20 MW flywheel plant for NYISO frequency regulation
Stephentown Spindle is a 20 MW flywheel facility in Stephentown, New York. Its 20 one-megawatt pods contain 200 flywheels and serve NYISO frequency regulation; Stephentown Spindle LLC owns the project and Convergent Energy + Power operates it. Convergent reports 5 MWh for the facility, while EIA's June 2026 inventory reports 15 MWh.
Answers use this researched asset profile with live NYISO data. Ask about ownership, equipment, project history, or current grid context.
Live NYISO public data · answers can be wrong, verify against source data or the ISO.
Exact-project and June 2026 EIA records.
Convergent and equipment-backed project rating.
June 2026 preliminary EIA inventory.
Twenty one-megawatt pods with ten flywheels each.
June 2026 preliminary EIA inventory; status OP.
Similar plants ranked by technology, capacity, and distance.
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| SRS1 | 20 MW 20 MW summer | Flywheels Electricity used for energy storage · FW | Jan 2011 | Operating |
Monthly EIA generation history and recent market-resource behavior where linked telemetry is available.
Deterministic links to ERCOT market resources, price records, outage disclosures, queue records, and nearby infrastructure. Candidate joins remain labeled until corroborated.
Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.
Project milestones and public references behind the asset profile.
Flywheel; June 2026 preliminary EIA inventory.
EIA-923 reports gross generation and net grid exchange for storage plants. Gross generation is shown as a discharge proxy; it is not a cycle count or conventional capacity factor.
| Largest reported plants | Capacity | State | |
|---|---|---|---|
| Stephentown SpindleCurrent | 20 MW | NY | |
| Hazle Spindle | 20 MW | PA | |
| Cicero Energy Storage 1 LLC | 10 MW | NY | |
| Henrietta D Energy Storage LLC | 10 MW | CA | |
| Cicero Energy Storage 2 LLC | 10 MW | NY | |
| Federalsburg Energy Storage 1 LLC | 2 MW | MD |
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
View full reporting portfolioAnswered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
Stephentown Spindle has a reported capacity of 20 MW. Source: EIA Form 860M.
Stephentown Spindle is a flywheel facility in Rensselaer County, NY, participating in the NYISO market.
Stephentown Spindle is in Rensselaer County, NY, inside the NYISO balancing area.
Stephentown Spindle is operated by Convergent Energy and Power LP according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
Stephentown Spindle reports a commercial operation date of 2011-01. Source: EIA Form 860M.
Stephentown Spindle reported 5.2 GWh over the twelve months to 2024-12. For a storage plant this is reported gross generation — a discharge proxy, not a cycle count or a conventional capacity factor.
By capacity, Stephentown Spindle ranks #1 of 3 operating plants of the same technology nationally. It ranks #1 of 1 in NY.
Plants within 25 km, nearest first, regardless of technology. Proximity is straight-line distance between mapped plant coordinates; it does not by itself establish a shared point of interconnection.