Is SSS a supplier qualification or a resource qualification?

Standard Supply Service (SSS) under the proposed GHG Protocol Scope 2 revisions (as of the public consultation draft, October 2024) is fundamentally a resource qualification, but it is contingent on the supplier's regulatory framework and the specific procurement and cost recovery mechanisms in place. SSS applies to electricity resources (e.g., generation from nuclear, hydro, or renewables) that are procured through traceable, mandatory financial relationships between consumers and the resource—typically via non-bypassable, regulated cost recovery in monopoly or publicly obligated supplier contexts. This ensures an equitable, pro-rata allocation of low- or zero-emission attributes in market-based Scope 2 reporting, without allowing resale or overclaiming.

It is not a blanket "supplier qualification" (e.g., any resource from a municipal utility automatically qualifies) nor solely a "resource qualification" independent of context (e.g., all nuclear generation qualifies regardless of ownership). Instead, eligibility hinges on demonstrating that the resource's costs are mandatorily recovered from customers who cannot opt out, creating a direct link that prevents voluntary market dynamics from influencing claims.

Example: Differential SSS Qualification for the South Texas Project (STP) Nuclear Plant

The STP, a 2,645 MW nuclear facility in ERCOT, illustrates this nuance with its ownership split: Constellation Energy (44%), CPS Energy (40%, City of San Antonio), and Austin Energy (16%, City of Austin).

• SSS-Eligible Portions (CPS Energy and Austin Energy): These municipal utilities operate as government-owned monopolies in their service territories, where customers have no retail choice and pay bundled rates that include STP costs via regulated, non-bypassable mechanisms. This establishes a mandatory financial tie, qualifying their 56% combined STP share as SSS. Customers can claim pro-rata zero-emission nuclear attributes (e.g., a customer with 1% of CPS's load claims 1% of CPS's 40% STP stake), aligned with Scope 2 Quality Criteria, such as hourly matching and deliverability. Attributes cannot be resold, ensuring no double-counting.

• Non-SSS Portion (Constellation Energy): As a competitive generator in ERCOT's deregulated market, Constellation's 44% share lacks a non-bypassable recovery mechanism—power is sold via voluntary contracts or wholesale agreements, and customers can switch providers. Although the resource is identical (nuclear), it does not qualify as SSS here; attributes must be conveyed through explicit contractual instruments (e.g., green tariffs or bundled certificates) that meet the full Quality Criteria. Without such conveyance, customers default to residual mix or fossil-based factors.

This example underscores that SSS evaluates the resource within its supplier-specific context: The same plant qualifies for SSS only where regulated monopoly structures enforce mandatory ties, as per the draft guidance's Criterion 6 and allocation rules (Public Consultation Sections 5.1.3 and 5.3.3). For Granular Registry users, verify eligibility via supplier disclosures or our platform's audit tools—contact support for STP-specific modeling or residual mix adjustments. Note: These revisions are under consultation until December 19, 2025, with potential updates in 2027; legacy clauses may apply during transition.