# Blenheim-Gilboa Pumped Storage Power Project

NYISO battery_storage · https://askthegrid.com/nyiso/assets/plant/blenheim-gilboa-pumped-storage-power-project

A 1,160 MW hydroelectric pumped-storage project on Schoharie Creek in the Towns of Blenheim and Gilboa, Schoharie County, New York, operated by the New York Power Authority. The facility uses two reservoirs at different elevations and four reversible pump-turbine units (approximately 290 MW each) to store and generate electricity, providing peak-demand capacity and grid-balancing services to the New York region. The project first generated power on July 5, 1973, and reached full production on December 17, 1973. Between 2006 and 2010, NYPA completed a Life Extension and Modernization program that refurbished all four turbine-generator units and increased plant capacity from approximately 1,040 MW to 1,160 MW.

## Key facts

- Technology: Hydroelectric Pumped Storage
- Power capacity: 1000 MW

## Grid and market context

- ISO/RTO: NYISO
- Balancing authority: NYISO

## Source-backed facts

- Identity.canonical name: Blenheim-Gilboa Pumped Storage Power Project — nypa.gov · confidence: review_required
- Technical.power mw: 1160 MW — ferc.gov · confidence: review_required
- Technical.energy mwh: 12000 MWh — en.wikipedia.org · confidence: review_required
- Operations.interconnection voltage kv: 345 kV — ahvsllc.com · confidence: review_required
- Operations.operating status: operating — nypa.gov · confidence: review_required
- Equipment.modernization capacity increase mw: 120 MW — renewableenergyworld.com · confidence: review_required
- Equipment.unit capacity increase per unit mw: 30 MW — renewableenergyworld.com · confidence: review_required
- Identity.owner name: New York Power Authority — ferc.gov · confidence: review_required
- Identity.identifiers.ferc project number: 2685 — ferc.gov · confidence: review_required
- Identity.identifiers.eia plant id: 2691 — mass.gov · confidence: review_required

## Timeline

- 2010-05 — Life Extension and Modernization program completed
  NYPA returned the last of Blenheim-Gilboa's four pump-turbine generating units to service as part of the Life Extension and Modernization program. All four units had completed refurbishment with increased capacity from 260 MW to 290 MW per unit, bringing total plant capacity to 1,160 MW.
  Source: renewableenergyworld.com (https://www.renewableenergyworld.com/energy-storage/pumped-storage/blenheim-gilboa-pumped-storage-hydro-project-upgrade-completion-marked-by-ceremony/)
- 2017-04-27 — Relicensing application filed
  NYPA filed an application with the Federal Energy Regulatory Commission for a new license to continue operating and maintaining FERC Project No. 2685. The application proposed no new generation capacity.
  Source: ferc.gov (https://www.ferc.gov/sites/default/files/2020-06/P-2685EA.pdf)

## Sources

- [ahvsllc.com](https://ahvsllc.com/projects/blenheim-gilboa-pumped-storage-hydro-project) — ahvsllc.com · tier public_source
- [en.wikipedia.org](https://en.wikipedia.org/wiki/Blenheim%E2%80%93Gilboa_Hydroelectric_Power_Station) — en.wikipedia.org · tier public_source
- [graconllc.com](https://graconllc.com/portfolio_page/blenheim-gilboa-life-extension-and-modernization/) — graconllc.com · tier public_source
- [ferc.gov](https://www.ferc.gov/sites/default/files/2020-06/P-2685EA.pdf) — ferc.gov · tier authoritative
- [hitachi.com](https://www.hitachi.com/ICSFiles/afieldfile/2009/10/28/r2009_05_104.pdf) — hitachi.com · tier public_source
- [mass.gov](https://www.mass.gov/doc/calculation-of-2017-ghg-emission-factors/download) — mass.gov · tier authoritative
- [nyiso.com](https://www.nyiso.com/documents/20142/2225293/2017-State-Of-Storage-Report.pdf) — nyiso.com · tier authoritative
- [nypa.gov](https://www.nypa.gov/News/Press-Releases/2026/20260604-bg) — nypa.gov · tier authoritative
- [nypa.gov](https://www.nypa.gov/Power/Generation/Blenheim-Gilboa-Pumped-Storage) — nypa.gov · tier authoritative
- [renewableenergyworld.com](https://www.renewableenergyworld.com/energy-storage/pumped-storage/blenheim-gilboa-pumped-storage-hydro-project-upgrade-completion-marked-by-ceremony/) — renewableenergyworld.com · tier public_source

## Data quality

- The project is consistently identified across FERC, NYPA, NYISO, and EIA-related records as the Blenheim-Gilboa Pumped Storage Power Project, associated with EIA plant ID 2691 and FERC Project No. 2685. No predecessor owner or sale transaction before initial construction was identified. The 2006–2010 Life Extension and Modernization program increased capacity from approximately 1,040 MW (four units × 260 MW) to 1,160 MW (four units × 290 MW) by refurbishing all four pump-turbine units; this was a modernization and expansion program, not a new facility construction. No retirement or repowering event was identified. Official NYPA material dated June 4, 2026, confirms the project remained active and operational, with ongoing emergency-action-plan reviews and feasibility studies for potential infrastructure modifications underway. Equipment attribution to Hitachi is supported by an official Hitachi technical paper dated 2009, which identifies Hitachi as the original equipment supplier and as the selected bidder for the LEM upgrades. A secondary project profile identifies Hitachi Mitsubishi Hydro; Hitachi is the primary company name in authoritative sources.

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