SPP Market Future: Lower Costs, Markets+, and RTOE Optimization

MCG Energy previously reported the coming day-ahead markets in the Western Interconnection including the Southwest Power Pool’s (SPP) initiatives, Markets+ and RTO Expansion (RTOE – formerly RTO West). Now the focus has shifted from design and planning to market system build-out and integration. As a keynote speaker at MCG Energy’s 2025 Software User Conference, on October 9, SPP Vice President of Markets Carrie Simpson spoke on these developments.

This market evolution promises tangible benefits: enhanced reliability, integration of renewables, and lower energy costs for end-users. For market participants, the time to ensure system compliance and readiness is now, before RTOE launches in 2026 and Markets+ goes live in 2027.

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Markets+ Timeline: From Proposal to FERC-Approved Reality

At MCG’s conference, Carrie Simpson recounted the history of SPP from its formation in 1941 to the rollout of the Western Energy Imbalance Service Market (WEIS) in 2021. Now Markets+ (M+) is set to be a game-changer for Western entities seeking the benefits of a day-ahead market and real-time commitment without the full obligations of RTO membership. SPP’s M+ will pave the way for a more reliable grid by providing transmission and optimizing diverse resource portfolios across the Western Interconnection.

Markets+ Timeline from 2025 to Launch:

• FERC Approval Secured: The Federal Energy Regulatory Commission (FERC) approved the Markets+ Tariff in January 2025, and followed up in April 2025 by approving the Phase Two Funding Agreement and its recovery mechanism. This regulatory certainty is the green light for full-scale development.
• Implementation is Underway: With financing secured and governance in place, SPP officially launched Phase Two – Implementation in mid-2025. This phase focuses intensely on building the necessary market systems and settlement changes, moving the initiative from paper to functional code.
• Confirmed Go-Live Date: The Markets+ service is still targeting a full market launch on October 1, 2027.
• Participant Momentum: Right now the growing list of participants that have committed to join is more than 40, including Bonneville Power Administration (BPA), Salt River Project (SRP), Tacoma Power, and Arizona Public Service (APS), solidifying Markets+’s position as a major competitor in the Western energy landscape.

Call to Action for Markets+ Participants

For potential Markets+ participants, the most pressing SPP Markets+ deadlines have been approaching rapidly:

• Balancing Authorities: September 1, 2025
• Transmission Service Providers: October 1, 2025

The next is for market participants:

• Market Participants: December 1, 2025

At MCG’s conference, Carrie Simpson said the next step will be to integrate participants into the system. To be included in the market’s October 2027 go-live, be sure to register on time. See MCG’s discussion on Markets+ system readiness to learn more and contact us for assistance.

RTO Expansion: The First Interconnection Bridge

SPP’s RTO Expansion initiative is a historic expansion creating the first RTO to span both the Eastern and Western Interconnections. Carrie Simpson described it as “one Balancing Authority with two Balancing Authority areas,” consolidating major functions (generator interconnection, transmission planning and resource adequacy) under SPP’s current tariff, resulting in “a single market solution optimized across DC ties.” This full RTO model will bring the benefits of a centralized, organized market—including the Integrated Marketplace and efficient transmission planning—to a new region.

RTOETimeline from (2025-2026):

• FERC Approval Granted: In March 2025, FERC approved the tariff revisions necessary for the RTO Expansion. This decision cements SPP’s plan to operate a single, optimized market across two separate Balancing Authority Areas by leveraging the 510 MW of bi-directional DC ties between the two interconnections.
• RTOE Go-Live Confirmed: The integration of the initial seven Western Interconnection entities into the SPP RTO is still on track for a Go-Live date of April 1, 2026. Internal and integration testing are a major focus throughout late 2025.
• Forecasting the Future: RTOE’s core benefit is its ability to access diverse resources and coordinate transmission planning across a massive footprint, ensuring greater reliability and cost savings by reducing congestion and leveraging optimal generation sources.

MCG Energy: Day One Readiness is Our Promise

For energy consumers to fully benefit from the advantages of Markets+ and RTOE, your mission-critical software must be ready.

At MCG Energy, we are leveraging our two decades of experience in the SPP Integrated Marketplace to ensure a seamless transition for our customers. We are prioritizing the future of your operations:

• MCG Energy Software Suite Readiness: We are devoting significant R&D to preparing the MCG Energy Software Suite for the launch of both RTOE in 2026 and Markets+ in 2027. Our solutions are being fine-tuned now to handle the unique day-ahead and real-time settlement, bidding, and unit commitment complexities of these new Western markets.
• Enhanced Compliance and Security: We met our goal of FedRAMP® authorization in 2025, providing an added layer of security and compliance to aid customers in making a seamless entry into emerging markets.

The future of the SPP market is being built today. Don’t wait until the last moment to ensure your systems can participate.

Contact our Sales Team today to discuss your energy market readiness and see how the MCG Energy Software Suite can help you succeed in the next chapter of the Western Interconnection.

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