Southwest Power Pool (SPP) will soon be the first regional transmission organization (RTO) in the U.S. to provide full services in both the Eastern and Western Interconnections of the nation’s power grid. On March 20, the Federal Energy Regulatory Commission (FERC) unanimously approved Southwest Power Pool’s amended tariff that includes provisions enabling Western members to join the RTO. The Commission’s approval paves the way for seven Western entities, all of whom are participants in SPP’s Western Energy Imbalance Service (WEIS) market today, to begin participating in SPP’s Integrated Marketplace, transmission planning, reliability coordination and other RTO services beginning in April 2026.
On June 4, 2024, SPP filed its amended tariff with FERC to accommodate requirements for Western entities pursuing RTO membership or increased participation as part of the expansion of the SPP RTO: 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.
“I am pleased to announce FERC’s approval of the amended RTO tariff,” said Barbara Sugg, SPP president and CEO. “Expanding the RTO into the Western Interconnection is an exciting step in SPP’s growth, bringing value to new and existing members while enhancing reliability in both interconnections.”
The expansion of the RTO is part of Aspire 2026, SPP’s five-year strategic plan, which details opportunities to fully integrate Western facilities into SPP’s existing market system in a way that creates meaningful, equitable value for new and existing members.
“The Western expansion of the SPP RTO bolsters reliability and resiliency for our members as we grow and diversify our resource portfolio while reducing emissions,” said Tri-State Generation and Transmission Association CEO Duane Highley. “We greatly value the full benefits of the SPP RTO, including day-ahead and ancillary services markets, efficient regional transmission planning, a common transmission tariff and participatory governance model that help us to further reduce costs for our members across the West. Prior to SPP RTO West entry, we will be making a filing with our state regulators highlighting these market benefits.”
“SPP’s RTO expansion into the Western Interconnect will help us to reduce our overall carbon footprint for MEAN’s power resources through the economic dispatch of a wholesale power market and maximizing operational efficiencies of renewable resources,” said MEAN Director of Wholesale Operations Brad Hans. “As a member of SPP’s RTO in the Eastern Interconnect for several years, MEAN recognizes the benefits of participating in that market and the energy cost savings it provides as well as SPP’s member-driven business model.”
“In 2018, when we outlined our plan to pursue a noncarbon energy portfolio, it was very clear to us that an integral component to this plan was to join a power market,” shares Jason Frisbie, CEO and general manager of Platte River Power Authority. “Over the last seven years our teams across the organization have been dedicated to this effort working closely with SPP to be ready for the moment we join the RTO, which will help us integrate more renewable energy onto our system and manage our energy costs.”
“With the complexities of today’s energy industry and the regulations that define it, an adaptable electric grid with access to both local and regional resources is essential for managing customer costs and maintaining service reliability,” said Colorado Springs Utilities Chief Executive Officer Travas Deal. “We strongly believe the SPP RTO will help us achieve this goal, while also connecting us with vital transmission resources as we pursue new and cleaner forms of electric generation. So, FERC’s approval of the amended tariff is very encouraging for us and our customers as we implement our Sustainable Energy Plan.”
SPP is working with additional Western utilities who have expressed interest in joining the RTO once this initial expansion is complete.
Separately, SPP is developing Markets+, another market designed to bring significant incremental value to the Western Interconnection. SPP received FERC’s approval of the Markets+ tariff in January, and is working with interested parties to finalize plans to fund the market’s development and launch. With the addition of Markets+, SPP will have a solid presence in the West, operating two markets and serving as the program administrator for the Western Power Pool’s Western Resource Adequacy Program (WRAP).
“Multiple markets maximize value for all participants,” said Sugg. “SPP has operated a Western market since 2021, and with the expansion of the RTO’s Integrated Marketplace in 2026 and launch of Markets+ in 2027, we’re looking forward to bringing additional affordability, reliability, equity and sustainability to the West.”
SPP first earned FERC’s approval as an RTO in October 2004, and over the last two decades has expanded its RTO footprint in the Eastern Interconnection from eight to 14 states. This expansion would grow SPP’s RTO service territory to encompass all or part of 17 states. SPP has been engaged with parties interested in evaluating the benefits and requirements of RTO membership in the Western Interconnection since Oct. 20, 2020. The SPP board of directors approved the initial RTO expansion terms and conditions in July 2021, the DC tie terms and conditions in July 2022 and the WAPA Colorado River Storage Project terms and conditions in January 2023. The expansion of the SPP RTO is scheduled to go live April 1, 2026.
