FERC accepted SPP’s tariff revisions for its Western Energy Imbalance Service (WEIS) market that allow the grid operator to begin a market hold for reliability-based concerns when requested by a balancing authority (ER25-1137).
In its June 20 order, the commission found the proposed tariff revisions to be just and reasonable and accepted them effective April 5, 2025. It said the changes will help facilitate the WEIS market’s operation by specifying that SPP will suspend the calculation of dispatch instructions for certain resources and treat them as self-dispatched if a participating BA asks for a market hold.
FERC said the changes allow the WEIS market’s relevant entities — the participating BAs, the SPP West Reliability Coordinator and SPP as the market operator — “to coordinate and timely respond to reliability-based events while avoiding significant disruptions to the operation of the WEIS market and providing clarity regarding settlements for the time period of those events.”
It noted that “importantly,” the BAs and SPP West RC “retain their NERC-mandated reliability responsibilities in the WEIS market.”
SPP’s Market Monitoring Unit protested the tariff revisions, saying they were not clarifying in nature. The MMU said a market hold initiated by a BA for reliability-based concerns instead is a new condition that would suspend the market dispatch.
The Monitor said that while a BA should be able to initiate the hold, a lack of detail in two key areas rendered the proposed revisions unjust and unreasonable. It argued they have neither clear guidelines for the types of reliability concerns that would trigger a market hold nor an explanation of the actions that should be taken leading up to and after the market hold. It also asserted the proposals lack transparent communication to market participants.
FERC disagreed, finding that a “reliability-based concern” is appropriate because the BAs are the entities ultimately responsible for initiating market holds in their respective areas. It noted that SPP said a market operator does not have authority to dictate what BAs can and cannot do for reliability reasons, pointing to a list of examples of reliability-based concerns that could warrant a market hold.
“These examples illustrate that there are myriad operational issues that could pose a risk to reliability,” the commission said. “We recognize a balancing authority’s responsibility to maintain reliability in the face of a wide range of potential operational issues and the necessary flexibility required to adequately do so.”
The commissioners also were “unpersuaded” by the MMU’s contention that the revisions are unjust and unreasonable because they fail to set forth an expectation that the BAs will exhaust alternative solutions before implementing a market hold. FERC found that the tariff doesn’t need to “set forth such an expectation in order to be just and reasonable because the tariff does not govern balancing authorities’ responsibilities to ensure reliability.” Those responsibilities are governed by the applicable reliability standards, it said.
SPP has administered the WEIS market on a contract basis since February 2021, balancing generation and load for 12 participants, primarily in the Rocky Mountain region. The RTO has said the market participants eventually will transition to either its Western RTO expansion or its Markets+ program. (See SPP to Phase Out WEIS as New Market Offerings Expand.)
