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We recently took a look at the history and broad structure of the EPEAT ecolabel. Let’s dig into EPEAT for PV modules and inverters. First, a brief reminder of how the EPEAT system works. EPEAT contains multiple ESG criteria for each product category that is covered. Those criteria are based on standards developed in voluntary, consensus based multi-stakeholder processes involving industry stakeholders. EPEAT is a tiered system with Bronze, Silver and Gold levels of recognition depending upon company performance against the criteria. Standards contain required criteria that a manufacturer must demonstrate compliance with to earn EPEAT Bronze, as well as optional criteria that earn additional points towards EPEAT Silver and Gold. All claims by manufacturers are verified by independent third-party organizations approved by the EPEAT steward the Global Electronics Council (GEC). Claims must be re-verified annually and GEC regularly audits company claims. In addition, every three years all of the criteria in a product category are revisited to see if they need to be updated.

A multi-stakeholder committee was formed by NSF International to develop the NSF 457 global sustainability standard for PV modules and inverters. The standard was published in 2017, then modified and adopted as an ANSI standard in 2019. The standard became the basis for the required and optional ESG criteria for EPEAT for PV. As NSF describes it, “This NSF/ANSI 457 Sustainability Leadership Standard for Photovoltaic Modules and Photovoltaic Inverters has been developed as part of the ongoing efforts of a number of interested parties to document and improve the sustainability performance profile of photovoltaic modules and inverters using established and advanced scientific principles, practices, materials, and standards.” You can find the standard at by scrolling down to PV Modules and Inverters. The NSF standard covers a range of ESG criteria across the product lifecycle, including:

  • management of hazardous substances,
  • elimination of substances of concern,
  • recycled content,
  • reduction in life cycle impacts,
  • energy and water use and related management systems,
  • end of life management and design for recycling,
  • product packaging,
  • corporate responsibility to include EHS management systems, social performance, and conflict minerals,
  • corporate EHS reporting
  • labor standards including consideration of forced labor.

The GEC gathered industry, government, academia and NGO representatives in 2020 to develop detailed lifecycle carbon footprint criteria to add to the EPEAT criteria for PV modules and inverters. As the GEC expressed it “The purpose of the Ultra-Low Carbon Solar (ULCS) Criteria (herein referred to as “Criteria”) is to establish a framework, standardized methodology, and performance objectives to incentivize manufacturers and suppliers to design and manufacture low embodied carbon photovoltaic (PV) modules. For purchasers, these Criteria provide a consensus-based definition of low-embodied carbon to aid in identifying and procuring low embodied carbon PV modules. These Criteria are used within EPEATTM, a global Type 1 ecolabel that helps purchasers identify and select sustainable electronic products and provides market recognition for conforming products.”

The carbon footprint criteria cover carbon emissions from cradle to gate, i.e. from quartz mining through module production. Life cycle analyses have shown that module transportation is a quite small element of total carbon footprint. The criteria contain two levels of embodied carbon; low carbon solar, demonstration of which is required to achieve EPEAT Bronze, and a significantly lower Ultra Low Carbon Solar level that provides additional points towards EPEAT Silver and Gold. The criteria lay out two pathways for determining the carbon footprint. Either pathway can be used at each step in the crystalline silicon PV lifecycle (polysilicon production silicon ingot/wafer production, silicon cell production and module production) as well as the correlative steps in CdTe thin film PV production to arrive at a total carbon footprint for a module across its supply chain. The criteria can be adapted to other PV technologies as well.

The first and simpler pathways is a series of look-up tables with embodied carbon levels in grams of CO2 per Kilowatt peak for each value chain step calculated for a variety of geographies using conservative assumptions and International Energy Agency PV Task 12 Life Cycle Inventory data. Manufacturers would have to demonstrate with documentation such as purchase orders and delivery receipts the sources and details of their various components (e.g. polysilicon from Germany, ingot and wafer from Norway, cell with so many grams silicon and module assembly in the US) and then would simply add the relevant values from the tables. The carbon footprint associated with energy inputs are derived from published values for national level grid carbon intensity contained in the IEA PV Task 12 Lifecycle Inventory and ecoinvent 3.8 commercial life cycle inventory database and are contained within the criteria.

Manufacturers can also use Path B for any given value chain step if they believe the added effort would demonstrate carbon footprint levels sufficiently lower than would be derived from the lookup tables to justify the cost of the detailed life cycle analyses and additional reviews required. In this case details about manufacturing operations and energy use are detailed in a site-specific life cycle analysis performed according to the requirements laid out in the criteria. The carbon intensity of input energy can reflect regional, rather than national, level grids where such data is contained in the IEA PV Task 12 Lifecycle Inventory and ecoinvent 3.8 database and listed in the criteria. On-site generated and consumed renewable energy is accounted for as it reduces the amount of grid energy consumed, and up to 25% of energy consumption across the supply chain can be attributed to clean energy purchased through market mechanisms such as via a power purchase agreement (PPA) where it can be demonstrated that any clean energy attributes (e.g. RECs) meet the requirements of the RE100 Credibility Claims and have been retired. Companies must also demonstrate that renewable energy use has been properly allocated across manufacturing operations and not just to particular production units. These renewable energy provisions are intended to encourage of the use of renewable energy to decarbonize grids and manufacturing while recognizing the varying degree of rigor and transparency in renewable energy market mechanisms globally. These renewable energy consumption provisions, like all criteria, are subject to review and revision every three years and could be expanded as the GEC accumulates experience with company claims.

For both Path A and Path B approaches detailed demonstration of the specific components of the relevant PV module are required, to include documentation such as purchase orders, shipping receipts and module production volumes, as well considerations of tare loss and breakage in manufacturing. In addition, the relevant module must be submitted to an independent laboratory for disassembly and measurement of the module components. Companies must also submit reports of independent inspections of suppliers’ manufacturing facilities performed within the previous year.

In the case of Path A the calculations must undergo review by an independent third party accredited LCA expert. In the case of Path B the calculations undergo the same review plus a review of the input energy carbon intensity calculations by an independent expert approved by GEC. Both Path A and Path B calculations then undergo an additional review by an independent third party Conformance Assurance Body approved by the GEC which reviews all claims. These CABs are located globally and include entities like TUV Rhineland.

Seeking and receiving EPEAT registration for a PV module or inverter will not be easy, nor is it intended to be; this is a leadership standard. It is intended to provide solar buyers with a transparent, rigorous and easy to apply process by which ESG and carbon footprint considerations of the life cycle of a particular PV module or inverter may be established through independent third parties following uniform processes. It is also a means by which PV buyers can signal preferences in ways that will encourage PV manufacturers to meet these standards, and in so doing raise the level of sustainability and carbon reduction in PV manufacturing and expand more localized PV manufacturing across the supply chain. It provides a tool to help ensure that current sustainability concerns in the PV lifecycle do not scale as PV itself scales.

Benefits of the use of the EPEAT ecolabel for PV for buyers include greater transparency and traceability in your supply chain with independent third-party verification, reduction in scope 3 emissions. It will also send a market signal that will incent more sustainable low carbon PV manufacturing, thereby expanding module supply. Many buyers have been trying to incent expanded domestic manufacturing through long term offtake agreements for modules. The use of EPEAT as the standard for such module agreements has the added benefit of clearly transmitting that demand signal throughout the supply chain, not just at the module level, as low carbon inputs from polysilicon forward are required to meet the EPEAT carbon levels. And finally, the use of EPEAT for PV in specification simplifies life for buyers; no need to review multiple life cycle analyses or validate suppliers’ claims – that is done for you by EPEAT.

For PV manufacturers benefits include demonstrating that your modules provide a low carbon footprint, validated transparency and traceability in your supply chain, demonstrated sustainability leadership and enhanced customer relationships.