Mount Signal Solar, also known as Imperial Valley Solar Project, is a 794 MWp (614 MWAC) photovoltaic power station west of Calexico, California, United States, in the southern Imperial Valley, near the Mexican border.

[1] Originally the project was called SES Solar Two, was to be of Stirling engine design, and was approved by California Energy Commission on September 29, 2010.

[4] The first phase started construction in 2012 and went online in 2014, providing 266 MWp (206 MWAC) to San Diego Gas & Electric under a 25-year agreement.

[5] More than 3 million thin-film CdTe photovoltaic modules from First Solar and 138 skids designed and manufactured by Elettronica Santerno are used.

[6] It was the world's largest solar project using single-axis trackers to follow the path of the sun upon completion.