How are Attributes Allocated for Vertically Integrated Utilities Offering Green Tariffs
This FAQ addresses common questions about how clean energy attributes are allocated under the proposed GHG Protocol Scope 2 revisions (October 2025 draft) when a vertically integrated utility provides both Standard Supply Service (SSS) and a green tariff program. Note that these revisions are in public consultation until December 19, 2025, and are not yet finalized. The guidance aims to ensure fair, proportional claims for shared resources while preventing overclaiming or resource shuffling.
What is Standard Supply Service (SSS)?
SSS refers to electricity from publicly funded, mandated, or shared resources (e.g., nuclear or other clean energy assets) delivered through a utility's default service. It recognizes a traceable financial relationship, such as non-bypassable charges paid by all ratepayers. Under the proposed revisions, SSS attributes are allocated pro rata across the utility's total load to promote equitable Scope 2 accounting.
How are clean energy attributes from SSS resources allocated when a utility offers a green tariff?
SSS resources (e.g., a clean energy asset like nuclear) are allocated pro rata across the utility's total load served. Green tariff programs are typically resource-specific supplier products separate from SSS, focusing on voluntary renewable energy certificates (RECs). Green tariff customers do not automatically claim SSS attributes; their reporting relies on the procured RECs. Any unexercised SSS share remains unclaimed and cannot be transferred or reallocated, preserving consistency for SSS customers.
Example Scenario: A vertically integrated utility serves a total load of 1,000 MWh, where:
SSS (default) load is 900 MWh.
Green tariff load is 100 MWh (customers opting for 100% renewable RECs).
An SSS-designated clean energy resource (e.g., nuclear) generates 100 MWh of carbon-free energy (CFE), funded by all ratepayers via non-bypassable charges.
Under the proposed revisions:
System-Wide Pro Rata Share: (100 MWh / 1,000 MWh) = 10% CFE for all customers based on shared funding.
Green Tariff Customers: They forgo their pro rata SSS share (10 MWh) and report only using 100% renewable RECs. The unclaimed 10 MWh is ineligible for transfer or resale.
SSS Customers: They claim the remaining 90 MWh, resulting in (90 MWh / 900 MWh) = 10% CFE—maintaining the system pro rata without inflation.
SSS (Default)
900
90
10%
Residual mix including pro rata SSS clean energy CFE (10%) + any other unclaimed attributes.
Green Tariff
100
0 (unclaimed)
0%
100% from procured renewable RECs only; SSS clean energy share forgone.
This ensures all attributes are accounted for equitably, with no harm to SSS customers from unrelated green tariff choices.
Can green tariff customers claim SSS attributes?
No, under the current draft, green tariff customers prioritize their voluntary REC-based claims and do not automatically include SSS attributes in market-based Scope 2 reporting. However, if the utility redesigns the green tariff to bundle SSS claims (e.g., pro rata clean energy CFE plus incremental renewables), customers could report combined attributes—subject to regulatory approval and alignment with Scope 2 Quality Criteria.
What happens to unclaimed SSS shares from green tariff customers?
Unclaimed shares (e.g., the pro rata portion not exercised by green tariff participants) remain unallocated and ineligible for claims by others. This prevents resource shuffling, resale, or concentrated allocation, ensuring no duplicative or inflated reporting.
How does this affect SSS customers?
The pro rata share of SSS customers remains consistent at the system-wide level (e.g., 10% in the example), unaffected by green tariff changes. Their claims are based on the residual mix after excluding voluntary and unclaimed attributes, promoting fairness without fluctuation from unrelated products.
For more details on the SSS methodology in the Granular Registry platform, refer to our full documentation or contact our support team. These interpretations are based on the proposed revisions and may evolve post-consultation.
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