# Delta Energy Center

CAISO Natural Gas Fired Combined Cycle · https://askthegrid.com/assets/facilities/delta-energy-center

Delta Energy Center is a natural gas-fired power facility with 943.5 MW of EIA-reported nameplate capacity in Contra Costa County, California, registered as EIA Plant ID 55333. Calpine Corporation is the current owner; Delta Energy Center LLC is the registered plant entity or operator. The plant's generating configuration is natural-gas-fired combined-cycle cogeneration facility with three Westinghouse 501F combustion-turbine generators, three HRSGs with duct burners, and one shared steam-turbine generator.
DELTA ENERGY CENTER AGGREGATE · 230 kV.

## Key facts

- Technology: Natural Gas Fired Combined Cycle
- Power capacity: 943.5 MW
- Operating status: operating

## Grid and market context

- ISO/RTO: CAISO
- Balancing authority: CAISO

## Source-backed facts

- Owner logo domain: constellationenergy.com — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Identifiers: [{"value":"55333","system":"EIA plant ID"},{"value":"G0783","system":"CEC plant ID"},{"value":"DELTA ENERGY CENTER (AGGREGATE)","system":"CAISO aggregate resource ID"},{"value":"DELTA_2_STG","system":"CAISO resource ID — steam turbine generator"},{"value":"DELTA_2_CTG1","system":"CAISO resource ID — combustion turbine generator 1"},{"value":"DELTA_2_CTG2","system":"CAISO resource ID — combustion turbine generator 2"},{"value":"DELTA_2_CTG3","system":"CAISO resource ID — combustion turbine generator 3"},{"value":"98-AFC-03","system":"CEC certification docket"},{"value":"98-AFC-03C","system":"CEC compliance docket"},{"value":"ER03-510-000","system":"FERC docket"},{"value":"SF Bay Area","system":"CAISO local capacity area"},{"value":"WECC","system":"NERC region"}] — Cross-Reference Table · confidence: medium
- Identifiers: [{"value":"55333","system":"EIA plant ID"},{"value":"G0783","system":"CEC plant ID"},{"value":"DELTA ENERGY CENTER (AGGREGATE)","system":"CAISO aggregate resource ID"},{"value":"DELTA_2_STG","system":"CAISO resource ID — steam turbine generator"},{"value":"DELTA_2_CTG1","system":"CAISO resource ID — combustion turbine generator 1"},{"value":"DELTA_2_CTG2","system":"CAISO resource ID — combustion turbine generator 2"},{"value":"DELTA_2_CTG3","system":"CAISO resource ID — combustion turbine generator 3"},{"value":"98-AFC-03","system":"CEC certification docket"},{"value":"98-AFC-03C","system":"CEC compliance docket"},{"value":"ER03-510-000","system":"FERC docket"},{"value":"SF Bay Area","system":"CAISO local capacity area"},{"value":"WECC","system":"NERC region"}] — Source · confidence: medium
- Identifiers: [{"value":"55333","system":"EIA plant ID"},{"value":"G0783","system":"CEC plant ID"},{"value":"DELTA ENERGY CENTER (AGGREGATE)","system":"CAISO aggregate resource ID"},{"value":"DELTA_2_STG","system":"CAISO resource ID — steam turbine generator"},{"value":"DELTA_2_CTG1","system":"CAISO resource ID — combustion turbine generator 1"},{"value":"DELTA_2_CTG2","system":"CAISO resource ID — combustion turbine generator 2"},{"value":"DELTA_2_CTG3","system":"CAISO resource ID — combustion turbine generator 3"},{"value":"98-AFC-03","system":"CEC certification docket"},{"value":"98-AFC-03C","system":"CEC compliance docket"},{"value":"ER03-510-000","system":"FERC docket"},{"value":"SF Bay Area","system":"CAISO local capacity area"},{"value":"WECC","system":"NERC region"}] — Delta Energy Center | California Energy Commission · confidence: medium
- Identifiers: [{"value":"55333","system":"EIA plant ID"},{"value":"G0783","system":"CEC plant ID"},{"value":"DELTA ENERGY CENTER (AGGREGATE)","system":"CAISO aggregate resource ID"},{"value":"DELTA_2_STG","system":"CAISO resource ID — steam turbine generator"},{"value":"DELTA_2_CTG1","system":"CAISO resource ID — combustion turbine generator 1"},{"value":"DELTA_2_CTG2","system":"CAISO resource ID — combustion turbine generator 2"},{"value":"DELTA_2_CTG3","system":"CAISO resource ID — combustion turbine generator 3"},{"value":"98-AFC-03","system":"CEC certification docket"},{"value":"98-AFC-03C","system":"CEC compliance docket"},{"value":"ER03-510-000","system":"FERC docket"},{"value":"SF Bay Area","system":"CAISO local capacity area"},{"value":"WECC","system":"NERC region"}] — California Energy Commission : Docket Log · confidence: medium
- Owner name: Constellation Energy Corporation — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Description: Delta Energy Center is an operational natural-gas-fired combined-cycle facility at 1200 Arcy Lane in Pittsburg, Contra Costa County, California. The California Energy Commission lists the facility at 880 MW with commercial operation beginning May 10, 2002, while the EIA plant record associated with plant 55333 lists 943.5 MW of nameplate capacity. The facility consists of three Westinghouse 501F combustion turbine generators, three heat-recovery steam generators, and a shared steam turbine generator. — Delta Energy Center | California Energy Commission · confidence: medium
- Identifiers.0: {"value":"55333","system":"EIA plant ID"} — Cross-Reference Table · confidence: high
- Identifiers.1: {"value":"G0783","system":"CEC plant ID"} — Cross-Reference Table · confidence: high
- Identifiers.3: {"value":"DELTA_2_STG","system":"CAISO resource ID — steam turbine generator"} — Source · confidence: medium
- Identifiers.4: {"value":"DELTA_2_CTG1","system":"CAISO resource ID — combustion turbine generator 1"} — Source · confidence: medium
- Identifiers.5: {"value":"DELTA_2_CTG2","system":"CAISO resource ID — combustion turbine generator 2"} — Source · confidence: medium
- Identifiers.6: {"value":"DELTA_2_CTG3","system":"CAISO resource ID — combustion turbine generator 3"} — Source · confidence: medium
- Identifiers.7: {"value":"98-AFC-03","system":"CEC certification docket"} — Delta Energy Center | California Energy Commission · confidence: high
- Identifiers.8: {"value":"98-AFC-03C","system":"CEC compliance docket"} — California Energy Commission : Docket Log · confidence: high
- Identifiers.10: {"value":"SF Bay Area","system":"CAISO local capacity area"} — Source · confidence: medium
- Identifiers.11: {"value":"WECC","system":"NERC region"} — Table of Operating Power Plants and Projects Under Construction as of: Friday, February 6, 2026 · confidence: high
- Parties.1: {"relationship":"Operator and 100% interest holder listed in the operating-plant portfolio","name":"Calpine Corporation","official_url":"https://www.calpine.com"} — Table of Operating Power Plants and Projects Under Construction as of: Friday, February 6, 2026 · confidence: medium
- Parties.2: {"relationship":"Current parent company of Calpine Corporation","name":"Constellation Energy Corporation","official_url":"https://www.constellationenergy.com"} — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Parties.5: {"relationship":"Engineering, procurement, and construction contractor","name":"Black & Veatch","official_url":"https://www.bv.com"} — Business Briefs - Power Engineering · confidence: medium
- Parties.6: {"relationship":"Combustion-turbine OEM","name":"Westinghouse","official_url":null} — Delta Energy Center | California Energy Commission · confidence: high
- Interconnection: Existing Pacific Gas and Electric (PG&E) substation near the Pittsburg Power Plant, connected by a 3.3-mile, 230-kV transmission line. — Delta Energy Center | California Energy Commission · confidence: high
- Unit configuration: Natural-gas-fired combined-cycle cogeneration facility with three Westinghouse 501F combustion-turbine generators, three HRSGs with duct burners, and one shared steam-turbine generator. — Delta Energy Center | California Energy Commission · confidence: medium
- Unit count: 4 — Delta Energy Center | California Energy Commission · confidence: medium
- Construction scope: An 880 MW natural-gas-fired combined-cycle cogeneration facility consisting of three Westinghouse 501F combustion-turbine generators, three heat-recovery steam-generator (HRSG) units with duct burners, one shared steam-turbine generator, cooling towers, associated support equipment, and two auxiliary boilers supplying process steam to Dow. — Delta Energy Center | California Energy Commission · confidence: medium
- Product url: https://www.psm.com/products/f-class-frames/501f — 501F Gas Turbine Aftermarket Upgrades & Parts | Hanwha Power · confidence: medium
- Kind: thermal — Delta Energy Center | California Energy Commission · confidence: high
- Manufacturer domain: westinghouse.com — Delta Energy Center | California Energy Commission · confidence: medium
- Manufacturer domain: westinghouse.com — 501F Gas Turbine Aftermarket Upgrades & Parts | Hanwha Power · confidence: medium
- Equipment models: [{"manufacturer_domain":"westinghouse.com","product_url":"https://www.psm.com/products/f-class-frames/501f","count":3,"unit_mw":null,"name":"Westinghouse 501F combustion-turbine generator"},{"manufacturer_domain":"deltak.com","product_url":"https://deltak.com/","count":3,"unit_mw":null,"name":"Deltak heat-recovery steam generator (HRSG)"},{"manufacturer_domain":"toshiba.com","product_url":"https://toshiba.com/taes/products/steam-turbine-generator/","count":1,"unit_mw":306,"name":"Toshiba steam-turbine generator"}] — Delta Energy Center | California Energy Commission · confidence: medium
- Product family: Westinghouse 501F (W501F) — Delta Energy Center | California Energy Commission · confidence: medium
- Product family: Westinghouse 501F (W501F) — 501F Gas Turbine Aftermarket Upgrades & Parts | Hanwha Power · confidence: medium
- Manufacturer name: Westinghouse — Delta Energy Center | California Energy Commission · confidence: medium
- Equipment models.0: {"manufacturer_domain":"westinghouse.com","product_url":"https://www.psm.com/products/f-class-frames/501f","count":3,"unit_mw":null,"name":"Westinghouse 501F combustion-turbine generator"} — Delta Energy Center | California Energy Commission · confidence: medium
- Equipment models.0: {"manufacturer_domain":"westinghouse.com","product_url":"https://www.psm.com/products/f-class-frames/501f","count":3,"unit_mw":null,"name":"Westinghouse 501F combustion-turbine generator"} — 501F Gas Turbine Aftermarket Upgrades & Parts | Hanwha Power · confidence: medium
- Equipment models.1: {"manufacturer_domain":"deltak.com","product_url":"https://deltak.com/","count":3,"unit_mw":null,"name":"Deltak heat-recovery steam generator (HRSG)"} — Delta Energy Center | California Energy Commission · confidence: medium
- Significance: CAISO identifies Delta Energy Center's steam-turbine generator and three combustion-turbine generators as separate resources in the San Francisco Bay Area local-capacity area. The facility is therefore a significant multi-resource grid asset, in addition to its cogeneration role supplying steam to Dow Chemical. — Source · confidence: medium
- Description: Delta Energy Center is an operational natural-gas-fired combined-cycle cogeneration facility at 1200 Arcy Lane in Pittsburg, Contra Costa County, California. The California Energy Commission describes an 880 MW configuration comprising three Westinghouse 501F combustion turbines, three heat-recovery steam generators, and a shared steam turbine; approximately 200,000 lb/hr of steam is supplied to Dow Chemical. EIA plant 55333 records 943.5 MW of nameplate capacity, while the CEC reports 880 MW. The project was initially developed by Calpine and Bechtel, became wholly owned by Calpine after Calpine acquired Bechtel's 50% interest in November 2001, and is now within Constellation Energy's portfolio following its January 2026 completion of the Calpine acquisition. — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Timeline: [{"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."},{"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."},{"event":"Acquisition of Bechtel's project interest","date":"2001-11-06","detail":"Calpine acquired Bechtel Enterprises Holdings' remaining 50% interest in Delta Energy Center, together with interests in Metcalf and Russell City, for approximately $154 million plus assumption of approximately $141 million of debt, making Calpine the 100% owner of Delta."},{"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."},{"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."},{"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."},{"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."},{"event":"Calpine take-private agreement announced","date":"2017-08-18","detail":"Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board."},{"event":"Calpine take-private transaction closed","date":"2018-03","detail":"Energy Capital Partners reports that its Calpine investment closed in March 2018; Delta remained part of Calpine's portfolio."},{"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."},{"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."}] — Source · confidence: medium
- Timeline: [{"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."},{"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."},{"event":"Acquisition of Bechtel's project interest","date":"2001-11-06","detail":"Calpine acquired Bechtel Enterprises Holdings' remaining 50% interest in Delta Energy Center, together with interests in Metcalf and Russell City, for approximately $154 million plus assumption of approximately $141 million of debt, making Calpine the 100% owner of Delta."},{"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."},{"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."},{"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."},{"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."},{"event":"Calpine take-private agreement announced","date":"2017-08-18","detail":"Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board."},{"event":"Calpine take-private transaction closed","date":"2018-03","detail":"Energy Capital Partners reports that its Calpine investment closed in March 2018; Delta remained part of Calpine's portfolio."},{"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."},{"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."}] — Delta Energy Center | California Energy Commission · confidence: medium
- Timeline: [{"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."},{"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."},{"event":"Acquisition of Bechtel's project interest","date":"2001-11-06","detail":"Calpine acquired Bechtel Enterprises Holdings' remaining 50% interest in Delta Energy Center, together with interests in Metcalf and Russell City, for approximately $154 million plus assumption of approximately $141 million of debt, making Calpine the 100% owner of Delta."},{"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."},{"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."},{"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."},{"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."},{"event":"Calpine take-private agreement announced","date":"2017-08-18","detail":"Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board."},{"event":"Calpine take-private transaction closed","date":"2018-03","detail":"Energy Capital Partners reports that its Calpine investment closed in March 2018; Delta remained part of Calpine's portfolio."},{"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."},{"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."}] — Source · confidence: medium
- Timeline: [{"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."},{"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."},{"event":"Acquisition of Bechtel's project interest","date":"2001-11-06","detail":"Calpine acquired Bechtel Enterprises Holdings' remaining 50% interest in Delta Energy Center, together with interests in Metcalf and Russell City, for approximately $154 million plus assumption of approximately $141 million of debt, making Calpine the 100% owner of Delta."},{"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."},{"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."},{"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."},{"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."},{"event":"Calpine take-private agreement announced","date":"2017-08-18","detail":"Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board."},{"event":"Calpine take-private transaction closed","date":"2018-03","detail":"Energy Capital Partners reports that its Calpine investment closed in March 2018; Delta remained part of Calpine's portfolio."},{"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."},{"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."}] — Constellation to Acquire Calpine; Creates America’s Leading Producer of Clean and Reliable Energy to Meet Growing Demand for Customers and Communities · confidence: medium
- Timeline: [{"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."},{"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."},{"event":"Acquisition of Bechtel's project interest","date":"2001-11-06","detail":"Calpine acquired Bechtel Enterprises Holdings' remaining 50% interest in Delta Energy Center, together with interests in Metcalf and Russell City, for approximately $154 million plus assumption of approximately $141 million of debt, making Calpine the 100% owner of Delta."},{"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."},{"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."},{"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."},{"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."},{"event":"Calpine take-private agreement announced","date":"2017-08-18","detail":"Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board."},{"event":"Calpine take-private transaction closed","date":"2018-03","detail":"Energy Capital Partners reports that its Calpine investment closed in March 2018; Delta remained part of Calpine's portfolio."},{"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."},{"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."}] — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Timeline.0: {"event":"Initial project development","date":"1999","detail":"Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California."} — Source · confidence: high
- Timeline.1: {"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."} — Delta Energy Center | California Energy Commission · confidence: high
- Timeline.1: {"event":"CEC certification and construction","date":"2000-02-09","detail":"The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000."} — Source · confidence: high
- Timeline.3: {"event":"Commercial operation","date":"2002-05-10","detail":"The CEC records the beginning of commercial operation."} — Delta Energy Center | California Energy Commission · confidence: high
- Timeline.4: {"event":"Cooling-tower expansion","date":"2002-11-14","detail":"The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower."} — Delta Energy Center | California Energy Commission · confidence: high
- Timeline.5: {"event":"Temporary simple-cycle modification","date":"2017-03-08","detail":"The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode."} — Delta Energy Center | California Energy Commission · confidence: high
- Timeline.6: {"event":"Return to combined-cycle operation","date":"2018-02-08","detail":"The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations."} — Delta Energy Center | California Energy Commission · confidence: high
- Timeline.9: {"event":"Constellation-Calpine acquisition announced","date":"2025-01-10","detail":"Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt."} — Constellation to Acquire Calpine; Creates America’s Leading Producer of Clean and Reliable Energy to Meet Growing Demand for Customers and Communities · confidence: high
- Timeline.10: {"event":"Constellation-Calpine acquisition completed","date":"2026-01-07","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners, placing Calpine's generation portfolio, including Delta Energy Center, within Constellation."} — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Commercial parties.1: {"relationship":"Original co-developer, subsequent 100% owner, and operator","name":"Calpine Corporation","detail":"Calpine developed Delta with Bechtel, acquired Bechtel's 50% interest in November 2001, and later listed Delta as a 100%-owned combined-cycle asset. Calpine continues as the operating company within Constellation's portfolio.","official_url":"https://www.calpine.com"} — Delta Energy Center, US · confidence: medium
- Commercial parties.1: {"relationship":"Original co-developer, subsequent 100% owner, and operator","name":"Calpine Corporation","detail":"Calpine developed Delta with Bechtel, acquired Bechtel's 50% interest in November 2001, and later listed Delta as a 100%-owned combined-cycle asset. Calpine continues as the operating company within Constellation's portfolio.","official_url":"https://www.calpine.com"} — Our Assets - Calpine · confidence: medium
- Commercial parties.3: {"relationship":"Current parent company","name":"Constellation Energy Corporation","detail":"Constellation completed its acquisition of Calpine from Energy Capital Partners on January 7, 2026; Delta Energy Center was identified as part of the combined portfolio.","official_url":"https://www.constellationenergy.com"} — Constellation Completes Calpine Transaction, Powering America's Clean Energy Future · confidence: medium
- Commercial parties.6: {"relationship":"Grid operator and market interface","name":"California Independent System Operator Corporation","detail":"CAISO identifies Delta's steam-turbine and three combustion-turbine resources in the San Francisco Bay Area local-capacity area.","official_url":"https://www.caiso.com"} — Source · confidence: medium
- Commercial parties.7: {"relationship":"Engineering, procurement, and construction contractor","name":"Black & Veatch","detail":"Black & Veatch completed full engineering, procurement, and construction services for Calpine's Delta Energy Center, which entered commercial operation in 2002.","official_url":"https://www.bv.com"} — Source · confidence: medium
- Commercial parties.8: {"relationship":"Combustion-turbine OEM","name":"Westinghouse","detail":"The CEC identifies three Westinghouse 501F combustion-turbine generators in the facility's original configuration.","official_url":"https://www.westinghousenuclear.com"} — Delta Energy Center | California Energy Commission · confidence: high

## Timeline

- 1999 — Initial project development
  Calpine and Bechtel Enterprises began developing an approximately 874 MW natural-gas-fired cogeneration project in Pittsburg, California.
  Source: Source (https://www.sec.gov/Archives/edgar/data/916457/000089161802001569/f80168e10-k.htm)
- 2000-02-09 — CEC certification and construction
  The California Energy Commission certified the project. Calpine's contemporaneous filing states that construction began in mid-2000.
  Source: Delta Energy Center | California Energy Commission (https://www.energy.ca.gov/powerplant/combined-cycle/delta-energy-center)
- 2001-11 — Acquisition closed
  Calpine acquired Bechtel's 50% interest in Delta Energy Center on November 6, 2001. Disclosed transaction package ($154M cash + $141M debt assumption) covered Delta plus Metcalf and Russell City; no Delta-specific allocation disclosed.
  Source: Source (https://www.sec.gov/Archives/edgar/data/916457/000089161802001569/f80168e10-k.htm)
- 2002-11-14 — Cooling-tower expansion
  The CEC approved construction of two additional cooling-tower cells for the existing 12-cell cooling tower.
  Source: Delta Energy Center | California Energy Commission (https://www.energy.ca.gov/powerplant/combined-cycle/delta-energy-center)
- 2017-03-08 — Temporary simple-cycle modification
  The CEC approved a post-certification amendment modifying the steam-turbine condenser so the facility could operate temporarily in simple-cycle mode.
  Source: Delta Energy Center | California Energy Commission (https://www.energy.ca.gov/powerplant/combined-cycle/delta-energy-center)
- 2017-08-18 — Calpine take-private agreement announced
  Calpine announced an agreement to be acquired for $15.25 per share in cash, or approximately $5.6 billion, by an investor consortium led by Energy Capital Partners, Access Industries, and Canada Pension Plan Investment Board.
  Source: Source (https://www.ecpgp.com/content/dam/bridgepoint/ecp/documents/news-and-insights/2017/calpine-agrees-to-be-acquired.pdf)
- 2018-02-08 — Return to combined-cycle operation
  The CEC docketed confirmation that Delta Energy Center had completed repairs and returned to combined-cycle power-plant operations.
  Source: Delta Energy Center | California Energy Commission (https://www.energy.ca.gov/powerplant/combined-cycle/delta-energy-center)
- 2025-01-10 — Constellation-Calpine acquisition announced
  Constellation announced a proposed acquisition of Calpine in a cash-and-stock transaction with approximately $16.4 billion of equity consideration plus assumed Calpine net debt.
  Source: Constellation to Acquire Calpine; Creates America’s Leading Producer of Clean and Reliable Energy to Meet Growing Demand for Customers and Communities (https://www.constellationenergy.com/news/2025/constellation-to-acquire-calpine-creates-americas-leading-producer-of-clean-and-reliable-energy-to-meet-growing-demand-for-customers-and-communities.html)

## Sources

- [Constellation Completes Calpine Transaction, Powering America's Clean Energy Future](https://www.constellationenergy.com/news/2026/01/constellation-completes-calpine-transaction-powering-americas-clean-energy-future.html) — constellationenergy.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
- [Source](https://www.caiso.com/documents/list-generationunitsbylocalcapacityarea.pdf) — caiso.com · tier other
- [Delta Energy Center | California Energy Commission](https://www.energy.ca.gov/powerplant/combined-cycle/delta-energy-center) — energy.ca.gov · tier regulatory
- [California Energy Commission : Docket Log](https://efiling.energy.ca.gov/Lists/DocketLog.aspx?docketnumber=98-AFC-03C) — efiling.energy.ca.gov · tier regulatory
- [Table of Operating Power Plants and Projects Under Construction as of: Friday, February 6, 2026](https://www.calpine.com/wp-content/uploads/2026/02/CPN-PORT-1_Q12026.pdf) — calpine.com · tier other
- [Business Briefs - Power Engineering](https://www.power-eng.com/business/business-briefs-3/) — power-eng.com · tier other
- [501F Gas Turbine Aftermarket Upgrades & Parts | Hanwha Power](https://www.psm.com/products/f-class-frames/501f) — psm.com · tier other
- [Source](https://www.sec.gov/Archives/edgar/data/916457/000089161802001569/f80168e10-k.htm) — sec.gov · tier regulatory
- [Source](https://www.ecpgp.com/content/dam/bridgepoint/ecp/documents/news-and-insights/2017/calpine-agrees-to-be-acquired.pdf) — ecpgp.com · tier other
- [Constellation to Acquire Calpine; Creates America’s Leading Producer of Clean and Reliable Energy to Meet Growing Demand for Customers and Communities](https://www.constellationenergy.com/news/2025/constellation-to-acquire-calpine-creates-americas-leading-producer-of-clean-and-reliable-energy-to-meet-growing-demand-for-customers-and-communities.html) — constellationenergy.com · tier other
- [Source](https://www.sec.gov/Archives/edgar/data/916457/000089161801501784/f75423e8-k.htm) — sec.gov · tier regulatory
- [Delta Energy Center, US](https://www.power-technology.com/marketdata/delta-energy-center-us/) — power-technology.com · tier other
- [Our Assets - Calpine](https://www.calpine.com/clean-and-reliable-power/our-assets/) — calpine.com · tier other
- [Source](https://power-eng.com/business/business-briefs-3) — power-eng.com · tier other
- [Source](https://constellationenergy.com/news/2026/01/constellation-completes-calpine-transaction-powering-americas-clean-energy-future.html) — constellationenergy.com · tier other
- [db130_source_and_sink](https://www.caiso.com/documents/crr-fnm-db130-source-and-sink-apnodes-v1-1-december-2024-monthly-process.xlsx) — caiso.com · tier other
- [Source](https://www.caiso.com/documents/list-generatingunitsbylocalarea.xls) — caiso.com · tier other

## Data quality

- Capacity is reported differently by source: the CEC lists 880 MW, whereas the EIA plant record lists 943.5 MW of nameplate capacity; both figures refer to Delta Energy Center plant ID 55333. The CEC documents a temporary 2017 steam-condenser modification allowing simple-cycle operation and confirms repairs were completed in February 2018 to restore combined-cycle operation. This was not a retirement or permanent repowering.

---

Canonical page: https://askthegrid.com/assets/facilities/delta-energy-center

Source: Ask the Grid — https://askthegrid.com/