Pattern Energy signed a power purchase agreement with Salt River Project to supply up to 600 megawatts of wind energy from its SunZia project, the companies announced Wednesday.
The agreement will supply Salt River Project with 400 MW of wind energy beginning this fall, increasing to 600 MW by the summer of 2027.
The companies said the contract ranks among the largest renewable power purchase agreements in the US.
Pattern Energy said the agreement will help Salt River Project meet rising electricity demand across the Phoenix metropolitan area while maintaining affordable, reliable and sustainable service for customers.
SunZia represents an $11 billion energy investment across the Southwest. The project combines 3.65 GW of wind generation with a 550-mile high-voltage direct current transmission line and will produce enough electricity to power about 1 million US homes each year, according to Pattern Energy.
Salt River Project currently supplies customers with 288 MW of wind energy. The SunZia agreement expands a generation portfolio that also includes hydroelectric, natural gas, solar and battery storage resources, the companies said.
The project also supports Salt River Project's plan to more than double its power system capacity by 2035 through the addition of thousands of megawatts of renewable generation, natural gas and battery energy storage.
"This PPA highlights SRP's leadership and our partnership, showing how a diverse and cost-effective energy portfolio can meet Arizona's needs today while supporting a reliable and resilient grid for the future," said Hunter Armistead, Pattern Energy's chief executive officer.