The Colorado Public Utilities Commission voted July 30 to allow Public Service Company of Colorado to join SPP’s Markets+ day-ahead market, with commissioners split on whether the move is a step toward or away from full RTO participation. 

Commission Chair Eric Blank and Commissioner Tom Plant voted in favor of PSCo’s participation in Markets+; Commissioner Megan Gilman was opposed. The decision is the latest step in the development of the West’s two competing day-ahead markets: Markets+ and CAISO’s Extended Day-Ahead Market (EDAM). 

And the vote might not be the final word on the matter: At least one group — Advanced Energy United — said it plans to ask the commission to reconsider its decision. 

The vote follows a commission debate July 23 on the Markets+ issue. Blank made the case for allowing PSCo to join Markets+, while the other two commissioners voiced concerns. (See Colorado Commissioners Spar Over PSCo’s Markets+ Choice.) 

During the July 30 hearing, Blank argued that joining Markets+ is a step on a “continuum” moving toward full RTO participation. 

“Whether we get to a full RTO or not, as additional market services become available along the continuum, the benefits of the market increase more toward the higher end, potentially into the hundreds of millions of dollars per year of savings,” Blank said. 

He sees benefits arising mainly from better integration of Colorado’s two balancing authorities, through steps such as optimizing dispatch and unit commitment between them. PSCo operates one of the state’s balancing authorities and the Western Area Power Administration (WAPA) runs the other. WAPA’s Rocky Mountain Region plans to join SPP’s RTO West. (See WAPA, Basin Electric Commit to SPP’s RTO West.) 

Blank previously pointed to benefits related to resource adequacy, greenhouse gas accounting and wholesale market price transparency. 

Gilman said she expects PSCo to request a waiver allowing it to sidestep a state requirement to join an RTO by Jan. 1, 2030. And with the costs of joining Markets+ projected to exceed financial benefits until after 2030, Gilman said the company will be able to use those figures as an argument against joining an RTO. 

“Instead of appearing like a rational continuum or plan to progress, this appears to in some ways work against the goal of moving to a full RTO,” she said. 

Plant said after reviewing the issue for the past week, he agreed with Blank that a day-ahead market offers benefits as an interim step toward RTO participation. He highlighted the “transparency benefits of wholesale pricing, consistency of a market structure, [and] the benefits of efficiency of joining the two BAs.” 

PSCo Pleased

PSCo, an Xcel Energy subsidiary, filed its request to join Markets+ in February. (See PSCo Seeks to Join SPP’s Markets+.) 

The commission on July 30 also approved the company’s request to recover Markets+ associated costs through the electric commodity adjustment tariff. 

Xcel Energy spokesperson Michelle Aguayo said the company was pleased with the decision. 

“This milestone follows years of working with [SPP], other utilities throughout the West and interested stakeholders to build a market that provides for the efficient dispatch and commitment of our resources, helping integrate larger amounts of renewable energy to our fleet, and improve efficiency and reliability while reducing customer costs,” Aguayo said in an email to RTO Insider. 

The company plans to execute agreements to help fund and implement Markets+ “shortly” and join the market in 2027. SPP has set a deadline of Sept. 1, 2025, for balancing authorities to join Markets+ in time to participate when it goes live Oct. 1, 2027. 

Hurdles Ahead?

Others were disappointed by the commission’s vote. 

“Joining a smaller, more balkanized market undermines the very affordability and reliability of clean energy resources that the region depends on, and rushing into this decision, Colorado risks hitching its wagon to the wrong horse,” Brian Turner, regulatory director at Advanced Energy United (AEU), said in a statement.  

Other Markets+ trading partners are far from Xcel’s neighbors, Turner said, and instead of delivering benefits, the participation will just create more seams. 

Turner said PSCo’s proposal was approved without the required legal analysis. AEU plans to file an application for reconsideration within 20 days of a final decision being issued.