Tenaska Imperial Solar Energy Center South


Tenaska Imperial Solar Energy Center South was the first large-scale solar project to begin construction in Imperial County, and it was the first large-scale solar project to transmit power from the Imperial Valley via San Diego Gas & Electric Company’s (SDG&E) Sunrise Powerlink transmission line. It was also one of the largest commercially financed solar projects in the United States at the time.

The ground-mounted photovoltaic solar power generating system is able to produce up to 130 megawatts (MW) of electricity under a 25-year power purchase agreement with SDG&E. When operating at peak times, it can produce enough electricity to meet the needs of approximately 44,000 California homes.

Tenaska Imperial Solar Energy Center South represents an investment of more than $500 million in the Imperial Valley’s economy. Local benefits include:
Installing Solar Panels

• Of the 500 construction workers hired to perform work at the site, more than 70 percent were from communities in Imperial County, including Brawley, El Centro, Heber, Imperial and Calexico.

• Tenaska has worked with the Imperial Valley Economic Development Corporation to establish a procurement program to help renewable energy projects in the Imperial Valley identify and accept bids from qualified local contractors and vendors during construction and operation. The Tenaska Imperial South project awarded more than $20 million in construction contracts to local companies, including Duggins Construction Inc. and Granite Construction.

• Tenaska was the first solar developer to designate Imperial County as the place of purchase for all of its solar panels and other local goods and services, ensuring the county would benefit from the sales tax. The county received more than $3 million total in local sales tax revenue from the project.




Photovoltaic (PV) technology is utilized. Photovoltaics is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors. Photovoltaic power generation employs an array of solar panels that do not produce noise or emit greenhouse gases. First Solar provided the technology.

Electric Capacity

Able to produce 130 megawatts (MW) of renewable power for customer San Diego Gas & Electric Company, enough to meet the needs of approximately 44,000 California homes.


The solar field occupies approximately 946 acres of previously disturbed private land in Imperial County, adjacent to the U.S. border with Mexico.

Minimal Water Use

Photovoltaic technology converts sunlight directly into electricity and, therefore, has minimal water supply requirements, an important consideration for the Imperial Valley. Water use is primarily for dust mitigation and sanitation uses.

Transmission Interconnection

The project connects with the California Independent System Operator (CAISO) at the existing Imperial Valley electric transmission substation located on U.S. Bureau of Land Management (BLM) land in the Yuha Desert.

Project Developer/Owner

Tenaska Solar Ventures, an affiliate of Tenaska, developed the project. CSOLAR IV South, LLC, a Tenaska affiliate, is owner of the solar field.