SRP and Invenergy reach agreement for new Arizona solar project as Phoenix-area electricity demand rises

Agreement targets additional utility-scale generation for a fast-growing grid

Salt River Project (SRP), the largest electricity provider in the greater Phoenix metropolitan area, has reached an agreement with renewable developer Invenergy to move forward with a new utility-scale solar project intended to help meet rising electricity demand in central Arizona. The deal comes as the Phoenix region faces rapid load growth driven by population increases, electrification and an expanding base of large industrial and commercial customers.

SRP’s service territory has recorded peak-demand highs during periods of extreme heat, underscoring the system’s sensitivity to summer conditions and the need for additional capacity that can reliably serve customers when temperatures rise and air-conditioning usage surges.

Why the Phoenix-area grid is tightening

Utilities serving metro Phoenix have been planning for a sharper upward demand trajectory than in the prior decade, when U.S. electricity use was comparatively flat. A major driver in Arizona is the data-center buildout, which brings large, concentrated loads that can range from a few megawatts to hundreds of megawatts per site. Within SRP’s system, data centers remain a minority of total demand, but are projected to be among the fastest-growing customer segments.

SRP has publicly estimated its current generation capacity at roughly 8,000 megawatts and has described some individual large-customer loads around 200 megawatts, illustrating how a small number of facilities can materially affect planning for generation, transmission and distribution upgrades.

How solar projects fit into reliability planning

Utility-scale solar can add substantial daytime energy and contribute to meeting overall annual demand, but Arizona’s highest stress periods often occur late afternoon and early evening, when solar output declines while air-conditioning demand can remain elevated. For that reason, many recent utility procurements pair solar with battery storage or are complemented by other resources that can provide capacity outside peak solar hours.

SRP has expanded its renewable portfolio over the past several years through contracts for new solar generation and has also pursued large-scale battery storage additions to shift renewable output to higher-demand periods. Invenergy, for its part, has been expanding its Arizona footprint, including bringing a solar-plus-storage facility online in Yuma County in 2025.

Key elements stakeholders will watch next

• Project scope and timeline: expected capacity, construction schedule and targeted in-service date.
• Grid integration: where the project interconnects and what transmission upgrades may be required.
• Resource adequacy: whether storage is included or how SRP plans to cover evening peak hours.
• Cost and customer impacts: how the contract is structured and how costs are allocated across customer classes.

In Arizona’s fastest-growing load pockets, new generation decisions increasingly hinge on matching the timing of output to when demand is highest, not only on adding megawatt-hours over the course of a day.

Further details on the SRP–Invenergy project, including final capacity, location and whether energy storage is part of the build, are expected as permitting and interconnection steps advance.