Salt River Project’s board didn’t just approve a power plant – it approved a template. The 1,675-megawatt Marigold Energy Center in Stanfield, Arizona pairs 600 MW of solar and 400 MW of eight-hour battery storage with 675 MW of natural gas, all behind a dedicated 230kV/500kV substation. It cleared the board just two months after staff proposed it, an unusually fast turnaround for a project of this size.
“The combination of resources at Marigold Energy Center represent a balanced system approach to providing affordable, reliable and sustainable power,” said Bobby Olsen, SRP’s associate general manager and chief power system executive, in the utility’s announcement – deliberately framing the project as neither a clean-energy showcase nor a gas plant, but both.
That framing matters because of who’s on SRP’s board. An April election handed renewable-leaning candidates an 8-6 majority, a result Arizona Capitol Times called a rebuke of a well-funded conservative campaign to block them. That this board’s first major test included 675 MW of gas is the real signal: even a “clean energy majority” utility is treating gas as non-negotiable ballast for firm capacity, not a technology to be phased out on principle.
SRP still needs the Arizona Corporation Commission to sign off on the gas and transmission components; that committee held hearings September 21-25, with a decision due in November. The build sequence tells its own story about priorities: the substation and transmission lines land first, in fall 2028, solar and storage follow in 2029, and the gas units – the piece needing the most regulatory scrutiny – don’t come online until 2032.
Bottom line: Marigold is a preview of how utilities in AI-growth corridors will structure new capacity going forward, not a bet on one technology, but a hedged portfolio built to survive both political turnover and the multi-year equipment queues now defining every gigawatt-scale interconnection in the country.
