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SAFER, SMARTER, GREENER SUNGROW LIQUID COOLING ENERGY STORAGE SYSTEM Technical Due Diligence Report Sungrow USA Corporation Document No. : 10330655-HOU-R-01 Issue: B, Status: Initial Release Date: 13 April 2022

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Energy USA Inc. ii IMPORTANT NOTICE AND DISCLAIMER 1. This document is intended for the sole use of the Customer as detailed on the front page of this document to whom the document is addressed and who has entered into a written agreement with the DNV entity issuing this document (“DNV”). To the extent permitted by law, neither DNV nor any group company (the "Group") assumes any responsibility whether in contract, tort including without limitation negligence, or otherwise howsoever, to third parties (being persons other than the Customer), and no company in the Group other than DNV shall be liable for any loss or damage whatsoever suffered by virtue of any act, omission, or default (whether arising by negligence or otherwise) by DNV, the Group, or any of its or their servants, subcontractors, or ag ents. This document must be read in its entirety and is subject to any assumptions and qualifications expressed therein as well as in any other relevant communications in connection with it. This document may contain detailed technical data which is intend ed for use only by persons possessing requisite expertise in its subject matter. 2. This document is protected by copyright and may only be reproduced and circulated in accordance with the Document Classification and associated conditions stipulated or refer red to in this document and/or in DNV's written agreement with the Customer. No part of this document may be disclosed in any public offering memorandum, prospectus, or stock exchange listing, circular, or announcement without the express and prior written consent of DNV. A Document Classification permitting the Customer to redistribute this document shall not thereby imply that DNV has any liability to any recipient other than the Customer. 3. This document has been produced from information relating to dates and periods referred to in this document. This document does not imply that any information is not subject to change. Except and to the extent that checking or verification of information or data is expressly agreed within the written scope of its service s, DNV shall not be responsible in any way in connection with erroneous information or data provided to it by the Customer or any third party, or for the effects of any such erroneous information or data whether or not contained or referred to in this docu ment. 4. Any forecasts, estimates, or predictions made herein are as of the date of this document and are subject to change due to factors beyond the scope of work or beyond DNV's control or knowledge. Nothing in this document is a guarantee or assurance of any particular condition or energy output.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Energy USA Inc. iii Project name: Sungrow Liquid Cooling Energy Storage System DNV Energy USA Inc. 4377 County Line Road Chalfont, PA 18914 USA Tel: +1 215 997 4500 Enterprise No. : 23-2625724 Report title: Technical Due Diligence Report Customer: Sungrow USA Corporation 47751 Fremont Blvd. Fremont, CA 94538 Contact person: Martial Yu Date of issue: 13 April 2022 Project No. : 10330655 Proposal Reference: 225012-HOU-P-01-A Document No. : 10330655-HOU-R-01 Issue/Status: B/Initial Release Task and objective: This report presents the results of analysis conducted by DNV on behalf of Sungrow USA Corporation. Prepared by: Verified by: Approved by: Zahra Gallehdari Senior Consultant, Energy Storage Engineering Shafi Sattar Senior Consultant, Storage & Grid Edge Intelligence Aditya Rohilla Senior Consultant, Energy Storage Engineering Mohammed Muthalib Head of Section, Storage & Grid Edge Intelligence ☐ Strictly Confidential For disclosure only to named individuals within the Customer's organization. Keywords: ☐ Private and Confidential For disclosure only to individuals directly concerned with the subject matter of the document within the Customer's organization. ☐ Commercial in Confidence Not to be disclosed outside the Customer's organization. ☐ DNV only Not to be disclosed to non-DNV staff ☒ Customer's Discretion Distribution for information only at the discretion of the Customer (subject to the above Important Notice and Disclaimer and the terms of DNV's written agreement with the Customer). ☐ Published Available for information only to the general public (subject to the above Important Notice and Disclaimer). © 2022 DNV Energy USA Inc. All rights reserved. Reference to part of this report which may lead to misinterpretation is not permissible. Issue Date Reason for Issue Prepared by Verified by Approved by A 09 March 2022 Draft Z. Gallehdari M. Koenig D. Lebowitz S. Sattar A. Rohilla M. Muthalib B 13 April 2022 Initial Release Z. Gallehdari H. Sanghadia S. Sattar A. Rohilla

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page iv www. dnv. com Table of contents EXECUTIVE SUMMARY ....................................................................................................................................................... VIII 1 INTRODUCTION ................................................................................................................................................................. 1 1. 1 Objective and scope of review .................................................................................................................................... 1 1. 2 Methodology ............................................................................................................................................................... 1 1. 3 Assumptions ............................................................................................................................................................... 2 2 COMPANY OVERVIEW ...................................................................................................................................................... 3 2. 1 Stationary energy storage pro duct history .................................................................................................................. 3 2. 2 Intellectual property .................................................................................................................................................... 4 2. 3 Sales revenues ........................................................................................................................................................... 5 3 SUNGROW LIQUID COOLING SYSTEM OVERVIEW ....................................................................................................... 6 3. 1 Product offerings ........................................................................................................................................................ 6 3. 2 Product specifications .............................................................................................................................................. 13 4 BATTERY COMPONENT EVALUATION .......................................................................................................................... 14 4. 1 Battery cell eval uation .............................................................................................................................................. 14 4. 2 Battery module and rack evaluation ......................................................................................................................... 32 4. 3 Operational evaluation ............................................................................................................................................. 36 4. 4 Thermal management system .................................................................................................................................. 38 4. 5 BMS functionality, faults and alarms ........................................................................................................................ 42 4. 6 Regulatory compliance and safety ........................................................................................................................... 43 5 POWER CONVERSION SYSTEM REVIEW ..................................................................................................................... 57 5. 1 DC/DC converter ...................................................................................................................................................... 57 6 INSTALLATION AND INTEGRATED SYSTEM EVALUATION ......................................................................................... 62 6. 1 On-site system integration ........................................................................................................................................ 62 6. 2 System space requirements ..................................................................................................................................... 64 6. 3 Site requirements ..................................................................................................................................................... 65 6. 4 Functional manuals .................................................................................................................................................. 65 7 MANUFACTURING AND QUALITY EVALUATION .......................................................................................................... 68 7. 1 Quality evaluation ..................................................................................................................................................... 68 7. 2 Manufacturing evaluation ......................................................................................................................................... 72 8 SERVICE INFRASTRUCTU RE EVALUATION ................................................................................................................. 73 8. 1 Service organization overview .................................................................................................................................. 73 8. 2 Warranty review ....................................................................................................................................................... 74 9 REFERENCES .................................................................................................................................................................. 76 List of tables Table 2-1 Sungrow company information [3]............................................................................................................................. 3

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page v www. dnv. com Table 2-2 Sungrow list of patents as of 10 June 2021 .............................................................................................................. 4 Table 3-1 Sungrow liquid cooling ESS product offerings .......................................................................................................... 6 Table 3-2 Product specifications for Sungrow ST2236UX-US and ST2752UX-US................................................................. 13 Table 4-1 CATL 280 Ah cel l specifications .............................................................................................................................. 19 Table 4-2 REPT 280 Ah cell specification ............................................................................................................................... 20 Table 4-3 Charge and discharge rates at different temperatures* .......................................................................................... 21 Table 4-4 Abuse test results ................................................................................................................................................... 24 Table 4-5 Temperature cyc le vs. time ..................................................................................................................................... 25 Table 4-6 Sungrow module specification ................................................................................................................................ 33 Table 4-7 Sungrow integrated rack specifications ................................................................................................................... 35 Table 4-8 BSS ratio of usable capacity-Model 1 ................................................................................................................... 36 Table 4-9 BSS ratio of usable capacity-Model 2 ................................................................................................................... 37 Table 4-10 RTE-Model 1 ....................................................................................................................................................... 37 Table 4-11 RTE-Model 2 ....................................................................................................................................................... 37 Table 4-12 Standards, codes and testing list .......................................................................................................................... 43 Table 4-13 UL 9540A cell-level test results ............................................................................................................................. 45 Table 4-14 UL 9540A cell-level test results ............................................................................................................................. 45 Table 4-15 UL 9540A module-level test results ...................................................................................................................... 46 Table 4-16 UL9540A module-level test results ....................................................................................................................... 48 Table 4-17 UL 9540A Unit performance conditions and observations .................................................................................... 51 Table 4-18 UL 9540A Unit performance conditions and observations .................................................................................... 53 Table 5-1 Discharge (DC BUS 1360 V) Table ......................................................................................................................... 60 Table 5-2 Charge (DC Bus 1360 V) Table .............................................................................................................................. 61 Table 6-1 Self-discharge rate .................................................................................................................................................. 66 List of figures Figure 2-1 Sungrow ESS product roadmap .............................................................................................................................. 3 Figure 3-1 Sungrow ST2236UX-US battery energy storage system ......................................................................................... 6 Figur e 3-2 Sungrow ST2752UX-US battery energy storage system ......................................................................................... 7 Figure 3-3 Sungrow BESS System Anatomy ............................................................................................................................ 7 Figure 3-4 Sungrow liquid cooling ESS components ................................................................................................................ 8 Figure 3-5 Liquid vs. air cooling area efficiency ........................................................................................................................ 8 Figure 3-6 Sungrow liquid coo ling design ................................................................................................................................. 9 Figure 3-7 Cluster-level energy management ........................................................................................................................... 9 Figure 3-8 New battery integration: Sungrow vs. traditional providers .................................................................................... 10 Figure 3-9 Sungrow system architecture, ST2236UX-US....................................................................................................... 11 Figure 3-10 Sungrow system ar chitecture, ST2752UX-US..................................................................................................... 12 Figure 4-1 CATL company network ........................................................................................................................................ 15 Figure 4-2 CATL's product lines .............................................................................................................................................. 15 Figure 4-3 Global EV and battery shipment tracker, from SNE ............................................................................................... 16 Figure 4-4 Projected production capacity ................................................................................................................................ 16 Figure 4-5 Tsingshan Holding Group overview ....................................................................................................................... 17 Figure 4-6 Tsingshan industrial raw material supply chain ...................................................................................................... 17 Figure 4-7 REPT technology roadmap to 2027 ....................................................................................................................... 19 Figure 4-8 CATL 280 Ah cell ................................................................................................................................................... 19 Figure 4-9 REPT 280 Ah battery cell ...................................................................................................................................... 20 Figure 4-10 Capacity and energy at 25 °C, 0. 5C .................................................................................................................... 22 Figure 4-11 Energy capacity and surface temperature impacts of various p-rates ................................................................. 22 Figure 4-12 High and low temperature performance testing re sults........................................................................................ 23 Figure 4-13 DCR and HPPC test results ................................................................................................................................. 24 Figure 4-14 Liquid-cooled rack cell degradation, percent nominal capacity per year .............................................................. 25 Figure 4-15 Temperature curve vs. time ................................................................................................................................. 26 Figure 4-16 High and low temperature capability .................................................................................................................... 26 Figure 4-17 Discharge capacity at various discharge rates ..................................................................................................... 27 Figure 4-18 Charge capacity at various charge rates ............................................................................................................. 28 Figure 4-19 Short circuit test data ........................................................................................................................................... 29 Figure 4-20 REPT 280 Ah accelerated cell test ...................................................................................................................... 30

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page vi www. dnv. com Figure 4-21 Temperature impact on storage life ..................................................................................................................... 31 Figure 4-22 Sungrow integrated modules ............................................................................................................................... 33 Figure 4-23 Example Sungrow integrated BESS with battery racks ....................................................................................... 34 Figure 4-24 ST2236 UX-US BESS Module and Rack Configuration ...................................................................................... 36 Figure 4-25 Module demonstrating cooling flow ...................................................................................................................... 38 Figure 4-26 Enclosure-level cooling diagram .......................................................................................................................... 39 Figure 4-27 Air-cooling flow diagram....................................................................................................................................... 39 Figure 4-28 CFD model at 25°C ambient ................................................................................................................................ 40 Figure 4-29 CFD model at 45°C ambient ................................................................................................................................ 41 Figure 4-30 CFD modeling of the dc/dc converter and wiring cabinet at 45°C ambient .......................................................... 41 Figure 4-31 Structure of BMS ................................................................................................................................................. 42 Figure 4-32 Location of heater in Module level test ................................................................................................................ 47 Figure 4-33 Location of initiating cell in battery module .......................................................................................................... 48 Figure 4-34 Initiating unit and targeted unit position ............................................................................................................... 50 Figure 4-35 Initiating module location ..................................................................................................................................... 50 Figure 4-36 Initiating unit and targeted unit position ............................................................................................................... 52 Figure 4-37 Initiating module location ..................................................................................................................................... 52 Figure 4-38 Main logic diagram ............................................................................................................................................... 54 Figure 4-39 Detailed Diagram after BSC (Battery System Controller) receives FACP signal ................................................. 54 Figure 4-40 Fire Suppression System layout .......................................................................................................................... 55 Figure 5-1 DC-DC Converter, SD175HV ................................................................................................................................. 57 Figure 5-2 DC-DC converter circuit diagram, SD175HV ......................................................................................................... 58 Figure 5-3 DC-DC converter, SD175HV, Specification Sheet ................................................................................................. 58 Figure 5-4 Temperature Derating ............................................................................................................................................ 59 Figure 5-5 Altitude dependent power derating ........................................................................................................................ 60 Figure 5-6 Discharge Efficiency Curve .................................................................................................................................... 61 Figure 5-7 Charge Efficiency Curve ........................................................................................................................................ 62 Figure 6-1 Power Titan container ............................................................................................................................................. 63 Figure 6-2 Space requ irements for installing ST2236UX-US: (a) single device (b) multiple devices ...................................... 64 Figure 6-3 Space requirements for installing a sing le ST2752UX-US: (a) single device (b) multiple device ........................... 65 Figure 7-1 Sungrow' quality management system model ........................................................................................................ 68 Figure 7-2 Quality management processes and relationship .................................................................................................. 69 Figure 7-3 Sungrow's ISO 9001 certification for quality management system ........................................................................ 70 Figure 7-4 Sungrow's ISO 14001 certification for environmental management system .......................................................... 70 Figur e 7-5 Sungrow's ISO 45001 certification for occupational health and safety management system ................................ 71 Figure 7-6 Sungrow's certification for hazardous substance process management ............................................................... 71 Figure 8-1 Sungrow service organization chart, North Americ a.............................................................................................. 73

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page vii www. dnv. com List of abbreviations Abbreviation Meaning BESS Battery energy storage system BMS Battery management system BSP Battery supply panel CC Constant current CFD Computational fluid dynamics CMU Cluster management unit CPG Capacity performance guarantee CV Constant voltage DCR Discharge capacity retention DNV DNV Energy USA Inc. DOD Depth of discharge EMS Energy management system ESS Energy storage system EV Electric vehicle FSS Fire suppression system HMA Hazard mitigation analysis HPPC Hybrid pulse power characterization HRR Heat release rate IEC International Electrotechnical Commission JV Joint venture LC Local controller LFP Lithium iron phosphate Li-ion Lithium ion MV Medium voltage NCM Nickel cobalt manganese PCS Power conversion system POI Point of interconnection RT Room temperature RTE Round-trip efficiency SMU System management unit SOC State of charge SOH State of health SRR Smoke release rate TSR Total smoke release UL Underwriters Laboratories UN United Nations

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page viii www. dnv. com EXECUTIVE SUMMARY DNV will include an executive summary in a later revision of the report.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 1 www. dnv. com 1 INTRODUCTION Sungrow USA Corporation (“Sungrow” or the “Customer”) retained DNV Energy USA Inc. (“DNV”) to complete a technical due diligence evaluation of its liquid cooling battery energy storage system (“BESS” or “ESS”), specifically, the ST2236UX-US and ST2752UX-US products. This evaluation is intended to serve as third-party vetting of the Sungrow liquid cooling BESS, which is being deployed in 2022 and beyond. Within this report, DNV has reviewed Sungrow's BESS, suppliers, designs, and integration capabilities. DNV opines o n Sungrow's specification, design for functionality and safety, performance, service infrastructure, guarantees and warranties, and manufacturing capabilities. The Sungrow ST2236UX and S2752UX products have been promoted by Sungrow to European markets and this report is focusing on the products' models that are to be deployed in the U. S. Sungrow's liquid cooling solution is offered in 1 hour (ST2236UX-US) and 2 to 4 hour (ST2752UX-US) options. The Sungrow liquid cooling ESS i ncludes an enclosure which is designed to be battery agnostic and can leverage battery cells from different battery suppliers. The focus of this report is on the liquid cooling ESS including available information from both cell suppliers, REPT and CATL. 1. 1 Objective and s cope of review The primary objective of this report is to assess factors that would affect the final product's performance, safety and reliability in the field and the Company's ability to deliver and service the products. Such factors will include the product design, qua lity of materials, product performance, regulatory compliance, reliability tests, and the manufacturing and quality control processes. DNV has divided the Technical Review into several main topic areas for evaluation: Company overview Battery product overview Battery review, including the cells, modules and racks Thermal management system BMS functionality Safety and certifications validation Integration and installation requirements Manufacturing, supply chain, and quality review Service infrastructure Key findings will be gathered in the executive summary. 1. 2 Methodology In general, this report contains information that would be included in a final Independent Engineering review intended for financial institutions, Sungrow customers, and project developers. DNV is uniquely qualified to conduct this study due to its extensive background and experience in solar, wind, and energy storage independent engineering and technology due diligence work. To perform th e assessment, DNV relied on documentation provided by Sungrow and conversations with key staff associated with the topic areas covered. DNV also visited Sungrow's production and manufacturing sites in [Location] and the results of those assessments are included this report.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 2 www. dnv. com As noted above, where applicable DNV will draw on previous technology review work performed with Sungrow. Where used, permission was acquired for the use of this information. Information was aggregated from multiple Sungrow sources and provided to DNV for generation of this report by: Colton Li u: Sales Center, Application Engineer 1. 3 Assumptions This Report summarizes the DNV assessment of the technology and relies on the accuracy of the information provided by Sungrow. Sungrow has been generally fort hcoming in providing the data that DNV has requested; where data was not provided or was incomplete is noted as such within the report. Some data received from Sungrow that has been used in the production of this Technology Review has been omitted from this report based on requirements from Sungrow that it remains confidential. This report is based on some information not within the control of DNV. DNV believes that the information provided by others is true, correct, and reasonable for the purposes of this report. DNV has not been requested to make an independent analysis or verification of the validity of such information. DNV does not guarantee the accuracy o f the data, information, or opinions provided by others. In preparing this report and the opinions presented herein, DNV has made certain assumptions with respect to conditions that may exist, or events that may occur in the future. DNV believes that thes e assumptions are reasonable for the purposes of this report but actual events or conditions may cause results to differ materially from forward-looking statements.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 3 www. dnv. com 2 COMPANY OVERVIEW Sungrow Power Supply Co., Ltd. ( SGPS ), founded in 1997, is a vertically integrated power conversion products and integrated BESS solutions provider and classed as a Tier-1 manufacturer as defined by Bloomberg New Energy Finance. SGPS has more than 20 subsidiaries worldwide and 200+ service fa cilities [1]. SGPS began its BESS product offerings with a joint venture (JV) known as Sungrow-Samsung SDI Energy Storage Power Supply Co, in Hefei, China, in July 2014. SGPS has approximately 5,000 employees and has solutions deployed in over 60 countries [2]. DNV request more specific documentation of Sun grow Americas history, financial, and sales performance DNV requests clarification of the end date, if any of the Sam sung ESS JV, and what, if any, future integrations are planned. Table 2-1 Sungrow company information [3] Name of corporation Sungrow Power Supply Co., Ltd.. Ownership status Joint-stock company (Shenzhen Stock Exchange) Corporate headquarters No. 1699 Xiyou Rd., High Tech Zone, Hefei, Anhui 230088, China Full-time employees 4,492 as of 10 June 2021 2. 1 Stationary energy storage product history Sungrow's ESS product deployment dates back to 2014 with product deployments in 2018 as shown in Figure 2-1 [4]. Through the JV, Sungrow leveraged Samsung SDI's nickel cobalt manganese (NCM) based lithium ion (Li-ion) cell technology for its initial project deployments. Starting in 2020, Sungrow started to use lithium iron phosphate (LFP) cell technology for its containerized solutions which aligns with trends in the industry of moving away from cobalt-based Li-ion cells. Sungrow tran sitioned away from containerized ESS to enclosure-based systems in 2022 which also aligns with trends seen from other major integrators in the energy storage industry. Figure 2-1 Sungrow ESS product roadmap 2021 Copyright SUN OW ST54 W 250 C Couple ST556 W 250UD ( C Couple) ST556 W D250 V 4 S 125 V (DC Couple) E2 E3 E3Battery C I ST500CS US Utility L Battery E2 ST4200 W 2000 ( CCouple)ST3 2 W 3450 ( CCouple)L ST3 2 W D1250 V S 3600UD MV (DC Couple)L L ST2 52UX US 0. 5C ( C Couple) L ST2236UX US 1C ( C Couple) ST2 52UX US S 3600UD MV 0. 5C (DC Couple)L

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 4 www. dnv. com In 2021, Sungrow shipped over 3 GWh of energy storage systems worldwide including in the U. S., Europe, Japan, Australia, China and others. Sungrow has deployed ac-coupled and dc-coupled energy storage projects in multiple states in the United States including California, Massachusetts and Texas. Sungrow acquired orders total 1. 4 GWh in Norther America in 2020 including standalone energy storage projects and storage in combination with power plants [5]. DNV requests clarifi cation of the end date, if any of the Samsung ESS JV, and what, if any, future integrations are planned. 2. 2 Intellectual property DNV reviewed Sungrow's energy storage patents covering energy storage equipment, photovoltaic and inverter systems, and testing. The list includes 21 patents which are valid for 10 years after the publication date shown in Table 2-2 below. Table 2-2 Sungrow list of patents as of 10 June 2021 No. Patent Name Application Date Publication Date 1 Energy storage cabinet Nov 18, 2020 Apr 13, 2021 2 Display screen panel with graphical user interface for device status Nov 03, 2020 Apr 13, 2021 3 Charging pile Oct 28, 2020 Apr 13, 2021 4 Charging pile Oct 23, 2020 Apr 13, 2021 5 Charging pile Oct 23, 2020 Apr 13, 2021 6 A three-level BOOST device Oct 20, 2020 Apr 13, 2021 7 A Parallel Interle aved Full Bridge LLC Circuit Oct 09, 2020 Apr 13, 2021 8 Clamping device and electronic equipment Oct 09, 2020 Apr 13, 2021 9 Wiring protective cover and photovoltaic equipment Sep 29, 2020 Apr 13, 2021 10 Motor Controller (EC31) Sep 27, 2020 Apr 13, 2021 11 Shutdown Sep 22, 2020 Apr 13, 2021 12 Communication module and inverter Sep 21, 2020 Apr 13, 2021 14 Reactor Sep 15, 2020 Apr 13, 2021 15 Outdoor cabinet frame structure and outdoor cabinet structure Sep 10, 2020 Apr 13, 2021 16 Drawer type module sealing structure of inverter Sep 09, 2020 Apr 13, 2021 17 An interlock switch and electrical equipment Sep 07, 2020 Apr 13, 2021 18 Power test device Sep 04, 2020 Feb 12, 2021 19 DC charging pile Sep 04, 2020 Feb 12, 2021 20 Wall-mounted components and electrical equipment Sep 03, 2020 Apr 13, 2021 21 Inverter and inverter system Sep 01, 2020 Apr 13, 2021 DNV considers that Sungrow' s supporting intellectual property will allow Sungrow to effectively customize its products towards targeted market segments. DNV did not review in detail any of Sungrow's patents or applications to assess their commercial releva nce or active use in the liquid cooling ESS products reviewed in this document. Sungrow's p roducts are protected by S S' patent portfolio, providing a solid basis for a potential competitive advantage.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 5 www. dnv. com 2. 3 Sales revenues DNV request more specific documenta tion of Sungrow America s and BESS history, financial, and sales performance

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 6 www. dnv. com 3 SUNGROW LIQUID COOLING SYSTEM OVERVIEW DNV performed a comprehensive review of all e xisting product documentation pertaining to the technical specifications of the Sungrow ST2236UX-US and ST 2752UX-US liquid cooling BESS products. The review focuses on Sungrow's current product offerings, their core components and the secondary components that interact with those products at a higher level. 3. 1 Product offerings Figure 3-1 Sungrow ST2236 UX-US battery energy storage system Sungrow's current stationary battery products are sold as outdoor BESS, which are installed in outdoor rated enclosures, of which multiple units may be installed in parallel. Sungrow designs turnkey, stand-alone or grid-tied energy storage systems comprised of Li-ion based battery modules that can be scaled for both power and energy to achieve the desired project ratings. This report reviews two Sungrow products, a 1-hour battery system, ST2236UX-US (Figure 3-1) and the 2-8 hour battery system, ST2752UX-US (Figure 3-2). Both Sungrow ESS products, and the possible battery cell suppliers, reviewed as part the report, are shown in Table 3-1. The various elements of the system architecture are described and opined upon in more detai l throughout the report. Table 3-1 Sungrow liquid cooling ESS p roduct offerings ESS product Application Duration Cell Suppliers ST2236UX-US Power 1-hour CATL, REPT ST2752UX-US Energy 2-hour, 8-hour CATL, REPT

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 7 www. dnv. com Figure 3-2 Sungrow ST 2752 UX-US battery energy storage system Sungrow's battery system ships with C TL or E T manufactured battery cells, integrated into modules and racks by Sungrow. The battery systems are completely integrated into single enclosures as a stand-alone turn-key energy product. This enables the system to be transported as a whole and minim izes onsite installation time and complexity. Figure 3-3, shows a breakdown of a typical Sungrow system and its con stituent components for a complete turnkey energy storage system with a battery cabinet and PCS container. DNV notes that the system s hown in Figure 3-3 is a representative system meant only for reference. Figure 3-3 Sungrow BESS System Anatomy Figure 3-4 shows an internal snapshot of the integrated Sungrow battery system. Each battery enclosure possesses its own liquid cooling unit along with cluster controller s, which are energy management devices designed to balance state of charge (SOC) to optimize power delivery. 2021 Copyright SUN OW. Confidential Confidential icture is for reference only

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 8 www. dnv. com Figure 3-4 Sungrow liquid cooling ESS components The highly integrated nature of the product along with the use of liquid cooling thermal management system means that the system is more space efficient. According to Sungrow, a s the battery enclosure has a smaller footprint, the ESS plant requires less la nd area for a comparable air cooled project of the same power and energy capacity. Figure 3-5 Liquid vs. air cooling area efficiency Sungrow's liquid cool ing battery system uses a liquid cooling unit that adjusts its output power according to the temperature of the cells using their proprietary intelligent control algorithm. This is said to reduce the auxiliary energy consumption requirements by more than 50% [6]. In addition to the reduced auxiliary energy load, liquid cooling has the added benefit of maintain a more uniform temperature differential inside the cabinet due to better thermal flow. The precise thermal design manages a temperature delta below 3 °C, which helps increase system life by 23% and power generation by 3. 3% compared to non-liquid cooled battery systems, according to Sungrow [6]. The liquid cooled thermal management s ystem is discussed further in Section 4. 4.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 9 www. dnv. com Figure 3-6 Sungrow liquid cooling design Sungrow uses a rack level energy management device, Cluster Controller, which performs energy management at the cluster-level. Battery cells tend to have small initial internal resistance differences between each cells. These initial cell differences lead to slight differences in cell operating characteristics such as temperatures and charge and discharge rates. Over the life-time of a cell the differences grow and cause a difference in the state of charge ( SOC ) of each rack. This difference between rack SOC limits the po wer output to the lowest performing rack. According to Sungrow, the Cluster controller rebalances the rack SOC to fully optimize power delivery. Figure 3-7 Cluster-level energy management

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 10 www. dnv. com The cluster controller enables Sungrow to offer customized rack configurations as racks with different modules can be mixed. The SOC calibration, that maps a cell voltage and Ah characteristics to 0%-100% SOC, is managed internally through the controller. This provides Sungrow with design flexibility and reduce s the operation and maintenance burden on the plant owner. In addition to the battery system, Sungrow is also capable of providing the power conversion system (PCS) which consists of the bi-directi onal inverter, and medium voltage (MV) transformer. Sungrow also provides the thermal management system, and the local controller to interface with a third party energy management system, or plant controller. The decoupled modular approach to the Sungrow p roduct means that Sungrow can provide a complete turnkey energy storage product to form a fully integrated BESS. Otherwise, they can also provide each component separately as its own stand-alone product based on project requirements. It also means that Sungrow is able to augment battery projects more easily as they only have to replace the battery unit and not the entire integrated PCS system unlike other equipment providers. Acco rding to Sungrow this reduces initial investment cost by 25% [6]. Figure 3-8 New battery integration: Sungrow vs. traditional providers A simplified Sungrow system diagram for the ST2236UX-US product is shown in Figure 3-9. The diagram shows all the different products that constitute the full ESS. Sungrow is capable of supplying all the equipment up to the MV point of interconnection (PO I or POC ). In an integrated or turnkey project scope, Sungrow ESS comprises of the entire syst em and equipment outlined in the figure. The local controller interacts with the PCS and BMS through a network switch. The local controller then provides a single point of connection for the plant controller/ energy management system ( EMS ) for the aggregate d system data and control information. DNV does not take any exception to the design architecture, however DNV recommends developing a recommended list of EMS integrators that are familiar with the Sungrow product

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 11 www. dnv. com architecture, who have worked closely with Sungrow to develop their EMS solutions and can easily provide plant level integration for plant owners. DNV requests detailed technical specification of the lo cal controller. Figure 3-9 Sungrow system architecture, ST223 6UX-US Similarly, Figure 3-10 shows the product architecture for the ST2752UX-US product. The system design is very closely related to the ST2236UX-US design with a few differences. In addition to the higher capacity compo nents in the ST2752UX-US product, the system uses a dc/dc converter to aid with voltage balancing, and battery augmentation tasks. The dc-dc converter is discussed in more detail in Section 5. 1.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 12 www. dnv. com Figure 3-10 Sungrow system architecture, ST2752UX-US

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 13 www. dnv. com 3. 2 Product specifications A summary of key parameters of the 2 Sungrow systems are shown in Table 3-2. Table 3-2 Product specifications for Sungrow ST2236UX-US and ST2752UX-US Parameter ST2236UX-US ST2752UX-US Primary intended use Power applications Energy applications Battery chemistry LFP LFP Maximum dc energy capacity (k Wh) 2236 2752 DC voltage range (V) 1123 ~ 1500 1160 ~1500 C-rate 1 0. 25 or 0. 5 Cell model CATL 280 Ah, REPT 280 Ah CATL 280 Ah, REPT 280 Ah Cell capacity (Ah) 280 280 Number of battery cells 416 384 Cell architecture 416s1p 384s1p Weight (kg) 24,500 26,400 Dimensions (width x height x depth ) (mm) 9340 x 2600 x 1730 9340 x 2600 x 1730 Enclosure protection rating IP54 IP54 Codes and standards compliance UL 9540, UL 9540A, NFPA 855 Ambient temperature rating -30 °C to 50 °C (> 45 °C derating) Relative humidity 0-95% (non-condensing) Maximum working altitude (m) 3,000 The two liquid cooling BESS products are comparable and utilize almost the same equipment and components. The major differen ce being the cell discharge rates, and volume of the enclosures, along with the higher voltage and dc energy capacity of the ST2752UX-US systems. Overall, the systems are high ly integrated ESS for ease of transportation, operation, and maintenance. The battery enclosures are pre-assembled by Sungrow in order to minimize module handling and installation on site. This helps lower the cost of installation, as well as increase system reliability and consistency. Due to the modular system architecture, it allows the systems to be easily parallel, and scale according to project needs.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 14 www. dnv. com 4 BATTERY COMPONENT EVALU ATION This section outlines the battery and supporting auxiliary equipment, s tarting at the battery cell, and building up to the full dc-side system specification. The Sungrow BESS systems are available in 1-hour to 2-8 hour configuration, which are reviewed separately as appropriate. The ST2236UX-US is a liquid cooled 1-hour sys tem, with the ST2752UX-US is a liquid cooled 2-8 hour system. Both the systems are capable of supporting cells from either CATL or REPT regardless of duration. DNV performed a comprehensive review of all existing product documentation provided by REPT pertaining to the technical specifications of E T's 2 0 h battery cell product as part of the DNV Technology Review Report issued by DNV on the request of Ruipu Energy Co. Ltd. The cell evaluation is based on a desktop review of the product specific ation sheet and test results by E T. DNV notes that it has not reviewed “raw” test data, nor validated the test results. Similarly, the DNV completed a desktop review of the product specification sheets and test results provided by CATL. All specificatio n and performance data were derived from test results provided by CATL, performed in the CATL in-house laboratory. The results of the review published by DNV as part of the CATL 280 Ah Cell Technology Review Report is reported here. 4. 1 Battery cell evaluatio n Sungrow provided DNV with data relating to two cell types approved for use in their integrated BESS system products. DNV has reviewed this data which demonstrates the level of detail and specifications for the two (2) cell types used in the Sungrow ST223 6UX-US and the ST2752UX-US systems. DNV recognizes that the cell evaluation process used to select these two cell types can be applied to any other cell variant as Sungrow continues to expand the cell types that can be approved for use in its BESS products. The Sungrow BESS products utilizes two (2) different cells-CATL 280 Ah (1C) Lithium Iron Phosphate (LFP) Li-ion cells and, the REPT 280 Ah ( 1C) LFP Li-ion cells. These cells were designed by Contemporary Amperex Technology Co. Limited (CATL ) and Ruipu Energy Co. Ltd (REPT), respectively, as part of their standard cell offering to system integrators, and their own integrated BESS products. Details on the company manufacturing evaluation is discussed in Section 4. 1. 1. Details on the cell specifications are provided in Section 4. 1. 2. How the cells are packaged into bat tery modules and complete systems are described in Section 4. 1. 3. 4. 1. 1 Battery cell manufacturer company evaluation 4. 1. 1. 1 CATL Contemporary Amper ex Technology Co. Limited, fou nded in 2011, is a manufacturer of lithium-ion (Li-ion) batteries for energy storage systems (ESS) and EVs. CATL has 14,711 employees with headquarters in Ningde, Fujian, China, four manufacturing sites, and two R&D sites located in China and Germany [7]. Upon establishment in 2011, C TL's initial product development centered around battery packs for BMW passenger cars [7]. Thereafter, the business was expanded to manufacture Li-ion batteries for ESS and battery packs for commercial vehicle manufacturer, Yutong. In 2014, offices in Germany and Beijing were established. CATL became the majority shareholder of Guandong Brunp Recycling Technology Limited in 2015. In 2017, offices in Fran ce, USA, Canada, and Japan were established and an initial public offering was held in 2018, raising approximately USD 850 million for 10% of its shares. CATL is led by Chief Executive Officer and founder, Dr. Zengyuqun. The current company network is show n in Figure 2-1.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 15 www. dnv. com Figure 4-1 CATL company network At present, CATL has two core product lines, as shown in Figure 2-2: stationary ESS and battery packs for EVs, including electric passenger vehicles, electric buses, and e lectric trucks. Figure 4-2 CATL's product lines C TL's leading technologies include Ener Magic, Ener Dura, Ener Lasting, Ener Climate, and Ener Speedy. As of 31 December 2017, 302,000 EVs with CATL batteries were on the road in 374 cities in China. According to SNE Research, C TL is the world's leading battery manufacturer-supplying more than 40% of all electric vehicle batteries in China [8]. CATL's annual shipment volume amounted to 32. 5 GWh of energy storage capacity in 201 9 [9].

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 16 www. dnv. com Figure 4-3 Global EV and battery shipment tracker, from SNE Figure 4-4 Projected production capacity CATL provided a list of 178 Chinese and 636 foreign issued and pending patents. Although a detailed review of intellectual property (I ) is not included within DNV's current scope of work, a company's volume of leveraged I typically supports further growth and maintenance of market share. DNV considers C TL's int ellectual property to be substantial and be indicative of a leading battery technology company.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 17 www. dnv. com 4. 1. 1. 2 REPT Ruipu Energy Co., Ltd. (abbreviated as REPT), established in 2017, is the first enterprise invested by Fortune Global 500 and Chinese nickel and stainless-steel giant, Tsingshan Holding Group. Tsingshan Holding Group was founded in 1992. After more than 30 years of rapid development, stainless steel output of Tsingshan Industry has been successively ranked the first in the world for many years. Also, Tsingsh an Industrial is the largest producer of nickel iron in the world currently. The industrial bases are distributed in China, Indonesia, the United States, India, Zimbabwe, etc. Tsingshan Industry started lithium battery business since 2017. Tsingshan invest ed USD 45 billion on new energy fields and rapidly completed the industrial chain layout from nickel cobalt ore resources, ternary material preparation to power battery production. Figure 4-5 Tsingshan Holding Group overview In April 2019, Tsingshan established ET group, which expanded Tsingshan new energy industry chain. Tsingshan has collaborated with a domestic supplier to set up graphite production base & me lting spodumene from Australia in Tsingshan Industrial park in Indonesia handling the upstream process from Coke plant. Also, Tsingshan has plans for development of Lithium Salt Lake in South America. Figure 4-6 Tsingshan industrial raw material supply chain

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 18 www. dnv. com By virtue of Tsingshan's rich resources of nickel mine, E T is principally engaged in research and development, production and sales of power lithium-ion battery and its syste matic application program and focuses on high-quality solutions providing for battery electric vehicle (EV) and Intelligent power storage. In 2020, REPT has become one of the top 10 automotive power battery enterprise. In the NCM category, Tsingshan has strong cooperation with QUM, GMA, Huayou and other raw material battery companies that develop laterite nickel ore resources, ternary materials, and precursor products, and planned for 2021 sales. REPT has built its manufacturing base in Wenz hou and R&D center in Shanghai. Situated at Airport New Area, Longwan District, Wenzhou Manufacturing Base covers up to 20. 2 hectares. The planned annual production capacity is expected to be 26 GWh with a total investment of more than 5 billion RMB 1. Out of this capacity, 6 GWh is developed in the first phase plan. The second phase plant is total 20 GWh, 10 GWh has been put into production, and another 10 GWh will be put into production and there will be 26 GWh in the end of 2021. By the end of 2020, abou t 2 billion RMB 1 of investment has been in place and 6 GWh has been put into production. Additionally, the second largest domestic manufacturing base with a capacity of 30 GWh in Foshan, Guangdong as the third phase expected to be in production by December 2022 and a 100 GWh base in Wenzhou have also been planned by 2024. E T's first long-life lithium-ion battery, the 50 Ah cell was developed for the field of household energy storage, and its annual shipments exceed 500 MWh. In 2019, REPT targeted the larg e-scale energy storage market. For a large-size square cell, the most concerned contents include battery consistency, safety, and heat generation under long-term cycles. REPT claims to have selected advanced lithium iron phosphate cathode materials, and b y constructing a porous electrode system with high reliability of electronic pathways, low expansion rate and stable electronic pathways of the positive electrodes during the life cycle is ensured. REPT thereby claims that long-term rigorous testing and ev aluation are carried out, and the cell formula and structure are continuously optimized to achieve high-quality energy storage cell. REPT manufactures its own lithium iron phosphate (Li Fe PO4, or LFP) batteries and nickel cobalt manganese (NCM) batteries f or its products. The 280 Ah lithium-ion battery product that can meet the full life cycle of more than 15-20 years, and it can cycle more than 8000 times under the condition of 0. 5P constant power that is used in its stationary energy storage products is t he focus of this review. DNV notes that REPT is vertically integrated in its battery manufacturing, from raw material through research, development, design, manufacture, end-product, and repurposing or recycling at the end of product life. DNV was provi ded with the REPT Technology roadmap from 2019 and forecasted till 2027 as shown below in Figure 4-7. DNV notes the actual plan for EV applications for LFP runs until 2025; LFP technology planned till 2022 is exclusively for energy storage applications. 1 1 RMB = 0. 15 USD conversion rate as of March 2021.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 19 www. dnv. com Figure 4-7 REPT technology roadmap to 2027 4. 1. 2 Battery cell specifications 4. 1. 2. 1 CATL 280 Ah battery cells Figure 4-8, shows a rendering of the CATL 280 Ah cell. Figure 4-8 CATL 280 Ah cell The CATL ESS 280 Ah LFP cell specifications are detailed in Table 4-1 [10]. Table 4-1 CATL 280 Ah cell specifications Cell specification Unit Parameter(s) Capacity @ 25°C, 1C (see Table 3-7) Ah ≥ 2 0 Nominal voltage V 3. 2 Nominal energy @ 25°C, 0. 5C Wh 896 Dimensions Mm 71. 7 x 173. 9 x 207. 2

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 20 www. dnv. com Cell specification Unit Parameter(s) Mass kg 5. 35 ± 0. 15 Specific energy Wh/kg 164. 10 Energy density (w/o terminal) Wh/L 346. 75 Cycle life @ 25°C, 0. 5C to 80% capacity Cycles 6,500 Operating temperature ( discharging ) °C-30 to 55 Operating temperature ( charging ) °C 0 to 55 Storing temperature (case dependent) °C-30 to 60 DNV considers the cell specifications to be in line with expectations and the specific energy to be above average for comparable LFP products. DNV notes that the information in this table came from the marketing presentation “ESS2 80Ah LFP Cell-Specification and erformance Summary. ” DNV notes that the operating temperature measurement location and procedure is not clearly defined. CATL noted that the listed temperatures are maximum cell-surface temperatures. 4. 1. 2. 2 REPT 280 Ah battery cells E T's in-house developed 280 Ah battery cells are based on LFP chemistry. The CB71173204EB 280 Ah cell is sealed in an aluminium enclosure, as shown in Figure 4-9. Figure 4-9 REPT 280 Ah battery cell The specifications for E T's 2 0 h cell, leveraged in E T's stationary storage product and used in electric vehicles, are provided in Table 4-2. Note that these results refer to individual cells and are not representative of module or rack level results. DNV considers the cell specifications to be in line with expectations [11]. Table 4-2 REPT 280 Ah cell specification Cell specification Unit Parameter(s) Product Model CB71173204EB Cell type LFP-C Capacity @ 25°C, 1C Ah 280

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 21 www. dnv. com Cell specification Unit Parameter(s) Nominal voltage V 3. 2 Nominal energy @ 25°C, 1C Wh 896 Dimensions mm 71. 7 x 174 x 206. 8 Mass kg 5. 4 ± 0. 15 Specific energy Wh/kg 166 Energy density (w/o terminal) Wh/L 351. 4 Cycle life @ 25°C, 0. 5C to 80% capacity Cycles 6,000 Operating temperature ( discharging ) °C-30 to 55 Operating temperature ( charging ) °C 0 to 55 Storing temperature (case dependent) °C-30 to 60 The cell is rated at 280Ah, 1C at 25°C and nominal voltage is 3. 2V, which equates to an energy capacity of 896 Wh. Energy density of the 280Ah is specified to be 166 Wh/kg. DNV consi ders the energy density to be above average compared with competing LFP technology. 4. 1. 3 Battery cell performance, degradation, retention, and cycle life DNV completed a full cell technology review for both the CATL and REPT 280 Ah cells. Sections of the review s as they pertain to the battery cell performance and cell degradations for each cell are noted below. 4. 1. 3. 1 CATL 280 Ah battery cells The cell is designed for charge and discharge at different c-rates based on temperature (see Table 4-3, which summarizes data provided in a CATL marketing presentation). The cell can operate at voltages from 2. 5 V to 3. 65 V, as shown in Figure 4-10. The curves in Figure 4-10 and Figure 4-11 are based on test conditions of 25 °C, 0. 5C charging to 3. 65 V, 30 minutes of rest, and then 0. 5 C discharging until 2. 5 V, followed by 30 minutes of rest. The results in Figure 4-10 indicates that up to 300 Ah can be provided from the cell when discharged to a low voltage cut-off of 2. 5 V at a constant power rate of 0. 5P, which supports the 280 Ah cell rating. DNV finds the test conditions and results to be in line with expectations. DNV notes that throughout the product specifications and warranty the temperature measurement points are n ot clearly defined, and recommends that these be more clearly specified. Table 4-3 Charge and discharge rates at different temperatures* Temperature, °C 0 2 5 7 10 12 15 20 25 35 45 50 55 60 Charge c-rate 0 0. 10 0. 12 0. 25 0. 30 0. 35 0. 5 0. 8 1 1 0. 8 0. 5 0. 25 0 Discharge c-rate 0. 2 n/a 0. 2 n/a 0. 3 n/a 1 1 1 n/a 1 1 0. 5 0 *Note: CATL did not provide the same temperature and c-rate combinations for charging and discharging.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 22 www. dnv. com Figure 4-10 Capacity and energy at 25 °C, 0. 5C Figure 4-11 illustrates the impact of p-rates from 0. 167C (~ 6-hour discharge at rated power) to 0. 5C (2-hour discharge at rated capacity) on energy capacity and surface temperature. The performance resul ts are in line with expectations. The results indicate that 100% of the cell rated energy can be provided between a voltage range of 2. 5 V to 3. 65 V at all three P-rates;0. 167P, 0. 25P, and 0. 5P. The results also indicate that higher P-rate operations produ ce more heat, which is as expected. Figure 4-11 Energy capacity and surface temperature impacts of various p-rates

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 23 www. dnv. com Figure 4-12 illustrates the impact of different temperatures on discharge energy and capacity. Test conditions were to charge at 0. 25C up to 3. 65 V and discharge at 0. 25C to 2. 0 V. The results indicate th at the cells are able to discharge closer to 100% capacity at temperatures of 25, 45, and 60 °C compared to temperatures of 5 °C and below. These results are in line with expectations for LFP cells. DNV expects that cell voltages will be limited to a 2. 5 V, and not allowed to reach 2. 0 V. The voltage vs, energy curves indicate that there will be no significant improvement in energy capacity from allowing cel l voltages to go below 2. 5 V. DNV notes that there is a significant drop in performance for the cell in colder temperatures. DNV requests confirmation that Sungrow will be integrating and configuring the cells and will observe the cell manufacturer thermal requirements. DNV notes that the results of temperature vs. capacity test demonstrate that the the rmal management system appears to be appropriately sized for the CATL integrated and configured cells. DNV notes that the performance of Sungrow integrated and configured cells may vary due to configuration or integration differences. Figure 4-12 High and low temperature performance testing results Internal resistance discharge capacity retention (DCR) and hybrid pulse power characterization (HPPC) test results are shown in Figure 4-13. Testing conditions were to discharge at 560 amps for 30 seconds and charge at 420 amps for 30 seconds.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 24 www. dnv. com Figure 4-13 DCR and HPPC test results CATL also provided abuse test results, summarized in Table 4-4. Table 4-4 Abuse test results Abuse t esting mode Testing condition (GBT 36276-20198) Hazard level Over charge -100% SOC, room temperature -1 C charge for 1 hr or voltage of one cell reaches 1. 5 times charged ended voltage 3 Drop -100% SOC, room temperature -1. 5-meter height to concrete floor with both terminals downward, 1 hr observation 2 Crush -100% SOC, room temperature -Crush head: 75 mm crush to 30% displacement or 0 V or the crush force reaches 13 KN 2 Over discharge -100% SOC, room temperature -1 C discharge for 1. 5 hr or voltage of one of cells falls to 0 V 2 Short circuit -100% SOC, room temperature -E ternal resistance < 5 mΩ held short circuit for 10 minutes 2 Heating -100% SOC, room temperature -Heating from room temperature to 130 °C at rate of 5 °C per minute. Temperatures maintained for 30 minutes 3 CATL provided typical 20-year degradation curves for its liquid cooled racks operating at 0. 25C and 0. 5C across a range of annual cycles. Tests assume a 99% depth of discharge (D OD) at 0. 25C and 97. 5% Do D for 0. 5, as shown in Figure 4-14. In the highest utilization case at 0. 5C for 365 cycles per year, the liquid cooled rack cell degradation after 20 years was 66%, respectively. The lines in Figure 4-14 illustrate 0. 25C while the solid lines are for 0. 5C. DNV notes that there is very little difference in degradation between the two c-rates. However, the difference in end of life capacity between 365 and 180 cycles per year use cases is nearly 10%, indicating that knowledge of use case and resulting cycling is a critical factor to understanding how cell capacity will change over a project life. DNV finds these results in line with commercial expectations for LFP cells in the market. DNV has not independently reviewed cell life testing data that were used to derive these expected degradation curves. Figure 4-14 show s the estimated degradation of the liquid-cooled racks.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 25 www. dnv. com Figure 4-14 Liquid-cooled rack cell degradation, percent nominal capacity per year DNV notes that the CATL battery cell performance and degradation information is based off of CATL integrated modules and cell configuration. The results described above are based off CATL provided information. DNV requests cell performance and degradation data as it pertains to Sungrow configured and integrated cells, as the configuration and thermal management of the Sungrow integration will i nfluence the cell performance within the Sungrow system. 4. 1. 3. 2 REPT 280 Ah battery cells REPT has provided DNV with specification datasheet that covers the following tabulated data [11]. Table 4-5 Temperature cycle vs. time Temperature ( °C) Time interval ( s) Total Time ( s) Temperature rate (°C/s) 25 0 0 0 -40 60 60 13/12 -40 90 150 0 25 60 210 13/12 85 90 300 2/3 85 110 410 0 25 70 480 6/7 The ambient charging operation temperature range is claimed to be 0 °C to 65 °C and ambient discharging operation temperature is claimed to be-30 °C to 60 °C. DNV considers the cell's thermal operating window appropriate for most environments so that the cells can meet all requirements of the BESS during normal operation and withstand minor unexpected excursions asso ciated with system integration. Further discussion on derating at extreme temperatures. REPT has provided the following curve in the specification datasheet [11].

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 26 www. dnv. com Figure 4-15 Temperature curve vs. time REPT provided DNV with various discharge rate curves for its 280 Ah cells. Figure 4-16, provides voltage and temperature test results as the cell is discharged at different C-rates [11]. Figure 4-16 shows test results for temperature effects on cell performance, where the cell temperature was varied from-20°C to 55°C. It is assumed that the measured temperature is the cell temperature. G iven the significant drops in capacity at 0°C and-20°C, the ideal charging temperature is at 25±2°C and operator should strive to operate in the temperature range as specified in Table 4-5.. The results in Figure 4-16 indicates that the rated 280 Ah can be provided from the cell when discharged to a low voltage cut-off of 2. 5 V at a c onstant C-rate of 1C. DNV notes that these results are in line with industry standard, the system air conditioning should be appropriately designed to maintain the cell temperature in the specified temperature range. Figure 4-16 High and low temperature capability

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 27 www. dnv. com The test procedures followed for the curves in Figure 4-17 are as follows: 1. 25℃ rest ≥ 5 hours; 1C CC 3. 65V CV 0. 05C; est 30 min. 2. Set to different temperatures, rest ≥5 hours @55 ℃/ 25 ℃/ 0℃, rest ≥10 hours @0 ℃, rest ≥24 hours @-20℃ 3. 1C dc 2. 5V @55 ℃/25℃, 2. 0V @0 ℃/-20℃. The above discharge rate test procedure has been conducted at different temperatures within operating range; 1C constant current (CC). DNV notes that this is in line with industry practice. However, DNV also observed that the lowest and highest temperature s in the specification datasheet are-30°C & 65°C respectively. Battery discharge capacity was tested with respect to varying discharge rates, as shown in Figure 4-17. Charge rate was held constant at 1C, and discharge rates were varied from 0. 1C to 2C. DNV notes both charge and discharge capacity decrease as C-rate increases. As expected, performance dropped slightly as c-rate increased, but limited capacity loss was observed. DNV considers the capacity retention of the battery cells over a wide range of c-rates as being advantageous in enabling it to perform various revenue-producing functions. Figure 4-17 Discharge capacity at various discharge rates Battery charging capacity was also tested with respect to varying charge rates, as shown in Figure 4-18. The discharge rate was held constant at 1C, and charge rates were varied from 0. 1C to 2C. After being charged at 0. 5C, the 280Ah capacity drops slightly after 1 C conditions. Given the indi cated loss of capacity significantly increase at >1C, DNV considers E T's maximum allowable charging c-rate of 0. 8C to be appropriate.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 28 www. dnv. com Figure 4-18 Charge capacity at various charge rates REPT provided data showing the results of a short-circuit test as shown in Figure 4-19. DNV adv ises that for purposes of fuse selection, a much more precise model of current flow is required. Such a test should simulate a bolted-fault condition, at an e ternal resistance of 0. 1 Ω dc or less, created by a device e ternal to the battery, and provide a short timescale (0-1000 ms or less) analysis of the current, as provided by an oscilloscope.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 29 www. dnv. com Figure 4-19 Short circuit test data DNV opines that the above test procedures by the GB/T 31845-2015 (National Standard of the eople's epublic of China-Safety Requirements and Test Methods for Traction Battery of Electric Vehicle) method conducted by REPT are in accordance with industry practices, however DNV has not independently validated these test results. One of the major challenges for Li-ion batteries is degradation. Degradation of batteries results in declining capacity, reduced round trip efficiency, and elevated self-discharge. Understanding the main drivers of battery degradation can help improve the BMS to prolong battery lifetime. The known drivers include total energy throughput, average SOC, average SOC swing (also described through depth of discharge ), charge/discharge ra te (c-rate), temperature, and calendar fade. REPT provided accelerated battery cycle life testing results, shown in Figure 4-20, which indicated approximately 96% capacity retention after 1000 100% DOD cycles at a 1C and 25 °C and 90% capacity retention after 1000 100% DOD cycles at a 1C and 45 °C. Separately, there is a pack test under room temperature (25 °C)-the tested capacity retention was around 90% at around 1000 cycles [11]. E T's e trapolation of the 25 °C cycle life testing data expects to retain greater than 80% capacity af ter 6,000 cycles, which is the life condition provided in the cell specification. DNV has not independently verified E T's cycle life e pectation.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 30 www. dnv. com Figure 4-20 REPT 280 Ah accelerated cell test Test procedures: (1) 25 ℃ Cycle; Rest 30min; 1C CC to 3. 65V & CV 0. 05C; Rest 30min; 1C dc to 2. 5V (2) 45 ℃ Cycle; Rest 30min; 1C CC to 3. 65V & CV 0. 05C; Rest 30min; 1C dc to 2. 5V. Based on th e degradation table provided by REPT, DNV considers 60% as End-of-Life Capacity retention. REPT testing results for calendar fade are shown in Figure 4-21. The cell's capacity retention for calendar fade at 100% SOC drops to 98% after 200 days and drops to around 97. 5% after 275 days at 25°C [11].

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 31 www. dnv. com Figure 4-21 Temperature impact on storage life Test procedures for the calendar life curves in Figure 4-21 are as follows: 1. 25℃ 1C CC to 3. 65V & CV 0. 05C; rest 30min; 1C dc 30mins. 2. 25℃ @ 100%SOC ，45℃ @ 50%SOC store 7d,14d,21d,28d, then every 30d test capacity 3. Room temperature (RT) rest 5h 4. 25℃ 1C C C to 3. 65V & CV 0. 05C; 1C dc to 2. 5V Additional degradation tests were conducted by REPT to indicate the safety of the cell including over discharge, over charge, drop, extrusion, low pressure, short circuit, heat, thermal runaway tests. The cell demonstr ated completion of the

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 32 www. dnv. com tests without the occurrence of explosion, fire, or leakage in compliance to the standards. The safety of the cell will be discussed further in Section 4. 6. DNV notes that the REPT battery cell performance and degradation information is based off of REPT integrated modules and cell configuration. The results described above are based off REPT provided information. DNV requests cell performance and degradation data as it pertains to Sungrow configured and integrated cells, as the configura tion and thermal management of the Sungrow integration will influence the cell performance within the Sungrow system. 4. 2 Battery module and rack evaluation Sungrow is the system level integrator for the BESS. Lithium ion batteries of LFP chemistry are being used as the battery of choice for the BESS systems. After receiving the cells from their manufacturers, Sungrow combines battery cells in series to form their modules. The module packing is finished using Sungrow's proprietary module packing design. Sungr ow has stated that they have a mature module packing production technology, strict quality inspection process, and that they have been producing modules for several years. The entire package is then branded and wrapped by Sungrow, who services, supports, and warranties the product throughout the lifetime of the project via Sungrow's e tensive service organization. Sungrow indicated that this approach gives them flexibility to utilize different cell suppliers. While less common, DNV considers integration of third-party battery cells into modules and racks to pose typical risks in designing a BESS, with the major exception being that Sungrow will have to manage the manufacturers cell design changes that affect the system integration and BMS. The 2 major systems being evaluated in this report are the: Sungrow ST2236UX-US (1-hour system) Sungrow ST2752UX-US (2-8 hour system) Each of these systems are comprised of modules and rack developed using CATL 280 Ah and REPT 280 Ah cells discussed in Section 4. 1. The details of the modules and their rack composition are discussed below. 4. 2. 1 Modules The review is based on the 'P573-111, P573B-111 & R344-111 Datasheet ' and the 'P573AL-1123, P573BL-1123, P286BL-1123 & R372-112 datasheet' provided by Sungrow. Figure 4-22 shows the Sungrow integrated modules. The module combines 64 cells in series in a string to provide 57. 34 k Wh, at 204. 8 V. Each cell within the module has a rated capacity of 280 Ah. Specification from the data sheet s is presented below in Table 4-6. Module Configuration: 1P 64S = 64 x 280 Ah = 17,920 Ah Nominal Energy Capacity = 17,920 Ah x 3. 2 V = 57,344 Wh = 57. 34 k Wh Module Energy Density = 57,344 Wh / 303. 37 L = 1 89. 02 Wh/L

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 33 www. dnv. com Figure 4-22 Sungrow integrated modules Alternatively, the 32-cell module combines 32 cells in series in a string to provide 28. 67 k Wh, at 102. 4 V. Each cell within the module has a rated capacity of 280 Ah. Specification from the data sheets is presented below in Table 4-6. Module Configuration: 1P 32S = 32 x 280 Ah = 8,960 Ah Nominal Energy Capacity = 8,960 Ah x 3. 2 V = 28,672 Wh = 28. 672 k Wh Module Energy Density = 28,672 Wh / 303. 37 L = 1 24. 66 Wh/L DNV notes that the two different cells have identical specification s when configured for the Sungrow modules. The same modules are used for both the ST2236 and the ST2752 short and long duration products respectively. DNV finds the liquid cooled module specif ications to be in line with industry expectations. The energy density of the modules is comparable to the highest available in the battery industry. DNV requests detailed technical specification on the mechanical design, electrical design, thermal managem ent and control system of the battery modules. Table 4-6 Sungrow module specification Parameter Units ST2236UX-US CATL / REPT 64 Cell Modules ST2236UX-US CATL / REPT 32 Cell Modules ST2752UX-US CATL / REPT 64 Cell Modules Cooling Liquid Liquid Liquid Application Outdoor Outdoor Outdoor Model P573AL-1123, P573BL-112 P286BL-112 P573-111, P573B-111 Cell Type LFP280Ah LFP280Ah LFP280Ah Height mm 247 247 247 Width mm 868 868 868 Depth mm 1415 1415 1415 Cells qty. 64 32 64 Configuration 1P64S 1P32S 1P64S Capacity Ah 17920 8960 17920

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 34 www. dnv. com Parameter Units ST2236UX-US CATL / REPT 64 Cell Modules ST2236UX-US CATL / REPT 32 Cell Modules ST2752UX-US CATL / REPT 64 Cell Modules Rated energy k Wh 57. 34 28. 67 57. 34 Rated voltage V dc 204. 8 102. 4 204. 8 Voltage minimum V dc 172. 8 86. 4 172. 8 Voltage maximum V dc 233. 6 116. 8 233. 6 Rated c-rate C <= 1 <= 1 <= 0. 5 Rated power k W <= 57. 34 <= 28. 67 4 <= 28. 67 Weight kg 400 230 400 Rack specific energy Wh / kg 143. 36 124. 66 143. 36 Rack energy density Wh / L 189. 02 94. 51 189. 02 4. 2. 2 Racks Figure 4-23 shows the Sungrow integrated battery racks. The same battery rack design is used in all CATL and REPT populated racks. Figure 4-23 Example Sungrow integrated BESS with battery rack s (6) 64 cell modules and (1) 32 cell module is integrated together to develop the Sungrow, CATL 280 Ah rack and REPT 280 Ah rack for the ST2236UX-US rack. The rack contains 416 cells in seri es. The nominal energy rating is 372. 2 k Wh per rack, with an output voltage around 1331. 2 V. Rack Configuration: 1P 416S = 416 x 280 Ah = 116,480 Ah Rack Energy Capacity = 116480 Ah x 3. 2 V = 372,736 Wh = 372. 7 k Wh (6) 64 cell modules are integrated together to develop the Sungrow, CATL 280 Ah rack and REPT 280 Ah rack for the ST2752UX-US rack. The rack contains 384 cells in series. The nominal energy rating is 344. 06 k Wh per rack, with an output voltage around 1228. 8 V.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 35 www. dnv. com Rack Configuration: 1P 384S = 384 x 280 Ah = 107,520 Ah Rack Energy Capacity = 107,520 Ah x 3. 2 V = 344,064 Wh = 344. 06 k Wh The specification sheet of the rack configurations are shown in Table 4-7 Table 4-7 Sungrow integrated rack specifications Parameter Units ST2236UX-US CATL / REPT Cell Racks ST2752UX-US CATL / REPT Cell Racks Cooling Liquid Liquid Application Outdoor Outdoor Model R372-112 R344-111 Cell Type LFP280Ah LFP280Ah Height mm-- Width mm-- Depth mm-- Cells qty. 416 384 Configuration 1P416S 1P384S Capacity Ah 116,480 107,520 Rated energy k Wh 372. 7 344. 06 Rated voltage V dc 1331. 2 1228. 8 Voltage minimum V dc 1123. 2 1036. 8 Voltage maximum V dc 1497. 6 1401. 6 Rated c-rate C <= 1 <= 0. 5 Rated power k W <= 372. 7 <= 172. 03 Weight Kg-- Rack specific energy Wh / kg -- Rack energy density Wh / L -- (6) racks are connected in parallel in an enclosure to build the ST2236UX BESS product. Figure 4-24, shows the integration of the racks into a ST2236UX-US enclosure. (8) racks are connected in parallel in an enclosure to build the ST2752UX BESS product.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 36 www. dnv. com Figure 4-24 ST2236 UX-US BESS Module and Rack Configuration DNV requests detailed technical specification on the mechanical design, electrical design, thermal management and control system of the battery racks. 4. 3 Operational evaluation 4. 3. 1 Power capability and duration Sungrow offers its BESS product s in three different C-rates: 1C, 0. 5C and 0. 25 C and two discharge models as described below: Charge: charge at CC to CP from 0% to 95% SOC, charge at CV with 0. 05C current from 95% to 100% SOC Discharge-model 1: discharge at CP from 100% to 40% SOC, disch arge at CC from 40% to 5% SOC, discharge at CC 0. 2 C rate from 5% to 0% SOC. Discharge-model 2: discharge at CP. The usable capacity for REPT and CATL battery cells in different state of health and C-rate for Model 1 and Model 2 are summarized in Table 4-8 and Table 4-9, respectively. Table 4-8 BSS ratio of usable capacity-Model 1 SOH 100% 90% 80% 70% 60% Cell supplier C-rate REPT CATL REPT CATL REPT CATL REPT CATL REPT CATL 1C 94. 02 96. 02 93. 91 95. 91 92. 86 94. 86 92. 49 94. 49 92. 07 94. 07 0. 5C 95. 80 96. 79 95. 49 96. 48 95. 18 96. 17 94. 77 95. 76 94. 50 95. 49 0. 25C 97. 50 100. 00 96. 91 97. 41 96. 71 97. 21 96. 45 96. 95 95. 93 96. 43

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 37 www. dnv. com Table 4-9 BSS ratio of usable capacity-Model 2 SOH 100% 90% 80% 70% 60% Cell supplier C-rate REPT CATL REPT CATL REPT CATL REPT CATL REPT CATL 1C 92. 02 94. 02 91. 91 93. 91 90. 86 92. 86 90. 49 92. 49 85. 89 92. 07 0. 5C 93,80 94. 79 93. 49 94. 48 93. 18 94. 17 92. 77 93. 76 89. 07 93. 49 0. 25C 95. 50 98. 00 94. 81 95. 41 94. 71 95. 21 91. 81 94. 95 91. 55 94. 43 The usable capacity is calculated as follows: 𝑅𝑎𝑡𝑖𝑜 𝑜𝑓 𝑢𝑠𝑎𝑏𝑙𝑒 𝑐𝑎𝑝𝑎𝑐𝑖𝑡𝑦 = 𝐸2 𝐸1 × 𝑆𝑡𝑜𝑟𝑎𝑔𝑒𝑅𝑒𝑡𝑒𝑛𝑡𝑖𝑜𝑛 × 𝑆𝑂𝐻 × 𝐷𝑂𝐷 where E1 is rack nominal capacity and E2 is dc discharge capacity. The results indicate that the usable capacity decreases at higher C-rate or lower SOH which is expected DNV request s information on test condition such as depth of discharge for the results shown above on usable capacity test s. 4. 3. 2 Efficiency Round-trip efficiency (RTE) is calculated as the ratio of dc charge capacity over dc discharge capacity. Table 4-10 and Table 4-11 summarizes rack RTE for model 1 and 2: Table 4-10 RTE-Model 1 SOH 100% 90% 80% 70% 60% Cell supplier C rate REPT CATL REPT CATL REPT CATL REPT CATL REPT CATL 1C 91. 50 91. 50 91. 30 91. 30 89. 30 89. 30 88. 60 88. 60 87. 80 87. 80 0. 5C 93. 52 94. 20 92. 72 93. 60 91. 92 93. 00 91. 46 92. 20 91. 00 91. 70 0. 25C 95. 60 95. 92 94. 80 95. 52 94. 00 95. 12 93. 75 94. 62 93. 50 93. 62 Table 4-11 RTE-Model 2 SOH 100% 90% 80% 70% 60% Cell supplier C rate REPT CATL REPT CATL REPT CATL REPT CATL REPT CATL 1C 89. 55 89. 59 89. 36 89. 40 87. 38 87. 42 86. 68 86. 72 85. 89 85. 93 0. 5C 91. 57 92. 25 90. 78 91. 66 89. 99 91. 07 89. 53 90. 27 89. 07 89. 78 0. 25C 93. 46 94. 00 92. 84 93. 56 92. 06 93. 16 91. 81 92. 67 91. 55 91. 68 DNV request s information on testing environment and RTE data for different operating temperature s, if available. DNV request system information on system RTE if availa ble.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 38 www. dnv. com 4. 4 Thermal management system 4. 4. 1 Documents received DNV received the following documents related to the thermal management system in the Sungrow ST2752UX and ST2752UX-US products: Sungrow Liquid Cooling ESS Presentation (8 April 2021) Conceptual t hermal design (25 December 2021) Test report for coolant, co nducted by SGS MSDS for coolant, conducted by Sinopec Power Titan System Manual, v12. 0, dated August 2021, detailing Ventilation design and operational thermal guidelines Characteristic Curves, showing temperature and altitude de-rating parameters 4. 4. 2 Summary of cooling system 4. 4. 2. 1 BESS cooling architecture The cooling system of the ST2236 UX-US and ST2752UX-US products occurs primarily at the module level. Each module, of which there are a maximum of 42 in the product, has an integral liquid cooling s ystem. The module and the liquid cooling flow is shown in Figure 4-25. Figure 4-25 Module demonstrating cooling flow Each enclosure has a compressor and heat exchanger which uses a liquid coolant to circulate and feed each of the battery modules. The coolant consists of an ethylene-glycol and water mixture, which is typical for products of this type.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 39 www. dnv. com Figure 4-26 Enclosure-level cooling diagram 4. 4. 2. 2 Air-cooling architecture The dc/dc converter, battery supply panel ( BSP) and wiring cabinet use an air-cooling system as described in Figure 4-27. The right side of Figure 4-27 shows the ventilation system of the BESS enclosure. Figure 4-27 Air-cooling flow diagram 4. 4. 2. 3 Energy consumption values DNV reviewed a 'Liquid Cooling System Self Energy Consumption' document detailing the provided energy at various conditions. DNV requests a description of the source of this technical information. The 'Characteristic Curves' document states that “When the battery system power is less than 80% of the maximum power, it can run for multiple cycles without rest. When the battery system is greater than or equal to 80% of the maximum power, i t

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 40 www. dnv. com can run for two consecutive cycles without rest, and there is a 90-minute interval between the second cycle and the third cycle. ” DNV requests laboratory data substantiating these recommendat ions. 4. 4. 2. 4 Cooling calculations DNV reviewed a brief summary of c omputational fluid dynamic s (CFD) modeling which showed the expected cooling to be achieved in the stack. The summary lists two ambient temperature s: 25°C and 45°C. The charging and dis charging method is listed as “0. 5 C, steady state. ” The maximum tempera ture difference is listed as 3. 4°C when ambient temperature is 25°C, and 4. 6°C when the ambient temperature is 45°C. The high temperatures are not provided, but the color-coded diagram appears to demonstrate that the high temperatures are approximately 35° C. DNV requests the full outputs of this CFD modeling showing the inputs of thermal generation on a module level and tabular data showing the temperature time series. DNV requests the inputs used in this CFD model, demonstrating the heat generation of the module at 0. 5C as backed by laboratory data. DNV requests the results of physical lab testing demonstrating the module, rack, and unit level thermal performance. Figure 4-28 CFD model at 25 °C ambient

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 41 www. dnv. com Figure 4-29 CFD model at 45°C ambient Figure 4-30 CFD modeling of the dc/dc converter and wiring cabinet at 45°C ambient 4. 4. 3 Opinion of cooling system DNV will form a complete opinion of the thermal management system when the remaining supporting documentation has been receiv ed.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 42 www. dnv. com 4. 5 BMS functionality, faults and alarms 4. 5. 1 BMS architecture Sungrow provided “Technical greement” to DNV for reviewing its ESS technical feature s. As part of this document, DNV reviewed ESS control and communication architecture. Sungrow's ESS control system includes a three layer s Battery Management System (BMS) and a Local Controller (LC). The BMS three layer s are battery management unit ( BMU ), cluster management unit ( CMU ) and system management unit ( SMU )/BMS. The ESS control architecture is depicted in Figure 4-31 below. Figure 4-31 Structure of BMS Through this architecture the monitoring and control of the BESS is performed in different levels: BMU : the BMU communicates with CMU. It collects module level voltage s and temperatures, executes balancing command. CMU: Cluster Management Unit (CMU ) communicates with BMU and SMU. It collects rack level current and voltage, perform SOC/SOH estimation, contactor control, safety related fault diagnosis. SMU: SMU communicat es with PCS, LC, CMU and thermal management system. It supports the safety protection system, and record system leve l fault and operation data. LC: the local controller is interface to EMS and helps EMS to communicate with ESS as one device. It collects and uploads the real-time information of PCSs, battery system and other equipment in the ESS through an ethernet connection and communicate with EMS. DNV finds the multi-level BMS architecture standard control strategy for BESS system.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 43 www. dnv. com 4. 5. 2 Alarm and warning systems DNV request s BMS faults and alarms list, and associated corrective actions to clear such faults/alarms. DNV request information on balancing circuit when available. 4. 6 Regulatory compliance and safety Safety is a critical design and operational aspect of energy storage devices. Safety of an energy storage system builds up from the battery cell and is relevant to every stage of product's lifecycle, based upon both code requirements and best practices. When assessing an energy storage d evice's safety program, DNV applies the approach of risk management; that is, the likelihood of an emergency event to occur and the severity of the event. DNV reviews certifications, test data, and quality management processes to address the likelihood fac tor of the equation; and reviews emergency response, installation protections and suppression/detection systems to address the severity factor of the equation. In general, DNV considers certifications to codes and standards to be minimum requirements. Sinc e codes and standards do not necessarily match up to best practices, DNV expects a robust safety program to go beyond the basic requirements. DNV reviewed documentation related to the Sungrow BESS and its components. 4. 6. 1 Standards, codes and testing The Sungr ow BESS and its components are designed to be compliant with United States (US) standards that are generally accepted to demonstrate minimum safety considerations in the system design for US installations. These standards include certifications of the batt eries by Underwriters Laboratories (UL) and International Electrotechnical Commission (IEC) standards, as well as UL and UN testing. A full listing of key standards and the status for each of the battery suppliers is provided in Table 4-12. DNV considers that design to these standards is in line with industry best practices. Table 4-12 Standards, codes and testing list Component Claimed Standard Title Certification/Test verified- Sungrow BESS (REPT) Certification/Test verified- Sungrow BESS (CATL) Cell UL 1642 Standard for Lithium Batteries (Cell level testing) This standard specifies the safety design aspects of individual Li-ion cells and evaluates the ability of the cells to withstand abuse conditions such as external short circuit, overcharge, over discharge, crush, (nail) impact, shock, vibration, heating, temperature cycling, low pressure, projectile, and external fire. Compliance to UL 1642 is covered by the UL 1973 certification. DNV has reviewed the UL 1973 certificate issued on 15 September 2021 and confirm s compliance to UL 1642. DNV has reviewed the UL 1973 certificate issued on 24 November 2021 and confirm s compliance to UL 1642. Module / Pack / String UL 1973 Standard for Batteries for Use in Stationary, Vehicle Auxiliary Power and Light Electric Rail (LER) Applications (module level testing) This standard specifies the safety design aspects of multiple battery cells that are integrated into a module, pack, or string and operated in parallel/series, often with a battery management system (BMS) and other instrumentation, and evaluates the ability of the package to withstand abuse conditions such as external short circuit, overcharge, over discha rge, crush, shock, vibration, temperature cycling, low pressure, projectile, external fire, drop, molded case heating, and internal short circuit. DNV has reviewed the UL 1973 certificate for battery rack dated 15 September 2021. DNV has re viewed the UL 1973 certificate for battery rack dated 24 November 2021.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 44 www. dnv. com Component Claimed Standard Title Certification/Test verified- Sungrow BESS (REPT) Certification/Test verified- Sungrow BESS (CATL) Full System UL 9540 Standard for Energy Storage Systems and Equipment (full system) DNV re quest s clarification on plans for UL 9540 certification for the Sungrow (REPT) BESS. DNV request clarification on plans for UL 9540 certificat ion for the Sungrow (CATL) BESS. Full system fault and fire testing UL 9540A Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems-cells DNV has reviewed the draft cell level UL 9540A (4th edition) test report dated 28 January 2 022. DNV request s the final UL 9540A cell-level test report, when available. DNV has reviewed the cell level UL 9540A ( 4th edition) test report dated 27 April 2021. Test Method for Evaluating Thermal Runaway Fire Propagation in Battery Energy Storage Systems- modules/packs and unit/enclosure DNV has reviewed the module level UL 9540A ( 4th edition) test report dated 1 1 March 2022. DNV has reviewed the Unit level UL 9540A ( 4th edition) test report dated 1 9 March 2022. DNV has reviewed the module level UL 9540A ( 4th edition) test report performed in November 2021. DNV has reviewed the Unit level UL 9540A ( 4th edition) test report performed in March 2021. Electrical and software protection controls UL 1998 Standard for Software in Programmable Components DNV request to review UL 1998 certificate for Sungrow (REPT) BESS. DNV request to review UL 1998 certificate for Sungrow (CATL) BESS. Thermal management system UL 1995 Heating and Cooling Equipment DNV request to review UL 1995 certificate for Sungrow (REPT) BESS. DNV request to review UL 1995 certificate for Sungrow (CATL) BESS. Transportation UN38. 3 Certification for Lithium Batteries This standard specifies the safety design aspects of a battery system during transport and evaluates its ability to withstand abuse and drop testing. DNV has reviewed the REPT Technology Review Report and confirm s compliance. [11] DNV has reviewed the UN38. 3 test report dated 1 April 2019. Fire code IFC 2018 /2021 International Fire Code Not Certifiable-While not certifiable the BESS is evaluated to this standard in the subsequent section as the IFC is adopted in local fire codes across the United States. Fire Protection and Safety NFPA 855 Standard for the Installation of Stationary Energy Storage Systems Not Certifiable-While not certifiable the BESS is evaluated to this standard in the subsequent section as this standard is representative of the industry best practices associated with stationary energy storage systems. 4. 6. 2 UL 9540A testing UL 9540A testing is a destructive test method used for evaluating the thermal runaway impacts in a BESS and gathering data to assist in assessing or developing mitigation measures for the failure event, propagation of the failure, or consequences of an event, such as an explosion or fire. The test, which does not have pass/fail criteria, can be performed on a cell, module, or unit level. UL 9540A is ANSI accredited and is currently considered to be the most appropriate published methodology to provide comprehensive, consistent, and reliable third-party data for battery failure testing. UL 9540A is currently in its 4th edition, with added reporting and data collection throughout the stages of the test. Furthermore, the 4th edition of UL 9540A has improved on the thermal runaway methodology that is carried out at the modules and unit (repeat of module test set up) levels when compared to the 3rd edition UL 9540A test standard. As such, assessments regarding cell-to-cell therm al runaway propagation are more comprehensive within the improved test methodology of the 4th edition. 4. 6. 2. 1 Cell-level (CATL) results

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 45 www. dnv. com CSA has performed cell level UL 9540A test in April 2021. The model no: CB2W0 and CB310 were tested to the 4th edition of the UL 9540A test methodology [12]. Table 4-13 provides an overview of the key components of the test report that DNV has reviewed. Table 4-13 UL 9540A cell-level test results Test parameter Data collected Thermal Runaway Methodology External heat at 4°C/min to 7°C/min up to thermal runaway Heating method External heating method with film heater Upper Cutoff Voltage 3. 65 V Average Cell Surface Temperature Gas Venting: 168. 2 °C Average Cell Surface Temperature at Thermal Runaway: 239. 6 °C Gas Volume: 221. 3 L Gas Composition (volumetric %): H2 35. 69 %, CO 11. 08 %, CO 2 33. 29 %, CH 4 10. 07 %, C 2H4 5. 25%, C 2H6 1. 089%, C 3H6 0. 57%, C 3H8 0. 23% Lower Flammability Limit: 7. 85% at ambient temperature Pmax: 103 psig Burn Velocity (S u) 64 cm/s In comparison with other tests DNV has reviewed that were conducted under the same or similar conditions, the gas composition r eported for CATL has a n average proportion of H 2. This large amount of hydrogen, in relation to other gas species released, has driven the Lower Flammability Limit lower and resulted in a higher P max. Although a detailed quantitative analysis of this data would be necessary to determine the exact impact of this, qualitatively, such characterist ics could relate to a more energetic explosion. However, the results of the module-level and unit-level UL 9540A testing will determine the resistance to propagation of thermal runaway events, which would decrease the explosion risk caused by the flammable gas mixture. Other factors to consider are design of ventilation (such that gases are not permitted to gather to levels which cou ld allow an explosion) and volume of the space in which the systems are installed. In comparison with other tests DNV has reviewed, that were conducted under the same or similar conditions, the volume of gas produced was below average on a per-Amp-hour ba sis. This may be a product of the form factor of the cell but would contribute favorably to the safety of the cell. 4. 6. 2. 2 Cell-level (REPT) results TUV Rheinland has conducted cell level UL 9540A test in January 2022. The model no: CB71173204EB, was tested to the 4th edition of the UL 9540A test methodology [13]. Table 4-14 provides an overview of the key components of the test report that DNV has reviewed. Table 4-14 UL 9540A cell-level test results Test parameter Data collected Thermal Runaway Methodology External heat at 5°C/min to 7°C/min up to thermal runaway Heating method External heating method with film heater

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 46 www. dnv. com Test parameter Data collected Upper Cutoff Voltage 3. 65 V Average Cell Surface Temperature Gas Venting: 260. 1 °C Average Cell Surface Temperature at Thermal Runaway: 318. 6 °C Gas Volume: 82 L Gas Composition (volumetric %): H2 49. 35 %, CO 7. 53%, CO 2 25. 66 %, CH 4 6. 37%, C 2H4 7. 14%, C 2H6 1. 84%, C 3H6 1. 09%, C 3H8 0. 39% Lower Flammability Limit: 6. 1% @ 24°C ±2°C Pmax: 0. 998 MPa Burn Velocity (S u) 0. 85 m/s In comparison with other tests DNV has reviewed that were conducted under the same or similar conditions, the gas composition reported for REPT has a higher proportion of H 2. This higher proportion, in relation to other cells, has driven the Lower Fla mmability Limit lower and resulted in a higher P max. Although a detailed quantitative analysis of this data would be necessary to determine the exact impact of this, qualitatively, such characteristics could relate to a more energetic explosion. However, t he results of the module-level and unit-level UL 9540A testing will determine the resistance to propagation of thermal runaway events, which would decrease the explosion risk caused by the flammable gas mixture. Other factors to consider are design of vent ilation (such that gases are not permitted to gather to levels which could allow an explosion) and volume of the space in which the systems are installed. In comparison with other tests DNV has reviewed, that were conducted under the same or similar conditions, the volume of gas produced was below average on a per-Amp-hour basis. This may be a product of the form factor of the cell but would contribute favorably to the safety of the cell. The cell venting and thermal runaway temp erature are higher than what is typically seen. This shows good cell resiliency to thermal runaway. 4. 6. 2. 3 Module-level (CATL) results Sung row has tested their battery module, model series P573-V113/P573B-V113/ P286B-V113/ P573-V111/ P573B-V111, to the 4th edition of the UL 9540A testing standard. TUV R heinland conducted the test in November 2021 [14]. DNV notes that unlike the 4th edition, the 3rd edition does not require cell-to-cell propagation to be a result of the testing methodology for the module-level tests. DNV views testing to the 4th edition of UL9540A favor ably. Table 4-15 provides an overview of the key components of the test report that DNV has reviewed. Table 4-15 UL 9540A module-level test results Test parameter Data collected Thermal runaway methodology External surface heat at 5°C/min to 7°C /min up to thermal runaway Heating method External heating method with two heater s Measured peak chemical heat release rate (HRR) 30. 26 k W Measured peak smoke release rate (SRR) 22. 58 m2/s External flaming and flying debris observation No fire or explosion occurred; cell-to-cell propagation was observed

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 47 www. dnv. com Total smoke release (TSR) 7608. 48 m2 Total Gas Volume 22081. 3 L Gas Composition 0. 18% CO, 0. 13% HF, 1. 28% hydrocarbons, 0. 11% nitrogen species, 96. 75 % CO 2 Figure 4-32 Location of heater in Module level test The testing was conducted within an individual battery module consisting of 6 4 LFP cells. All cells were connected in series. The battery module consists of a BMU and a fuse. The module-level test applied heat to one battery cell within the module to force thermal runaway. The two ceramic heaters were placed on cell # 13 between cell # 12 and # 14. Figure 4-32 shows the location of the initiating cell in the module and heater. The initiating cells were heated between 5 °C/min and 7 °C/min and kept increasing until the cell reached thermal runaway. This test methodology is in line with section 8 of UL 9540A. The test report indicate s that no fire, explosion, or flying debris was observed during the module-level test. Cell-to-cell propagation occurred during the test to cells #15, 16, and 11. It is unclear if cell #10 also went into thermal runaway. From the test report summary, it also indicates that 281. 9 L of hydrocarbons were released, and 40. 4 L of carbon monoxide generated from the test. Hydrocarbons such as methane and propane are explosive and flammable gases. In addition, carbon monoxide is a toxic gas as well as an extremely flammable gas that can readily form an explosive mixture with air. Explosion controls, such as ventilation or deflagration panels, are recommended as a best practice to mitigate hazards associated with the amount of off-gas produced. Overall, DNV views the results of the module level test favorably. 4. 6. 2. 4 Module-level (REPT) results Sungrow has tested their battery module, model series P573AL-121 and P573BL-121 to the 4th edition of the UL 9540A testing standard. TUV Rheinland conducted the test in March 2022 [15]. Table 4-16 provides an overview of the key components of the test report that DNV has reviewed.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 48 www. dnv. com Table 4-16 UL9540A module-level test results Test parameter Data collected Thermal runaway methodology External surface heat at 4°C/min to 7°C /min up to thermal runaway Heating method External heating method with two aluminium heater s Measured peak chemical heat release rate (HRR) 8. 86 k W Measured peak smoke release rate (SRR) 11. 78 6 m2/s External flaming and flying debris observation Explosi ve gases discharge occurred, and fire observed ; cell-to-cell propagation was observed Total smoke release (TSR) 1945. 8 m2 Total Gas Volume 12329. 3 L Gas Composition 1. 36% CO, 0. 51% HF, 3. 05% hydrocarbons, 0. 38% nitrogen species, 86. 59 % CO 2 Figure 4-33 Location of initiating cell in battery module The testing was conducted within an individual battery module consisting of 64 LFP cells. All cells were connected in series. The battery module consists of a BMU and a fuse. The module-level test applied heat to one battery cell within the module to force thermal runaway. The two aluminium heaters were placed on cell #1 2 between cell #1 1 and #1 3. Figure 4-33 shows the location of the initiating cell in the module and heater. The initiating cells were heated between 5 °C/min and 7 °C/min and kept increasing unti l the cell reached thermal runaway. This test methodology is in line with section 8 of UL 9540A. Cell-to-cell propagation occurred to cell # 10, cell #14, cell #15, and cell #16 during the test. A total of seven cells went under thermal runaway and five additional cells were distorted. The module's enclosure was damaged and an electro lyte leak was reported outside the mo dule. The test report indicate d that 380. 2 L of hydrocarbons were released, and 167. 6 L of carbon monoxide gas was generated during the test. Hydrocarbons such as methane and propane are explosive and flammable gases. In addition, carbon monoxide is a toxic gas as well as an extremely flammable gas that can readily form an explosive mixture with air.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 49 www. dnv. com The test report indicated that “four times explosive discharge of gases ” and flam es were observed during the test. DNV notes that the rapid release of explosive gases likely contributed to the flames observed. DNV recommends explosion controls, such as ventilation or deflagration panels, a s a best practice to mitigate hazards associated with the amount o f off-gas produced. DNV also recommends adequate fire safety protections within the enclosure to mitigate any potential flames. 4. 6. 2. 5 Unit-level (CATL ) results Sungrow has tested their battery Unit, model series R287-111, R344-111, R575-111, and R688-111, to the 4th edition of the UL 9540A test methodology. TUV Rheinland conducted the test in December 2021 [16]. The Unit level test report mention s the Unit is considered the open rack without the enclosure, however the racks are tested within the enclosure. Further, the enclosure contains a separate column for the controls of each rack. The Unit is defined as o ne column of the rack with nine complete modules was considered as a unit, however DNV notes that six module s were used as a unit during this test. Figure 4-35 indicates the Unit consists of 2 rows of 3 modules each for a total of 6 module s. Four Units are then stacked on top of one another. In the Unit level test, a complete Unit is installed and surrounded by target (dummy) BESS and walls at the distance intended in its installation. The Unit level test results are intended to report whether a fire or thermal runaway will propagate between modules and other Units, and whether there will be flying debris or explosive discharge of gas. Thermal runaway is induced in battery cells of one of the modules in the initiating BESS unit using the same approach as the module level testing. According to the test methodology outlined in the standard, the same heating approach used in the module level testing (See Section 4. 7. 2. 2) must be used in the Unit level testing. The text of UL 9540A allows the BESS to be tested with its integral fire protection system provided by the manufacturer in the test set up, however none was used during this test. The following provides an overview of the test set up: The rack was cycled fully 3 times and left at 100% S OC; Two instrumented walls (3. 8 m high and 3. 55 m long) were constructed to form a parameter around the back and side of the initiating and target units. The walls were constructed covered with 5/8 in gypsum wall board and painted flat black; Module M 7 to M12 was considered the initializing Unit A, M 1 to M6 formed target Unit B, and M1 3 to M18 formed target Unit C (see Figure 4-35 for arrangement); Minimum separation distance from rack to wall as displayed in Figure 4-34. However, distance between Unit to Unit is not reported. DNV requests information about the distance between Unit to Unit in the Unit level test report. M8 was chosen to be the initiating modu le, shown in Figure 4-35.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 50 www. dnv. com Figure 4-34 Initiating unit and targeted unit position Figure 4-35 Initiating module location No flames, flying debris, or explosions, occurred during the Unit level test. However, there was a n electrolyte leakage noted outside the initiating module. Cell-to-cell thermal runaway propagation occurred, but module-to-module thermal runaway propagation was not observed during the test. Table 4-17 provides an overview of the performance conditions set forth by UL 9540A in addition to the summary of the Unit test observations.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 51 www. dnv. com Table 4-17 UL 9540A Unit performance conditions and obse rvations Performance condition Test observation/remark If flaming outside the unit is observed, separation distances to exposures shall be determined by the greatest flame extension observed during the test. No flaming was observed internally or externally of the Unit during the test. Surface temperatures of modules within the target units adjacent to the initiating unit do not exceed the temperature at which thermally initiated cell venting occurs. The maximum surface temperature of the target Unit B, adjacent to the initiating module was 121. 5 °C, which is less than the cell venting temperature reported in the cell-level test. The maximum surface temperature of the modules within the target Units C was 21. 2 °C, which is less than the cell venting temperature reported in the cell-level test. The temperature of cell venting was not reported. For units intended for installation near exposures, surface temperature measurements on wall surfaces do not exceed 97 °C of temperature rise above ambient temperature. The maximum surface temperature on the adjacent wall A was 21. 4 °C and the temperature on wall B was 24. 6 °C, which are both below from the 97 °C temperature rise performance criteria. Explosion hazards are not observed, including deflagration, detonation, or accumulation of battery vent gases. Explosion hazards were not observed during the test (internal and external). Heat flux in the center of the accessible means of egress shall not exceed 1. 3 k W/m2 The heat flux on instrumented wall A was roughly 1. 2 k W/m2 which is less than 1. 3 k W/ m2 performance criteria. While cell-to-cell propagation occurred during the test, module-to-module propagation was not observed indicating an adequate thermal barrier between modules. The Unit level results show a resiliency of the Unit to thermal runaway propagation and fire hazard in a single failure event. 4. 6. 2. 6 Unit-level (REPT ) results Sungrow has tested their battery Unit, model series R286AL-121, R344AL-121, R573AL-123, R688AL-123, to the 4th edition of the UL 9540A test methodology. TUV Rheinland conducted the test in March 2022 [17]. The Unit level test report mentions the Unit is considered the open rack without the enclosure, however the racks are tested within the enclosure. Further, the enclosure contains a separate column for the controls of each rack. The Unit is defined as one column of the rack with nine complete modules, however DNV notes that six modules were used during this test. Figure 4-37 indicates the Unit consists of 2 rows of 3 modules each for a total of 6 modules. Four Units are then stacked on top of one anothe r. In the Unit level test, a complete Unit is installed and surrounded by target (dummy) BESS and walls at the distance intended in its ins tallation. The Unit level test results are intended to report whether a fire or thermal runaway will propagate between modules and other Units, and whether there will be flying debris or explosive discharge of gas. Thermal runaway is induced in battery cel ls of one of the modules in the initiating BESS unit using the same approach as the module level testing. According to the test methodology outlined in the standard, the same heating approach used in the module level testing (See Section 4. 7. 2. 2) must be u sed in the Unit level testing. The text of UL 9540A allows the BESS to be tested with its integral fire protection system provided by the manufacturer in the test set up, however none was used during this test. The following provides an overview of the tes t set up: The rack was cycled fully 3 times and left at 100% SOC;

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 52 www. dnv. com Two instrumented walls (3. 8 m high and 3. 55 m long) were constructed to form a parameter around the back and side of the initiating and target units. The walls were constructed covered w ith 5/8 in gypsum wall board and painted flat black; Module M7 to M12 was considered the initia ting Unit A, M1 to M6 formed target Unit B, and M13 to M18 formed target Unit C (see Figure 4-37 for arrangement); Minimum separation distance from rack to wall as displayed in Figure 4-36. However, distance between Unit to Unit is not reported. DNV requests information about the distance between Unit to Unit in the Unit level test report. M8 was chosen to be the initiating module, shown in Figure 4-37. Figure 4-36 Initiating unit and targeted unit position Figure 4-37 Initiating module location

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 53 www. dnv. com No flames, flying debris, or explosions, occurred during the Unit level test. However, there was an electrolyte leakage noted outside the initiating module. Cell-to-cell thermal runaway propagation occurred, but module-to-module thermal runaway propagation was not observed during the test. Table 4-18 provides an overview of the performance conditions set forth by UL 9540A in addition to the summary of the Unit test obser vations. Table 4-18 UL 9540A Unit performance conditions and observations Performance condition Test observation/remark If flaming outside the unit is observed, separation distances to exposures shall be determined by the greatest flame extension observed during the test. No flaming was observed internally or externally of the Unit during the test. Surface temperatures of modules within the target units adjacent to the initiating unit do not exceed the te mperature at which thermally initiated cell venting occurs. The maximum surface temperature of the target Unit B, adjacent to the initiating module was 31. 4 °C which is less than the cell venting temperature reported in the cell-level test. The maximum su rface temperature of the modules within the target Units C was 26. 5 °C which is less than the cell venting temperature reported in the cell-level test. The temperature of cell venting was not reported. For units intended for installation near exposures, surface temperature measurements on wall surfaces do not exceed 97 °C of temperature rise above ambient temperature. The maximum surface temperature on the adjacent wall A was 2 4. 3 °C and the temperature on wall B was 2 3. 9 °C, which are both below from the 97 °C temperature rise performance criteria. Explosion hazards are not observed, including deflagration, detonation, or accumulation of battery vent gases. Explosion hazards were not observed during the test (internal and external). Heat flux in the center of the accessible means of egress shall not exceed 1. 3 k W/m2 Measured heat flux were zero. While cell-to-cell propagation occurred in initiating module during the test, module-to-module propagation was not observed indicating an adequate thermal barrier between modules. The Unit level results show a resiliency of the Unit to Unit thermal runaway propagation and fire hazard in a single failure event indicating the spacing laid ou t in Figure 4-36 is adequate for Project layout requirements. 4. 6. 3 Safety design and features 4. 6. 3. 1 Enclosure design The Sungrow BESS (model no: ST2236UX and ST2236UX ) is enclosed in a 9. 340 m x 2. 600 m x 1. 730 m enclosure rated to IP5 4 and NEMA 3R. In general, a NEMA 3R rated enclosure is intended for outdoor applications and it provides protection against rain, snow, ice and falling dirt. The IP54 rating indicates the level of protections that enclosure provides against the solid objects (first number) and the level of protection against liquids (second number). DNV finds the BESS enclosures to be typical for t he industry and suited for outdoor use.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 54 www. dnv. com 4. 6. 3. 2 Controls and monitoring The control system used in the Sungrow BESS m onitors the smoke detector, flammable gas detector, alarms, temperature, fault signals, and fire alarm panel. The control system executes control actions in order to safely stop the operation of the batteries in case of faults or severe abnormalities. The control system acts on information from both the sensors and equipment in the battery management system. Sungrow has provided Fire Suppression System ( FSS) logic and detail diagram after receiving the FACP (Fire Alarm Control Panel) signal. Figure 4-38 is the main logic diagram for the control system and Figure 4-39 is the detailed diagram after the BSC (Battery System Controller) receives FACP signal s. Figure 4-38 Main logic diagram Figure 4-39 Detailed Diagram after BSC (Battery System Controller) receives FACP signal

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 55 www. dnv. com 4. 6. 3. 3 Fire protection Thermal runaway-defined as the rapid and self-perpetuating chain reaction that generates significant heat and gases that can be toxic and flammable-is a well-known cause of battery fires due to the generation of heat and gasses that can be toxic and flammable. Lithium batteries of any chemistry can be forced into thermal runaway. The off-gases and failure modes of lithium-ion batteries vary depending on the cell chemistry and form factor. DNV understands that the Sungrow BESS used in this Project employs batteries with LFP cell chemistry. LFP cells, like other chemistries, can experience thermal runaway. However due to their chemistry, LFP batteries have a somewhat greater resiliency to th ermal runaway. DNV has observed in its own testing that “it was common for Li e O4, LTO, and the BM-LMP cells to off-gas without flame, but their off-gas composition contains the same flammable and toxic constituents as batteries with higher temperature failures”, such as NMC. s such, all the same mitigative and safety considerations should be made for L as for other chemistries. Figure 4-40 Fire Suppression System layout Sungrow's BESS has a FSS which uses water as extinguishing medium during an event of fire. Figure 4-40 is overall layout of FSS for both BESS model s ST2236UX and ST2236UX. Each enclosure contains smoke detectors, water-based pipe networks, fused sprinkler heads, and water inlets. Sungrow has provide d a hydraulic calculations report based on system require ment. DNV notes that it has not independently verified these calculations, but views water-based suppression systems favorably. 4. 6. 3. 4 Explosion protection The Sungrow BESS has a combustible gas detection system and a ventilation exhaust system included in the ST2236UX and ST2236UX models. DNV finds the use of gas detection as a detective device to safeguard against failure modes associated with off gassing (e. g. thermal runaway) favourably. The gases that can be detect ed by the gas detection system,

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 56 www. dnv. com CO and H 2, are the most prevalent flammable/explosive off gasses from the battery cells. As such, DNV finds that the gas detection system selected is suitable for the batteries leveraged. In addition to combustible gas detection, the ventilation exhaust system consists of air inlets and exhaust fan windows. I n the event of flammable gases released from the LFP batteries, the ventilation exhaust syste m can reduce the explosion hazard by removing the flammable gases from air outlets as shown in Figure 4-40. DNV views the use of ventilation system favourably. However, DNV has not reviewed CFD simulations nor calculations to veri fy that the ventilation system is adequately sized and in line with NFPA 69. 4. 6. 4 Hazard mitigation analysis (HMA) The hazard mitigation analysis (HMA) is an industry best practice that is established by chapter 4 of NFPA 855. NFPA 855 is the Standard for the Installation of Stationary Energy Storage Systems, which DNV views as the most comprehensive set of best practice guide in the industry. The HMA is also a requirement by many fire codes across the United States. For example, California, Arizona and New Yo rk all require HMA for stationary energy storage systems. The FMEA is a tool to evaluate the critical safety components and circuits of the Sungrow's BESS by identifying the potential failure modes and their potential causes, consequences, and recommended mitigations to r educe the risk. DNV has reviewed the FMEA provided by the Sungrow, which consider the following major functions: Power failure communicatio n, dc main circuit and FSS. DNV notes that Sungrow has two different modules, ST2236UX and ST2752UX, hence request product specific HMA. 4. 6. 5 Emergency response plan Emergency response planning is a crucial aspect in BESS project safety. Emergency response planning is the guidance and training that is provided to facility and first responder personnel, which accounts for the existing safety features of the B ESS. The co mbination of system safety features and proper guidance and training provides for the safe operation and response during an emergency or safety event associated with the BESS. Enhanced first responder training and guidance is required to enter the closing stages of a safety event. DNV has reviewed the ERP document provided by the Sungrow and has found it to be a comprehensive document that outline the following: Product overview Lithium-ion battery emergency response First Aid Measures Contact Information Sungrow described lithium-ion battery emergency response such as handling met hod o f hazard related to hot cells, handling method of vented electrolyte, handling method of batteries explosion and handling method of fire invol ving lithium batteri es. DNV finds the lithium-ion battery emergenc y overview to be extensive and views guidance provided by Sungrow favorably. In addition, first aid measures which covers contact with electrolyte and inhalation of harmful gases provide initial safeguard to the person who are working on-site or responding to the BESS event. DNV notes that the ERP should consist of BESS specific hazards and response plans to those specific hazards. The HMA developed for the project should be used as a guide for the relevant hazards associated with the BESS and the project. DNV strongly advises to include the BESS specific hazards for the projects in the ERP. Typically, the ERP should be effective from the start of co mmissioning and the end of decommissioning periods. DNV finds the ERP to be generic and will require site-specific updates on a project-by-project basis, which is in line with expectations.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 57 www. dnv. com 5 POWER CONVERSION SYSTEM REVIEW DNV notes that Sungrow also manufactures its own solar PV and BESS inverte rs which may be combined with the ESS depending on Sungrow's customers' needs. DNV is of the opinion that combining a Sungrow ESS with a Sungrow PCS may result in product integratio n and customer support efficiencies given that both major pieces of equipment are supplied from the same entity. 5. 1 DC/DC converter A dc-dc converter is included as part of the ST2752UX-US product, the system uses a dc/dc converter to aid with voltage balancing, and battery augmentation tasks. The dc-dc converter used with the product is the SD175HV converter. Figure 5-1 DC-DC Converter, SD175HV Figure 5-1 shows the dc-dc converter by Sunrun used in the ST2752UX-US product. The product has a max efficiency of 99%, and is capable of operating up to 45 °C without derating with just the forced air cooling system. The device is bidirectional and compatible with a 1500V battery system. It accepts input voltage between 500-1500V, and is capable of matching different batte ries within the range. Figure 5-2, shows the system circuit d iagram for the dc-dc converter.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 58 www. dnv. com Figure 5-2 DC-DC converter circuit diagram, SD175HV Figure 5-3 shows the specification sheet for the dc-dc converter. DNV notes that the system has a IP65 rating, certifying it for outdoor application. The system is also capable of operating in an ambient temperature range between-30 to 60°C, with the power being derated above 45°C. The system also possesses Bluetooth, along with RS485/Ethernet/CAN communication abilities. DNV views the several forms of communication connectivity favourably as the system will be capable of suppor ting multiple co nnection mediums to connect to different equipment, and likely increase system uptime as there are communication redundan cy. The Bluetooth and App connectivity also means that the system can be monitored remotely to ensure seamless operation. The power rating of a sin gle rack of modules on the ST2752UX-US is around 172 k W. The nominal power rating of the dc-dc converter for each rack is 175k W. DNV notes that while the power rating of the converter is within the rack level specification at nominal operation, higher temperature derating may cause the dc-dc converter to fall ou tside operation specification unless the rack level power output is also appropriately derated. Figure 5-3 DC-DC converter, SD175HV, Specification Sheet

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 59 www. dnv. com 5. 1. 1 Temperature and altitude derating Excessive internal temperature shortens the service life of electronic devices. The SD 175HV dc-dc converter derates its output power for high ambient temperature conditions in preserve device life and ensure safe operation. Figure 5-4 Temperature Derating Figure 5-4 shows the temperature derating curve of the dc-dc converter. Under all operating condition, the device ceases operation below-30 °C and above 60°C. Within its operating temperature, DNV notes that the device prefers high battery voltage and bu s voltage, as it is capable of optimal power output of 175 k W up to a temperature of 45°C. As the battery voltage or bus voltage drop below the ideal range, the converter power output begins to drop. Arou nd a battery voltage of 870V and bus voltage between 1250-1500V, the device begins to experience derating at 40 °C, and can only output a power of 121 k W. Based on the data, DNV notes that the dc-dc converter is most impacted by the battery voltage levels, and prefers high battery voltages around 1000 V to 1250V, it also prefers to have the bus voltage around 1150V to 1400V. At these le vels the power output i s at its highest, and it is able to maintain it for a higher temperature condition. At high altitudes, the air density is lo w and the atmospher ic pressure is reduced. The cooling ability of electrical equipment is affected as the ability o f the air to remove the heat from the device is reduced. More air is required to achieve the same level of temperature reduction under the same operating condition. Therefore equipment is derated to reflect the different atmospheric condition and thermal p erformance. Figure 5-5 shows the impact of altitude on power derating. DNV notes that the equipment is derated above 3000 m, and considered outside its operating range at 4000 m. DNV considers the altitude ranges and performance to be in line with industry standard performance.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 60 www. dnv. com Figure 5-5 Altitude dependent power derating 5. 1. 2 Efficiency Curve The efficiency curve and performance of the dc-dc converter is provided below. DNV notes that the data is provided directly by Sungrow and has not been independently verified by DNV. Table 5-1 shows the discharge curve of the dc-dc converter. The data is graphed in Figure 5-6. DNV not es that the dc-dc converter achieves its highest level of efficiency around a battery voltage of 1200 V, with the battery discharge level around 20 to 40%. The converter achieves higher efficiency at higher b attery voltages, and at discharge levels around 20% to 50%. When the b attery voltage is around 1100 V, the efficiency of the converter is at its lowest, especially around the 100% level of discharge. Table 5-1 Discharge (DC BUS 1360 V) Table

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 61 www. dnv. com Figure 5-6 Discharge Efficiency Curve Similarly, Table 5-2 shows the charging efficiency data for the dc-dc converter, which is then graphed in Figure 5-7. Based on the data DNV notes that the highest level of efficiency is obtained when the dc-dc converter is at a 1200 V battery voltage, and charging around 20 to 50%, whereas the lowest efficie ncy performance is when the operating b attery voltage is 1100 V and the charging level is around 100%. This demonstrates the converter efficiency drops near high charge levels and low operating b attery voltages. Table 5-2 Charge (DC Bus 1360 V) Table

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 62 www. dnv. com Figure 5-7 Charge Efficiency Curve 6 INSTALLATION AND INTEGRATED SYSTEM EVALUATION This section provides an overview of the installation requirements for the Sungrow ST2236UX-US and ST2752UX-US liquid cooling BESS products. As part of this review DNV reviewed the following documents: Wiring Installation Guide for ST2752UX-US Power Titan-ST2236UX-US Battery Energy Storage System Manual [18] ST2752UX/ST2752UX-US Power Titan System Manual [19] Liquid Cooling ESS Storage Guide The system manual [18] and [19] both include the safety requirements and guidelines, a descrip tion of the product, product storage and transportation manual, mechanical installation instruction, electrical connection instruction and maintenance manual. The system manual for Power Titan-ST2236UX-US [18] also includes a section for fire suppression while system manual for Power Titan ST2752UX/ ST2752UX-US includes instruction for disconnecting system, and troubleshooting. The summary presented here follows the basic structure and order of the various instructions, ranging from site design through to operation. 6. 1 On-site system integration Power Titan is a modular BESS system that is mainly used in large and medium-sized energy storage power plants. A schematic of Power Titan container is provided in Figure 6-1 below:

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 63 www. dnv. com Figure 6-1 Power Titan container The Power Titan system on-site installation include s the following step s: Delivery inspection Lifting, unpacking, and f ixing the cabinet s Electrical connection 6. 1. 1 Delivery inspection Sungrow's requests the following inspect ions upon delivery and before installation: Verifying the deliverable s against the attached packing list and assure that the package is complete. Verifying the received container specification and assure that it is the ordered product. Verifying that the BESS and the internal equipment have no damag e or deterioration. DNV recommend s including a detailed list of equipment and verification criteria for BESS to ensure that all devices are intact before installation. 6. 1. 2 Lifting, unpacking, and fixing the cabinet s DNV reviewed t he procedure for l ifting, unpacking, and fixing for ST2236UX-US in Section 4. 4 of [18] and procedures for ST2752UX-US provided in Section s 5. 3, 5. 5 and 5. 7 of [19]. DNV finds that the procedure s for both are quite similar, but the documentation for ST2236UX-US is more compact. A summary of key requirements for lifting the BESS is stated below: The BESS should be lifted vertically, and container shall not be dragged on the ground or on the top of the lower container, and it should not be pulled or push ed on any surface. The BESS should be lifted slowly and during lifting, the center of the hanger and the center of the BESS top is exactly right In practice, try to minimize the deviation of the two centers, and ensure that the hanger and the BESS top is parallel through visual inspection to ensure the stability of the lifting. The crane should move at a very slow speed during lifting and it should be at a constant speed.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 64 www. dnv. com The BESS should be placed lightly and smoothly and on a vertical landing place. The BESS should be placed on a solid and flat site with good drainage and no obstacles or protrusions. For ST2752UX-US, the length of the sling rope connected to the top of the cabinet should be greater than 8 m, and a single sling rope can bear a load of more than 25,000 kg. After placing the BESS, to unpack the package first the fastening bolts at the bottom of the cabinet and the transport box and on the top of the cabinet and the transport box should be removed and then the cabinet should be lifted out of the shipping box. After unpacking, the bottom and front of the battery containers should be fi ed using the Sungrow's fi ing procedure which depends on the cabinets depends on the BESS container s distances and their configurations, e. g. back-to-back or back-to front. DNV finds th at the manuals provide required safety precautions, list of required tools and sufficient details and graphics to ease the site integration. 6. 1. 3 Electrical connection The electrical connection instruction for Power Titan ST2236U /ST2236UX-US includes a brief preparation guideline, ground connection, DC output port connection, auxiliary power supply port connection and post-wiring operations. DNV notes that section s 6. 7 and 6. 8 of [19] only include an overview or schematics and do not include any description. DNV recommends providing details to these sections or providing a reference to “Wiring Installation uide” document. DNV notes that the grounding connection requirements for of ST2236U / ST2236UX-US and ST2752UX / ST2752UX-US are also provided in a separate document in [20] and [21], respectively. DNV finds the provided step by step guideline, descriptions, listing of applicable tools and PPE to be in line with expectations. 6. 2 System space requirements To ensure better heat dissipation at the air outlet, reserve enough space around the installation site. The minimum spacing requirements for installing one ST2236UX-US and ST2752UX-US are given in (a) (b) Figure 6-2 Space requirements for i nstalling ST2236UX-US: (a) single device (b) multiple device s

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 65 www. dnv. com (a) (b) Figure 6-3 Space requirements for i nstalling a single ST2752UX-US: (a) single device (b) multiple device 6. 3 Site requirements To install the system t he climate environment and geological conditions, such as stress wave emission and underground water level should be considere d. Sungrow provided environmental requirements as well as foundation requirement for installation site. Environmental requirement s are summarized as follows The installation site should be dry and well ventilated. No trees should be around the installation site to prevent branches or leaves blown off by heavy winds from blocking the door or air inlet. The installation site should be away from areas where toxic and harmful gases are concentrated, and free from inflammable, explosive and corrosive materials. The installation site should be far away from residential areas to avoid noises. The foundation of the BESS must be designed and constructed according to certain standards to meet the requirements of mechanical support, cable routing, and site maintenance and overhaul. DNV notes that the foundation requirements for ST2236UX-US and ST2752UX-US are quite similar. A summary of key requirements is presented below: The soil at the installation site should be compact and the bottom of foundation should be firm enough. The foundation pit should provide sufficient and effective support for the system. The foundation should be r aised to prevent the container base and the interior from rain erosion. The cross-sectional area and height of the foundation should meet the requirements. A corresponding drainage in conjunction with local geological conditions should be c onstruct ed. The foundation should have sufficient cross-sectional area and height. The foundation height is determined by the construction party according to the site geology. The foundation shall consider the cable routing. A maintenance platform should be built around the foundation to facilitate future site maintenance. Enough space should be reserved for the AC/DC side cable trench according to the position and size of the cable inlet and outlet holes of the BESS and pre-embed the cable conduit. 6. 4 Functional manuals 6. 4. 1 User manual DNV requests to review user manual when it 's available.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 66 www. dnv. com 6. 4. 2 Transportation and storage All devices in the BESS have been installed and fixed before leaving the factory, and they can be hoisted and transported as a whole during transportation. The following conditions should be considered during transportation All cabinet doors should be locked. Appropriate crane or lifting tool according to the site conditions should be selected. The lifting tool shall have a sufficient load bearing capacity, boom length and radius of rotation. It is recommended to use two cranes when hoisting the BESS. All obstacles that exist or may exist on the way, such as tree branches, cables, etc. must be removed. The BESS should be transported and moved under good weather conditions. Warning signs or warning area should be set to prevent non-staff from entering the lifting area to avoid accidents. Additional traction may be required if BESS needs to be transported on slopes. The following requirements apply to ST2236UX-US: During shipping, the BESS must be placed in the transportation frame to avoid excessive tilt of the BESS. If transportation frame is not provided during land transportation, the lifting ring on the top of the BESS shall be secured to the hangers on the base via ropes, and then the hanger on the bottom to the transportation vehicle shall be fixed to avoid excessive tilt during transportation. Power Titan could be stored up to a maximum of duration of 12 months. Sungrow require s to keep the BESS system SOC in range of 40% to 60% as the self-discharge would cause SOC decay as shown the Table 6-1 Table 6-1 Self-discharge rate Temperature ranges Self-discharge [%] / month -30°C ~ 0°C 3% / Month 1°C ~ 25°C 4% / Month 26°C ~ 35°C 5% / Month 36°C ~ 45°C 8% / Month If the system is not commissioned but an external power source is available, then the cooling system can operate and keep the temperature in range of-30°C~ 25°C to maintain the battery capa city. However, if the system is commissioned, Sungrow, request to power off the site by opening the AC and DC connec tion as well as the DC switch in DC/DC converter. The capacity retention data for storage systems with CATL, BYD and REPT and under different storage temperature are provided in detail in [22]. According to [22], the capacity of the system with CATL would remain at 100% if stor age temperature is in the range of-30°C to 25 °C. 6. 4. 3 Maintenance The Power Titan can be installed outdoor, and t he regular maintenance can help to increase s ystem life and performance. Sungrow provide s a reference maintenance scheduling for Power Titan and its component s, but it notes that these scheduled should be adjusted depending on the site specific environmenta l and operation condition. The regular maintenances for Power Titan are summarized as follow:

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 67 www. dnv. com Biennial maintenance : BESS system and battery cluster status and cleaning, warning labels and marks, shield ground wires and cabling, lightning proof device s and fuses, container corrosion Annual maintenance: container exterior, power box, air inlet/outlet, cable connection and routing, grounding and equipotential connections, fan s, DC/DC cable entr y Semi-annual maintenance: safety system check, battery cluster f unction check, switch and contactor s liquid system water pump and water system check, BESS electrical connection 6. 4. 4 Commissioning DNV requests to review commissioning manual when it's available.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 68 www. dnv. com 7 MANUFACTURING AND QUALITY EVALUATION 7. 1 Quality evaluation Sungrow provided following quality control documents to DNV for review: Energy Storage System FAT Report Sungrow power supply quality and hazardous substance process management manual [23] Quality Management System-Quality Management center presentation [24] Sungrow's quality management manual [23] includes the quality management system and process for leadership, policies, planning, resources, operation, performance evaluation and improvement s. Figure 7-1 and Figure 7-2 indicate Sungrow's quality management system model and process : Figure 7-1 S ' quality management system model

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 69 www. dnv. com Figure 7-2 Quality management processes and relationship Sungrow's Quality Management System -Quality Management center [24] presents the company's quality tools, quality management team, quality management center, life cycle quality management system and q uality innovation and activities. The l ife cycle quality management covers four main parts: R&D process describes Sungrow's R&D investment and achievement, Integrated Product Development (IPD) process, capability accreditation and testing capacity Supply chain quality management including list of Sungrow 's partners, management methodology, performance evaluation, coaching, sub-supplier management, engineering change management, component's reliability management system. Production process quality management covers Sungrow's production capacity, Manufactur ing Execution System (MES ), barcode traceability system, and workshop s. Customer services including pre-sale/sale service, after-sale service and p roblem-solving process. DNV also reviewed Sungrow's certificates for quality management (ISO 9001), occupational health and safety management (ISO 45001), environmental management (ISO 14001), hazardous substance process management (IECQ HSPM ). A copy of these certificates shown in Figure 7-3 to Figure 7-5.

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf

DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 70 www. dnv. com Figure 7-3 ' O 9 Figure 7-4 ' O v

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 71 www. dnv. com Figure 7-5 ' O 45001 certification for occupational health and safety management system Figure 7-6 ' azardous substance process management

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 72 www. dnv. com DNV also reviewed a copy of CMMi level 3 certification for process level improvement training and appraisal program and SA 8000:2014 for develop ing, maintain ing and apply ing socially acceptable practices in the workplace. These qualifications ensure a process which reduces safety risk, for both employees and the e nvironment. These certifications also lay the groundwork for efficiency in production and for ensuring high and consistent quality of the final product. DNV notes that the quality certifications and associated documentation meet industry best practices. 7. 2 Manufacturing evaluation DNV will update this section after it has performed a visit of Sungrow's BESS integration facility.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 73 www. dnv. com 8 SERVICE INFRASTRUCTURE EVALUATION 8. 1 Service organization overview Sungrow, as a company, leverages a vast service organization that provides services in the following regions: China, Europe, Asia/Pacific, India / Middle East / North Africa and the Americas. This includes over 320 staff in over 30 countries with over 80 p rofessional service partners around the globe [25]. Within the U. S., Sungrow hosts field service engineers in various locations and service partners who cover many regions, as shown in Figure 8-1 [26]. It also maintains a service center located in Phoenix, Arizona which houses spare parts and provides training to staff. Figure 8-1 Sungrow service organization chart, North America Sungrow's technical support services are available 24 hours a day, days a week. Once a service call is registered in Sungrow's customer relationship management (C M) tool, Sungrow's support team contacts the customer. Sungrow then initiates an exchange, as appropriate, per the warranty or sends a field engineer to the project site for more support in ord er to resolve the problem. DNV requests more information about the suppo rt infrastructure. Does Sungrow use a tier-based system to record service calls? If so, how many tiers are there and what is the typical response time for each tier including typical response strategy? Sungrow provides preventative maintenance for warran ty compliance and to ensure that equipment is operating as effectively and efficiently as possible. For battery equipment, Sungrow checks battery system and performs charging and discharging processes. DNV requests more information about maintenance tasks offered by Sungrow for its liquid cooling product including service intervals for those tasks. Sungrow's service infrastructure also includes the following services: Spare parts management according to the following plans:

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 74 www. dnv. com o Managed inventory: Sungrow offers this service for customers who have high uptime requirements or want to ensure spare parts availability but do not want to establish a storage facility for spare parts. Sungrow and its partners store and manage c ustomer-owned spares within this plan with multiple locations available for parts storage. o Consignment inventory: Sungrow manages the spares at a customer's location. Sungrow will adjust the inventory as necessary based on observed failure rates. o Standard inventory: Sungrow manages the spares in ce ntral or regional warehouses and ship s spare parts to project site within 24 to 48 hrs after notification. Remote monitoring o Sungrow provide s remote monitoring service and automatically dispatch es field service engineers for failed equipment. Performance monitoring o Sungrow provide s monitoring service and performance analysis of the site. Sungrow can provide detailed report of potential issues that could cause problems in the future. Capacity testing o Annual visits to test and verify the real capacity of the batteries. Availability guarantee o Depending on the size and location of the project, Sungrow can provide availability guarantee programs that can fit to each customer requirements. DNV looks favorably on the types of services offered by Su ngrow and finds them to be align with expectations. 8. 2 Warranty review DNV has reviewed Sungrow Manufacturer's limited warranty [27] including "Preventative Maintenance Services" and "Capacity Performance" for LFP products for a p eriod of five (5) years. The warrant y covers the cost to repair or replace any defect(s) in the design, engineering, materials, manufacturing, production, workmanship or assembly of the Product or Product Components that does not conform to the Product Spe cifications during “ warranty period”. The warrant y covers the cost to repair or replace of any defect(s) in the design, engineering, materials, manufacturing, production, workmanship or assembly of the Product or Product Components that does not conform to the Product Specifications. The Warranty Period w ith respect to any repaired or replaced Product Component will be extended for the longer of twelve months from the date of completion of the repair or replacement provided or the remainder of the original Warranty Period. However, if a Product Component i s replaced by authorized technician after the expiration of the Warranty eriod and at owner's e pense, an e tended Warranty eriod for such replaced component(s) will be in effect for a period of twelve months from the date of repair. The Warranty does no t cover defects arises from normal wear and tear in the operation of the Product, cosmetic defects after product acceptance, vandalism, force majeure, air pollution, sea wind and sulfur corrosion, or smoke or other pollutant s present in excessive quantitie s. The warranty is void in the cases of o peration and maintenance of the Product in any manner other than specified in the Product Specification, Product User Manual, Preventative Maintenance Plan, or safety regulations applicable in the country in which t he Product is being operated. Furthermore, the warranty does not cover defects due to changes made by the Owner without Supplier's consent to the “Product Specifications of the Products or Product Components ”, removal/installation/repair/replacement or dis assembly of the Product or any Product Component s by any person not authorized by Sungrow. Furthermore, Bank Product warranty will terminate under abnormal environment condition s such as condensation with the BESS due to humidity, water, excessive dust, or pollutants enter s the BESS.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 75 www. dnv. com DNV finds the above warrantee terms common within industry. The Bank Product component warrantee wil l void if any batter y rack remains at 0% SOC for more than 120 hours or any cell voltage sustains below 2. 7 volt for more than 120 hours or any cell voltage reaches 2. 5 volt and trigger ing battery protection system or product operates in high SOC. DNV notes that the definition for high SOC is not specified in the warrantee document. DNV request s specif ication on high SOC range that voids the B ank Product Component warranty. DNV finds the Bank component warrantee terms more stringent as compared to industry standard. DNV finds this a risk in full operation of the system and recommends configuring BMS parameters attentively to reduce the risk of operation in end of operational range. 8. 2. 1 Performance guarantee Sungrow offers Capacity Performance Guarantee (CPG) during warranty period if owner agrees. PMP allows Sungrow monitor the product and reduces the risk of early failure or degradation. Owner can purchase Preventative Maintenance service from supplier or perform mainten ance service as per supplier specifications upon supplier approval. Failure to allow supplier to perform maintenance for more than sixty days after the start of new Project Year will void the CPG warranty. In case owner fails to perform main tenance service correctly supplier issue a written warning, however CPG warranty will termina te if the deficient in maintenance service persists after second warning. DNV reviewed the guaranteed energy performance for one of Sungrow's project, which Sungrow guaranteed energy capacity of 83. 31% at the end of year fifteen (15) and it had total capacity augmentation of 12. 83% within 10 and 14 months of initial installation. 8. 2. 2 Long term services agreement (LTSA) DNV request s to review Long Term Services Agreement (LTSA) document.

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DNV Document No. : 10330655-HOU-R-01, Issue: B, Status: Initial Release Page 76 www. dnv. com 9 REFERENCES [1] Sungrow, "PT_20210819_SUNGROW PV Inverter & ESS Intro_V6. 1," 2021. [2] Sungrow, "Case," Sungrow, 2022. [Online]. Available: https://en. sungrowpower. com/case Home. [Accessed March 2022]. [3] Huaxia D&B China, "Business Information Report-2020, Sungrow Power Supply Co., Ltd.," 10 June 2021. [4] Sungrow, "Overall Product Ro admap 202108," 2021. [5] PR Newswire, "Sungrow Supplies a 100 MW Energy Storage Project in Texas," 22 January 2021. [Online]. Available: https://www. prnewswire. com/news-releases/sungrow-supplies-a-100-mw-energy-storage-project-in-texas-301213083. html. [A ccessed February 2022]. [6] Sungrow, "Sungrow Liquid Cooling ESS," Sungrow, 2021. [7] CATL, "The No. 1 Li-ion EV battery Manufacturer-Introducton of Contemporary Amperex Technology Co., Limited," 2018. [8] [Online]. Available: https://qz. com/1585662/how-catl-became-the-worlds-biggest-electric-car-battery-company/. [9] ""Achievement CATL"". www. catlbattery. com. [10] DNV, "CATL 280Ah Cell Technology Review," DNV, 2022. [11] DNV, "REPT 280 Ah Battery cell Technology Review," DNV, 2021. [12] CSA Group, "CATL cell level test report-UL 9540A: Third Edition," 2020. [13] TUV Rheinland, "REPT cell level test report-UL 9540A: 2019 (Fourth Edition)," 2021. [14] TUV Rheinland, "CATL module level test repo rt-UL 9540A: 2019 (Fourth Edition)," 2021. [15] TUV Rheinland, "REPT Module level test report-UL 9540A Fourth edition," 2022. [16] TUV Rheinland, "CATL unit level test report-UL 9540A: 2019 (Fourth Edition)," 2021. [17] TUV Rheinland, "REPT Unit level test report : UL 9540A Fourth edition," 2022. [18] "Power Titan-ST2236UX-US Battery Energy Storage System System Manual," 2022. [19] "ST2752UX/ST2752UX-US Power Titan System Manual," 2019. [20] "Liquid cooling ESS(1C)-Grounding," 2021. [21] "Liquid Cooling ESS (0. 5C)-Grounding," 2021. [22] "Sungrow: Liquid Cooling ESS Storage Guide," 2021. [23] "Sungrow Power Supply Co., Ltd. Quality and Hazardous Substance Process Management Manual," 2021. [24] "Quality Management System-Quality Management center," 2021. [25] Sungrow, "Organization Chart of Customer Service Center," 10 November 2021. [26] Sungrow, "Service Presentation-March 2021 REV 2," March 2021. [27] "M NU CTU E 'S LIMITED W NTY," 2021. [28]

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About DNV We are the independent expert in assurance and risk management. Driven by our purpose, to safeguard life, property and the environment, we empower our customers and their stakeholders with facts and reliable insights so that critical decisions can be made with confidence. s a trusted voice for many of the world's most successful organizations, we use our knowledge to advance safety and performance, set industry benchmarks, and inspire and invent solutions to tackle global transformations

10330655-HOU-R-01-B Sungrow Liquid Cooling BESS Technology Review.pdf