From Plant Design to Field Operations - Optimizing Key Component Selection and Reliability - TerraForm - Carmen Morilla

Penang, October 23 rd , 2018 From Plant Design to Field Operations Optimizing Key Component Selection and Reliability2 Robust Technology Selection Greenfield Equipment Selection Construction Phase Procurement And Material Reception Commissioning Process Operational Assets EPC Warranty Period PV Module Product Warranty PV Module Performance Warranty ▪ PV Modules and associated performance risks are key in investment decision for both new and operational assets ▪ Technology provider relationship, standing in industry and prior track record are critical criteria for us ▪ For PV modules, stages of analysis areAssessing Risks Of Module Selection Technology assessment Warranty scheme Commercial Acceptance tests Bankability Manufacturing surveys Reception inspections Validation, acceptance Periodic quality checks Special purpose inspections Quality system Certifications Module performance data Operational performance and past experience will strongly influence risk assessment on new projects 4 Case Study I Spares Availability5 Case Study I Spares Availability 1/2 Issue Commercial Impact ▪ Redesign of solar field to accommodate for new electrical specifications ▪ Engineering resources to identify compatible replacement model ▪ Retrofit of structures - increase on Capex ▪ Address regulatory obligations ▪ Spares modules under EPC agreement are not sufficiently dimensioned for the entire plant lifetime ▪ Exceptional events thefts, storms, lightning strikes typically result in fast stock consumption requiring inventory replenishment ▪ Market unavailability of compatible modules may result in a significant challenge Manufacturer no longer active in the market Technology no longer available Only higher Wattage modules available Dimensions and frame design not compatible with existing structures6 Case Study I Spares Availability 2/2 What Can A Module Manufacturer Do ▪ Module manufacturer propose or identify alternative model ▪ Proactive communication to customer of roadmap and minor manufacturing changes ▪ Tools software, apps to propose redesign and validate implementation based on main drivers regulatory compliance cost reduction performance improvement7 Case Study II Data Traceability 8 Case Study II Data Traceability 1/2 Issue Example ▪ Thunderstorm with strong winds during construction phase caused modules ripped from structure ▪ Modules with actual damage are easily identified on the field i.e. scratches, broken frame/glass ▪ Potentially damaged modules or with reliability concerns hot spot, snail trails require a deep analysis ▪ Owner / operators often require detailed information from the PV modules manufacturing process ▪ Specific Data might include BOM, manufacturing dates, location or manufacturing lines and specific parameters like cure time in lamination process, quality controls carried out during manufacturing process or specific data acquired for a specific group of modules9 Case Study II Data Traceability 2/2 What Can A Manufacturer Do ▪ PV module manufacturer had a full quality system in place ▪ Serial numbers of affected and potentially affected modules were shared and manufacturing data provided ▪ Electroluminescence images of selected modules were provided by manufacturer ▪ Comparative analysis of images allowed to identify cracks induced by the force majeure event ▪ Manufacturer Acceptance Quality criteria was shared and adopted to identify modules with potential reliability concern ▪ Available information lead to compile a full documentation package which supported the EPC claim, insurance claim and ensured the validity of modules product and performance warranties10 Case Studies III, IV V Warranty Management11 Warranty Management ▪ Module performance warranty is intended to minimize performance risks over the project lifetime ▪ Minimum of 20 years on a two-steps or linear scheme are a minimum requirement ▪ Other points to evaluate Warranty documentation package ‒ Terms of warranty ‒ Warranty assignment to owner ‒ Associated purchase orders ‒ Sales purchase agreement ‒ Modules details serial number, manufacturing dates, etc. Clarity on claim submission process ‒ Single point of contact ‒ Checklist with information required to be compiled Defined criteria ‒ Thermal difference for hot spots ‒ Product defects outside product warranty period12 Case Study III Warranty Management Issue Commercial Impact Solution / Expectations ▪ Expected a RCA that would lead to a BOM or manufacturing defect ▪ Recommendations for replacement or risk mitigation ▪ Issues that would be typically covered under product warranty should be extended beyond 5 years when having a performance impact ▪ Double coverage of product and performance warranties should not be used as a gap to not honor committed warranties ▪ Replacement of glass damaged modules required to assess and initiate a warranty claim under performance warranty. ▪ Cost of replacement borne by owner in spite of acknowledgement of product defect ▪ Partial or complete glass breakage observed in several modules of a site ▪ Field analysis discarded OM or installation related causes ▪ Breakage pattern suggested thermal related event13 Case Study IV Warranty Management Issue Failed expectations ▪ Impact in plant performance is negligible given limited extent of defects ▪ It would have been expected a proper RCA with detailed assessment of defect and plan to repair / minimize impact ▪ Owner to define their own monitoring plan of defect evolution ▪ Appearance of white spots on thin film modules ▪ Evidence of hot spots leading to TCO corrosion and delamination ▪ Constitute a reliability issue with potential performance impact ▪ Weak manufacturer response with reference to expected limited impact in performance14 Case Study V Warranty Management Issue Commercial Impact What can manufacturer do ▪ Claim is honored by manufacturer ▪ Replacement modules delivered by manufacturer ▪ Reliability risks are addressed with minimal impact in plant performance ▪ Degradation of back sheet observed in a percentage of installed modules ▪ Defect represents a potential safety and reliability issue ▪ Good quality system in place with full visibility of claim tracking process ▪ RCA conducted by module manufacturer pointing out to a material issue ▪ Traceability of modules will allow to identify those that could potentially develop the same issue ▪ System provides comfort on detection of potentially affected modules is not subject to just visual inspectionConclusions Field operations provide main information to optimize key components selection and define risk mitigation measures on new projects ➢ Operational performance ➢ Quality, warranty response and after-sales support provided by manufacturer ➢ Module manufacturer alignment with owner interest ➢ Good technical support field, manufacturing and quality control data on new technologies16