Salt River Project has signed a second agreement for the purchase of 49 megawatts of geothermal energy from a plant to be built in Southern California.

SRP is the largest provider of electricity to the greater Phoenix area, serving nearly 950,000 electric customers.

The proposed geothermal generating station will be owned and operated by Hudson Ranch Power II LLC, and constructed in the Imperial Valley near the Salton Sea. The Salton Sea geothermal resource is one of the world’s hottest and most prolific for the production of energy.

In 2007, SRP executed an agreement to purchase 49 megawatts of geothermal energy from Hudson Ranch I. The project is nearly complete and is expected to begin producing energy in February 2012.

This second 30-year agreement is for SRP to purchase power beginning in mid-2014 when the plant is completed. SRP will arrange transmission of the energy from the point of delivery to Arizona.

A geothermal power plant produces electricity from naturally-occurring geothermal steam. The steam is formed when production wells tap into superheated water reservoirs thousands of feet beneath the Earth's surface.

Unlike other forms of renewable energy including solar or wind, geothermal power plants produce energy continuously, irrespective of the time of the day or weather conditions. 

Geothermal is one of the cleanest energy sources because, instead of burning a fuel to heat water into steam as seen in conventional forms of generation, heat from the Earth is used to create steam that powers a turbine generator.

Geothermal energy is considered renewable energy because no fuel is consumed and the energy is from a naturally occurring source.

Under SRP’s Sustainable Portfolio goals, SRP must secure sustainable and renewable resources to meet 20 percent of its retail load by the year 2020.

Currently SRP’s sustainable portfolio, which consists of energy-conservation programs and renewable-energy sources, including solar, wind, landfill gas, geothermal and low-head hydro, is a little more than 7 percent.

Hudson Ranch Power II is owned by EnergySource, a renewable energy company focused on the Salton Sea geothermal resource. A sister company, Hudson Ranch Energy Services, will operate Hudson Ranch I and II.