# AEUG Union Solar, LLC PJM Solar Photovoltaic · https://askthegrid.com/assets/facilities/aeug-union-solar-llc AEUG Union Solar, LLC is a solar power facility with 325 MW of EIA-reported operating capacity in Union County, Ohio, registered as EIA Plant ID 64660. ACCIONA is the public owner or developer; Acciona Energy USA Global, LLC is the registered plant entity or operator. Project filings list 760,000 solar panels for the facility. Commercial operation began on December 26, 2024. ## Key facts - Technology: Solar Photovoltaic - Power capacity: 325 MW - Operating status: operating - Retirement: 2026-07 ## Grid and market context - ISO/RTO: PJM - Balancing authority: PJM ## Source-backed facts - Owner logo domain: acciona.com — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Identifiers: [{"value":"64660","system":"EIA plant code"},{"value":"AF1-227","system":"PJM queue position"},{"value":"6061","system":"PJM interim interconnection service agreement"},{"value":"ER21-1865-000","system":"FERC docket"},{"value":"ER23-2749-000","system":"FERC docket"},{"value":"EG23-175-000","system":"FERC docket"},{"value":"20-1405-EL-BGN","system":"Ohio Power Siting Board docket"}] — Source · confidence: medium - Identifiers: [{"value":"64660","system":"EIA plant code"},{"value":"AF1-227","system":"PJM queue position"},{"value":"6061","system":"PJM interim interconnection service agreement"},{"value":"ER21-1865-000","system":"FERC docket"},{"value":"ER23-2749-000","system":"FERC docket"},{"value":"EG23-175-000","system":"FERC docket"},{"value":"20-1405-EL-BGN","system":"Ohio Power Siting Board docket"}] — Federal Register, Volume 88 Issue 110 (Thursday, June 8, 2023) · confidence: medium - Description: AEUG Union Solar, LLC is a 325 MW solar photovoltaic generating facility in Union County, Ohio, interconnected through PJM. PJM records identify the customer facility as Union Solar and specify a 325 MW maximum facility output. ACCIONA announced commercial operation on December 26, 2024, and identified Amazon as the project's long-term power-purchase agreement counterparty. — Source · confidence: medium - Description: AEUG Union Solar, LLC is a 325 MW solar photovoltaic generating facility in Union County, Ohio, interconnected through PJM. PJM records identify the customer facility as Union Solar and specify a 325 MW maximum facility output. ACCIONA announced commercial operation on December 26, 2024, and identified Amazon as the project's long-term power-purchase agreement counterparty. — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Parties: [{"relationship":"Owner / parent company","name":"ACCIONA","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","official_url":"https://www.acciona.us/"},{"relationship":"PJM transmission provider / RTO","name":"PJM Interconnection, L.L.C.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","official_url":"https://www.amazon.com/"}] — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Parties: [{"relationship":"Owner / parent company","name":"ACCIONA","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","official_url":"https://www.acciona.us/"},{"relationship":"PJM transmission provider / RTO","name":"PJM Interconnection, L.L.C.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","official_url":"https://www.amazon.com/"}] — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Identifiers.1: {"value":"AF1-227","system":"PJM queue position"} — Source · confidence: medium - Identifiers.4: {"value":"ER23-2749-000","system":"FERC docket"} — Federal Register :: AEUG Union Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization · confidence: high - Identifiers.5: {"value":"EG23-175-000","system":"FERC docket"} — Federal Register, Volume 88 Issue 110 (Thursday, June 8, 2023) · confidence: high - Parties.0: {"relationship":"Owner / parent company","name":"ACCIONA","official_url":"https://www.acciona.com/"} — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Parties.5: {"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","official_url":"https://www.amazon.com/"} — Union Solar farm powers up Ohio with start of commercial operations · confidence: high - Interconnection: PJM interconnection via AEP Ohio Transmission Company, Inc., the interconnected transmission owner; the specific POI/substation name is not stated. — Source · confidence: medium - Site acres: 3355 — OPSB approves solar energy project in Union County · confidence: medium - Product url: https://www.waaree.com/upload/media/datasheet_bi_55_520_550_12_03012025_1756379026.pdf — AHNAY SERIES - Bi-55-520 to Bi-55-550... · confidence: medium - Product url: https://www.waaree.com/upload/media/datasheet_bi_55_520_550_12_03012025_1756379026.pdf — Aeug Union Solar Llc | See Full Importer History | ImportGenius · confidence: medium - Manufacturer domain: waaree.com — Aeug Union Solar Llc | See Full Importer History | ImportGenius · confidence: medium - Equipment models.0: {"manufacturer_domain":"waaree.com","product_url":"https://www.waaree.com/upload/media/datasheet_bi_55_520_550_12_03012025_1756379026.pdf","count":null,"unit_mw":0.00054,"name":"Waaree Bi-55-540WP"} — Aeug Union Solar Llc | See Full Importer History | ImportGenius · confidence: medium - Significance: ACCIONA announced commercial operation on 2024-12-26, marking the start of energy injection into the Ohio grid. ACCIONA states that the project can serve nearly 62,000 households. — Union Solar farm powers up Ohio with start of commercial operations · confidence: high - Description: AEUG Union Solar, LLC is a utility-scale solar photovoltaic facility in Union County, Ohio, with a 325 MW maximum facility output in PJM records; ACCIONA's project page separately lists 415 MW PV. The project applicant and interconnection customer is AEUG Union Solar, LLC, with Acciona Energy USA Global, LLC identified as operator or utility and ACCIONA as owner. The site uses tracker-mounted solar panels and covers about 22 square miles; ACCIONA reports 760,000 panels. Permitting ran from 2020 to 2021, construction from 2021 to 2024, and commercial operation began in December 2024; Amazon is the long-term power-purchase agreement counterparty. — Source · confidence: medium - Description: AEUG Union Solar, LLC is a utility-scale solar photovoltaic facility in Union County, Ohio, with a 325 MW maximum facility output in PJM records; ACCIONA's project page separately lists 415 MW PV. The project applicant and interconnection customer is AEUG Union Solar, LLC, with Acciona Energy USA Global, LLC identified as operator or utility and ACCIONA as owner. The site uses tracker-mounted solar panels and covers about 22 square miles; ACCIONA reports 760,000 panels. Permitting ran from 2020 to 2021, construction from 2021 to 2024, and commercial operation began in December 2024; Amazon is the long-term power-purchase agreement counterparty. — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Description: AEUG Union Solar, LLC is a utility-scale solar photovoltaic facility in Union County, Ohio, with a 325 MW maximum facility output in PJM records; ACCIONA's project page separately lists 415 MW PV. The project applicant and interconnection customer is AEUG Union Solar, LLC, with Acciona Energy USA Global, LLC identified as operator or utility and ACCIONA as owner. The site uses tracker-mounted solar panels and covers about 22 square miles; ACCIONA reports 760,000 panels. Permitting ran from 2020 to 2021, construction from 2021 to 2024, and commercial operation began in December 2024; Amazon is the long-term power-purchase agreement counterparty. — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Quality notes: ["PJM and EIA-related records identify a 325 MW maximum facility output, while ACCIONA's project page reports 415 MW PV; both source-reported ratings are retained without attempting to normalize them.","The December 2025 MIP transaction was a proposed portfolio stake sale rather than project-level financing or a Union Solar-specific sale consideration; the Union Solar allocation was not disclosed.","ACCIONA is identified as owner in the project materials and 2024 corporate ownership records; no predecessor owner, retirement, repowering, or separate expansion event is identified."] — Source · confidence: medium - Quality notes: ["PJM and EIA-related records identify a 325 MW maximum facility output, while ACCIONA's project page reports 415 MW PV; both source-reported ratings are retained without attempting to normalize them.","The December 2025 MIP transaction was a proposed portfolio stake sale rather than project-level financing or a Union Solar-specific sale consideration; the Union Solar allocation was not disclosed.","ACCIONA is identified as owner in the project materials and 2024 corporate ownership records; no predecessor owner, retirement, repowering, or separate expansion event is identified."] — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Financing summary: No project-level debt, tax-equity commitment, construction-financing amount, or project lender is disclosed in the cited records. Separately, on 2025-12-15 ACCIONA Energía agreed with Mexico Infrastructure Partners (MIP) to sell a 49% stake in its 1.3 GW U.S. photovoltaic portfolio, including Union Solar, together with the full stakes in two Mexican wind farms, for approximately US$1 billion (€855 million equity value). No Union Solar-specific portion of that portfolio value was disclosed, and official late-July 2026 materials still listed the U.S. 49% transaction as pending closing. — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Financing summary: No project-level debt, tax-equity commitment, construction-financing amount, or project lender is disclosed in the cited records. Separately, on 2025-12-15 ACCIONA Energía agreed with Mexico Infrastructure Partners (MIP) to sell a 49% stake in its 1.3 GW U.S. photovoltaic portfolio, including Union Solar, together with the full stakes in two Mexican wind farms, for approximately US$1 billion (€855 million equity value). No Union Solar-specific portion of that portfolio value was disclosed, and official late-July 2026 materials still listed the U.S. 49% transaction as pending closing. — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Timeline: [{"event":"Local permitting","date":"2020-2021","detail":"ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm."},{"event":"Interconnection agreement","date":"2021-05-07","detail":"PJM filed an executed Interim Interconnection Service Agreement among PJM, AEUG Union Solar, LLC, and AEP Ohio Transmission Company for the Union Solar facility."},{"event":"Construction","date":"2021-2024","detail":"ACCIONA identifies construction as running from 2021 through 2024."},{"event":"Commercial operation","date":"2024-12-26","detail":"ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid."},{"event":"Proposed portfolio sale","date":"2025-12-15","detail":"ACCIONA Energía announced an agreement with MIP for the sale of a 49% interest in a U.S. solar portfolio that includes Union Solar; ACCIONA said it would retain a 51% majority interest and continue operating and managing the assets."},{"event":"Sale status","date":"2026-07","detail":"ACCIONA's late-July 2026 H1 materials still described the U.S. 49% transaction as pending closure. No completed acquisition month or year is established."},{"event":"Ownership and predecessor history","date":null,"detail":"ACCIONA project materials identify ACCIONA as owner, and the 2024 corporate ownership schedule shows AEUG Union Solar, LLC held through AEUG Union Solar Holding LLC and AEUG Union Solar Finance LLC; no predecessor owner is identified."}] — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Timeline: [{"event":"Local permitting","date":"2020-2021","detail":"ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm."},{"event":"Interconnection agreement","date":"2021-05-07","detail":"PJM filed an executed Interim Interconnection Service Agreement among PJM, AEUG Union Solar, LLC, and AEP Ohio Transmission Company for the Union Solar facility."},{"event":"Construction","date":"2021-2024","detail":"ACCIONA identifies construction as running from 2021 through 2024."},{"event":"Commercial operation","date":"2024-12-26","detail":"ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid."},{"event":"Proposed portfolio sale","date":"2025-12-15","detail":"ACCIONA Energía announced an agreement with MIP for the sale of a 49% interest in a U.S. solar portfolio that includes Union Solar; ACCIONA said it would retain a 51% majority interest and continue operating and managing the assets."},{"event":"Sale status","date":"2026-07","detail":"ACCIONA's late-July 2026 H1 materials still described the U.S. 49% transaction as pending closure. No completed acquisition month or year is established."},{"event":"Ownership and predecessor history","date":null,"detail":"ACCIONA project materials identify ACCIONA as owner, and the 2024 corporate ownership schedule shows AEUG Union Solar, LLC held through AEUG Union Solar Holding LLC and AEUG Union Solar Finance LLC; no predecessor owner is identified."}] — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Timeline: [{"event":"Local permitting","date":"2020-2021","detail":"ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm."},{"event":"Interconnection agreement","date":"2021-05-07","detail":"PJM filed an executed Interim Interconnection Service Agreement among PJM, AEUG Union Solar, LLC, and AEP Ohio Transmission Company for the Union Solar facility."},{"event":"Construction","date":"2021-2024","detail":"ACCIONA identifies construction as running from 2021 through 2024."},{"event":"Commercial operation","date":"2024-12-26","detail":"ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid."},{"event":"Proposed portfolio sale","date":"2025-12-15","detail":"ACCIONA Energía announced an agreement with MIP for the sale of a 49% interest in a U.S. solar portfolio that includes Union Solar; ACCIONA said it would retain a 51% majority interest and continue operating and managing the assets."},{"event":"Sale status","date":"2026-07","detail":"ACCIONA's late-July 2026 H1 materials still described the U.S. 49% transaction as pending closure. No completed acquisition month or year is established."},{"event":"Ownership and predecessor history","date":null,"detail":"ACCIONA project materials identify ACCIONA as owner, and the 2024 corporate ownership schedule shows AEUG Union Solar, LLC held through AEUG Union Solar Holding LLC and AEUG Union Solar Finance LLC; no predecessor owner is identified."}] — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Timeline: [{"event":"Local permitting","date":"2020-2021","detail":"ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm."},{"event":"Interconnection agreement","date":"2021-05-07","detail":"PJM filed an executed Interim Interconnection Service Agreement among PJM, AEUG Union Solar, LLC, and AEP Ohio Transmission Company for the Union Solar facility."},{"event":"Construction","date":"2021-2024","detail":"ACCIONA identifies construction as running from 2021 through 2024."},{"event":"Commercial operation","date":"2024-12-26","detail":"ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid."},{"event":"Proposed portfolio sale","date":"2025-12-15","detail":"ACCIONA Energía announced an agreement with MIP for the sale of a 49% interest in a U.S. solar portfolio that includes Union Solar; ACCIONA said it would retain a 51% majority interest and continue operating and managing the assets."},{"event":"Sale status","date":"2026-07","detail":"ACCIONA's late-July 2026 H1 materials still described the U.S. 49% transaction as pending closure. No completed acquisition month or year is established."},{"event":"Ownership and predecessor history","date":null,"detail":"ACCIONA project materials identify ACCIONA as owner, and the 2024 corporate ownership schedule shows AEUG Union Solar, LLC held through AEUG Union Solar Holding LLC and AEUG Union Solar Finance LLC; no predecessor owner is identified."}] — Acciona Energía H1 2026 slides: asset sales to lift weak first half By Investing.com · confidence: medium - Commercial parties: [{"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","detail":"EIA-related plant records identify Acciona Energy USA Global, LLC as the utility associated with AEUG Union Solar, LLC.","official_url":"https://www.acciona.us/"},{"relationship":"Transmission provider / RTO","name":"PJM Interconnection, L.L.C.","detail":"PJM is the regional transmission organization and party to the Union Solar Interim Interconnection Service Agreement.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"},{"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"}] — Source · confidence: medium - Commercial parties: [{"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","detail":"EIA-related plant records identify Acciona Energy USA Global, LLC as the utility associated with AEUG Union Solar, LLC.","official_url":"https://www.acciona.us/"},{"relationship":"Transmission provider / RTO","name":"PJM Interconnection, L.L.C.","detail":"PJM is the regional transmission organization and party to the Union Solar Interim Interconnection Service Agreement.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"},{"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"}] — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Commercial parties: [{"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","detail":"EIA-related plant records identify Acciona Energy USA Global, LLC as the utility associated with AEUG Union Solar, LLC.","official_url":"https://www.acciona.us/"},{"relationship":"Transmission provider / RTO","name":"PJM Interconnection, L.L.C.","detail":"PJM is the regional transmission organization and party to the Union Solar Interim Interconnection Service Agreement.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"},{"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"}] — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Commercial parties: [{"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","detail":"EIA-related plant records identify Acciona Energy USA Global, LLC as the utility associated with AEUG Union Solar, LLC.","official_url":"https://www.acciona.us/"},{"relationship":"Transmission provider / RTO","name":"PJM Interconnection, L.L.C.","detail":"PJM is the regional transmission organization and party to the Union Solar Interim Interconnection Service Agreement.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"},{"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"}] — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Commercial parties: [{"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"},{"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"},{"relationship":"Operator / utility","name":"Acciona Energy USA Global, LLC","detail":"EIA-related plant records identify Acciona Energy USA Global, LLC as the utility associated with AEUG Union Solar, LLC.","official_url":"https://www.acciona.us/"},{"relationship":"Transmission provider / RTO","name":"PJM Interconnection, L.L.C.","detail":"PJM is the regional transmission organization and party to the Union Solar Interim Interconnection Service Agreement.","official_url":"https://www.pjm.com/"},{"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"},{"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"},{"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"}] — Mexico Infrastructure Partners – We are the leading asset... · confidence: medium - Timeline.0: {"event":"Local permitting","date":"2020-2021","detail":"ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm."} — Union County Solar Farm | ACCIONA | Business as unusual · confidence: high - Timeline.2: {"event":"Construction","date":"2021-2024","detail":"ACCIONA identifies construction as running from 2021 through 2024."} — Union County Solar Farm | ACCIONA | Business as unusual · confidence: high - Timeline.3: {"event":"Commercial operation","date":"2024-12-26","detail":"ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid."} — Union Solar farm powers up Ohio with start of commercial operations · confidence: high - Timeline.4: {"event":"Proposed portfolio sale","date":"2025-12-15","detail":"ACCIONA Energía announced an agreement with MIP for the sale of a 49% interest in a U.S. solar portfolio that includes Union Solar; ACCIONA said it would retain a 51% majority interest and continue operating and managing the assets."} — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: high - Timeline.5: {"event":"Sale status","date":"2026-07","detail":"ACCIONA's late-July 2026 H1 materials still described the U.S. 49% transaction as pending closure. No completed acquisition month or year is established."} — Acciona Energía H1 2026 slides: asset sales to lift weak first half By Investing.com · confidence: medium - Quality notes.0: PJM and EIA-related records identify a 325 MW maximum facility output, while ACCIONA's project page reports 415 MW PV; both source-reported ratings are retained without attempting to normalize them. — Union County Solar Farm | ACCIONA | Business as unusual · confidence: medium - Quality notes.1: The December 2025 MIP transaction was a proposed portfolio stake sale rather than project-level financing or a Union Solar-specific sale consideration; the Union Solar allocation was not disclosed. — Source · confidence: high - Quality notes.1: The December 2025 MIP transaction was a proposed portfolio stake sale rather than project-level financing or a Union Solar-specific sale consideration; the Union Solar allocation was not disclosed. — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: high - Commercial parties.0: {"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"} — Union Solar farm powers up Ohio with start of commercial operations · confidence: medium - Commercial parties.0: {"relationship":"Owner / parent company","name":"ACCIONA","detail":"ACCIONA's project materials identify ACCIONA as the owner. Under the proposed MIP transaction, ACCIONA would retain a 51% majority interest and continue operating and managing the assets.","official_url":"https://www.acciona.com/"} — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Commercial parties.1: {"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"} — 20-1405-EL-BGN: Union Solar - Ohio Power Siting Board · confidence: high - Commercial parties.1: {"relationship":"Project applicant and interconnection customer","name":"AEUG Union Solar, LLC","detail":"AEUG Union Solar, LLC proposed the Union County facility and is the PJM interconnection customer for Union Solar.","official_url":"https://www.acciona.com/projects/union-solar-farm"} — Source · confidence: high - Commercial parties.4: {"relationship":"Interconnected transmission owner","name":"AEP Ohio Transmission Company, Inc.","detail":"AEP Ohio Transmission Company is the transmission-owner party named in the Union Solar interconnection agreement.","official_url":"https://www.aep.com/"} — Source · confidence: medium - Commercial parties.5: {"relationship":"Long-term power-purchase agreement counterparty","name":"Amazon","detail":"ACCIONA states that Union Solar benefits from a long-term power-purchase agreement with Amazon.","official_url":"https://www.amazon.com/"} — Union Solar farm powers up Ohio with start of commercial operations · confidence: high - Commercial parties.6: {"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"} — ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN · confidence: medium - Commercial parties.6: {"relationship":"Proposed 49% portfolio buyer","name":"Mexico Infrastructure Partners (MIP)","detail":"MIP agreed in December 2025 to acquire a 49% interest in ACCIONA's U.S. photovoltaic portfolio, including Union Solar. The transaction remained pending closing in late-July 2026 materials.","official_url":"https://mexicoinfra.com/en/"} — Mexico Infrastructure Partners – We are the leading asset... · confidence: medium - Later sale or transfer: The announced 49% portfolio-stake sale to MIP remained unresolved; a 2026-07-31 report described the ACCIONA-MIP asset sale as faltering. — Acciona's US$1bn asset sale to Mexican investor MIP falters - BNamericas · confidence: medium ## Timeline - 2020-2021 — Local permitting ACCIONA's project materials give the local-permitting period as 2020-2021 for the Union County solar farm. Source: Union County Solar Farm | ACCIONA | Business as unusual (https://www.acciona.com/projects/union-solar-farm) - 2021-05-07 — Interconnection agreement PJM filed an executed Interim Interconnection Service Agreement among PJM, AEUG Union Solar, LLC, and AEP Ohio Transmission Company for the Union Solar facility. Source: federal energy regulatory commission (https://www.pjm.com/pub/planning/project-queues/isa/af1_227_isa2.pdf) - 2021-2024 — Construction ACCIONA identifies construction as running from 2021 through 2024. Source: Union County Solar Farm | ACCIONA | Business as unusual (https://www.acciona.com/projects/union-solar-farm) - 2024-12-26 — Commercial operation ACCIONA announced the commercial-operation date for Union Solar and the start of energy injection into the Ohio grid. Source: Union Solar farm powers up Ohio with start of commercial operations (https://www.acciona.com/updates/news/union-solar-farm-powers-up-ohio-start-commercial-operations) ## Sources - [Union County Solar Farm | ACCIONA | Business as unusual](https://www.acciona.com/projects/union-solar-farm) — acciona.com · tier other - [Source](https://www.pjm.com/pub/planning/project-queues/isa/af1_227_isa2.pdf) — pjm.com · tier other - [Federal Register :: AEUG Union Solar, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket Section 204 Authorization](https://www.federalregister.gov/documents/2023/09/08/2023-19413/aeug-union-solar-llc-supplemental-notice-that-initial-market-based-rate-filing-includes-request-for) — federalregister.gov · tier regulatory - [Federal Register, Volume 88 Issue 110 (Thursday, June 8, 2023)](https://www.govinfo.gov/content/pkg/FR-2023-06-08/html/2023-12240.htm) — govinfo.gov · tier regulatory - [Union Solar farm powers up Ohio with start of commercial operations](https://www.acciona.com/updates/news/union-solar-farm-powers-up-ohio-start-commercial-operations) — acciona.com · tier other - [OPSB approves solar energy project in Union County](https://opsb.ohio.gov/wps/portal/gov/opsb/news/opsb-approves-solar-energy-project-in-union-county) — opsb.ohio.gov · tier regulatory - [Union Solar Project Economic Impact and Land Use Analysis](https://www.unionsolarfarm.com/content/dam/accionacom/media/uirnw5qu/infographic-solar-union.pdf) — unionsolarfarm.com · tier other - [Source](https://acciona.com/updates/news/union-solar-farm-powers-up-ohio-start-commercial-operations) — acciona.com · tier other - [Union County Solar Farm | ACCIONA | Business as unusual](https://www.unionsolarfarm.com/) — unionsolarfarm.com · tier other - [20-1405-EL-BGN: Union Solar - Ohio Power Siting Board](https://opsb.ohio.gov/cases/20-1405-el-bgn) — opsb.ohio.gov · tier regulatory - [AHNAY SERIES - Bi-55-520 to Bi-55-550 ...](https://www.waaree.com/upload/media/datasheet_bi_55_520_550_12_03012025_1756379026.pdf) — waaree.com · tier other - [Aeug Union Solar Llc | See Full Importer History | ImportGenius](https://www.importgenius.com/importers/aeug-union-solar-llc) — importgenius.com · tier other - [Source](https://pjm.com/pub/planning/project-queues/isa/af1_227_isa2.pdf) — pjm.com · tier other - [Source](https://www.acciona-energia.com/content/dam/energiacom/media/qhdkoiz5/annual-accounts-consolidated-2024-ane.pdf) — acciona-energia.com · tier other - [ACCIONA Energía agrees to sell a wind and solar portfolio in the US and Mexico for US$1BN](https://www.acciona-energia.com/updates/news/acciona-energia-agrees-sell-wind-solar-portfolio-us-mexico-us-1-bn) — acciona-energia.com · tier other - [Acciona Energía H1 2026 slides: asset sales to lift weak first half By Investing.com](https://www.investing.com/news/company-news/acciona-energia-h1-2026-slides-asset-sales-to-lift-weak-first-half-93CH-4827472) — investing.com · tier other - [Mexico Infrastructure Partners – We are the leading asset ...](https://mexicoinfra.com/en/) — mexicoinfra.com · tier other - [A C C IONA ENE R GÍA A GR EE S T O S EL L A W IND AND](https://www.cnmv.es/webservices/verdocumento/ver?t=%7Ba378461e-ed46-4fb0-9f9f-d319b872b535%7D) — cnmv.es · tier other - [Acciona's US$1bn asset sale to Mexican investor MIP falters - BNamericas](https://www.bnamericas.com/en/news/accionas-us1bn-asset-sale-to-mexican-investor-mip-falters) — bnamericas.com · tier other - [Preliminary Monthly Electric Generator Inventory (based on Form EIA-860M as a supplement to Form EIA-860) - U.S. Energy Information Administration (EIA)](https://www.eia.gov/electricity/data/eia860m/) — eia.gov · tier regulatory ## Data quality - PJM and EIA-related records identify a 325 MW maximum facility output, while ACCIONA's project page reports 415 MW PV; both source-reported ratings are retained without attempting to normalize them. ACCIONA is identified as owner in the project materials and 2024 corporate ownership records; no predecessor owner, retirement, repowering, or separate expansion event is identified. --- Canonical page: https://askthegrid.com/assets/facilities/aeug-union-solar-llc Source: Ask the Grid — https://askthegrid.com/