# Imperial Valley Solar, LLC CAISO Solar Photovoltaic · https://askthegrid.com/assets/facilities/imperial-valley-solar-llc Imperial Valley Solar, LLC is a solar power facility with 199.9 MW of EIA-reported nameplate capacity in Imperial County, California, registered as EIA Plant ID 56917. Imperial Valley Solar, LLC is the registered plant entity or operator. Project filings list 3,100,000 solar panels and 138 inverters for the facility. ## Key facts - Technology: Solar Photovoltaic - Power capacity: 199.89999999999998 MW - Operating status: operating ## Grid and market context - ISO/RTO: CAISO - Balancing authority: California Independent System Operator (CISO) - Substation: Imperial Valley Substation - Point of interconnection: Imperial Valley Substation - Transmission owner: San Diego Gas & Electric (SDG&E) - Interconnection voltage: 230 kV ## Source-backed facts - Identifiers: [{"value":"56917","system":"EIA plant ID"},{"value":"CAISO","system":"ISO/RTO"},{"value":"CISO","system":"Balancing authority"},{"value":"1","system":"EIA generator ID"},{"value":"1A","system":"EIA generator ID"},{"value":"1B","system":"EIA generator ID"},{"value":"ER13-1139-000","system":"FERC MBR docket"},{"value":"W3592 / 61292A","system":"California Energy Commission cross-reference"}] — Federal Register :: Imperial Valley Solar 1, LLC: Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization · confidence: medium - Identifiers: [{"value":"56917","system":"EIA plant ID"},{"value":"CAISO","system":"ISO/RTO"},{"value":"CISO","system":"Balancing authority"},{"value":"1","system":"EIA generator ID"},{"value":"1A","system":"EIA generator ID"},{"value":"1B","system":"EIA generator ID"},{"value":"ER13-1139-000","system":"FERC MBR docket"},{"value":"W3592 / 61292A","system":"California Energy Commission cross-reference"}] — 2023 Power Source Disclosure Annual Report · confidence: medium - Canonical name: Imperial Valley Solar, LLC — 2023 Power Source Disclosure Annual Report · confidence: high - Identifiers.6: {"value":"ER13-1139-000","system":"FERC MBR docket"} — Federal Register :: Imperial Valley Solar 1, LLC: Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization · confidence: medium - Identifiers.7: {"value":"W3592 / 61292A","system":"California Energy Commission cross-reference"} — 2023 Power Source Disclosure Annual Report · confidence: medium - Parties.1: {"relationship":"Registered project company and FERC applicant","name":"Imperial Valley Solar 1, LLC","official_url":null} — Federal Register :: Imperial Valley Solar 1, LLC: Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization · confidence: high - Parties.1: {"relationship":"Registered project company and FERC applicant","name":"Imperial Valley Solar 1, LLC","official_url":null} — 2023 Power Source Disclosure Annual Report · confidence: high - Parties.4: {"relationship":"EPC contractor","name":"Abengoa","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.5: {"relationship":"Tracker supplier","name":"Array Technologies","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.6: {"relationship":"PV module supplier","name":"First Solar","official_url":"https://www.firstsolar.com"} — Mount Signal Solar · confidence: medium - Parties.7: {"relationship":"Investor","name":"Google Inc.","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.8: {"relationship":"Joint lead placement agent","name":"Morgan Stanley & Co.","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.9: {"relationship":"Joint lead placement agent","name":"Citigroup Global Markets","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.10: {"relationship":"Co-placement agent","name":"Rabo Securities USA","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.11: {"relationship":"Co-placement agent","name":"DNB Markets","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.12: {"relationship":"Cash-grant loan provider","name":"Morgan Stanley Senior Funding","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.13: {"relationship":"Cash-grant loan provider","name":"Citibank","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Parties.14: {"relationship":"Power purchaser under PPA","name":"San Diego Gas & Electric (SDG&E)","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Product url: https://www.firstsolar.com/-/media/First-Solar/Technical-Documents/Series-3-Datasheets/Series-3-Black-Datasheet---North-America.PDF — First Solar® FS Series 3™ Black PV Module · confidence: medium - Manufacturer domain: firstsolar.com — First Solar® FS Series 3™ Black PV Module · confidence: medium - Product family: First Solar FS Series 3™ thin-film PV module — First Solar® FS Series 3™ Black PV Module · confidence: medium - Manufacturer name: First Solar — First Solar® FS Series 3™ Black PV Module · confidence: medium - Financing summary: Project financing was reported in two tranches: a $416 million long-term institutional tranche led by Morgan Stanley & Co. and Citigroup Global Markets, with Rabo Securities USA and DNB Markets as co-placement agents; and a $220 million cash-grant loan from Morgan Stanley Senior Funding and Citibank. Financial closure followed Imperial County approval in April 2012. Google became a project partner and invested approximately $103 million in October 2013. Separately, SunEdison agreed on June 16, 2014 to pay AES $165 million for 50% of Silver Ridge Power, with the acquisition completed on July 3, 2014 for approximately $178.6 million after adjustments; that was portfolio-level equity consideration, not project financing. — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Timeline: [{"event":"County approval and financial closure","date":"2012-04","detail":"Imperial County approved the project in April 2012, after which financial closure was reached."},{"event":"Preconstruction","date":"2012-11","detail":"Preconstruction began in November 2012."},{"event":"Groundbreaking","date":"2013-02","detail":"The official groundbreaking ceremony took place in February 2013."},{"event":"Google investment","date":"2013-10","detail":"Google became a project partner and invested approximately $103 million in Silver Ridge Power's Mount Signal project."},{"event":"First unit entered service","date":"2013-11-01","detail":"EIA-derived operating data record the first generating unit online on November 1, 2013."},{"event":"Construction completion","date":"2014-05","detail":"Project construction was reported complete in May 2014."},{"event":"Indirect ownership acquisition agreement","date":"2014-06-16","detail":"SunEdison and its subsidiary agreed to purchase 50% of Silver Ridge Power from AES Solar for $165 million, subject to closing adjustments. The transaction included SunEdison's indirect 50% interest in the Mount Signal project."},{"event":"Indirect ownership acquisition closed","date":"2014-07-03","detail":"SunEdison completed the acquisition of a 50% interest in Silver Ridge Power from an AES subsidiary for approximately $178.6 million in cash after pre-closing adjustments. Riverstone retained the other 50% of Silver Ridge Power."},{"event":"Project commissioning reported","date":"2014-12","detail":"A later project profile reported commissioning in December 2014; this is presented alongside, rather than substituted for, the EIA-derived first-unit online date because the project was developed in phases and sources use different capacity and operating-date conventions."}] — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Timeline: [{"event":"County approval and financial closure","date":"2012-04","detail":"Imperial County approved the project in April 2012, after which financial closure was reached."},{"event":"Preconstruction","date":"2012-11","detail":"Preconstruction began in November 2012."},{"event":"Groundbreaking","date":"2013-02","detail":"The official groundbreaking ceremony took place in February 2013."},{"event":"Google investment","date":"2013-10","detail":"Google became a project partner and invested approximately $103 million in Silver Ridge Power's Mount Signal project."},{"event":"First unit entered service","date":"2013-11-01","detail":"EIA-derived operating data record the first generating unit online on November 1, 2013."},{"event":"Construction completion","date":"2014-05","detail":"Project construction was reported complete in May 2014."},{"event":"Indirect ownership acquisition agreement","date":"2014-06-16","detail":"SunEdison and its subsidiary agreed to purchase 50% of Silver Ridge Power from AES Solar for $165 million, subject to closing adjustments. The transaction included SunEdison's indirect 50% interest in the Mount Signal project."},{"event":"Indirect ownership acquisition closed","date":"2014-07-03","detail":"SunEdison completed the acquisition of a 50% interest in Silver Ridge Power from an AES subsidiary for approximately $178.6 million in cash after pre-closing adjustments. Riverstone retained the other 50% of Silver Ridge Power."},{"event":"Project commissioning reported","date":"2014-12","detail":"A later project profile reported commissioning in December 2014; this is presented alongside, rather than substituted for, the EIA-derived first-unit online date because the project was developed in phases and sources use different capacity and operating-date conventions."}] — Power plant profile: Imperial Valley- Solar Park, US · confidence: medium - Timeline.0: {"event":"County approval and financial closure","date":"2012-04","detail":"Imperial County approved the project in April 2012, after which financial closure was reached."} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Timeline.1: {"event":"Preconstruction","date":"2012-11","detail":"Preconstruction began in November 2012."} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high - Timeline.2: {"event":"Groundbreaking","date":"2013-02","detail":"The official groundbreaking ceremony took place in February 2013."} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high - Timeline.3: {"event":"Google investment","date":"2013-10","detail":"Google became a project partner and invested approximately $103 million in Silver Ridge Power's Mount Signal project."} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Timeline.8: {"event":"Project commissioning reported","date":"2014-12","detail":"A later project profile reported commissioning in December 2014; this is presented alongside, rather than substituted for, the EIA-derived first-unit online date because the project was developed in phases and sources use different capacity and operating-date conventions."} — Power plant profile: Imperial Valley- Solar Park, US · confidence: medium - Commercial parties.3: {"relationship":"Developer and co-developer","name":"8minutenergy Renewables","detail":"Handled preconstruction activities with AES Solar, including transmission, land, permitting, engineering, and environmental work; identified as a project co-developer.","official_url":null} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Commercial parties.7: {"relationship":"Investor and project partner","name":"Google Inc.","detail":"Invested approximately $103 million and became a partner in the Mount Signal project in October 2013.","official_url":"https://www.google.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Commercial parties.8: {"relationship":"EPC contractor","name":"Abengoa","detail":"Awarded a contract reported at approximately $365 million for engineering, construction, and commissioning.","official_url":"https://www.abengoa.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Commercial parties.10: {"relationship":"Joint lead placement agent","name":"Morgan Stanley & Co.","detail":"Joint lead placement agent for the $416 million long-term institutional financing tranche.","official_url":"https://www.morganstanley.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high - Commercial parties.11: {"relationship":"Joint lead placement agent","name":"Citigroup Global Markets","detail":"Joint lead placement agent for the $416 million long-term institutional financing tranche.","official_url":"https://www.citigroup.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high - Commercial parties.12: {"relationship":"Co-placement agent","name":"Rabo Securities USA","detail":"Co-placement agent for the long-term institutional financing tranche.","official_url":"https://www.rabobank.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Commercial parties.13: {"relationship":"Co-placement agent","name":"DNB Markets","detail":"Co-placement agent for the long-term institutional financing tranche.","official_url":"https://www.dnb.no"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: medium - Commercial parties.14: {"relationship":"Cash-grant loan provider","name":"Morgan Stanley Senior Funding","detail":"Provided the reported $220 million cash-grant loan tranche.","official_url":"https://www.morganstanley.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high - Commercial parties.15: {"relationship":"Cash-grant loan provider","name":"Citibank","detail":"Provided the reported $220 million cash-grant loan tranche alongside Morgan Stanley Senior Funding.","official_url":"https://www.citi.com"} — Mount Signal Solar Power Plant, Imperial County, California - Power Technology · confidence: high ## Timeline - 2014-06-16 — Indirect ownership acquisition agreement SunEdison and its subsidiary agreed to purchase 50% of Silver Ridge Power from AES Solar for $165 million, subject to closing adjustments. The transaction included SunEdison's indirect 50% interest in the Mount Signal project. Source: Source (https://www.sec.gov/Archives/edgar/data/945436/000094543614000117/a8-ksilverridgepowerllcacq.htm) ## Sources - [Google to invest in Silver Ridge Power solar project](https://virginiabusiness.com/google-to-invest-in-silver-ridge-power-solar-project/) — virginiabusiness.com · tier other - [Federal Register :: Imperial Valley Solar 1, LLC: Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization](https://www.federalregister.gov/documents/2013/03/27/2013-06988/imperial-valley-solar-1-llc-supplemental-notice-that-initial-market-based-rate-filing-includes) — federalregister.gov · tier regulatory - [Source](https://efiling.energy.ca.gov/GetDocument.aspx?tn=257766&DocumentContentId=93677) — efiling.energy.ca.gov · tier regulatory - [Mount Signal Solar Power Plant, Imperial County, California - Power Technology](https://www.power-technology.com/projects/mount-signal-solar-power-plant-imperial-county-california/) — power-technology.com · tier other - [Mount Signal Solar](https://en.wikipedia.org/wiki/Mount_Signal_Solar) — en.wikipedia.org · tier other - [Power plant profile: Mount Signal Solar Farm, US](https://www.power-technology.com/data-insights/power-plant-profile-mount-signal-solar-farm-us/) — power-technology.com · tier other - [Santerno gets the green light to start the supply of the inverter systems for one of the largest solar projects in the world.](https://www.prnewswire.com/news-releases/santerno-gets-the-green-light-to-start-the-supply-of-the-inverter-systems-for-one-of-the-largest-solar-projects-in-the-world-181012271.html) — prnewswire.com · tier other - [First Solar® FS Series 3™ Black PV Module](https://www.firstsolar.com/-/media/First-Solar/Technical-Documents/Series-3-Datasheets/Series-3-Black-Datasheet---North-America.PDF) — firstsolar.com · tier other - [Source](https://www.sec.gov/Archives/edgar/data/945436/000094543614000117/a8-ksilverridgepowerllcacq.htm) — sec.gov · tier regulatory - [Power plant profile: Imperial Valley- Solar Park, US](https://www.power-technology.com/data-insights/power-plant-profile-imperial-valley-solar-park-us/) — power-technology.com · tier other - [Source](https://www.sec.gov/Archives/edgar/data/1599947/000119312515005773/d827028d424b3.htm) — sec.gov · tier regulatory - [Source](https://www.sec.gov/Archives/edgar/data/1599947/000119312515111111/d900218dex992.htm) — sec.gov · tier regulatory ## Data quality - The EIA-derived plant record identifies 199.9 MW across three operational units, while project-era sources quote approximately 206 MW or 265.7 MW for Mount Signal; the difference is treated as a project-phase, capacity-definition, or reporting-scope variance rather than evidence of a different asset. The June 2014 agreement and July 2014 closing involved SunEdison's purchase of 50% of Silver Ridge Power from AES. The $165 million agreement value and approximately $178.6 million closing payment are portfolio-level ownership consideration, not project-construction financing or a standalone plant sale price. No expansion, retirement, or repowering milestone is listed in the operating record; it reports three operational units and zero planned units. A separate Southern Power transaction for a 150 MW First Solar facility is excluded because its cited capacity, seller, and ownership context do not match this 199.9 MW Silver Ridge Power plant. --- Canonical page: https://askthegrid.com/assets/facilities/imperial-valley-solar-llc Source: Ask the Grid — https://askthegrid.com/