Four Arizona utilities announced Monday they will join Southwest Power Pool’s day-ahead and real-time energy market, or Markets+, when it launches in 2027.
The participation of Arizona Public Service, Salt River Project, Tucson Electric Power and UniSource Energy Services will “support the addition of more renewable resources to the energy grid, as Arizona continues to experience residential and business growth and record-breaking energy demand,” they said in a joint statement.
The new market is expected to bring enhanced reliability and savings of “almost $100 million above current market participation,” the utilities said.
“Together with our neighboring utilities, APS plans to join Markets+ to efficiently deliver energy and bolster the resilience of our shared energy grid in Arizona and across the region,” Brian Cole, APS vice president of resource management, said in a statement.
SRP’s participation in Markets+ is “a key component of our plan to meet the growing energy needs of our customers reliably and affordably,” said Josh Robertson, the utility’s director of energy market strategy.
The day-ahead market is designed to expand on SPP’s Western Energy Imbalance Services market, which began operating in 2021.
SPP submitted its 600-page Markets+ tariff in March to the Federal Energy Regulatory Commission.
More than three dozen stakeholders participated in the first phase of Markets+ development, which culminated in filing the tariff with federal regulators. SPP said the second phase will begin once FERC approves the tariff, including acquiring necessary software and hardware while participating entities are integrated into the system.
SPP has been competing for market participants with California Independent System Operator’s extended day-ahead market, which is expected to begin operations in 2026. Earlier this month, Public Service Co. of New Mexico committed to joining the CAISO market.
There have been concerns raised by environmental groups about SPP’s market proposal, including how to manage the seams that would be created between the Markets+ footprint and CAISO’s pending market.
