Salt River Project (SRP) will host two public events this month to gather community feedback on the planned Marigold Energy Center. This mixed generation and storage facility would bring up to 1,275 megawatts of combined solar (600 MW) and natural gas (up to 675 MW) generation capacity plus 400 megawatts of battery storage near Stanfield, AZ.
For comparison, Electrical District No. 3 (ED3) set a system peak demand record of 280 megawatts in August 2025. The Marigold project’s generation capacity alone would be more than four times that peak. The battery storage component would add another 400 megawatts.
The public can attend an in-person open house on December 10 or join a virtual summary meeting on December 18. Visit SRP’s Marigold Energy Center page to register.
What the Marigold Energy Center Would Include
The Marigold Energy Center would add significant energy infrastructure to Pinal County. Beyond the generation and storage capacity, the project includes a 230-kilovolt/500-kilovolt substation and approximately four miles of new 230 kV transmission lines.
According to SRP’s development timeline, the solar and storage components target fiscal years 2029 and 2030. The natural gas turbines would follow in fiscal years 2033 and 2034. SRP plans to seek approval from its own board in summer 2026. The December public events are part of SRP’s community outreach process leading up to that decision.
According to SRP, Electrical District No. 3 (ED3) is evaluating a potential partnership to procure a portion of the energy generated by the Marigold Energy Center. ED3 serves Maricopa, Stanfield, and surrounding communities.
Where the Marigold Energy Center Would Be Located
The proposed site sits near Stanfield in Pinal County. SRP has published a map showing the location on its project website. The site is near existing 500kV transmission lines and a natural gas pipeline.
Several other major energy projects have recently received approval in the surrounding area.
Growing Energy and Data Center Development in Pinal County
The Marigold Energy Center proposal comes amid a wave of energy and data center projects across Pinal County. The table below summarizes county projects proposed to address growing electricity demand from tech firms and an expanding regional population.
| Project Name | Status | Total Acreage | Project Type | Solar Capacity | Battery Storage | Natural Gas Generation | Power Demand |
|---|---|---|---|---|---|---|---|
| SRP Marigold | Pending | - | Solar, Battery, Gas | 600 MW | 400 MW | Up to 675 MW | |
| La Osa | Approved | 3,385 | Data Center, Gas Power | — | — | TBD | — |
| Griffin Energy | Approved | 2,685 | Solar, Battery, Gas | Up to 550 MW | Up to 550 MW | Up to 500 MW | — |
| Energy Generation & Technology Campus | Approved | 495 | Data Center, Gas, Battery | — | TBD | TBD | — |
| Project Bella | Approved | 352 | Gas, Battery | 400-440 MW | 480-520 MW | — | |
| Project Midway | Approved | 215 | Data Center | — | — | — | Requires 225 MW |
| Frontier East | Approved | 160 | Solar, Battery | 50 MW | 300 MW | ||
| Silver King | Withdrawn | 12,915 | Solar, Battery | Up to 1100 MW | Up to 1100 MW | — | — |
| Silver Reef | Withdrawn | 801 | Solar, Battery | 150 MW | 200 MW | — | — |
Note on “Approved” Status: Approval by the Board of Supervisors does not mean these projects have completed all necessary stages for development. Each project must still complete additional approval stages before construction can begin.
Just southeast of Stanfield, the Griffin Energy Project received approval for a solar, natural gas, and battery storage facility. That project is intended to support the Energy Generation and Technology Campus, a data center development three miles south of Maricopa bordering the Ak-Chin Indian Community.
The Cactus Wren Energy Storage project won planning commission approval in November. That facility would sit south of the City of Maricopa.
South of Casa Grande and southeast of Stanfield, the Project Midway Data Center cleared a major hurdle in November.
The Table Top Solar Park won planning commission support southwest of Casa Grande.
The Frontier East Solar project received approval near the City of Maricopa.
How to Participate
SRP is holding two public events for community input. The in-person open house takes place Wednesday, December 10, from 5 p.m. to 7 p.m. It will be held at Stanfield Elementary School Cafeteria, located at 515 S. Stanfield Road in Stanfield. Registration is recommended but not required.
A virtual summary meeting is scheduled for Thursday, December 18, at 5:30 p.m. Registration is required for the virtual event.
Visit SRP’s Marigold Energy Center page to register and find more information. Those with questions can also call (602) 236-2872 or email [email protected].
