Mount Signal Solar
| Company type | Private |
|---|---|
| Industry | Solar energy |
| Founded | 2012 |
| Headquarters | Imperial County, California , United States |
Area served | California |
Key people | 8minutenergy Renewables (developer and builder) |
| Products | Photovoltaic power generation |
Mount Signal Solar, also referred to as the Imperial Valley Solar Project, is a 794 MWp (614 MWAC) photovoltaic power station situated west of Calexico in Imperial County, California, close to the border with Mexico. Developed and built by 8minutenergy Renewables across three stages—with two phases completed by 2018 and the final one in 2020—it is among the largest photovoltaic solar farms worldwide. The project made use of low-yield agricultural land, earning backing from environmental advocates.
History
Originally called SES Solar Two and authorized by the California Energy Commission in 2010 as a Stirling engine project, it was subsequently renamed Imperial Valley Solar by AES Solar. AES exited the project in 2011 but re-engaged with 8minutenergy Renewables in 2012, transitioning to photovoltaic technology and adopting the name Mount Signal Solar.
Phase 1 construction commenced in 2012 and became operational in 2014, generating 266 MWp (206 MWAC) supplied to San Diego Gas & Electric under a 25-year power purchase agreement. This phase incorporated over three million thin-film CdTe modules from First Solar and included 138 skids provided by Elettronica Santerno. Upon completion, it was the largest solar facility globally employing single-axis tracking systems. The investment for this phase totaled $365 million.
Phases two and three contributed an additional 200 MWp and 328 MWp, respectively, spread over , with contracts awarded to Southern California Edison. Phase 3 began operations in July 2018 featuring 2.8 million Series 4 thin-film panels from First Solar, while Phase 2 started service in January 2020.
Project units
The Mount Signal Solar complex consists of three development stages:
- Mount Signal 1 – a photovoltaic solar power plant rated at 266 MWDC (206 MWAC). Construction on this site started in November 2012 and concluded by May 2014.
- Mount Signal 2 – a photovoltaic facility with a capacity of 200 MWDC (154 MWAC) spanning roughly , commissioned in January 2020.
- Mount Signal 3 – a photovoltaic solar station rated at 328 MWDC (254 MWAC) covering , finalized in July 2018. Series 4 thin-film solar panels were supplied by American manufacturer First Solar, while NEXTracker provided NX Horizon intelligent solar tracking technology.
Electricity production
Mount Signal 1 holds nameplate ratings of 260 MWDC and 206 MWAC, achieving an average annual net generation of 537 GW·h between 2015 and 2017, corresponding to a capacity factor of 29.7%.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2013 | 14,324 | 22,836 | 37,160 | ||||||||||
| 2014 | 22,740 | 28,996 | 52,995 | 50,216 | 54,049 | 45,771 | 41,333 | 54,391 | 49,421 | 41,741 | 34,314 | 24,588 | 500,555 |
| 2015 | 26,785 | 36,002 | 48,988 | 54,670 | 57,135 | 57,622 | 58,306 | 56,135 | 41,832 | 40,183 | 32,880 | 28,148 | 538,685 |
| 2016 | 28,732 | 39,221 | 45,763 | 51,495 | 62,321 | 60,274 | 60,762 | 54,169 | 45,606 | 39,605 | 28,038 | 20,539 | 536,525 |
| 2017 | 21,264 | 23,751 | 44,398 | 47,373 | 60,412 | 65,437 | 59,589 | 55,128 | 51,371 | 47,328 | 29,254 | 30,779 | 536,083 |