This case study is a consultation draft. The EFI Foundation welcomes your feedback on the analysis. Please submit comments and suggestions here.
Integrated Product- and Entity-Level Carbon Accounting Case Study: Power Sector (September 2026) applies the EFI Foundation’s ledger-based carbon accounting framework, first described in the October 2025 report, to the electric power sector.
Electricity use is growing across transportation, buildings, manufacturing, and data centers. Electricity-related emissions contribute a substantial proportion of the carbon footprint of many industries. Credible data about product-level emissions is increasingly sought by governments, companies, and consumers to inform corporate reporting, trade policy, and decisions on procurement, investment, and consumption. Accurate accounting of electricity-related emissions is needed more than ever.
Quantifying emissions from electricity use poses a distinct accounting challenge. The grid carries power from many generators, and individual electrons cannot be traced to a specific generator, making it difficult to attribute electricity to a specific generation source or end user. Electricity is bought and sold through multiple market layers, while contractual instruments such as power purchase agreements (PPAs) and energy attribute certificates (EACs) further complicate the picture by allowing the low-carbon attributes of generation to be purchased separately from the physical electricity delivered from the grid.
The study models a simplified electricity grid based on New York Independent System Operator (NYISO) data. It compares three scenarios using the same underlying mix of natural gas, nuclear, solar, and wind generation: a reference case with no contractual instruments; a case in which renewable generation is assigned to buyers through physically directed PPAs; and a case in which carbon attributes from renewable generation are unbundled and traded through a renewable energy certificate (REC) registry. Holding the physical grid constant enables the analysis to isolate the accounting effects of different contractual arrangements.
The analysis shows that ledger-based accounting can establish an average carbon intensity for grid electricity based on the mix of generation sources. This physical carbon intensity remains the same across all three scenarios because the generation mix and associated emissions do not change. What changes is how the carbon attributes are allocated among market participants through contractual arrangements, allowing those attributes to be tracked separately without changing the underlying emissions of the grid.
The study proposes assigning each EAC a fixed carbon value at the time the electricity is generated, reflecting both the renewable generator’s supply chain emissions and the emissions avoided on the grid at that moment. Under this method, the value can be transferred and retired later without requiring the buyer’s consumption to match the certificate’s generation by time or location.
The analysis concludes that ledger-based carbon accounting can connect physical electricity flows with contractual carbon claims without gaps or double counting, providing a stronger basis for credible carbon information to support a range of business and policy decisions.
This case study is a consultative draft. The EFI Foundation welcomes your feedback on the analysis. Please submit comments and suggestions here.
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