Market interruptions prompt Southwest Power Pool to propose real-time market execution changes

Washington — Southwest Power Pool is seeking Federal Energy Regulatory Commission sign-off of new tariff language that would bring some flexibility to the grid operator's execution of its real-time balancing market process in order to account for periodic market interruptions.

SPP's tariff currently requires the grid operator to execute the real-time balancing market for each five-minute dispatch interval. But this fails to account for planned and unplanned market interruptions that SPP may periodically face, the grid operator said in a filing (ER20-1263) with FERC.

As such, each occurrence of an interruption presented the grid operator with a potential tariff violation. To remedy this, SPP staff and stakeholders convened to devise a solution for coordinating real-time balancing market execution with market interruptions.

Proposed tariff changes filed Friday add clarifying language allowing for flexibility in SPP's execution of the market.

The proposal makes clear that SPP will "attempt to" execute the real-time balancing market every five minutes, but in the event it cannot due to a planned or unplanned interruption, the most recently approved market dispatch and pricing will carry forward until the market interruption ends or SPP is again able to clear the market.

The filing also proposes to nix a reference to system-wide failure as "a strict reading of the phrase ... does not allow SPP to continue to settle financially under the tariff when a failure is not system-wide but does result in a loss of the ability to calculate locational marginal prices."

By removing "system-wide" from the phrase at issue, SPP will be free to continue settling energy transactions in the real-time balancing market based on estimated LMPs during a market interruption until such time as SPP can execute the market again, the grid operator said.

The proposal was reviewed and approved through SPP's stakeholder process. Under that process, support for the changes was garnered among the grid operator's Market Working Group, Operating Reliability Working Group, Reliability Compliance Working Group, Regional Tariff Working Group and Markets and Operations Policy Committee.

"While SPP recognizes that stakeholder approval does not by itself cause a filing to be just and reasonable, SPP requests that the commission extend appropriate deference to the wishes of SPP's stakeholders, consistent with commission precedent," the filing said.

SPP requested a May 13 effective date for the tariff changes.