur Ch a an di ga rh

0

Design Analysis of Solar Photovoltaic Power Plants 89

Figure 3.2 Solar Potential map of India.

India Solar Resource Direct Normal Solar Resource This map depicts model estimates af annual average direct normal irradiance (DNI) at 10 km resolution based on hourly estimates of radiation over 7 years (2002-2008). The inputs are visible imagery from geostationary satelites, aerosol optical depth, water vapor, and ozone.

Srinagar (Capital) Amritsar

Shimla (Capital) Dehradun (Capital)

Chandigarh (Capital) New Delhi Jaipur (Capital)

Gangtok (Capital)

Lucknow (Capital) Kanpur

Itanagan (Capital)

Dispul (Capital) Patna (Capital)

Gandhinagar (Capital) Ahmedabad

Agartala (Capital) Ranchi (Capital) Kolkata (Capital)

Bhopal (Capital)

Imphal (Capital) Aizawl (Capital)

Raipur (Capital)

Nagpur

Daman

Bhubaneshwar (Capital)

Silvassa (Capital) Mumbai (Capital)

Kohima (Capital)

Shillong (Capital)

Varanasi

Pune Hyderabad (Capital)

Vishakhapatnam

Panaji (Capital) N Bangalore (Capital) Mangalore

Chennai (Capital)

0

100 200 300 400 Kilometers

Pondicherry

Port Blair (Capital)

Kavaratti (Capital)

Annual DNI (KWh / m2/day)

Cochin >9 8.5 - 9.0 8.0 - 9.5 7.5 - 8.0 7.0 - 7.5 6.5 - 7.0 6.0 - 6.5 5.5 - 6.0 5.0 - 5.5 4.5 - 5.0 4.0 - 4.5 3.5 - 4.0 3.0 - 3.5 2.5 - 3.0 2.0 - 2.5 = 1.25 x Imp (string) • 2.4 x Isc (string) > Itrip (string fuse) > 1.5 x Isc (string) Step 7: Inter row distance of modules and tilt angle

D’/D h

x θ

α

South

Figure 6.12 Inter row distance of modules and tilt angle.

South

D’

D ψ

Figure 6.13 Detailed drawing to calculate Inter row distance of modules and tilt angle.

The Design of Rooftop Solar PV Systems =Solar azimuth angle; α = solar altitude angle a)

Azimuth and Elevation angle

Up z

h North A

h = elevation angle, measured up from horizon

z = zenith angle, measured from vertical

A = Azimuth angle, measured clockwise from North

Figure 6.14 Azimuth and Elevation angle.

b)

Optimum array row spacing

D = h/tan(α)

(6.12)

D = D cos(180 − ψ) (morning)

(6.13)

D = D cos (ψ − 180) (afternoon)

(6.14)

or

• D = maximum shadow length • D = minimum array row spacing

h = x sin(θ) • h = height of obstruction • x = length of tilted modules • θ = tilt angle

(6.15)

329

330

Progress in Solar Energy Technologies and Applications c)

Tilt angle As a quick calculation, PV panel can be mounted at a tilt angle (ϕ) equal to 0.9 times latitude of location. For seasonal variation, the tilt angle varies as follows • In winters optimum tilt angle is ϕ−15 • In summer optimum tilt angle ϕ−15

6.2.4 Stand-Alone Solar PV System Design and Safety Standards • IEC 62548 – Design (safety) requirements for photovoltaic (PV) arrays including d.c. array wiring, electrical protection devices, switching and earthing provisions. (off-grid and on-grid systems) • IEC 62124 – PV stand-alone systems design verification – Check functionality, autonomy and ability to recover after periods of low state of charge of the battery. • IEC62111 – Specifications for use of Rural Electrifications Systems • IEC62257 – Small Renewable energy and Hybrid Systems for Rural Electrification • Doc ETD28 (10084, 10085) – Test Methods for standalone electrical lighting appliances

6.3 Grid-Connected Solar PV System There are two types of Grid-connected Solar PV systems: 1. Rooftop Grid-connected solar PV system 2. Utility Scale Grid-connected Solar PV Power Plant 1. Rooftop grid-connected solar PV system PV

D.C Protection and Switchgears

LT Distribution Grid

Inverter

A.C Protection and Switchgears

AC Electrical Loads Main LT Panel

Figure 6.15 Rooftop grid-connected solar PV system.

The Design of Rooftop Solar PV Systems

331

2. Utility Scale Grid-connected Solar PV Power Plant

PV Array

D.C Protection and Switchgears

Inverter

A.C Protection and Switchgears

Distribution/ Transmission Grid

MV/HV Transformer

Figure 6.16 Utility Scale Grid-connected Solar PV Power Plant.

In this chapter, we would be elaborating the design aspects of a Rooftop Grid-connected Solar PV system. The design of Utility Scale Grid connected Solar PV Power Plant is not in the scope of this chapter and is an advanced designing concept, explained in a separate chapter.

6.3.1 Step by Step Procedure for Designing a Rooftop Grid-Connected Solar PV System Rooftop Grid-connected Solar PV system can be designed as follows: I. Based on available area, the steps for sizing a solar PV system are as follows: • Divide available area by single module area, will give plant capacity (keeping in mind gap between modules) • Once plant capacity is known then select inverter of same or less (depending on inverter performance) capacity. • Configure string size to obtain the inverter input voltage range. • Number of string in parallel will be decided by inverter input current capacity

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Progress in Solar Energy Technologies and Applications II. Step by step procedure for PV array sizing, when area is not the constraint: a. Sizing of Solar PV modules • Step 1: Daily energy requirements (kWh) • Step 2: Yearly Average daily peak sun hours (PSH) for selected tilt and orientation of PV array. • Step 3: System Efficiency Factor (SYSEF): • Step 4: Peak PV Watts (Total kWp)= kWh/(PSH* SYSEF) • Step 5: Select module Wp and size based on available space, installation and maintenance requirements. • Step 6: No. of PV Modules = Total Wp/Module Wp • Step 7: Use nearest larger number of modules b. Array Inverter Matching • Match array to voltage spec of Inverter • Min. no of modules in string at max. cell temp. • Max. no of modules in string at min. cell temp. • Matching array to current spec of inverter • Matching array to inverter power rating • Integration of voltage, current and power rating c. Max number of strings • Max. array current at max. cell temp. should be below max. inverter input current. • Multiply max. inverter input current by 0.9 (safety factor). • Calculate max. string Isc at max. cell temp. • Divide safe max. inverter input current by max. string Isc (Round down) to get max. no. of strings that can make an array for connecting to inverter. d. Max number of modules in an array • Multiply max. DC input rated power of inverter by 0.9 (safety factor). • Divide safe max. DC input rated power of inverter by module rated power (Round down) to get max. no. of modules in an array. (Consider DC Loading Factor)

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• If PV array power at inverter input exceeds max. DC input rated power of inverter, inverter limits power input by lowering its input operating voltage which reduces input power. (Array operates at power lower than MPP.) • Verify voltage and current calculations for matching array and inverter. • Ensure power, voltage and current calculations all meet the requirements. Salient points: • Max. PV array rated power (kWp) • PV array max. DC power < Max. DC inverter power • Max. AC output power inverter can produce is governed by its efficiency at the DC input power level • PV array max. DC power > max. inverter AC output

6.3.2 Grid-Tied Solar PV System Standards • IEC 62548 – Design (safety) requirements for photovoltaic (PV) arrays including D.C. array wiring, electrical protection devices, switching and earthing provisions. (off-grid and on-grid systems) • IEC 62446-3 Draft – Grid-connected PV systems – minimum requirements for system documentation, commissioning tests, and inspection. • IEC 61724-2 Draft – Photovoltaic system performance monitoring - Guidelines for measurement, data exchange and analysis. • CEA Technical Standards for Grid Connectivity-2007 (Amendments to accommodate renewables above and below 33kV applicable to Distributed Generation Resources) Note: For a PV-based hybrid system, generally, diesel generator is added with PV system to provide better reliability of system. Solar PV-diesel-battery hybrid system follows the mechanism of starting a diesel generator i.e., load following and cycle charging. For the understanding of detailed design concept, case studies are being developed through the setup of pilot projects, for analysis of data.

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6.3.3 Performance Analysis of a Solar PV System • Types of losses in PV system ➢ Radiation losses ➢ PV conversion losses ➢ Inverter losses • Performance index ➢ Reference system yield ➢ Array yield ➢ System yield ➢ Performance ratio (PR) a)

Temperature losses calculation: ➢ Solar PV modules have negative temperature coefficient of power, i.e., as temperature increases, power output of SPV module decreases. ➢ An approximate expression for calculating the cell temperature is given by

Tcell Where S Tamb b)

Tamb

NOCT 20 S 80

(6.15)

is incident solar radiation (kWh/m2/Day) is ambient temperature

Reference system yield ➢ Reference system yield: it is the total incident energy on the collector plane ➢ Array yield: array daily output energy ➢ System yield: it is system daily useful energy. ➢ All are expressed in kWh/kWp/day ➢ The “specific yield” (kWh/kWp) is the total annual energy generated per kWp installed. It is often used to compare operating results from different technologies and systems. ➢ The specific yield of a plant depends on: ➢ The total Annual Irradiation falling on the modules ➢ Performance of the module ➢ System Losses

The Design of Rooftop Solar PV Systems c)

Performance Ratio It is defined as ratio of final yield to the reference yield.

PR

FinalYield Reference yield

(6.16)

• Depending on geographical location and season, the PR values fall normally within the range 0.4 to 0.9 • If PR decreases yearly, this may indicate a permanent loss in performance. • For a well-designed grid connected system, the Performance Ratio (PR) varies between 70% to 85%. • For any given system, location and time; an increase in the PR amounts to increase in the annual energy yield. d)

Capacity Utilization Factor The capacity factor of a PV System (usually expressed as a percentage) is the ratio of the actual output over a period of one year and its output if it had operated at nominal power, the entire year, as described by the formula: Energy Generated per annum = E kWh Installed Capacity = P kWp No. of hours in a year = H hrs = 365 x 24 = 8760 hrs

Capacity Utilization Factor (CUF) = [ E / (H x P) ] x 100% (6.17) e)

Calculations for plant efficiency Plant efficiency is multiplication of all components efficiency used in PV system.

ηp = ηinv*ηbat*ηMPPt*ηCC ηp = plant efficiency ηinv = Inverter efficiency ηbat = Battery efficiency ηMPPT = MPPT efficiency ηcc = Charge controller efficiency

(6.18)

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Loss Analysis • A typical example of the range of losses occurring in a Stand-alone Solar PV System

Table 6.5 Typical total system efficiency range is 60-70% in a Stand-alone Solar PV System. Factors

% Loss

PV Response to Insolation (IAM, DI)

2-3

PV Mismatch

1-2

PV Soiling

1-2

PV Thermal Loss

8-10

DC Cable Loss

1-1.5

MPPT Charge Controller

1-2

Battery

12-15

Inverter including Transformer

4-5

AC Cable Loss

0.5-1

Total System Loss

30-40

• A typical example of the range of losses occurring in a Grid-connected Solar PV System Table 6.6 Typical total system efficiency range is 75-85% in a Grid-connected Solar PV System. Factors

% Loss

PV Response to Insolation (IAM, DI)

2-3

PV Mismatch

1-2

PV Soiling

1-3

PV Thermal Loss

8-10

DC Cable Loss

1-2

Inverter

1-2

Transformer

1-2

AC Cable Loss

0.5-1

Total System Loss

15-25

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6.4 Costing Analysis for a Solar PV System A. Simple payback period (6.19)Simple payback period = total investment Cost of annual energy savings (6.19) It does consider the following factors in evaluating payback period: • Time value of money • Inflation rate • Lifetime of system • Operation and maintenance cost B. Life cycle cost (LCC) In order to calculate LCC, the following three components must be known: • Capital cost is known at the time of investment. • O&M cost and replacement cost occurs in the future. • Time value of money There are two ways in which value of money changes • Inflation rate Inflation rate: measure of the decline in the value of money over time C(n)=C_o [(1+i)]^n (20) C(n) is future cost of product after n year C_o is inflation rate n is number of years • Interest rate (Discount rate) Value of money increases due to interest it can earn.

Discount rate future value present value future valuee Interest rate future value present value present valu ue

(6.21)

(6.22)

Note: The present worth of the future is defined as the amount of money that needs to be invested today with discount rate and inflation rate such that we

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would be able to purchase that product in future. The detailed calculations for costing analysis are not in the scope of this chapter; is a topic which has to be dealt with separately. However, the solar design simulation softwares like PVSOL, PVsyst, SAM, RETSREEN, Homer, etc. can be used for ease of doing detailed calculations and estimating the Solar PV system performance parameters. The next section has sample Software simulation report for energy & performance estimation as well as financial modelling of the project, using PVsyst. Example 8: Sample PVsyst report for energy generation study and performance analysis • Grid-Connected System Grid-Connected System: Simulation parameters Project: 5MWdc Solar Power Project Country India Geographic Velligallu Tummukunta, Andhra Pradesh Longitude 78.3°E Latitude 14.0°N Sitution Altitude 400 m Legal Time Time zone UT+5.5 Time defined as Albedo 0.20 Meteo data: Velligallu Tummukunta, Andhra Pradesh Meteonorm 7.1 (1981-2010), Sat=100% - Synthetic Simulation variant:

Simulation parameters Collector Plane Orientation Models used Horizon Near Shadings

New simulation variant Simulation date 07/06/17 19h36

Tilt 26° Transposition Perez Free Horizon No Shadings

PV Array Characteristics PV module Si-poly Model Original PVsyst database Manufacturer Number of PV modules In series Total number of PV modules Nb. modules Array global power Nominal (STC) Array operating characteristics (50°C) U mpp Total area Module area Inverter Original PVsyst database Characteristics Inverter pack

Diffuse Perez, Meteonorm

Poly 285 Wp 72 cells Generic 12 modules In parallel 17544 Unit Nom. Power 5000 kWp At operating cond. 388 V I mpp 34042 m2 Cell area

1462 strings 285 Wp 4477 kWp (50°C) 11544 A 30695 m2

Model 500 kWac inverter Manufacturer Generic Unit Nom. Power 500 kWac Operating Voltage 320–700 V Nb. of inverters 8 units

PV Array loss factors Array Soiling Losses Uc (const) 29.0 W/m2K Thermal Loss factor Global array res. 0.57 mOhm Wiring Ohmic Loss LID - Light Induced Degradation Module Quality Loss Module Mismatch Losses IAM = 1 - bo (1/cos i - 1) Incidence effect, ASHRAE parametrization User’s needs: Auxiliaries loss

Azimuth 0°

Total Power 4000 kWac

Loss Fraction Uv (wind) Loss Fraction Loss Fraction Loss Fraction Loss Fraction bo Param.

1.0 % 0.0 W/m2K / m/s 1.5 % at STC 2.0 % –0.8 % 1.0 % at MPP 0.05

Unlimited load (grid) Constant (fans) 80000 W ... from Power thresh. 40.0 kW

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• Grid-Connected System: Main results Grid-Connected System: Main results Project: Simulation variant:

5MWdc Solar Power Project New simulation variant

Main system parameters PV Field Orientation PV modules PV Array Inverter Inverter pack User’s needs

System type tilt Model Nb. of modules Model Nb. of units Unlimited load (grid)

Main simulation results System Production

Grid-Connected 26° azimuth Poly 285 Wp 72 cells Pnom 17544 Pnom total 500 kWac inverter Pnom 8.0 Pnom total

Produced Energy 7667 MWh/year Specific prod. 1533 kWh/kWp/year Performance Ratio PR 77.50%

Normalized productions (per installed kWp): Nominal power 5000 kWp 8

PR: Performance Ration (Yf/Yr) 0.775

0.8 6 Performance Ratio PR

Normalized Energy [kWh/kWp/day]

Performance Ratio PR 1.0

0.91 kWh/kWp/day 0.31 kWh/kWp/day 4.2 kWh/kWp/day

Lc: Collection Loss (PV-array losses) LS: System Loss (inverter, ...) Yf: Produced useful energy (inverter output)

7

0° 285 Wp 5000 kWp 500 kW ac 4000 kW ac

5 4 3

0.6

0.4

2 0.2 1 0

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

0.0

Dec

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

New simulation variant Balance and main results GlobHor kWh/m2

T Amb °C

GlobInc kWh/m2

GlobEff kWh/m2

EArray MWh

E_Grid MWh

EffArrR %

EffSysR %

January February March April May June July August September October November December

169.1 163.9 199.4 186.9 181.9 151.3 146.5 141.2 149.7 144.3 143.1 146.7

24.79 27.28 30.25 31.78 31.75 28.92 28.40 27.64 27.22 26.80 24.67 23.82

211.3 188.4 206.9 175.1 158.3 129.7 126.5 129.8 147.9 155.3 167.6 182.0

204.4 181.8 199.3 167.8 150.9 123.3 120.3 123.9 141.9 149.4 161.7 175.9

881.9 778.3 840.5 711.2 646.7 544.5 531.4 545.6 618.6 654.4 708.7 773.2

829.4 731.5 789.1 662.7 598.1 499.5 485.7 500.7 572.4 608.5 663.7 725.6

12.26 12.14 11.93 11.93 12.00 12.33 12.34 12.35 12.29 12.38 12.42 12.48

11.53 11.41 11.20 11.12 11.10 11.32 11.28 11.33 11.37 11.51 11.63 11.71

Year

1924.0

27.78

1978.6

1900.3

8235.1

7666.9

12.23

11.38

Legends:

GlobHor T Amb GlobInc GlobEff

Horizontal global irradiation Ambient Temperature Global incident in coll. plane Effective Global, corr. for IAM and shadings

EArray E_Grid EffArrR EffSysR

Effective energy at the output of the array Energy injected into grid Effic. Eout array/rough area Effic. Eout system/rough area

Nov

Dec

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Progress in Solar Energy Technologies and Applications • Grid-Connected System: Loss diagram Grid-Connected System: Loss diagram Project:

5MWdc Solar Power Project

Simulation variant:

New simulation variant

Main system parameters System type PV Field Orientation tilt PV modules Model PV array Nb. of modules Inverter Model Inverter pack Nb. of units User’s needs Unlimited load (grid)

Grid-Connected 26° azimut Poly 285 Wp 72 cells Pnom 17544 Pnom total 500 kWac inverter Pnom 8.0 Pnom total

0° 285 Wp 5000 kWp 500 kW ac 4000 kW ac

Loss diagram over the whole year

+2.8%

Horizontal global irradiation Global incident in coll. plane

–3.0%

IAM factor on global

–1.0%

Soiling loss factor

1924 kWh/m2

1900 kWh/m2 * 34042 m2 coll.

Effective irradiance on collector

efficiency at STC = 14.78% 9564 MWh

–0.4%

PV conversion Array nominal energy (at STC effic.) PV loss due to irradiance level

–10.4% PV loss due to temperature +0.8%

Module quality loss

–2.0% –1.0% –1.1%

LID - Light induced degradation Module array mismatch loss Ohmic wiring loss Array virtual energy at MPP

8249 MWh –2.9% –0.2% 0.0% 0.0% 0.0%

Inverter Loss during operation (efficiency) Inverter Loss over nominal inv. power Inverter Loss due to power threshold Inverter Loss over nominal inv. threshold Available Energy at Inverter Output

–4.1%

Auxiliaries (fans, other)

7992 MWh

7667 MWh

Energy injected into grid

The Design of Rooftop Solar PV Systems • Grid-Connected System: P50-P90 evaluation Grid-Connected System: P50–P90 evaluation Project: Simulation variant:

5MWdc Solar Power Project New simulation variant

Main system parameters PV Field Orientation PV modules PV Array Inverter Inverter pack User’s needs

System type tilt Model Nb. of modules Model Nb. of units Unlimited load (grid)

Grid-Connected 26° azimuth Poly 285 Wp 72 cells Pnom 17544 Pnom total 500 kWac inverter Pnom 8.0 Pnom total

0° 285 Wp 5000 kWp 500 kW ac 4000 kW ac

Evaluation of the Production probability forecast The probability distribution of the system production forecast for different years is mainly dependent on the meteo data used for the simulation, and depends on the following choices: Meteo data source Meteo data Specified Deviation Year-to-year variability

Kind Climate change Variance

Meteonorm 7.1 (1981–2010), Sat=100% Monthly averages Synthetic Multi-year average 0.0% 2.5%

The probability distribution variance is also depending on some system parameters uncertainties Specified Deviation PV module modelling/parameters 2.0% Inverter efficiency uncertainty 0.5% Soiling and mismatch uncertainties 1.0% Degradation uncertainty 1.0% Global variability (meteo + system) Variance 3.5% (quadratic sum) Variability P50 P90 P75

Annual production probability

271 MWh 7667 MWh 7319 MWh 7484 MWh

Probability distribution 0.50 0.45

P50 = 7667 MWh E_Grid simul = 7667 MWh

Probability

0.40 0.35

P75 = 7484 MWh

0.30 0.25 0.20

P90 = 7319 MWh

0.15 0.10 0.05 0.00 6800

7000

7200

7400

7600

7800

8000

8200

E_Grid system production MWh

8400

8600

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• National Qualification - SGJ/Q0110 Solar PV Designer Table 6.7 Summary of SGJ/Q0110 Solar PV Designer. Job Role

Solar PV Designer

Role Description

Solar PV Designer specializes in the designing of solar PV power plant

NSQF level Minimum Educational Qualifications

7

Maximum Educational Qualifications

B. Tech/ B.E. (Solar/ Electrical, Electronics, Civil, Mechanical/ Energy Systems) or M.Tech. (Solar/ Renewables/ Energy Studies) Not Applicable

Minimum Job Entry Age

25 years

Experience

3 years of Solar PV experience for B.Tech./ B.E. and No experience for M.Tech.

Applicable National Occupational Standards (NOS)

Compulsory: 1. SGJ/N0128: Review the structural design of solar PV power plant 2. SGJ/N0129: Review the electrical design of solar PV power plant and the energy simulation report 3. SGJ/ N0106: Maintain personal health & safety at solar PV project site 4. SGJ/N0120: Work effectively with others

Performance Criteria

As described in the relevant OS units

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Table 6.8 SGJ/N0128 - Review the structural design of solar PV power plant. Unit Code

SGJ/N0128

Unit Title (Task)

Review the structural design of Solar PV Power Plant

Description

This unit is about reviewing the structural design of solar PV power plant

Scope

This unit/task covers the following: • study the site survey and soil test reports • review the design for plant Infrastructure • review the design of solar module mounting system • review the design of foundation for other components • review the design of plant switchyard and power transmission system • review the design of mounting structures for Rooftop / Canal Top Plants

Performance Criteria (PC) w.r.t. the Scope Element

Performance Criteria

Study the site survey and soil test reports

To be competent, the user/individual must be able to: PC1. study the soil test reports, water table depth report and pull test data to ensure the design meets requirement

Review the design for plant Infrastructure

To be competent, the user/individual must be able to: PC2. review the overall plant layout PC3. review the layout for solar field compound wall / entry gate PC4. review the layout for in plant roads with material specifications PC5. review the design for water distribution network inside the plant PC6. review the design for water drainage system PC7. review the design for pathways between the solar arrays

Review the design of solar module mounting system

To be competent, the user/individual must be able to: PC8. review the design for the foundation for mounting solar PV panel support structure PC9. review the design for the tilt brackets and mounting frames for solar panels with fastening arrangement (Continued)

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Table 6.8 SGJ/N0128 - Review the structural design of solar PV power plant. (Continued) Unit Code

SGJ/N0128

Review the design of foundation for other components

To be competent, the user/individual must be able to: PC10. document the details of RCC foundation, plan of the inverter room PC11. document the details of the bolt, base plates etc. used in structure, foundation of inverter and control room PC12. document the transformer foundation details PC13. document the foundation and design details of the control room PC14. review the design plan for earthing pits PC15. review the design plan for lightning arrestor foundation PC16. review the design plan for street light foundation

Review the design of plant switchyard and power transmission system

To be competent, the user/individual must be able to: PC17. review the structural design for plant switchyard as per the grid code and transmission authority regulations PC18. review the foundation plan for the transmission tower PC19. review the design for structure of the transmission tower PC20. review the design for stub and cleats of transmission tower PC21. review the design for corridor of transmission line

Review the design of mounting structures for Rooftop / Canal Top Plants

To be competent, the user/individual must be able to: PC22. review the foundation design for module mounting structures such that the dead and dynamic loads on modules are transferred to the beam and columns of the building PC23. review the design for walk ways for maintenance of modules and system PC24. review the design for movable mounting structure for canal top plant to increase output (Continued)

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Table 6.8 SGJ/N0128 - Review the structural design of solar PV power plant. (Continued) Unit Code

SGJ/N0128

Knowledge and Understanding (K) A. Organizational Context (Knowledge of the organization and its processes)

The user/individual on the job needs to know and understand: KA1. government/corporate policies and guidelines on: workplace safety, identification and mitigation of safety hazards, work procedures and guidelines for working at height KA2. document information using appropriate corporate forms KA3. obtain authorization from specified field safety officer and superiors KA4. legislative, organization, site requirements and procedures

B. Technical Knowledge

The user/individual on the job needs to know and understand: KB1. site survey reports, availability of shadow free space for installation of solar power plant KB2. solar resource assessment including terms like DNI, DHI, GHI and albedo and their interpretation KB3. structural designs for the foundations for module structures / inverters / transformers prepared by the structural design engineer/civil engineer KB4. design/drawing of the module mounting structure KB5. solar cells / modules / module technologies KB6. shading analysis and its importance and effect on solar PV power plant KB7. efficiency, cost and typical specifications, functioning and operating principle of different types of Solar PV Plants, commercially available PV modules, inverters, transformers, charge controllers, battery, mounting structures, cables, junction boxes and other components KB8. solar irradiation including GHI, DHI and DNI KB9. mechanical and electrical features necessary for the long life of the PV Power Plant under a wide range of operating conditions KB10. solar PV Power Plant design software such as PVSYST, PV*SOL etc. (Continued)

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Table 6.8 SGJ/N0128 - Review the structural design of solar PV power plant. (Continued) Unit Code

SGJ/N0128

Skills (S) A. Core Skills/ Generic Skills

Writing Skills The user/individual on the job needs to know and understand how to: SA1. prepare documentation as per relevant industry standards SA2. present information in a logical and organized way Reading Skills The user/individual on the job needs to know and understand: SA3. advanced level of English language SA4. how to interpret manuals, health and safety instructions, memos, other company documents SA5. how to read and interpret data from various sources Oral Communication (Listening and Speaking skills) The user/individual on the job needs to know and understand how to: SA6. express statements or information clearly so that others can hear and understand SA7. participate in and understand the main points of simple discussions SA8. respond appropriately to any queries SA9. communicate with peers, superiors and sub-ordinates

B. Professional Skills

Decision Making The user/individual on the job needs to know and understand how to: SB1. follow organization rule-based decision making process SB2. take decision with systematic course of actions and/or response (Continued)

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Table 6.8 SGJ/N0128 - Review the structural design of solar PV power plant. (Continued) Unit Code

SGJ/N0128 Plan and Organize The user/individual on the job needs to know and understand how to: SB3. plan and organize work to meet deadlines SB4. plan to utilise time and equipment effectively SB5. work constructively and collaboratively with others Customer Centricity The user/individual on the job needs to know and understand how to: SB6. follow organisation code of conduct SB7. manage relationships with customers with intent on satisfying its requirements for service delivery Problem Solving The user/individual on the job needs to know and understand how to: SB8. generate solutions to specific problems for a wide range of activities SB9. choose best methods to complete assigned tasks Analytical Thinking The user/individual on the job needs to know and understand how to: SB10. apply wide range of factual and theoretical knowledge to select the right course of action to perform tasks related to solar photovoltaic power plant Critical Thinking The user/individual on the job needs to know and understand how to: SB11. use reasoning skills to identify and resolve basic problems SB12. use intuition to detect any potential problems which could arise during operations SB13. use acquired knowledge of the process for identifying and handling issues

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Table 6.9 SGJ/N0129 - Review the electrical design of solar PV power plant and the energy simulation report. Unit Code

SGJ/N0129

Unit Title (Task)

Review the electrical design of solar PV power plant and the energy simulation report

Description

This unit is about reviewing the electrical design of solar PV power plant and preparation of energy generation report

Scope

This unit/task covers the following: • work out the capacity of solar power plant • review the design and selection of solar modules • review the design and selection of inverters • review the design and selection of strings • review the design and selection of combiner boxes and switchgear • prepare energy simulation report • selection of batteries for rooftop off-grid solar power plant

Performance Criteria(PC) w.r.t. the Scope Element

Performance Criteria

Workout the capacity of solar power plant

To be competent, the user/individual must be able to: PC1. analyze the availability of shadow free space available PC2. analyze the global solar irradiation at the site PC3. Work out the capacity of the solar power plant

Review the design and selection of solar modules

To be competent, the user/individual must be able to: PC4. select solar module technology and size, based on analysis of cost, power output, quality, climatic conditions of the site, global and diffused irradiance ratio at the site, etc. PC5. Work out the total numbers of modules based on the total capacity of the plant and the capacity of selected modules PC6. review the earthing design of solar module arrays (Continued)

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Table 6.9 SGJ/N0129 - Review the electrical design of solar PV power plant and the energy simulation report. (Continued) Unit Code

SGJ/N0129

Review the design and selection of inverters

To be competent, the user/individual must be able to: PC7. select inverter, based on compatibility with module technology, compliance with grid code and other applicable regulations, reliability, system availability, serviceability, quality, cost, DC TO AC conversion efficiency PC8. in case of a roof top power plant, decide on specifications of the inverter to power the AC loads in the building PC9. decide on number of inverters to be used based on the capacity and specifications of the inverter selected PC10. finalize the inverter layout and inverter locations on the basis of total capacity PC11. review the earthing design of inverters

Review the design and selection of strings

To be competent, the user/individual must be able to: PC12. work out number of modules in a string based on the input voltage and MPPT voltage range of the inverter PC13. work out number of strings connected to a combiner box based on minimum run of DC connecting cables to minimized DC losses PC14. finalize the inter row distance between the solar modules on the basis of minimum inter row shading, adequate space for cleaning and maintenance of solar modules and the tilted to south at an angle that optimizes the annual energy yield PC15. specify DC cabling material, size, type of PVC for cables connecting modules, junction boxes to the combiner boxes and combiner boxes to the inverter panels etc. PC16. review the specification of DC connectors (plugs and sockets) to be used (Continued)

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Table 6.9 SGJ/N0129 - Review the electrical design of solar PV power plant and the energy simulation report. (Continued) Unit Code

SGJ/N0129

Review the design and selection of combiner boxes and switchgear

To be competent, the user/individual must be able to: PC17. review the design specifications for junction boxes/combiner including IP number PC18. review the specifications for disconnects/ switches PC19. Work out number of combiner boxes connected to one panel of the inverter based on the input current rating of the inverter PC20. review islanding facility for grid connected power plant, in case of non-availability of grid PC21. protect incorrect polarity, over-voltage and overload for the DC cables

Prepare energy simulation report

To be competent, the user/individual must be able to: PC22. decide on specification of charge controller/ inverter to the control the overcharging/ discharging of batteries PC23. select the suitable simulation software PC24. feed the parameters in the software basis on the electrical design PC25. prepare the energy simulation report PC26. analyse the energy simulation report and provide to superiors

Selection of batteries for rooftop off grid solar power plant

To be competent, the user/individual must be able to: PC27. decide the battery storage capacity (AH) based on the number of days autonomy required (KWH/WH) and the depth of discharge of the battery bank PC28. decide on the specifications for the charge controller/inverter to control the overcharging/discharging of the batteries, prepare energy generation report using simulation software (Continued)

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Table 6.9 SGJ/N0129 - Review the electrical design of solar PV power plant and the energy simulation report. (Continued) Unit Code

SGJ/N0129

Knowledge and Understanding (K) A. Organizational Context (Knowledge of the organization and its processes)

The user/individual on the job needs to know and understand: KA1. government/corporate policies and guidelines on: workplace safety, identification and mitigation of safety hazards, work procedures and guidelines for working at height KA2. document information using appropriate corporate forms KA3. obtain authorization from specified field safety officer and supervisor KA4. legislative, organization, site requirements and procedures

B. Technical Knowledge

The user/individual on the job needs to know and understand: KB1. efficiency, cost and typical specifications, functioning and operating principle of different types of solar PV plants, commercially available PV cells and modules, inverters, transformers, charge controllers, battery, mounting structures, cables, junction boxes and other components KB2. site survey reports, availability of shadow free space for installation of solar power plant KB3. the survey equipment and the methodology of survey KB4. electrical designs for the module/inverters and balance of system KB5. solar irradiation including GHI, DHI and DNI KB6. mechanical and electrical features necessary for the long life of the PV Power Plant under a wide range of operating conditions KB7. solar PV Power Plant design software such as PVSYST and PV*SOL, etc. KB8. energy simulation report and its parameters and effect on solar PV plants

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Table 6.10 SGJ/N0106 - Maintain personal health & safety at project site. Unit Code

SGJ/N0106

Unit Title (Task)

Maintain personal health & safety at project site

Description

This unit is about maintaining health & safety at solar PV project site

Scope

This unit/task covers the following: • establish and follow safe work procedure • use and maintain personal protective equipment • identify and mitigate safety hazards • demonstrate safe and proper use of required tools and equipment • identify work safety procedures and instructions for working at height

Performance Criteria (PC) w.r.t. the Scope Element

Performance Criteria

Establish and Follow safe work procedure

To be competent, the user/individual on the job must be able to: PC1. identify corporate policies required for workplace safety PC2. identify requirements for safe work area and create a safe work environment PC3. identify contact person when workplace safety policies are violated PC4. provide information about incident/violation PC5. identify the location of first aid materials and administer first aid

Use and maintain personal protective equipment

To be competent, the user/individual on the job must be able to: PC6. identify the PPE required for specific locations on-site PC7. identify expiry dates and wear & tear issues of specified equipment PC8. demonstrate safe and accepted practices for personal protection (Continued)

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Table 6.10 SGJ/N0106 - Maintain personal health & safety at project site. (Continued) Unit Code

SGJ/N0106

Identify and mitigate safety hazards

To be competent, the user/individual on the job must be able to: PC9. identify environmental hazards associated with the project site PC10. identify electrical hazards PC11. identify personal safety hazards or work site hazards and mitigate hazards

Demonstrate safe and proper use of required tools and equipment

To be competent, the user/individual on the job must be able to: PC12. select tools, equipment and testing devices needed to carry out the work PC13. demonstrate safe and proper use of required tools and equipment

Identify work safety procedures and instructions for working at height

To be competent, the user/individual on the job must be able to: PC14. check access from ground to work area to ensure it is safe and in accordance with requirements PC15. reassess risk control measures, as required, in accordance with changed work practices and/or site conditions and undertake alterations PC16. inspect/install fall protection and perimeter protection equipment ensuring adequacy for work and conformance to regulatory requirements PC17. identify approved methods of moving tools and equipment to work area and minimize potential hazards associated with tools at heights PC18. select and install appropriate signs and barricades PC19. place tools and materials to eliminate or minimize the risk of items being knocked down PC20. dismantle plant safely in accordance with sequence and remove from worksite to clear work area (Continued)

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Table 6.10 SGJ/N0106 - Maintain personal health & safety at project site. (Continued) Unit Code

SGJ/N0106

Knowledge and Understanding (K) A. Organizational Context (Knowledge of the organization and its processes)

The user/individual on the job needs to know and understand: KA1. company’s installation policy KA2. company’s customer support policy KA3. company’s documentation policy KA4. document information using appropriate corporate forms KA5. obtain authorization from specified field safety officer and supervisor KA6. company’s reporting structure & organization culture KA7. company’s different department and concerned authority

B. Technical Knowledge

The user/individual on the job needs to know and understand: KB1. relevant personal protective equipment’s required for installation KB2. relevant standards and regulations for installation of solar photovoltaic power plant in India KB3. occupational health and safety (OHS) standards for installation of solar photovoltaic power plant KB4. risk identification and mitigation procedure for safe installation of solar photovoltaic power plant KB5. knowhow of tools & tackles required to carry out the work

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Table 6.11 SGJ/N0120 - Work effectively with others. Unit Code

SGJ/N0120

Unit Title (Task)

Work effectively with others

Description

This unit covers basic etiquette and competencies that a candidate is required to possess and demonstrate in their behavior and interactions with others at the workplace

Scope

This unit/task covers the following: • working with others

Performance Criteria(PC) w.r.t. the Scope Element

Performance Criteria

Working with others

The user/individual on the job should be able to: PC1. accurately pass on information to the authorized persons who require it and within agreed timescale and confirm its receipt PC2. assist others in performing tasks in a positive manner where required and possible PC3. consult and assist others to maximize effectiveness and efficiency in carrying out tasks PC4. display appropriate communication etiquette while working PC5. display active listening skills while interacting with others at work PC6. demonstrate responsible and disciplined behaviors at the workplace PC7. escalate grievances and problems to appropriate authority as per procedure to resolve them and avoid conflict PC8. identify the need for common grounds with clients, team members, etc., and negotiate in an effective manner to achieve the same PC9. consider and respect the opinions, creativity, values, beliefs and perspectives of others PC10. ensure collaboration and group participation to achieve common goals PC11. promote a friendly, cooperative environment that is conducive to employee’s sense of belonging PC12. facilitate an understanding and appreciation of the differences among team members (Continued)

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Table 6.11 SGJ/N0120 - Work effectively with others. (Continued) Unit Code

SGJ/N0120

Knowledge and Understanding (K) A. Organizational Context (Knowledge of the company / organization and its processes)

The user/individual on the job needs to know and understand: KA1. legislation, standards, policies, and procedures followed in the organization relevant to own employment and performance conditions KA2. reporting structure, interdependent functions, lines and procedures in the work area KA3. relevant people and their responsibilities within the work area KA4. escalation matrix and procedures for reporting work and employment related issues

B. Technical Knowledge

The user/individual on the job needs to know and understand: KB1. various categories of people that one is required to communicate and coordinate with in the organization KB2. importance of effective communication in the workplace KB3. importance of teamwork in organizational and individual success KB4. various components of effective communication KB5. key elements of active listening KB6. value and importance of active listening and assertive communication KB7. barriers to effective communication KB8. importance of tone and pitch in effective communication KB9. importance of avoiding casual expletives and unpleasant terms while communicating professional circles KB10. how poor communication practices can disturb people, environment and cause problems for the employee, the employer and the customer KB11. key elements and importance of non-verbal communication KB12. importance of ethics for professional success (Continued)

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Table 6.11 SGJ/N0120 - Work effectively with others. (Continued) Unit Code

SGJ/N0120 KB13. importance of discipline for professional success KB14. what constitutes disciplined behavior for a working professional KB15. common reasons for interpersonal conflict KB16. importance of developing effective working relationships for professional success KB17. expressing and addressing grievances appropriately and effectively KB18. importance and ways of managing interpersonal conflict effectively KB19. importance of teamwork and collaboration

Skills A. Core Skills/ Generic Skills

Writing Skills The user/individual on the job needs to know and understand how to: SA1. note the information communicated SA2. record the readings of various parameters in the prescribed format SA3. note down observations related to the activity SA4. write information documents to internal departments/internal teams Reading Skills The user/individual on the job needs to know and understand how to: SA5. read vernacular/English language SA6. read and understand equipment manuals, health and safety instructions, memos, other company documents SA7. read from different sources- books, screens in machines and signage SA8. read internal information documents sent by internal teams (Continued)

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Table 6.11 SGJ/N0120 - Work effectively with others. (Continued) Unit Code

SGJ/N0120 Oral Communication (Listening and Speaking skills) The user/individual on the job needs to know and understand how to: SA9. express statements or information clearly so that others can hear and understand SA10. participate in and understand the main points of simple discussions SA11. respond appropriately to any queries SA12. communicate effectively with supervisor, peers and subordinates

B. Professional Skills

Decision Making The user/individual on the job needs to know and understand how to: SB1. follow organization rule-based decision-making process SB2. analyse critical points in day to day tasks and identify control measures to solve the issue SB3. handle issues in case the superior is not available (as per the authority matrix defined by the organisation) Plan and Organize The user/individual on the job needs to know and understand how to: SB4. planning and organization of work to meet deadlines SB5. work constructively and collaboratively with others SB6. support the superiors in scheduling tasks Customer Centricity The user/individual on the job needs to know and understand how to: SB7. follow organisation code of conduct SB8. manage relationships with customers with intent on satisfying its requirements for service delivery (Continued)

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Table 6.11 SGJ/N0120 - Work effectively with others. (Continued) Unit Code

SGJ/N0120 Problem Solving The user/individual on the job needs to know and understand how to: SB9. recognize problems and search for solutions SB10. choose best methods to complete assigned tasks SB11. approach relevant authority when required Analytical Thinking The user/individual on the job needs to know and understand how to: SB12. apply domain knowledge, observations and data to select course of action to perform tasks Critical Thinking The user/individual on the job needs to know and understand how to: SB13. critically evaluate information obtained from customers, supervisor and co-workers to perform day to day activities SB14. ask questions for better understanding

6.5 Conclusion Designing of different types of solar PV power plants demands wide range of specialized theoretical skill for reviewing the overall structural layout of the plant, reviewing the assumptions made by the structural design engineer for preparing the structural design, ensuring the specifications are as per industry standards, ensuring that the structural design is as per the findings of the site survey report, working out the capacity of the solar PV power plant by analysing radiation data, selecting the type and number of solar modules, inverters, batteries (if required) technology based on conditions at site, etc., and specialised practical skills such as designing the earthing system, designing the inverter layout, designing the interconnection between strings, inverters, etc., including the specification of the materials to be used for cabling, connectors, switchgears, etc., and preparing the energy simulation report for the solar PV power plant by using appropriate simulation software. Good logical and mathematical skills are also required while designing, so as to ensure that the designs are created as per site survey reports,

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compute site parameters like irradiation data, etc., for deciding the overall plant output, deciding of the specifications and number of solar PV power plant components such as solar modules, inverters, etc., understanding of social, political environment prevalent at that time so as to interact with the customers as well as helpers who are primarily from the local environment. During extensive industry interactions carried out while creating occupational maps and prioritization of job roles for Qualification Pack development, the solar PV designer qualification was indicated as a key requirement by the industry. In addition, the SCGJ Skill Gap Report for the solar energy sector has indicated that a significant proportion of the workforce is going to be involved in this work function, apart from many other fields, as available on www.sscgj.in. The research provides the data that the discussed qualification is one of the critical roles in the sector and the increase in workforce requirements (as per projections) from 2017 to 2025 is approx. 13 times for the role of solar PV designing. Currently, Skill Council for Green Jobs is the Sector Skill Council set up with the mandate of Certification and Assessment of candidates undergoing Skill Development courses in the Solar Photovoltaic domain, apart from other Green businesses.

Bibliography 1. Al-Sabounchi, A.M., Effect of ambient temperature on demanded energy of solar cells at different inclinations. Renewable Energy, 14, 1–4, 149–155, 1998. 2. Hirata, Y. and Tani, T., Output variation of photovoltaic modules with environmental factors-I, the effect of spectral solar radiation on photovoltaic module output. Solar Energy, 55, 6, 463–468, 1995. 3. Gonzalez, M.C. and Carroll, J.J., Solar cells efficiency variations with varying atmospheric conditions. Solar Energy, 53, 5, 395–402, 1994. 4. Alamsyah, T.M.I., Sopian, K., Shaharir, A., Techno economics analysis of a photovoltaic system to provide electricity for a household in Malaysia. Proceedings of the International Symposium on Renewable Energy: Environment Protection and Energy Solution for Sustainable Development, Kuala Lumpur, Malaysia, 2003. 5. Messenger, R.A. and Ventre, J., Photovoltaic Systems Engineering. CRC Press; 3 edition, 2010. 6. Standalone Power Supply Systems Design and Install, Global Sustainable Energy Solutions (GSES), Australia, 3 edition, 2015. 7. Photovoltaics: Design and Installation Manual, New Society, 1st edition (2004). 8. Antony, F., Durschner, C. and Remmers, K., Photovoltaics for professionals: Solar electric systems marketing, design and installation, Earthscan, UK, 2007. 9. Planning and installing photovoltaic systems: a guide for installers, architects and engineers (Planning and Installing Series) by German Solar Energy Society, 2nd edition, Earthscan, UK, 2007.

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10. Solanki, C.S, Solar Photovoltaic Technology and Systems, PHI Learning Private Limited, 1st Edition, 2013. 11. Kimber, A., Mitchell, L., Nogradi, S., Wenger, H., The effect of soiling on large grid-connected photovoltaic systems in California and the Southwest regions of the US. 4th IEEE World Conference on Photovoltaic Energy Conversion, Hawaii, 2006. 12. Betts, T.R., Infield, D.G., Spectral Irradiance Correction for PV system Yield Calculations. 19th European Photovoltaic Solar Energy Conference, Paris, June 2004. 13. Mermoud, A. and Lejeune, T., Performance assessment of a simulation model for PV modules of any available technology. Poster paper presented at the 25-th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC), Valencia, Spain, 6–10 September, 2010. 14. Ministry of New and Renewable Energy, Government of India, 2018. [www. mnre.gov.in] 15. SGJ/Q0110: Solar PV Designer, National Qualifications Register, National Skill Development Agency, Delhi, India, 2017, [www.nqr.gov.in].

Index A Availability of solar irradiance, 47 Air refrigeration cycle, 193 B Battery backup inverters, 128 Battery sizing for SPV plant, 318 C Capacity utilization factor for PV plant, 335 Correction Factor, 16 Cumulative number of module failures, 27 Concentrated solar thermal potential, 60 Charge Controller, 129 Coefficient of performance, 191 Cold storage, 196 Combined rankine-ejector refrigeration cycle, 244 Combined organic rankine cycle with double ejector, 261 D Delamination of solar cell, 10 Dark I-V Curve, 18 Degradation analysis, 18 Direct normal irradiance, 47 Domestic wastewater of RajasthanIndia, 54 Design of compressor, 204 Design of condenser, 205 Design of throttling device, 206 Design of evaporator, 206

E Efficiency of different PV module technologies, 19 Earthing, 132 Energy audit analysis, 173 Ejector cooling cycle, 250 Ejector organic rankine cycle, 255 Exergy destruction rate, 249 F Financial Analysis, 150 First law efficiency, 247 First law analysis for DEORC, 264 G Global Horizontal Irradiance, 47 Grid-tie inverters, 128 Grid-Connected Solar PV system, 311 Grid-Tied Solar PV System Standards, 333 Grid connected SPV plant, 338 H Humidification dehumidification cycle, 45 I International Electrotechnical Commission, 4 IEC 61215: 2016, 4 IEC 61215-2:2016, 5 IEC 61730:2016, 5 IEC TS 62804-1:2015, 6 IEC 61701:2011, 6 IEC 62716:2013, 6

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Index

IEC 62759-1:2015, 6 IEC TS 62782:2016, 7 IEC 60891, 15 IR thermography procedure, 20 I-V Tracer, 11 I-V Curve, 12, 13, 16 Insulation resistance testing procedure, 22 Interconnect breakage testing procedure, 25 Installation capacity of renewable energy, 40 Inverter Specification, 140 Inverter selection and sizing, 317 Ideal vapour compression cycle, 194 IRR analysis data sheet, 224 Investment cost analysis, 225 J Jawaharlal Nehru National Solar Mission, 84 L LMTD of condenser, 205 Load estimation, 317 Life cycle cost, 337 M Multi-stage flash distillation, 44 Multi-effect distillation, 44 Major components of SPV system, 125 Module to Module Earthing, 133 Monitoring system, 153 N Net zero energy, 167 Net zero energy emissions building, 171 NPV analysis data sheet, 224 P Potential on solar distillation in Rajasthan, India, 45 Phase Change Material, 206 Payback Period of SPV cold storage, 221

Properties of ecofriendly refrigerants, 251 SPV plant efficiency, 335 Q Quantification of reliability of PV module, 26 Quality Management of SPV system, 157 R Rainfall of Rajasthan-India, 54 Refrigeration, 190 Refrigerant R-404a, 208 S Second law efficiency, 248 Second law analysis for DEORC, 266 Sizing of PV modules for plant design, 321 Stand-Alone Solar system, 311 Surface water resources of RajasthanIndia, 51 Solar photovoltaic potential, 59 Solar potential map, 89 Solar cell, 126 Stand-alone inverters, 128 SPV standards, 144 Solar Island, 154 Solar radiation, 187 Solar wind hybrid power plant, 311 System design concept of SPV, 314 T Temperature co-efficient, 14 Testing report format for PV module, 33 Temperature losses calculation of PV system, 334 Thermal vapor compression, 45 V Visual Inspection Procedure, 8