DESIGN AND ECONOMIC EVALUATION OF MW SCALE HYBRID RENEWABLE ENERGY SYSTEM WITH BATTERY
STORAGE
JATINDER SINGH CHANDOK
CENTRE FOR ENERGY STUDIES
INDIAN INSTITUTE OF TECHNOLOGY DELHI
JULY 2020
©Indian Institute of Technology Delhi (IITD), New Delhi, 2020
i
DESIGN AND ECONOMIC EVALUATION OF MW SCALE HYBRID RENEWABLE ENERGY SYSTEM WITH
BATTERY STORAGE
by
JATINDER SINGH CHANDOK Centre for Energy Studies
Submitted
in fulfilment of the requirements of the degree of Doctor of Philosophy to the
INDIAN INSTITUTE OF TECHNOLOGY DELHI
JULY 2020
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CERTIFICATE
This is to certify that the thesis entitled, “DESIGN AND ECONOMIC EVALUATION OF MW SCALE HYBRID RENEWABLE ENERGY SYSTEM WITH BATTERY STORAGE”
being submitted by Mr. Jatinder Singh Chandok to the Indian Institute of Technology Delhi for the award of Doctor of Philosophy is a record of bonafide research work carried by him under our guidance and supervision in conformity with the rules and regulations of Indian Institute of Technology Delhi.
The research report and results presented in this thesis have not been submitted, in part or full, to any other university or institute for the award of any degree or diploma.
Dr Viresh Dutta Dr B Panigrahi
Professor Professor
Centre for Energy Studies Electrical Engineering Department Indian Institute of Technology Delhi Indian Institute of Technology Delhi
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ACKNOWLEDGMENTS
I extend my profound gratefulness to my research supervisors Prof. Viresh Dutta and Prof. B Panigrahi for providing all support and guidance throughout my research work. I feel fortunate enough to receive continuous encouragement from them graciously in various ups and downs of this research period. They always encourage creative ideas and implementation. A technical discussion with them was always fruitful and thought-provoking.
I am thankful to Prof. T. C Kandpal (Head of the Centre) and other faculty members for providing me this opportunity, facilities, and guidance. I am also thankful to Prof T S Bhatti and Prof Nilanjan Senroy for their guidance and support during my journey in this research work. I feel indebted to the ‘Center for Energy Studies department’ and IIT, Delhi for developing my research competency.
I would like to thank Power System Operation Company (POSOCO) Limited for their support in making me understand the Indian Power system and sharing the grid frequency data.
I express my deep sense of appreciation for my organization, NTPC Limited, for permitting me to pursue PhD at IIT, Delhi. The culture of continuous learning has been a source of inspiration for me to embark on a doctoral program, while at work. I feel indebted to my organization. I thank my seniors and colleagues, for their support.
I would like to thank my lab member Mr Kuldeep Kumar, Mr. Mohd Alam, Mrs Shilpi and Mr Ankit Bharaj who helped me in technical discussions and sharing literature.
I gratefully acknowledge the unfailing silent encouragement, emotional support, patience and understanding of my wife Manjeet, who has driven me to complete this doctoral program. Taking care of all the family aspects on her shoulder has enabled me to dedicate myself to this research work. Our two children, Ashmeet and Rajmeet provided continuous moral support for carrying out with the research work unstintingly
I acknowledge with gratitude the contribution of my Mother Mrs Kuldeep Kaur and late Father and my elder brothers and sisters who have spent their prime time for the upbringing and instigated the hunger for knowledge and education in me. I am obliged to them for their unconditional love and efforts
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Finally, I thank each and every one who has contributed directly or indirectly to my thesis work.
Jatinder Singh Chandok
iv ABSTRACT
The present research aims to focus on addressing the issues emerging due to the large penetration of Renewable Energy (RE) into the Indian grid. The study deals with integrating the optimally designed RE Hybrid systems with the Indian grid and proposed to be participating in the electricity markets and environment which will be subjected to free competition. The hybrid plants are those which are designed to reduce the variability by combining mainly two major resources e.g. solar and wind and further improving the controllability of the system through charging and discharging capability from Battery Energy Storage System.
In this study, optimal sizing of a grid-connected solar-wind hybrid plant of 3.37 MW size is designed and installed with an objective to maximize the yield from a given piece of land based on local observation data and electrical connections at NTPC Kudgi, in Karnataka. The variability or ramp-rate of power generated from the RE plant is a major concern that affects adversely on the power quality of the grid. Globally the ramp-rate of 10%/min is being imposed as a regulation for renewable integration and in India, though such regulation is not in place, but with increasing renewable presence, soon this will become a regulation.
The ramp-rate of solar, wind and hybrid system were evaluated by collecting real-time data of 5-sec interval from this plant. MATLAB simulation code was developed to size the single battery system or hybrid battery energy system. The hybrid battery system was sized by decomposing the power signal through a method called Variational Mode Decomposition (VMD) into two separate low and high-frequency components and thereby providing a combination of high energy and high-power batteries respectively.
Further to sensitized on the high cost of the battery, a concept of Levelized Cost of Storage (LCOS) is proposed and technological details of the various batteries was analyzed, which takes care of not only the capital cost but also the degradation, life cycle, and efficiency cost into consideration. The LCOS has been calculated for various technologies and application and sensitivity analysis were performed.
Lastly, a techno-economic study has been performed to make this a business case generating positive revenue for the primary frequency response market. Different control logics were proposed and the simulation code was developed to evaluate the same.
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The proposed study is not only providing insight about the various design and technical aspects but also pave way for policy advocacy in bringing the technical and economic regulation for flexible renewable generation and grid operation in India with large RE penetration.
सार
वर्तमान शोध का उद्देश्य भारर्ीय ग्रिड में नवीकरणीय ऊर्ात (आरई) की बडी पैठ के कारण उभर रहे मुद्दों पर ध्यान देना है। भारर्ीय ग्रिड के साथ आशावादी रूप से डडजाइन ककए गए आरई हाइब्रिड ससस्टम को एकीकृर् करने के सिए अध्ययन का प्रस्र्ाव है और ब्रबर्िी बार्ारों और पयातवरण में भाग िेने का प्रस्र्ाव है र्ो कक मुफ्र् प्रतर्स्पधात के अधीन होगा। हाइब्रिड पौधे वे हैं
र्ो मुख्य रूप से दो प्रमुख संसाधनों र्ैसे कक संयुक्र्र्ा से पररवर्तनशीिर्ा को कम करने के सिए डडजाइन ककए गए हैं। सौर और पवन और बैटरी ऊर्ात भंडारण प्रणािी से क्षमर्ा का तनवतहन और तनवतहन के माध्यम से प्रणािी की तनयंत्रणीयर्ा में और सुधार।
इस अध्ययन में, एनटीपीसी कुडगी में स्थानीय अविोकन डेटा और ववद्युर् कनेक्शन के आधार पर र्मीन के ददए गए टुकडे से उपर् को अग्रधकर्म करने के उद्देश्य से 3.37 मेगावाट आकार के ग्रिड-कनेक्टेड सौर-पवन हाइब्रिड संयंत्र के इष्टर्म आकार को डडर्ाइन और स्थावपर् ककया गया
है। कनातटक। आरई संयंत्र से उत्पन्न ब्रबर्िी की पररवर्तनशीिर्ा या रैंप-दर एक प्रमुख ग्र ंर्ा है
र्ो ग्रिड की ब्रबर्िी की गुणवत्ता पर प्रतर्कूि प्रभाव डािर्ी है। ववश्व स्र्र पर 10% / समनट की
रैंप-दर को नवीकरणीय एकीकरण के सिए एक ववतनयमन के रूप में िगाया र्ा रहा है और भारर्
में, हािांकक ऐसा ववतनयमन िागू नहीं है, िेककन नवीकरणीय उपस्स्थतर् बढ़ने के साथ, र्ल्द ही यह एक ववतनयमन बन र्ाएगा।
इस संयंत्र से 5-सेकंड के अंर्राि का वास्र्ववक समय डेटा एकत्र करके सौर, पवन और संकर प्रणािी की रैंप-दर का मूल्यांकन ककया गया था। MATLAB ससमुिेशन कोड एकि बैटरी प्रणािी
या हाइब्रिड बैटरी ऊर्ात प्रणािी को आकार देने के सिए ववकससर् ककया गया था। हाइब्रिड बैटरी
ससस्टम को वारीनेशनि मोड डडकम्पोस्र्शन (VMD) नामक एक पॉवर ससग्नि को दो अिग-अिग तनम्न और उच् -आवृवत्त वािे घटकों में बदिकर क्रमशः उच् ऊर्ात और उच् -शस्क्र् बैटरी का
संयोर्न प्रदान करके आकार ददया गया था।
बैटरी की उच् िागर् पर संवेदीकरण करने के सिए, स्टोरेर् की अनुमातनर् िागर् (LCOS) की एक अवधारणा प्रस्र्ाववर् है और ववसभन्न बैटररयों के र्कनीकी वववरणों का ववश्िेषण ककया गया, र्ो
न केवि पूंर्ीगर् िागर् का बस्ल्क ग्रगरावट, र्ीवन क्र का भी ध्यान रखर्ा है, और वव ार में
दक्षर्ा िागर्। LCOS की गणना ववसभन्न र्कनीकों और अनुप्रयोग के सिए की गई है और संवेदनशीिर्ा ववश्िेषण ककया गया था।
अन्र् में, प्राथसमक आवृवत्त प्रतर्कक्रया बार्ार के सिए सकारात्मक रार्स्व उत्पन्न करने के सिए इसे
व्यावसातयक मामिा बनाने के सिए एक र्कनीकी-आग्रथतक अध्ययन ककया गया है। ववसभन्न तनयंत्रण िॉस्र्क्स प्रस्र्ाववर् ककए गए थे और उसी का मूल्यांकन करने के सिए ससमुिेशन कोड ववकससर् ककया गया था।
प्रस्र्ाववर् अध्ययन न केवि ववसभन्न डडर्ाइन और र्कनीकी पहिुओं के बारे में अंर्र्दतस्ष्ट प्रदान कर रहा है, बस्ल्क बडे आरई प्रवेश के साथ भारर् में ि ीिी नवीकरणीय पीढ़ी और ग्रिड सं ािन के सिए र्कनीकी और आग्रथतक ववतनयमन िाने में नीतर्गर् वकािर् के सिए मागत प्रशस्र् करर्ा
है।
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Table of Contents
ACKNOWLEDGMENTS ... ii
ABSTRACT ... iv
Table of Contents ... vi
Chapter 1 Introduction ... 1
1.1 Indian energy scenario 1 1.2 Flexible grid operation with large renewable integration 5 1.2.1 Solar wind hybrid system 6 1.2.2 Storage technologies 6 1.2.3 Economic valuation of the hybrid system with flexible operation 7 1.3 Research objective and motivation 7 1.4 Organization of thesis work 8 Chapter 2 Literature review ... 11
2.1 Introduction 11 2.2 Research activities on hybrid system: design, sizing and selection 11 2.3 Research activities on power fluctuation and ramp-rate control using hybrid battery storage 13 2.4 Research Activities on Battery storage technologies and economic evaluation 16 2.5 Research Activities on evaluating the value of storage for frequency regulation. 19 2.6 The objective of the work 22 Chapter 3 Design of hybrid system and ramp-rate control ... 23
3.1 Introduction 23
3.2 Design of solar wind hybrid system 25
3.2.1 Renewable hybrid systems 25
3.2.2 Solar and wind resource assessment 26
3.2.3 Hybrid configuration and system modelling 28
3.2.4 Economic evaluation of hybrid technology selection 34
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3.3 Ramp-Rate control of solar wind hybrid plant 36
3.3.1 Data collection 36
3.3.2 Power fluctuations from solar wind hybrid plants 37
3.3.3 PV and wind power smoothing with storage 38
3.3.4 State of charge 43
3.3.5 Sizing of battery and supercapacitor using Variational Mode Decomposition
(VMD) 49
3.3.6 Results & analysis 53
3.4 Summary 55
Chapter 4 Techno-economic selection of battery energy storage system ... 57
4.1 Introduction 57
4.2 Battery storage technologies 58
4.2.1 Available batteries technologies 58
4.2.2 Technical characteristics of batteries 62
4.3 Battery Energy Storage System (BESS) 63
4.4 Utility-scale application of BESS 64
4.5 Levelized Cost of Storage (LCOS) 66
4.6 BESS cost breakup and sensitivity analysis 69
4.6.1 BESS cost breakup 69
4.6.2 Sensitivity analysis 70
4.7 LCOS Calculation for Various Battery Technologies and Applications 74
4.7.1 Cost calculation for battery technologies 74
4.7.2 Cost calculation for various application 76
4.8 Selection of hybrid battery for solar wind hybrid system 78
4.9 Levelized cost of Electricity (LCOE) with BESS 79
4.9.1 Project technical details 79
4.9.2 Project cost details and financing 79
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4.9.3 LCOE Results 81
4.10 Summary 81
Chapter 5 Value of battery storage for frequency regulation ... 82
5.1 Introduction 82
5.2 Ancillary services market 82
5.3 Benefit of BESS for PFR 84
5.4 Development of control algorithm for BESS support for PFR 86
5.4.1 Frequency regulation for Indian grid 86
5.4.2 Factors for developing an operating strategy for India 87
5.4.3 Brief about control algorithm 87
5.4.4 Description of control logic and algorithm 89
5.4.5 Results and discussion 93
5.5 Economic analysis for using BESS as Primary Frequency Reserve (PFR) 97
5.6 Summary 101
Chapter 6 Conclusions and future scope of work ... 102
6.1 Conclusions 102
6.2 Future scope of work 104
References ... 106
APPENDIX A1: Operational and field trial of NAS battery ... 113
APPENDIX A2: Sample MATLAB Simulation Code for Ramp-rate Control and Hybrid Battery Sizing ... 118
APPENDIX A3: MATLAB Code for Normal and SOC Optimization Control
strategy for Primary frequency Reserve ... 123
List of Publications ... 127
About the Author ... 128
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List of Figure
Figure 1.1 Growth of installed capacity in India (Data source: CEA Website, Installed
Capacity) ... 2
Figure 1.2 Generation mix (Data source: CEA Website, Installed Capacity) ... 3
Figure 1.3 Growth of RE capacity in India (Data source: CEA Website) ... 3
Figure 1.4: Projection of RE capacity and generation 2029-30. (CEA Report: Optimal Generation Mix) ... 4
Figure 2.1 Types of Energy Storage System ... 16
Figure 3.1: Hybrid plant with both AC and DC Integration ... 25
Figure 3.2: Hybrid plant with DC Integration ... 26
Figure 3.3: Annual ambient temperature plot ... 26
Figure 3.4: Annual solar irradiance plot ... 27
Figure 3.5: Annual wind speed plot ... 27
Figure 3.6: Prominent wind direction (West), annual wind rose ... 27
Figure 3.7: Shadow of wind turbine during a different time of day ... 31
Figure 3.8: Plot of shadow length with a time of day ... 32
Figure 3.9: Power generation plot for May & June ... 33
Figure 3.10: Power generation plot for 4th May ... 33
Figure 3.11: Solar, wind and hybrid generation ... 37
Figure 3.12: Ramp-rate profile for the worst fluctuation data form plant ... 38
Figure 3.13: Flowchart for the Ramp-rate control algorithm ... 40
Figure 3.14: Battery power (Wind only) with 10% RRC ... 41
Figure 3.15: Battery power (Wind only) with 40% RRC ... 42
Figure 3.16: Battery power (Solar PV only) with 10% RRC ... 42
Figure 3.17: Battery power (Solar PV only) with 40% RRC ... 42
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Figure 3.18: Battery power (Hybrid) with 10% RRC ... 43
Figure 3.19: Battery power (Hybrid) with 40% RRC ... 43
Figure 3.20: Battery capacity and SOC plot with 10% RRC ... 45
Figure 3.21: Battery size with allowed violation ... 45
Figure 3.22: Battery power (Hybrid) with MA 5 Min and 15 Min... 46
Figure 3.23: Battery power (Hybrid) with 10% RRC + 15 Min MA ... 47
Figure 3.24: Battery capacity & SOC with 10% RRC + 15 Min MA ... 47
Figure 3.25: Mode and central frequency for 10% C and 15 Min MA case for hybrid power ... 51
Figure 3.26: Reconstructed power error vs Alpha ... 51
Figure 3.27: Low frequency & high-Frequency signals for the case of 10% RRC and 15 Min MA Hybrid power ... 52
Figure 3.28: Size reduction with a combination of battery and supercapacitor hybrid storage system ... 53
Figure 4.1: Classification of applications served by BESS ... 65
Figure 4.2: Cost break-up and the contribution of different components ... 70
Figure 4.3: LCOS Sensitivity with the initial cost ... 71
Figure 4.4: LCOS Sensitivity with Service life ... 71
Figure 4.5: LCOS Sensitivity with Operating cost ... 72
Figure 4.6: LCOS Sensitivity with Efficiency ... 72
Figure 4.7: LCOS Sensitivity with Degradation ... 73
Figure 4.8: Relative comparison of % effect on LCOS due to various factor ... 73
Figure 4.9: Capital cost and LCOS for various battery technologies ... 75
Figure 4.10: LCOS comparison of various Technologies for Cycle operation ... 77
Figure 4.11: LCOS Comparison of various technologies for high power applications ... 77
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Figure 5.1: Ancillary services categories (Courtesy: EURELECTRIC) ... 83
Figure 5.2: Energy of power ramp up for fast and slow response system ... 85
Figure 5.3: Typical frequency pattern in India ... 87
Figure 5.4: Frequency profile ... 88
Figure 5.5: Normal Control Logic ... 89
Figure 5.6: Control logic with SOC Optimization ... 90
Figure 5.7: Flow chart for the control algorithm ... 91
Figure 5.8: Frequency plot for high variation day ... 93
Figure 5.9: Battery power charge/discharge plot ... 93
Figure 5.10: Battery power charge/discharge Plot with SOC Optimization @ 0.5 C rate ... 94
Figure 5.11: Battery power charge/discharge plot with SOC Optimization @ 1C rate... 95
Figure 5.12: Histogram of power with normal control logic ... 95
Figure 5.13: Histogram of SOC with normal logic... 95
Figure 5.14: Histogram of power with SOC optimization logic ... 96
Figure 5.15: Histogram of SOC with SOC optimization control logic... 96
Figure 5.16: Performance parameters value for control logic with SOC & charging rate ... 97
Figure 5.17: Cash Flow for high frequency Variation (Case-1)) ... 99
Figure 5.18: Cumulative NPV for normal and SOC optimization for (Case-1) ... 99
Figure 5.19: Cash Flow considering average data (Case-2) ... 100
Figure 5.20: Cumulative NPV for normal and SOC Optimization (Case-2) ... 100
Figure A1.1: NAS battery ... 113
Figure A1.2 Charge discharge mechanism ... 114
Figure A1.3 Configuration drawing of installed system ... 115
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List of Tables
Table 1.1: Renewable energy generation growth, CAGR ... 4
Table 3.1: Solar PV technology comparison ... 29
Table 3.2: Shadow length from wind base... 31
Table 3.3: Value of ramp-rate limit globally ... 38
Table 3.4: Battery sizing for different MA and RRC combinations ... 48
Table 3.5: Battery and SC size for various cases ... 54
Table 4.1: Comparative chart of various Li-ion Chemistries ... 59
Table 4.2: BESS application and their characteristics ... 65
Table 4.3: Li-Ion Battery Cost ($/kWh) break-up as per C-rating ... 69
Table 4.4: Relative comparison of % effect on LCOS due to various factor ... 74
Table 4.5: LCOS calculated for different technologies ... 74
Table 4.6: Technical details for LCOE calculations ... 79
Table 4.7: Cost and financing details for LCOE calculations ... 80
Table 4.8: LCOE results ... 81
Table 5.1: Data analysis of frequency data ... 89
Table 5.2: Performance parameters value for normal control logic ... 94
Table 5.3 Performance parameters for control logic with SOC & charging rate ... 96
Table 5.4: Assumptions for techno-economic evaluation of two control logic ... 98
Table 5.5: Results of techno-economic analysis considering high-frequency variation data (Case-1) ... 99
Table 5.6: Result of Techno-economic analysis considering average of two data (Case- 2) ... 100
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Nomenclature
Abbreviation
ANFCR Annual Fixed Charge rate
BESS Battery Energy Storage System
BMS Battery Management System
BOL Beginning of Life
CAGR Compound Annual Growth Rate
CUF Capacity Utilization Factor
DFIG Doubly Fed Induction Generator
DOD Depth of Discharge
EMD Empirical Mode Decomposition
EOL End of Life
ESS Energy Storage System
FCR Frequency Containment reserve
FRC Frequency Response Characteristic
GHI Global Horizontal Irradiance
HESS Hybrid Energy Storage System
HiT Heterojunction Intrinsic Thin layer
IMF Intrinsic Mode Functions
LCOE Levelized cost of Electricity
LCOS Levelized Cost of Storage
MA Moving Average
MPPT Maximum Power Point Transfer
NOCT Nominal Operating Cell Temperature
NPV Net present value
PCU Power Conditioning Unit
PFR Primary Frequency Reserve
PSOC Partial State of Charge
PWF Present Worth Factor
RE Renewable Energy
RFB Redox Flow Battery
RRC Ramp-rate Control
SC Supercapacitor
SPV Solar Photovoltaic
STC Standard Test condition
SWH Solar Wind Hybrid
UF Utilization Factor
WAsP Wind Atlas Analysis and Application
Symbols
Imp (A) Maximum Point Current of Solar Panel
Isc(A) Short Circuit Current of Solar Panel Vmp (volt)
Voc(Volt)
Maximum point voltage of Solar Panel Open circuit Voltage of Solar panel
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r (%) Ramp-rate
Ps (kW) Solar Power
Pw (kW) Wind Power
Ph (kW) Hybrid Power
Pgw(kW) Wind Power injected to grid for the desired ramp-rate
Pbw(kW) Battery power for the case of wind
Ess (kWh) Energy Capacity of Battery
Esc (kWh) Energy Capacity of Supercapacitor
SOC (%) State of charge of battery
SOC0(%) Initial state of charge of battery
SOCup(%) Upper limit of SOC
SOCdn(%) Lower limit of SOC
