# Edwards Sanborn E4 CAISO Batteries, Solar Photovoltaic · https://askthegrid.com/assets/facilities/edwards-sanborn-e4 Edwards Sanborn E4 is a hybrid solar and battery storage facility with 248.9 MW of EIA-reported operating capacity in Kern County, California, registered as EIA Plant ID 65675. Terra-Gen Operating Co-Hybrid is the registered plant entity or operator. Mortenson built the facility using Power Electronics HEM FS3430M equipment; public project records list 1 battery units. Commercial operation began in 2024. ## Key facts - Technology: Batteries, Solar Photovoltaic - Power capacity: 248.9 MW - Commercial operation: 2024 - Operating status: operating ## Grid and market context - ISO/RTO: CAISO - Balancing authority: California Independent System Operator (CISO) ## Source-backed facts - Identifiers: [{"value":"65675","system":"EIA plant ID"},{"value":"64366","system":"EIA utility ID"},{"value":"PV","system":"EIA generator ID"},{"value":"BESS","system":"EIA generator ID"},{"value":"CAISO","system":"ISO/RTO"},{"value":"CISO","system":"Balancing authority"},{"value":"EDWARD_2_ESSSB2","system":"CAISO market-resource ID"},{"value":"Sanborn Solar 2","system":"CAISO market-resource name"},{"value":"65032C","system":"California Energy Commission plant ID"},{"value":"W13935","system":"CAISO/CEC resource identifier"}] — Cross-Reference Table · confidence: medium - Identifiers: [{"value":"65675","system":"EIA plant ID"},{"value":"64366","system":"EIA utility ID"},{"value":"PV","system":"EIA generator ID"},{"value":"BESS","system":"EIA generator ID"},{"value":"CAISO","system":"ISO/RTO"},{"value":"CISO","system":"Balancing authority"},{"value":"EDWARD_2_ESSSB2","system":"CAISO market-resource ID"},{"value":"Sanborn Solar 2","system":"CAISO market-resource name"},{"value":"65032C","system":"California Energy Commission plant ID"},{"value":"W13935","system":"CAISO/CEC resource identifier"}] — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Identifiers.6: {"value":"EDWARD_2_ESSSB2","system":"CAISO market-resource ID"} — Cross-Reference Table · confidence: medium - Identifiers.6: {"value":"EDWARD_2_ESSSB2","system":"CAISO market-resource ID"} — CAISO Resource Visibility Template · confidence: medium - Identifiers.7: {"value":"Sanborn Solar 2","system":"CAISO market-resource name"} — Cross-Reference Table · confidence: medium - Identifiers.7: {"value":"Sanborn Solar 2","system":"CAISO market-resource name"} — CAISO Resource Visibility Template · confidence: medium - Identifiers.8: {"value":"65032C","system":"California Energy Commission plant ID"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Identifiers.9: {"value":"W13935","system":"CAISO/CEC resource identifier"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Parties.3: {"relationship":"EPC contractor for the Edwards Sanborn second phase","name":"Mortenson","official_url":"https://www.mortenson.com/"} — Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen · confidence: medium - Parties.3: {"relationship":"EPC contractor for the Edwards Sanborn second phase","name":"Mortenson","official_url":"https://www.mortenson.com/"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Parties.4: {"relationship":"Solar-module supplier for the Edwards Sanborn second phase","name":"First Solar","official_url":"https://www.firstsolar.com/"} — Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen · confidence: medium - Parties.4: {"relationship":"Solar-module supplier for the Edwards Sanborn second phase","name":"First Solar","official_url":"https://www.firstsolar.com/"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Parties.5: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"LG Chem","official_url":"https://www.lgchem.com/"} — Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen · confidence: medium - Parties.5: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"LG Chem","official_url":"https://www.lgchem.com/"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Parties.6: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"Samsung","official_url":"https://www.samsung.com/"} — Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen · confidence: medium - Parties.6: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"Samsung","official_url":"https://www.samsung.com/"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Parties.7: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"BYD","official_url":"https://www.byd.com/"} — Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen · confidence: medium - Parties.7: {"relationship":"Battery supplier for the Edwards Sanborn second phase","name":"BYD","official_url":"https://www.byd.com/"} — CPA_Power_Source_Disclosure_ Annual_ Report 06012023 · confidence: medium - Product url: https://power-electronics.com/en/solar/hem — HEM | Power Electronics · confidence: medium - Manufacturer domain: power-electronics.com — HEM | Power Electronics · confidence: medium - Equipment models: [{"manufacturer_domain":"firstsolar.com","product_url":"https://www.firstsolar.com/en/Products/Series-6","count":null,"unit_mw":null,"name":"First Solar solar modules (exact model not specified)"},{"manufacturer_domain":"power-electronics.com","product_url":"https://power-electronics.com/en/solar/hem","count":null,"unit_mw":null,"name":"Power Electronics HEM FS3430M integrated inverter modules"},{"manufacturer_domain":"lgchem.com","product_url":null,"count":null,"unit_mw":null,"name":"LG Chem batteries (exact model not specified)"},{"manufacturer_domain":"samsungsdi.com","product_url":"https://www.samsungsdi.com/business/index.html","count":null,"unit_mw":null,"name":"Samsung SDI batteries (exact model not specified)"},{"manufacturer_domain":"bydenergy.com","product_url":"https://www.bydenergy.com/","count":null,"unit_mw":null,"name":"BYD batteries (exact model not specified)"}] — Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson · confidence: medium - Equipment models: [{"manufacturer_domain":"firstsolar.com","product_url":"https://www.firstsolar.com/en/Products/Series-6","count":null,"unit_mw":null,"name":"First Solar solar modules (exact model not specified)"},{"manufacturer_domain":"power-electronics.com","product_url":"https://power-electronics.com/en/solar/hem","count":null,"unit_mw":null,"name":"Power Electronics HEM FS3430M integrated inverter modules"},{"manufacturer_domain":"lgchem.com","product_url":null,"count":null,"unit_mw":null,"name":"LG Chem batteries (exact model not specified)"},{"manufacturer_domain":"samsungsdi.com","product_url":"https://www.samsungsdi.com/business/index.html","count":null,"unit_mw":null,"name":"Samsung SDI batteries (exact model not specified)"},{"manufacturer_domain":"bydenergy.com","product_url":"https://www.bydenergy.com/","count":null,"unit_mw":null,"name":"BYD batteries (exact model not specified)"}] — Q4 2023 - Solar power—and battery storage—take off at Edwards Air Force Base : BackIssues, altenerG.com - enerG Alternative Sources Magazine - enerG,Archives · confidence: medium - Product family: HEM FS3430M — Source · confidence: medium - Manufacturer name: Power Electronics — Source · confidence: medium - Equipment models.0: {"manufacturer_domain":"firstsolar.com","product_url":"https://www.firstsolar.com/en/Products/Series-6","count":null,"unit_mw":null,"name":"First Solar solar modules (exact model not specified)"} — Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson · confidence: medium - Equipment models.1: {"manufacturer_domain":"power-electronics.com","product_url":"https://power-electronics.com/en/solar/hem","count":null,"unit_mw":null,"name":"Power Electronics HEM FS3430M integrated inverter modules"} — Source · confidence: medium - Equipment models.2: {"manufacturer_domain":"lgchem.com","product_url":null,"count":null,"unit_mw":null,"name":"LG Chem batteries (exact model not specified)"} — Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson · confidence: medium - Equipment models.2: {"manufacturer_domain":"lgchem.com","product_url":null,"count":null,"unit_mw":null,"name":"LG Chem batteries (exact model not specified)"} — Q4 2023 - Solar power—and battery storage—take off at Edwards Air Force Base : BackIssues, altenerG.com - enerG Alternative Sources Magazine - enerG,Archives · confidence: medium - Equipment models.3: {"manufacturer_domain":"samsungsdi.com","product_url":"https://www.samsungsdi.com/business/index.html","count":null,"unit_mw":null,"name":"Samsung SDI batteries (exact model not specified)"} — Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson · confidence: medium - Equipment models.4: {"manufacturer_domain":"bydenergy.com","product_url":"https://www.bydenergy.com/","count":null,"unit_mw":null,"name":"BYD batteries (exact model not specified)"} — Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson · confidence: medium - Quality notes: ["The 248.9 MW total is explicitly reported as two generating units comprising a 148.9 MW photovoltaic unit and a 100 MW battery unit.","The disclosed $959 million financing relates to the Edwards Sanborn second phase and is not identified as an E4-specific financing amount or sale consideration.","The October 2022 Axium transaction involved an 80% interest in Edwards Sanborn 1A acquired from Terra-Gen; it should not be treated as an acquisition of Edwards Sanborn E4.","No E4-specific predecessor-owner transaction, acquisition consideration, retirement, or repowering event is disclosed in the cited record."] — Source · confidence: medium - Financing summary: The Edwards Sanborn second phase was financed with $959 million of senior secured credit facilities, comprising a $460 million construction and term loan facility, a $403 million tax-equity bridge facility, and a separately identified $96 million construction facility whose full description is not stated in the available record. The financing date and any E4-specific allocation are not disclosed; this amount is distinct from sale consideration. No E4-specific acquisition price or sale consideration is identified. — Source · confidence: medium - Timeline: [{"event":"Solar unit entered operation","date":"2022-12","detail":"The 148.9 MW solar photovoltaic generator at Edwards Sanborn E4 is reported as operating from December 2022."},{"event":"Battery unit entered operation","date":"2023-11","detail":"The 100 MW battery generator at Edwards Sanborn E4 is reported as operating from November 2023."},{"event":"Broader Edwards Sanborn 1B facility reached full commercial operations","date":"2024","detail":"Terra-Gen states that the broader Edwards Sanborn 1B facility was commissioned in phases and reached full commercial operations in 2024; this is a phase-level milestone rather than a separate E4 commissioning date."},{"event":"Second-phase financing disclosed","date":null,"detail":"Public materials disclose $959 million of senior secured credit facilities for the Edwards Sanborn second phase, but the available record does not provide the financing announcement month or year."},{"event":"E4-specific acquisition or sale record","date":null,"detail":"No E4-specific acquirer, seller, predecessor owner, transaction month/year, or sale consideration is identified. The separately disclosed October 2022 Axium acquisition concerned an 80% interest in Edwards Sanborn 1A, not E4."},{"event":"Operating status","date":"2026-08-02","detail":"The cited plant record identifies Edwards Sanborn E4 as operational, with two operational units and no planned units."}] — Source · confidence: medium - Timeline: [{"event":"Solar unit entered operation","date":"2022-12","detail":"The 148.9 MW solar photovoltaic generator at Edwards Sanborn E4 is reported as operating from December 2022."},{"event":"Battery unit entered operation","date":"2023-11","detail":"The 100 MW battery generator at Edwards Sanborn E4 is reported as operating from November 2023."},{"event":"Broader Edwards Sanborn 1B facility reached full commercial operations","date":"2024","detail":"Terra-Gen states that the broader Edwards Sanborn 1B facility was commissioned in phases and reached full commercial operations in 2024; this is a phase-level milestone rather than a separate E4 commissioning date."},{"event":"Second-phase financing disclosed","date":null,"detail":"Public materials disclose $959 million of senior secured credit facilities for the Edwards Sanborn second phase, but the available record does not provide the financing announcement month or year."},{"event":"E4-specific acquisition or sale record","date":null,"detail":"No E4-specific acquirer, seller, predecessor owner, transaction month/year, or sale consideration is identified. The separately disclosed October 2022 Axium acquisition concerned an 80% interest in Edwards Sanborn 1A, not E4."},{"event":"Operating status","date":"2026-08-02","detail":"The cited plant record identifies Edwards Sanborn E4 as operational, with two operational units and no planned units."}] — Source · confidence: medium - Commercial parties.3: {"relationship":"EPC contractor","name":"Mortenson","detail":"Full engineering, procurement, and construction contractor for the solar and storage scopes of the Edwards Sanborn second phase; an E4-specific contract allocation is not separately stated.","official_url":"https://www.mortenson.com/"} — Source · confidence: medium - Commercial parties.4: {"relationship":"Solar-module supplier","name":"First Solar","detail":"Solar-module supplier identified for the Edwards Sanborn second phase; an E4-specific module allocation is not separately stated.","official_url":"https://www.firstsolar.com/"} — Source · confidence: medium - Commercial parties.5: {"relationship":"Battery supplier","name":"LG Chem","detail":"Battery supplier identified for the Edwards Sanborn second phase; an E4-specific battery allocation is not separately stated.","official_url":"https://www.lgchem.com/"} — Source · confidence: medium - Commercial parties.6: {"relationship":"Battery supplier","name":"Samsung","detail":"Battery supplier identified for the Edwards Sanborn second phase; an E4-specific battery allocation is not separately stated.","official_url":"https://www.samsung.com/"} — Source · confidence: medium - Commercial parties.7: {"relationship":"Battery supplier","name":"BYD","detail":"Battery supplier identified for the Edwards Sanborn second phase; an E4-specific battery allocation is not separately stated.","official_url":"https://www.byd.com/"} — Source · confidence: medium - Quality notes.1: The disclosed $959 million financing relates to the Edwards Sanborn second phase and is not identified as an E4-specific financing amount or sale consideration. — Source · confidence: medium - Timeline.2: {"event":"Broader Edwards Sanborn 1B facility reached full commercial operations","date":"2024","detail":"Terra-Gen states that the broader Edwards Sanborn 1B facility was commissioned in phases and reached full commercial operations in 2024; this is a phase-level milestone rather than a separate E4 commissioning date."} — Source · confidence: medium - Timeline.3: {"event":"Second-phase financing disclosed","date":null,"detail":"Public materials disclose $959 million of senior secured credit facilities for the Edwards Sanborn second phase, but the available record does not provide the financing announcement month or year."} — Source · confidence: medium - Resource type: Hybrid — 2023 Resource Adequacy Report · confidence: medium - Grid role: Hybrid solar generation with DC-coupled battery storage that directly supports the PV unit and stores excess wind and solar generation. — Edwards Sanborn (Edsan) Solar Storage Phase 1A & 1B - Terra-Gen · confidence: medium ## Timeline - 2024 — Broader Edwards Sanborn 1B facility reached full commercial operations Terra-Gen states that the broader Edwards Sanborn 1B facility was commissioned in phases and reached full commercial operations in 2024; this is a phase-level milestone rather than a separate E4 commissioning date. Source: Source (https://terra-gen.com/terragen_project/edwards-sanborn-1b) ## Sources - [Edwards Sanborn (Edsan) Solar Storage Phase 1A & 1B - Terra-Gen](https://terra-gen.com/edwards-sanborn/) — terra-gen.com · tier other - [Cross-Reference Table](https://www.energy.ca.gov/sites/default/files/2025-04/Energy_Commission_Power_Plant_ID_Cross_Reference_Table_2024.xlsx) — energy.ca.gov · tier regulatory - [CPA_Power_Source_Disclosure_ Annual_ Report 06012023](https://efiling.energy.ca.gov/GetDocument.aspx?tn=250462&DocumentContentId=85217) — efiling.energy.ca.gov · tier regulatory - [Terra-Gen Closes Financing for Second Phase of Edwards Sanborn Solar Storage Franchise in California - Terra-Gen](https://terra-gen.com/news-release-1/) — terra-gen.com · tier other - [Edwards & Sanborn Solar + Energy Storage | Mortenson](https://www.mortenson.com/projects/edwards-sanborn-solar-plus-storage) — mortenson.com · tier other - [CAISO Resource Visibility Template](https://www.caiso.com/documents/caiso-resource-visibility-template.xlsx) — caiso.com · tier other - [Source](https://mortenson.com/projects/edwards-sanborn-solar-plus-storage) — mortenson.com · tier other - [Source](https://terra-gen.com/terragen_project/edwards-sanborn-1b) — terra-gen.com · tier other - [HEM | Power Electronics](https://power-electronics.com/en/solar/hem) — power-electronics.com · tier other - [Source](https://sanjosecleanenergy.org/wp-content/uploads/2021/02/Terra-Gen.Edwards.LGIA_.PUBLIC.pdf) — sanjosecleanenergy.org · tier other - [Edwards Sanborn (EdSan) Solar Storage](https://terra-gen.com/wp-content/uploads/2026/04/20260421-Edwards-Sanborn-Solar-Storage.pdf) — terra-gen.com · tier other - [Mortenson Announces Completion of Edwards & Sanborn Solar + Storage Project | Mortenson](https://www.mortenson.com/news-insights/edwards-sanborn-solar-storage-completion) — mortenson.com · tier other - [Q4 2023 - Solar power—and battery storage—take off at Edwards Air Force Base : BackIssues, altenerG.com - enerG Alternative Sources Magazine - enerG,Archives](https://www.altenerg.com/back_issues/story.php?sid=3125) — altenerg.com · tier other - [Series 6 Family | First Solar](https://www.firstsolar.com/en/Products/Series-6) — firstsolar.com · tier other - [Source](https://terra-gen.com/news-release-1) — terra-gen.com · tier other - [JANUARY 11, 2024 - AXIUM INFRASTRUCTURE INVESTS IN PHASE 1B OF THE EDWARDS SANBORN SOLAR STORAGE FACILITY – Axium Infrastructure](https://www.axiuminfra.com/2024/01/12/january-11-2024-axium-infrastructure-invests-in-phase-1b-of-the-edwards-sanborn-solar-storage-facility/?lang=en) — axiuminfra.com · tier other - [2023 Resource Adequacy Report](https://www.cpuc.ca.gov/-/media/cpuc-website/divisions/energy-division/documents/resource-adequacy-homepage/2023-resource-adequacy-reportv2.pdf) — cpuc.ca.gov · tier regulatory ## Data quality - The 248.9 MW total is explicitly reported as two generating units comprising a 148.9 MW photovoltaic unit and a 100 MW battery unit. The disclosed $959 million financing relates to the Edwards Sanborn second phase and is not identified as an E4-specific financing amount or sale consideration. No E4-specific predecessor-owner transaction, acquisition consideration, retirement, or repowering event is disclosed in the cited record. --- Canonical page: https://askthegrid.com/assets/facilities/edwards-sanborn-e4 Source: Ask the Grid — https://askthegrid.com/