The power purchase agreement goes until 2039 and will bring the existing capacity of CalEnergy’s geothermal facilities to 40%.

CalEnergy president Steve Larsen said it is exciting to welcome Salt River Project to the company’s list of growing customers and to send renewable baseload power to Arizona.

"This contract builds on our earlier agreement with the city of Riverside and will bring the benefits associated with our geothermal portfolio to key customers for the next 30 years," Larsen added.

In capital improvements, the company will invest over $1 billion to its existing facilities to sustain Salton Sea facilities for the next 30 years, the company said.

"We remain committed to the importance of economic development in the Imperial Valley area, where our power plants are located," Larsen further added.

"It is important to the future of our community and environment, and we will continue doing our part to facilitate growth of the renewable energy economy."