Arizona Utilities Will Join Markets+ Energy Pool in 2027
Arizona power providers aim to exit California-led trading systems for regional energy market control.
Updated on Oct. 5, 2026 in Utilities
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Arizona utilities including APS, SRP, and Tucson Electric Power plan to join the Markets+ energy trading pool in 2027. This move shifts regional power operations away from the California-led market structure that currently serves 80% of Western utilities.
Why it matters
Utilities are seeking to escape the current governance structure of the Western Energy Imbalance Market, which is tied to California leadership. By joining the Southwest Power Pool-operated Markets+, Arizona providers aim to gain more direct control over their energy trade operations.
The Western Energy Imbalance Market currently covers 80% of utilities in the West, but Arizona utilities represent a growing coalition looking to alternative structures. The final impact on overall market share remains unresolved as major players assess their long-term trading strategies.
The players
APS
An Arizona-based utility provider planning to transition to the Markets+ energy pool.
SRP
A major utility provider in Arizona that is part of the coalition moving to Markets+.
Tucson Electric Power
An Arizona-based utility company participating in the shift to the new regional energy market.
Bonneville Power Administration
A Pacific Northwest power authority currently evaluating its participation in Western energy markets.
Lea Márquez Peterson
A commissioner overseeing the regulatory inquiry into the impact of these energy market shifts.
The details
Utilities use these energy pools to buy and sell power, balancing supply and demand to avoid waste or shortages during high-demand periods. The transition to Markets+ follows a change in California state law that now permits the Western Energy Imbalance Market to be governed by a separate entity. Arizona regulators are now requiring utilities to formally explain how these shifting market alliances will impact grid stability and operational costs.
Timeline
2014: The Western Energy Imbalance Market was launched by California Independent System Operator.
September 3, 2026: Travis Kavulla sent a formal letter to the Regional Organization for Western Energy.
October 9, 2026: Deadline for utilities to respond to Commissioner Lea Márquez Peterson.
2027: Arizona utilities plan to formally join the Markets+ energy pool.
January 1, 2028: Regional Organization for Western Energy assumes oversight of the Western Energy Imbalance Market.
Market Landscape
The regional energy market is undergoing a significant transition as Arizona providers move away from the California-led oversight model. This pivot marks a structural departure from the regulatory patterns established by the Western Energy Imbalance Market since its 2014 launch.
Operators should monitor upcoming regulatory filings from Arizona utilities to understand potential changes in power procurement costs. Keep a close watch on how the final decision of the Bonneville Power Administration shifts the regional competitive landscape for energy pricing in 2027.
The takeaway
The move to Markets+ signals a major fragmentation in how Western states coordinate grid resources, moving power management authority away from California. Keep a close watch on the official response filings due in October to gauge how these market changes will influence regional utility rates.
What happens next
Utilities must submit responses regarding the impact of the Bonneville Power Administration letter to Commissioner Lea Márquez Peterson by October 9, 2026.
Further reading
Read more about how shifts in power grid management affect regional costs in the Utilities section.
Source note: This article includes information reported by KJZZ.
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Should your local utility prioritize local energy market control over participating in larger regional pools?
