# Hecate Energy Longhorn Solar LLC

ERCOT Solar Photovoltaic · https://askthegrid.com/assets/facilities/hecate-energy-longhorn-solar-llc

Hecate Energy Longhorn Solar LLC is a solar power facility with 650 MW of EIA-reported operating capacity in Jack County, Texas, registered as EIA Plant ID 68839. Repsol Renewables NA owns and operates the plant. Project filings list 1,500,000 solar panels and 170 inverters for the facility. Commercial operation began on May 21, 2026. The facility interconnects at Long Hollow Switch at 345 kV.

## Key facts

- Technology: Solar Photovoltaic
- Power capacity: 650 MW
- Operating status: operating

## Grid and market context

- ISO/RTO: ERCOT
- Balancing authority: ERCO (ERCOT)
- Substation: Long Hollow Switch
- Point of interconnection: Long Hollow Switch
- Transmission owner: Oncor Electric Delivery Company LLC
- Interconnection voltage: 345 kV

## Source-backed facts

- Owner logo domain: repsol.com — Source · confidence: medium
- Identifiers: [{"value":"68839","system":"EIA plant ID"},{"value":"65265","system":"EIA entity ID"},{"value":"RRPS","system":"EIA generator ID"},{"value":"ERCOT","system":"ISO/RTO"},{"value":"ERCO","system":"Balancing authority"},{"value":"24INR0010","system":"ERCOT queue ID"},{"value":"35077","system":"PUCT control number"},{"value":"1506 Long Hollow Switch 345kV","system":"Point of interconnection"}] — Source · confidence: medium
- Parties: [{"relationship":"Registered plant and interconnecting entity","name":"Hecate Energy Longhorn Solar LLC","official_url":null},{"relationship":"EIA-listed operator","name":"Repsol Renewables NA","official_url":"http://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml"},{"relationship":"Project developer","name":"Repsol","official_url":"http://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml"},{"relationship":"Engineer and builder","name":"Black & Veatch","official_url":"http://bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations"},{"relationship":"Construction subsidiary of Black & Veatch","name":"Overland Contracting Inc. (OCI)","official_url":null},{"relationship":"Interconnecting utility and GIA counterparty","name":"Oncor Electric Delivery Company LLC","official_url":null}] — Source · confidence: medium
- Parties: [{"relationship":"Registered plant and interconnecting entity","name":"Hecate Energy Longhorn Solar LLC","official_url":null},{"relationship":"EIA-listed operator","name":"Repsol Renewables NA","official_url":"http://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml"},{"relationship":"Project developer","name":"Repsol","official_url":"http://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml"},{"relationship":"Engineer and builder","name":"Black & Veatch","official_url":"http://bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations"},{"relationship":"Construction subsidiary of Black & Veatch","name":"Overland Contracting Inc. (OCI)","official_url":null},{"relationship":"Interconnecting utility and GIA counterparty","name":"Oncor Electric Delivery Company LLC","official_url":null}] — Source · confidence: medium
- Identifiers.6: {"value":"35077","system":"PUCT control number"} — Source · confidence: medium
- Parties.2: {"relationship":"Project developer","name":"Repsol","official_url":"http://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml"} — Source · confidence: medium
- Parties.3: {"relationship":"Engineer and builder","name":"Black & Veatch","official_url":"http://bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations"} — Source · confidence: medium
- Parties.4: {"relationship":"Construction subsidiary of Black & Veatch","name":"Overland Contracting Inc. (OCI)","official_url":null} — Source · confidence: medium
- Parties.5: {"relationship":"Interconnecting utility and GIA counterparty","name":"Oncor Electric Delivery Company LLC","official_url":null} — Source · confidence: medium
- Significance: Repsol and Black & Veatch describe Pinnington Solar as the largest single renewable project ever to reach commercial operation in ERCOT and among the largest single-injection renewable projects commissioned in the United States. — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Quality notes: ["EIA reports 650 MW for plant 68839, while Repsol and Black & Veatch describe Pinnington Solar as an 825 MW project; No separate buyer, seller, or transaction value for the plant itself was identified.","No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington."] — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Quality notes: ["EIA reports 650 MW for plant 68839, while Repsol and Black & Veatch describe Pinnington Solar as an 825 MW project; No separate buyer, seller, or transaction value for the plant itself was identified.","No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington."] — Repsol allies with Stonepeak on solar and storage portfolio for its first us renewables partnership · confidence: medium
- Quality notes: ["EIA reports 650 MW for plant 68839, while Repsol and Black & Veatch describe Pinnington Solar as an 825 MW project; No separate buyer, seller, or transaction value for the plant itself was identified.","No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington."] — Hecate Energy - Projects · confidence: medium
- Financing summary: No debt financing, project-finance lender, or plant-specific tax-equity amount was disclosed for EIA plant 68839. Repsol disclosed on April 29, 2025 that Stonepeak would invest $340 million for a 46.3% stake in a separate 777 MW solar-and-storage portfolio, alongside $60 million of previously raised tax equity; the named assets were Frye in Texas and the Jicarilla complex in New Mexico, while Pinnington was identified separately as an asset under construction. Those portfolio amounts should not be treated as financing or sale consideration for Pinnington Solar. — Repsol allies with Stonepeak on solar and storage portfolio for its first us renewables partnership · confidence: medium
- Financing summary: No debt financing, project-finance lender, or plant-specific tax-equity amount was disclosed for EIA plant 68839. Repsol disclosed on April 29, 2025 that Stonepeak would invest $340 million for a 46.3% stake in a separate 777 MW solar-and-storage portfolio, alongside $60 million of previously raised tax equity; the named assets were Frye in Texas and the Jicarilla complex in New Mexico, while Pinnington was identified separately as an asset under construction. Those portfolio amounts should not be treated as financing or sale consideration for Pinnington Solar. — Longhorn Solar · confidence: medium
- Commercial parties.1: {"relationship":"EIA-listed operator and project developer","name":"Repsol Renewables NA","detail":"EIA lists Repsol Renewables NA as operator, while Repsol identifies Pinnington Solar as a Repsol-developed project.","official_url":"https://www.repsol.com/en/index.cshtml"} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high
- Commercial parties.3: {"relationship":"Engineer and builder","name":"Black & Veatch","detail":"Repsol and Black & Veatch identify Black & Veatch as the project's engineer and builder.","official_url":"https://www.bv.com/"} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high
- Commercial parties.3: {"relationship":"Engineer and builder","name":"Black & Veatch","detail":"Repsol and Black & Veatch identify Black & Veatch as the project's engineer and builder.","official_url":"https://www.bv.com/"} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas | Black & Veatch · confidence: high
- Commercial parties.4: {"relationship":"Construction subsidiary","name":"Overland Contracting Inc. (OCI)","detail":"OCI, a Black & Veatch construction subsidiary, performed construction work on Pinnington Solar.","official_url":"https://www.bv.com/"} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Commercial parties.4: {"relationship":"Construction subsidiary","name":"Overland Contracting Inc. (OCI)","detail":"OCI, a Black & Veatch construction subsidiary, performed construction work on Pinnington Solar.","official_url":"https://www.bv.com/"} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas | Black & Veatch · confidence: medium
- Timeline.0: {"event":"ERCOT interconnection queue entry","date":"2020-12-02","detail":"Pinnington Solar entered the ERCOT interconnection queue under queue ID 24INR0010."} — Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch · confidence: medium
- Timeline.0: {"event":"ERCOT interconnection queue entry","date":"2020-12-02","detail":"Pinnington Solar entered the ERCOT interconnection queue under queue ID 24INR0010."} — Repsol sells 40% stake in Hecate Energy, settles legal dispute - PV Tech · confidence: medium
- Timeline.0: {"event":"ERCOT interconnection queue entry","date":"2020-12-02","detail":"Pinnington Solar entered the ERCOT interconnection queue under queue ID 24INR0010."} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Timeline.0: {"event":"ERCOT interconnection queue entry","date":"2020-12-02","detail":"Pinnington Solar entered the ERCOT interconnection queue under queue ID 24INR0010."} — Repsol allies with Stonepeak on solar and storage portfolio for its first us renewables partnership · confidence: medium
- Timeline.0: {"event":"ERCOT interconnection queue entry","date":"2020-12-02","detail":"Pinnington Solar entered the ERCOT interconnection queue under queue ID 24INR0010."} — Longhorn Solar · confidence: medium
- Timeline.3: {"event":"Construction agreement and mobilization","date":"2024-05","detail":"Black & Veatch states that the full agreement was signed in May 2024 and that crews mobilized within four days."} — Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch · confidence: medium
- Timeline.4: {"event":"Construction disruption","date":"2025-03","detail":"A tornado damaged one of the project's 170 solar arrays during construction; Black & Veatch states that construction momentum continued."} — Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch · confidence: high
- Timeline.7: {"event":"ERCOT queue completion","date":"2026-04-22","detail":"The matched ERCOT queue record reports an actual completion date of April 22, 2026."} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Timeline.8: {"event":"Commercial operation","date":"2026-05-21","detail":"Repsol announced that its 825 MW Pinnington Solar project had reached commercial operations in Texas."} — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Quality notes.0: EIA reports 650 MW for plant 68839, while Repsol and Black & Veatch describe Pinnington Solar as an 825 MW project. — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high
- Quality notes.1: The operational dates are not identical across records: EIA reports April 1, 2026, the ERCOT queue record reports actual completion on April 22, 2026, and Repsol reports commercial operations on May 21, 2026. — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high
- Quality notes.2: The disclosed 2021 acquisition and 2025 sale concerned equity in Hecate Energy Group, not a documented project-level acquisition or sale of EIA plant 68839. No separate buyer, seller, or transaction value for the plant itself was identified. — Repsol enters the U.S. renewables market with the purchase of 40% of project developer Hecate Energy · confidence: medium
- Quality notes.2: The disclosed 2021 acquisition and 2025 sale concerned equity in Hecate Energy Group, not a documented project-level acquisition or sale of EIA plant 68839. No separate buyer, seller, or transaction value for the plant itself was identified. — Repsol sells 40% stake in Hecate Energy, settles legal dispute - PV Tech · confidence: medium
- Quality notes.3: No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington. — Repsol allies with Stonepeak on solar and storage portfolio for its first us renewables partnership · confidence: medium
- Quality notes.3: No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington. — Longhorn Solar · confidence: medium
- Quality notes.3: No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington. — Hecate Energy - Projects · confidence: medium
- Status date: 2026-05-21 — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high
- Status detail: The exact plant is operating. EIA lists Hecate Energy Longhorn Solar LLC as operational, Repsol announced Pinnington Solar reached commercial operation on 2026-05-21, and ERCOT's 2026 resource records identify three solar unit resources under the Pinnington Solar station. No retirement, mothball, standby, deactivation, or repowering date is stated in the cited operating and interconnection records. — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: medium
- Operating status: operating — Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas · confidence: high

## Timeline

- 2023-11-29 — Generation interconnection agreement
  Oncor Electric Delivery Company LLC filed the generation interconnection agreement with Hecate Energy Longhorn Solar LLC, identified as Pinnington Solar.
  Source: Interchange - Filings (https://interchange.puc.texas.gov/search/filings?ControlNumber=35077&DocumentType=ALL&SortBy=FilingDescription&SortOrder=Ascending&UtilityType=E)
- 2024-05 — Construction agreement and mobilization
  Black & Veatch states that the full agreement was signed in May 2024 and that crews mobilized within four days.
  Source: Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch (https://www.bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations)
- 2025-03 — Construction disruption
  A tornado damaged one of the project's 170 solar arrays during construction; Black & Veatch states that construction momentum continued.
  Source: Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch (https://www.bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations)
- 2026-05-21 — Commercial operation
  Repsol announced that its 825 MW Pinnington Solar project had reached commercial operations in Texas.
  Source: Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas (https://www.repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml)

## Sources

- [Source](https://repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml) — repsol.com · tier other
- [Interchange - Filings](https://interchange.puc.texas.gov/search/filings?ControlNumber=35077&DocumentType=ALL&SortBy=FilingDescription&SortOrder=Ascending&UtilityType=E) — interchange.puc.texas.gov · tier regulatory
- [Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas](https://www.repsol.com/en/press-room/press-releases/2026/repsol-achieves-commerical-operations-825-mw-pinnington-solar-facility-texas/index.cshtml) — repsol.com · tier other
- [Pinnington Solar: Delivering one of America’s largest solar projects came against mighty odds, expectations | Black & Veatch](https://www.bv.com/projects/pinnington-solar-delivering-one-of-americas-largest-solar-projects-came-against-mighty-odds-expectations) — bv.com · tier other
- [Hecate Energy - Projects](https://www.hecateenergy.com/projects/) — hecateenergy.com · tier other
- [Repsol allies with Stonepeak on solar and storage portfolio for its first us renewables partnership](https://www.repsol.com/en/press-room/press-releases/2025/repsol-allies--stonepeak-solar-storage-portfolio-first-us-renewables-partnership/index.cshtml) — repsol.com · tier other
- [Longhorn Solar](https://apps.easydoc.jackcounty.org/minutes/LinkedDir/2023/Links%202023-07-31-Special/14%20RUA%20Longhorn%20Solar.pdf) — apps.easydoc.jackcounty.org · tier other
- [Repsol enters the U.S. renewables market with the purchase of 40% of project developer Hecate Energy](https://www.repsol.com/en/press-room/press-releases/2021/repsol-enters-the-us-renewables-market-with-the-purchase-of-40-of-project-developer-hecate-energy/index.cshtml) — repsol.com · tier other
- [Repsol sells 40% stake in Hecate Energy, settles legal dispute - PV Tech](https://www.pv-tech.org/repsol-sells-40-stake-in-hecate-energy-settles-legal-dispute/) — pv-tech.org · tier other
- [Repsol achieves commercial operations at its 825 MW Pinnington solar facility in Texas | Black & Veatch](https://www.bv.com/news/repsol-achieves-commercial-operations-at-its-825-mw-pinnington-solar-facility-in-texas) — bv.com · tier other
- [~ > X E T ~](https://interchange.puc.texas.gov/Documents/35077_1713_1349269.PDF) — interchange.puc.texas.gov · tier regulatory

## Data quality

- EIA reports 650 MW for plant 68839, while Repsol and Black & Veatch describe Pinnington Solar as an 825 MW project; The operational dates are not identical across records: EIA reports April 1, 2026, the ERCOT queue record reports actual completion on April 22, 2026, and Repsol reports commercial operations on May 21, 2026. The disclosed 2021 acquisition and 2025 sale concerned equity in Hecate Energy Group, not a documented project-level acquisition or sale of EIA plant 68839. No separate buyer, seller, or transaction value for the plant itself was identified. No plant-specific debt financing, lender, tax-equity amount, expansion, retirement, or repowering disclosure was identified. Repsol's disclosed $60 million of tax equity and Stonepeak's $340 million investment related to a separate 777 MW portfolio comprising Frye and Jicarilla, not Pinnington.

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