# Keystone

PJM Conventional Steam Coal · https://askthegrid.com/assets/facilities/keystone

Keystone is a coal-fired power facility with 1,872 MW of EIA-reported nameplate capacity in Armstrong County, Pennsylvania, registered as EIA Plant ID 3136. When constructed, Keystone Generating Station's two generating units were reported to be the largest generating units in the world. Reported commercial-operation dates are 1967 (Unit 1); 1968 (Unit 2).

## Key facts

- Technology: Conventional Steam Coal
- Power capacity: 1872 MW
- Commercial operation: 1967
- Operating status: operating
- Retirement: 2032

## Grid and market context

- ISO/RTO: PJM
- Balancing authority: PJM
- Substation: Keystone Substation
- Point of interconnection: Keystone Substation
- Transmission owner: Pennsylvania Electric Co. (Penelec)
- Interconnection voltage: 500 kV

## Source-backed facts

- Owner logo domain: keyconops.com — KeyCon Operating LLC · confidence: medium
- Identifiers: [{"value":"3136","system":"EIA ORIS plant number"},{"value":"PJM-PN","system":"PJM market location"},{"value":"Unit-1","system":"EPA SE unit ID"},{"value":"Unit-2","system":"EPA SE unit ID"},{"value":"03-00027","system":"Pennsylvania DEP Title V permit"},{"value":"83-3299524-2","system":"Pennsylvania DEP plant code"}] — Source · confidence: high
- Identifiers: [{"value":"3136","system":"EIA ORIS plant number"},{"value":"PJM-PN","system":"PJM market location"},{"value":"Unit-1","system":"EPA SE unit ID"},{"value":"Unit-2","system":"EPA SE unit ID"},{"value":"03-00027","system":"Pennsylvania DEP Title V permit"},{"value":"83-3299524-2","system":"Pennsylvania DEP plant code"}] — Keystone Generating Station - Talen Energy · confidence: high
- Description: Keystone Generating Station is an approximately 1,700-megawatt baseload coal-fired steam electric plant in Shelocta, western Pennsylvania. The station has two units that entered commercial operation in 1967 and 1968 and is located in the PJM-PN market. Talen Energy owns a 12% share of the station. — Keystone Generating Station - Talen Energy · confidence: high
- Description: Keystone Generating Station is an approximately 1,700-megawatt baseload coal-fired steam electric plant in Shelocta, western Pennsylvania. The station has two units that entered commercial operation in 1967 and 1968 and is located in the PJM-PN market. Talen Energy owns a 12% share of the station. — Source · confidence: high
- Canonical name: Keystone Generating Station — Source · confidence: high
- Identifiers.0: {"value":"3136","system":"EIA ORIS plant number"} — Source · confidence: high
- Identifiers.1: {"value":"PJM-PN","system":"PJM market location"} — Keystone Generating Station - Talen Energy · confidence: high
- Identifiers.2: {"value":"Unit-1","system":"EPA SE unit ID"} — Source · confidence: high
- Identifiers.3: {"value":"Unit-2","system":"EPA SE unit ID"} — Source · confidence: high
- Identifiers.5: {"value":"83-3299524-2","system":"Pennsylvania DEP plant code"} — Source · confidence: medium
- Parties.2: {"relationship":"Co-owner","name":"Talen Energy","official_url":"https://www.talenenergy.com/"} — Keystone Generating Station - Talen Energy · confidence: high
- Parties.3: {"relationship":"Operating company / CCR compliance publisher","name":"KeyCon Operating LLC","official_url":"https://ccr.keyconops.com/"} — KeyCon Operating LLC · confidence: medium
- Interconnection: Keystone 500-kV Substation in MAIT-PN, connected to the Keystone–Conemaugh 500-kV line; PJM-PN — Keystone - Susquehanna Dual 500 kV Single Circuits · confidence: medium
- Commercial operation date: 1967 (Unit 1); 1968 (Unit 2) — Keystone Generating Station - Talen Energy · confidence: medium
- Product url: https://www.gevernova.com/steam-power/services/boilers/legacy-boiler-services — In focus: Combustion Engineering | GE Vernova · confidence: medium
- Product url: https://www.gevernova.com/steam-power/services/boilers/legacy-boiler-services — Turbine Services | Westinghouse Nuclear · confidence: medium
- Kind: thermal — Source · confidence: high
- Kind: thermal — Keystone Generating Station - Talen Energy · confidence: high
- Quality notes: ["Reported capacity differs by source and basis: Talen reports approximately 1,700 MW and 213 MW attributable to its 12% interest, Global Energy Monitor reports at least 1,872 MW, and Pennsylvania permitting records describe two units with 910 MW gross output each.","The $173 million amount was the purchase price for a combined 108-MW portfolio interest in Keystone and Conemaugh, not a Keystone-only sale price. The separately disclosed $200 million term loan was acquisition financing arranged for that combined purchase, not identified as standalone project financing.","The disclosed record supports environmental-control and wastewater upgrades, but no distinct repowering project or separately documented generation-capacity expansion was identified. The 1968 milestone is treated primarily as Unit 2 commercial operation, with some sources also describing the plant as expanded in 1968.","Ownership percentages are not fully consistent across public sources; the directory uses Talen's official 12% figure rather than the 12.34% figure reported by Global Energy Monitor."] — Keystone Generating Station - Talen Energy · confidence: medium
- Quality notes: ["Reported capacity differs by source and basis: Talen reports approximately 1,700 MW and 213 MW attributable to its 12% interest, Global Energy Monitor reports at least 1,872 MW, and Pennsylvania permitting records describe two units with 910 MW gross output each.","The $173 million amount was the purchase price for a combined 108-MW portfolio interest in Keystone and Conemaugh, not a Keystone-only sale price. The separately disclosed $200 million term loan was acquisition financing arranged for that combined purchase, not identified as standalone project financing.","The disclosed record supports environmental-control and wastewater upgrades, but no distinct repowering project or separately documented generation-capacity expansion was identified. The 1968 milestone is treated primarily as Unit 2 commercial operation, with some sources also describing the plant as expanded in 1968.","Ownership percentages are not fully consistent across public sources; the directory uses Talen's official 12% figure rather than the 12.34% figure reported by Global Energy Monitor."] — Source · confidence: medium
- Financing summary: On September 1, 2006, Duquesne Light Holdings completed its purchase from Atlantic City Electric of a 2.47% Keystone interest, together with a 3.83% Conemaugh interest, for a combined purchase price of $173 million. Two banks committed a $200 million term-loan facility on August 4, 2006, primarily to finance the combined acquisition; the banks were not named in the cited record. The $173 million is sale consideration for the combined Keystone-Conemaugh portfolio interest, while the $200 million is acquisition financing. — Duquesne Light Holdings Completes Purchase of 108-Megawatt Share of Two Coal-Fired Pennsylvania Generation Plants · confidence: medium
- Commercial parties.1: {"relationship":"Operator / CCR compliance publisher","name":"KeyCon Operating LLC","detail":"Associated with operation and public Coal Combustion Residuals compliance information for Keystone and Conemaugh.","official_url":null} — KeyCon Operating LLC · confidence: medium
- Commercial parties.2: {"relationship":"Co-owner","name":"Talen Energy","detail":"Official portfolio page reports a 12% Keystone ownership interest and 213 MW of attributable capacity.","official_url":"https://www.talenenergy.com/"} — Keystone Generating Station - Talen Energy · confidence: high
- Commercial parties.3: {"relationship":"Acquirer and co-owner","name":"ArcLight Capital Partners","detail":"Acquired Exelon's reported approximately 42% Keystone interest in 2014, Duquesne's 2.47% interest in 2015, and PSEG's interest in 2019; the ownership record identifies Chief Keystone Power as its Keystone vehicle.","official_url":"https://arclight.com/"} — Source · confidence: medium
- Commercial parties.7: {"relationship":"Seller","name":"PSEG Power","detail":"Agreed in June 2019 and completed in September 2019 the sale of its Keystone and Conemaugh interests to ArcLight Capital Partners.","official_url":"https://corporate.pseg.com/"} — Public Service Enterprise Group Inc - PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants · confidence: high
- Commercial parties.7: {"relationship":"Seller","name":"PSEG Power","detail":"Agreed in June 2019 and completed in September 2019 the sale of its Keystone and Conemaugh interests to ArcLight Capital Partners.","official_url":"https://corporate.pseg.com/"} — Note 7. Regulatory Assets and Liabilities · confidence: high
- Timeline.0: {"event":"Unit 1 commercial operation","date":"1967","detail":"Keystone's first coal-fired generating unit entered commercial operation in 1967."} — Keystone Generating Station - Talen Energy · confidence: high
- Timeline.0: {"event":"Unit 1 commercial operation","date":"1967","detail":"Keystone's first coal-fired generating unit entered commercial operation in 1967."} — Source · confidence: high
- Timeline.1: {"event":"Unit 2 commercial operation","date":"1968","detail":"The second coal-fired generating unit entered commercial operation in 1968; sources also describe the plant as expanded in 1968."} — Keystone Generating Station - Talen Energy · confidence: medium
- Timeline.1: {"event":"Unit 2 commercial operation","date":"1968","detail":"The second coal-fired generating unit entered commercial operation in 1968; sources also describe the plant as expanded in 1968."} — Keystone Generating Station · confidence: medium
- Timeline.3: {"event":"Duquesne Light acquisition and acquisition financing","date":"2006-09-01","detail":"Duquesne Light Holdings completed the purchase from Atlantic City Electric of 42.3 MW, or 2.47%, of Keystone and 65.6 MW, or 3.83%, of Conemaugh for $173 million; a $200 million term-loan facility was used to finance the combined purchase."} — Duquesne Light Holdings Completes Purchase of 108-Megawatt Share of Two Coal-Fired Pennsylvania Generation Plants · confidence: high
- Timeline.3: {"event":"Duquesne Light acquisition and acquisition financing","date":"2006-09-01","detail":"Duquesne Light Holdings completed the purchase from Atlantic City Electric of 42.3 MW, or 2.47%, of Keystone and 65.6 MW, or 3.83%, of Conemaugh for $173 million; a $200 million term-loan facility was used to finance the combined purchase."} — Source · confidence: high
- Timeline.4: {"event":"Exelon interest sale to ArcLight","date":"2014-11","detail":"Exelon's sale of its Keystone and Conemaugh ownership interests to ArcLight Capital Partners was reported in November 2014; the Keystone share was reported as approximately 42%."} — Source · confidence: medium
- Timeline.4: {"event":"Exelon interest sale to ArcLight","date":"2014-11","detail":"Exelon's sale of its Keystone and Conemaugh ownership interests to ArcLight Capital Partners was reported in November 2014; the Keystone share was reported as approximately 42%."} — Exelon Selling Last Major Coal Generation in Fleet - RTO Insider · confidence: medium
- Timeline.8: {"event":"PSEG sale agreement","date":"2019-06-24","detail":"PSEG Power announced an agreement to sell its 776-MW combined interest in Keystone and Conemaugh, including related assets and assumed liabilities."} — Public Service Enterprise Group Inc - PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants · confidence: medium
- Timeline.9: {"event":"PSEG interest sale completed","date":"2019-09","detail":"PSEG Power completed the sale of its Keystone and Conemaugh ownership interests to ArcLight Capital Partners; the combined interest represented 776 MW."} — Note 7. Regulatory Assets and Liabilities · confidence: high
- Timeline.9: {"event":"PSEG interest sale completed","date":"2019-09","detail":"PSEG Power completed the sale of its Keystone and Conemaugh ownership interests to ArcLight Capital Partners; the combined interest represented 776 MW."} — PSEG completes sale of stakes in Keystone and Conemaugh coal... | Energy Finance & Investment · confidence: high
- Timeline.10: {"event":"Planned retirement","date":"2021","detail":"Key-Con announced plans to cease burning coal at Keystone and Conemaugh by the end of 2028, consistent with the then-scheduled December 31, 2028 cessation date."} — Pa.'s largest coal-fired power plants would stay open until 2032 in proposed DEP deal • Pennsylvania Capital-Star · confidence: medium
- Timeline.10: {"event":"Planned retirement","date":"2021","detail":"Key-Con announced plans to cease burning coal at Keystone and Conemaugh by the end of 2028, consistent with the then-scheduled December 31, 2028 cessation date."} — Keystone Generating Station - Global Energy Monitor · confidence: medium
- Timeline.11: {"event":"Operation extended under proposed consent decree","date":"2026-04-21","detail":"Pennsylvania announced a proposed consent decree allowing Keystone and Conemaugh to continue operating through 2032, contingent on upgraded wastewater-treatment equipment and related bottom-ash-system compliance work."} — Shapiro Administration Files Motion to Enter Consent Decree on Power | Commonwealth of Pennsylvania · confidence: high
- Quality notes.0: Reported capacity differs by source and basis: Talen reports approximately 1,700 MW and 213 MW attributable to its 12% interest, Global Energy Monitor reports at least 1,872 MW, and Pennsylvania permitting records describe two units with 910 MW gross output each. — Keystone Generating Station - Talen Energy · confidence: medium
- Quality notes.0: Reported capacity differs by source and basis: Talen reports approximately 1,700 MW and 213 MW attributable to its 12% interest, Global Energy Monitor reports at least 1,872 MW, and Pennsylvania permitting records describe two units with 910 MW gross output each. — Shapiro Administration Files Motion to Enter Consent Decree on Power | Commonwealth of Pennsylvania · confidence: medium
- Quality notes.1: The $173 million amount was the purchase price for a combined 108-MW portfolio interest in Keystone and Conemaugh, not a Keystone-only sale price. The separately disclosed $200 million term loan was acquisition financing arranged for that combined purchase, not identified as standalone project financing. — Duquesne Light Holdings Completes Purchase of 108-Megawatt Share of Two Coal-Fired Pennsylvania Generation Plants · confidence: high
- Quality notes.1: The $173 million amount was the purchase price for a combined 108-MW portfolio interest in Keystone and Conemaugh, not a Keystone-only sale price. The separately disclosed $200 million term loan was acquisition financing arranged for that combined purchase, not identified as standalone project financing. — Source · confidence: high
- Quality notes.2: The disclosed record supports environmental-control and wastewater upgrades, but no distinct repowering project or separately documented generation-capacity expansion was identified. The 1968 milestone is treated primarily as Unit 2 commercial operation, with some sources also describing the plant as expanded in 1968. — Keystone Generating Station - Talen Energy · confidence: high
- Quality notes.2: The disclosed record supports environmental-control and wastewater upgrades, but no distinct repowering project or separately documented generation-capacity expansion was identified. The 1968 milestone is treated primarily as Unit 2 commercial operation, with some sources also describing the plant as expanded in 1968. — Shapiro Administration Files Motion to Enter Consent Decree on Power | Commonwealth of Pennsylvania · confidence: high
- Quality notes.3: Ownership percentages are not fully consistent across public sources; the directory uses Talen's official 12% figure rather than the 12.34% figure reported by Global Energy Monitor. — Keystone Generating Station - Talen Energy · confidence: high
- Seller: PSEG Power — PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants · confidence: high
- Transaction scope: portfolio_includes_asset — PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants · confidence: high
- Balancing authority: PJM — Keystone Generating Station - Talen Energy · confidence: high
- Grid role: Baseload coal-fired steam-electric generation — Keystone Generating Station - Talen Energy · confidence: high

## Timeline

- 1967 — Unit 1 commercial operation
  Keystone's first coal-fired generating unit entered commercial operation in 1967.
  Source: Keystone Generating Station - Talen Energy (https://www.talenenergy.com/plant/keystone-generating-station/)
- 1967 (Unit 1); 1968 (Unit 2) — Commercial operation
  Keystone entered commercial operation.
  Source: Keystone Generating Station - Talen Energy (https://www.talenenergy.com/plant/keystone-generating-station/)
- 1968 — Unit 2 commercial operation
  The second coal-fired generating unit entered commercial operation in 1968; sources also describe the plant as expanded in 1968.
  Source: Keystone Generating Station - Talen Energy (https://www.talenenergy.com/plant/keystone-generating-station/)
- 2005-11-14 — Atlantic City Electric sale agreement
  Duquesne Light Holdings entered a purchase and sale agreement to acquire Atlantic City Electric's combined 108-MW interests in Keystone and Conemaugh, including a 2.47% Keystone interest.
  Source: Source (https://www.sec.gov/Archives/edgar/data/30573/000095015206006772/l21304ae10vq.htm)
- 2018-12-14 — GenOn Chapter 11 reorganization
  GenOn completed its reorganization and transferred its interests in Keystone and Conemaugh, together with other consideration, to new owners.
  Source: GenOn Completes Reorganization and Emerges from Chapter 11 with New Management Team and Board of Directors — GenOn (https://www.genon.com/genon-news/2018/12/14/genon-completes-reorganization-and-emerges-from-chapter-11-with-new-management-team-and-board-of-directors)
- 2026-04-21 — Operation extended under proposed consent decree
  Pennsylvania announced a proposed consent decree allowing Keystone and Conemaugh to continue operating through 2032, contingent on upgraded wastewater-treatment equipment and related bottom-ash-system compliance work.
  Source: Shapiro Administration Files Motion to Enter Consent Decree on Power | Commonwealth of Pennsylvania (https://www.pa.gov/governor/newsroom/2026-press-releases/shapiro-administration-files-motion-to-enter-consent-decree-on-p)

## Sources

- [KeyCon Operating LLC](https://ccr.keyconops.com/) — ccr.keyconops.com · tier other
- [Source](https://downloads.regulations.gov/EPA-HQ-OW-2009-0819-8800/attachment_1.pdf) — downloads.regulations.gov · tier regulatory
- [Keystone Generating Station - Talen Energy](https://www.talenenergy.com/plant/keystone-generating-station/) — talenenergy.com · tier other
- [Source](https://files.dep.state.pa.us/RegionalResources/NWRO/NWROPortalFiles/RACT_II/1-16-24/Keystone/Keystone%20Draft%20Permit.pdf) — files.dep.state.pa.us · tier other
- [Shapiro Administration Files Motion to Enter Consent ...](https://www.pa.gov/governor/newsroom/2026-press-releases/shapiro-administration-files-motion-to-enter-consent-decree-on-p) — pa.gov · tier regulatory
- [Source](https://www.pjm.com/-/media/DotCom/planning/rtep-dev/expan-plan-process/ferc-order-1000/rtep-proposal-windows/2025-rtep-window-1-redacted-proposals/2025-w1-838.pdf) — pjm.com · tier other
- [Source](https://files.dep.state.pa.us/RegionalResources/NWRO/NWROPortalFiles/RACT_II/03-00027-RevMemo-20210909-SigMod.pdf) — files.dep.state.pa.us · tier other
- [Keystone Generating Station](https://en.wikipedia.org/wiki/Keystone_Generating_Station) — en.wikipedia.org · tier other
- [In focus: Combustion Engineering | GE Vernova](https://www.gevernova.com/steam-power/services/boilers/legacy-boiler-services) — gevernova.com · tier other
- [Turbine Services | Westinghouse Nuclear](https://www.westinghousenuclear.com/operating-plants/outage-services/turbine-services/) — westinghousenuclear.com · tier other
- [Pa.'s largest coal-fired power plants would stay open until ...](https://penncapital-star.com/energy-environment/pa-s-largest-coal-fired-power-plants-would-stay-open-until-2032-in-proposed-dep-deal/) — penncapital-star.com · tier other
- [Keystone Generating Station - Global Energy Monitor](https://www.gem.wiki/Keystone_Generating_Station) — gem.wiki · tier other
- [Duquesne Light Holdings Completes Purchase of 108-Megawatt Share of Two Coal-Fired Pennsylvania Generation Plants](https://br.advfn.com/noticias/PRNUS/2006/artigo/16689017) — br.advfn.com · tier other
- [Source](https://www.sec.gov/Archives/edgar/data/30573/000095015206006772/l21304ae10vq.htm) — sec.gov · tier regulatory
- [Source](https://ieefa.org/sites/default/files/2022-06/Private%20Equitys%20Losing%20Bet%20on%20PJM%20Coal%20Plants_June%202022.pdf) — ieefa.org · tier other
- [GenOn Completes Reorganization and Emerges from Chapter 11 with New Management Team and Board of Directors — GenOn](https://www.genon.com/genon-news/2018/12/14/genon-completes-reorganization-and-emerges-from-chapter-11-with-new-management-team-and-board-of-directors) — genon.com · tier other
- [Public Service Enterprise Group Inc - PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants](https://investor.pseg.com/investor-news-and-events/financial-news/financial-news-details/2019/PSEG-Power-Has-Agreed-to-Sell-Its-Interest-in-Keystone-and-Conemaugh-Coal-Plants/default.aspx) — investor.pseg.com · tier other
- [Note 7. Regulatory Assets and Liabilities](https://www.ezodproxy.com/pseg/2020/10k/PDF/pseg-10k2019_0114.pdf) — ezodproxy.com · tier other
- [PSEG Power Has Agreed to Sell Its Interest in Keystone and Conemaugh Coal Plants](https://nj.pseg.com/newsroom/newsrelease91) — nj.pseg.com · tier other
- [Exelon Selling Last Major Coal Generation in Fleet - RTO Insider](https://www.rtoinsider.com/23817-exelon-selling-last-major-coal-generation-in-fleet/) — rtoinsider.com · tier other
- [PSEG completes sale of stakes in Keystone and Conemaugh coal... | Energy Finance & Investment](https://www.ippjournal.com/update/pseg-completes-sale-of-stakes-in-keystone-and-conemaugh-coal-fired-power-plants) — ippjournal.com · tier other
- [Document](https://www.sec.gov/Archives/edgar/data/81033/000078878419000028/pseg-6302019q210xq.htm) — sec.gov · tier regulatory

## Data quality

- Reported capacity differs by source and basis: Talen reports approximately 1,700 MW and 213 MW attributable to its 12% interest, Global Energy Monitor reports at least 1,872 MW, and Pennsylvania permitting records describe two units with 910 MW gross output each. The $173 million amount was the purchase price for a combined 108-MW portfolio interest in Keystone and Conemaugh, not a Keystone-only sale price. The separately disclosed $200 million term loan was acquisition financing arranged for that combined purchase, not identified as standalone project financing. The disclosed record supports environmental-control and wastewater upgrades, but no distinct repowering project or separately documented generation-capacity expansion was identified. The 1968 milestone is treated primarily as Unit 2 commercial operation, with some sources also describing the plant as expanded in 1968. Ownership percentages are not fully consistent across public sources; the directory uses Talen's official 12% figure rather than the 12.34% figure reported by Global Energy Monitor.

---

Canonical page: https://askthegrid.com/assets/facilities/keystone

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