Southwest Power Pool (SPP) is moving further and further West with its RTO services, including its wholesale market, making it the first regional transmission organization to serve both coasts.

Derrick Wingfield, SPP’s manager, communications and stakeholder affairs, told NPM that the Western expansion was recently approved by the Federal Energy Regulatory Commission (FERC). Specifically, FERC’s action approved amendments to SPP’s tariff to enable interested Western utilities to join SPP’s existing RTO.

“This puts us on track to fully integrate the participating entities into the RTO, meaning they’ll participate in our transmission planning process, our day-ahead market, and our reliability coordination services, among others as part of our full portfolio of RTO services,” Wingfield said.

SPP’s planned timeline for this to go live is April 2026.

Members of the expansion include Basin Electric Power Cooperative, Colorado Springs Utilities, Deseret Power Electric Cooperative, the Municipal Energy Agency of Nebraska (MEAN), Platte River Power Authority, Tri-State Generation and Transmission Association, and the Western Area Power Administration Colorado River Storage Project, Rocky Mountain and Upper Great Plains regions.

This expansion, according to a March press release from SPP, is part of its five-year strategic plan Aspire 2026. This plan aims to fully integrate Western facilities into SPP’s existing market.

Wingfield said that SPP began looking at a Westward push for its RTO services after interest was expressed by utilities in the region.

“Several Western utilities saw potential value in participating in an RTO, and SPP worked with them – informally at first, and eventually through formal agreements – to evaluate the benefits and other impacts of RTO membership to joining utilities and SPP’s existing stakeholders,” he said.

The decision to move services West was officially made in 2020.

Wingfield said that the expansion is anticipated to cost approximately USD 40m, which was budgeted through SPP’s stakeholder process.

“That budget covers everything from establishing connectivity between SPP and member facilities to providing training on SPP’s functions and RTO expansion, and it’s expected to be quickly offset by benefits that are expected to exceed USD 49m annually,” he said, pointing to a 2020 SPP Brattle study. That study also showed that Western utilities would also receive USD 25m in adjusted production cost savings and revenue from off-system sales, while SPP’s Eastern members would benefit from USD 24m in savings from the expanded market, transmission network, and generation fleet.

Markets+

SPP also received FERC approval for its Markets+ tariff in January and is working to finalize plans to fund its development and launch.

According to Wingfield, there are eight parties that have signed the funding agreement to support Markets+ Phase II implementation. This includes Arizona Public Service (APS), Bonneville Power Administration, Chelan County PUD, Grant County PUD, Powerex, Salt River Project, Tacoma Power and Tucson Electric Power.

The signed executed funding agreements will fund Phase II development and launch of the market. Wingfield said that some entities have stated their intent to participate in the market after its launch in 2027.

When asked about the BPA signed Markets+ Phase II funding agreement, Wingfield said that the agency will fund its share of market development but so far has not decided whether to participate in the market once it launches.

“Their final decision about market participation is expected in May,” he said, adding that Markets+ is a contracted service separate from the SPP RTO. SPP’s transmission, he said, is intended to mean the transmission facilities under the RTO and not the Markets+ wholesale market.

So far, Markets+ Phase II participants are in the Pacific Northwest and Desert Southwest regions. Entities in the Mountain West have stated intent to participate, giving the market a footprint in the Western Interconnection.

ERAS

Wingfield said that SPP is developing its own Expedited Resource Addition Study (ERAS) proposal aimed to provide a policy and study to expedite generator interconnection requests required to meet resource adequacy (RA) and mitigate increasing reliability challenges.

“We anticipate presenting a recommendation to our board in early May, and assuming their approval, file with FERC in early summer,” he said.