Willis Battery Storage
New York Power AuthorityFranklin County
A NYPA construction engineer walks the completed Northern New York Energy Storage Project beside the Willis substation.
Source: New York Power AuthorityWillis Battery Storage is a 20 MW grid-connected lithium-ion battery energy storage project located in Chateaugay, Franklin County, New York, approximately 40 miles northwest of Plattsburgh. The facility consists of five 53-foot walk-in battery enclosures, each containing more than 19,500 batteries arranged in modules and racks, with each enclosure rated at 4 MW. The system includes inverters, transformers, a control house, and backup generator connected to the Willis substation at 115 kV. The project stores excess renewable generation and discharges during peak demand periods to relieve transmission congestion, support renewable energy integration, and supply the New York wholesale energy and ancillary-service markets. The facility is owned and operated by the New York Power Authority and maintained by the St. Lawrence-Franklin D. Roosevelt Power Project.
Mapped infrastructure geometry associated with this asset.
EIA plant 63238 · Inventory for Aug 2026.
No operating capacity reported in this inventory.
| Generator | Technology | Status | Power (MW) | Energy (MWh) |
|---|---|---|---|---|
| WB1 | Batteries | Planned | 20 | 20 |
Operating generator records and technology attributes reported through EIA-860.
| Generator | Capacity | Technology | Operation | Status |
|---|---|---|---|---|
| WB1 | 20 MW 20 MW summer | Batteries Electricity used for energy storage · BA | Jul 2023 | 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.
Source-backed project transactions, agreements, land records, permits, and environmental disclosures. Portfolio and adjacent-project facts remain explicitly scoped.
Parties, market resources, and identifiers tied to this asset, with owner, operator, developer, EPC, compliance provider, and interconnecting entity roles kept separate.
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Project milestones and public references behind the asset profile.
The NYPA Board of Trustees initially approved $6.0 million for the project in October 2018.
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 | |
|---|---|---|---|
| Robert Moses Niagara | 2,429.1 MW | NY | |
| Blenheim Gilboa | 1,000 MW | NY | |
| Robert Moses Power Dam | 855 MW | NY | |
| Zeltmann | 528 MW | NY | |
| Lewiston Niagara | 220 MW | NY | |
| Richard M Flynn | 170 MW | NY | |
| Joseph J Seymour Power Project | 94 MW | NY | |
| Vernon Boulevard | 94 MW | NY |
Portfolio membership follows the latest EIA-860 reporting entity. It does not imply ultimate ownership.
View full reporting portfolioThe NYPA Board of Trustees approved an additional $23.8 million in project financing at its July 30, 2019 meeting.
NYPA announced the start of construction of the 20 MW Chateaugay battery facility, which was then expected to enter service in early 2021.
EIA-860 lists generator WB1 with this operating date.
Answered from the published record above. Questions whose inputs this profile does not carry are omitted rather than estimated.
Willis Battery Storage reports No operating capacity reported of operating nameplate capacity. These technology ratings do not establish a common export limit. Source: EIA Aug 2026.
Willis Battery Storage is a batteries facility in Franklin County, NY, participating in the NYISO market.
Willis Battery Storage is in Franklin County, NY, inside the NYISO balancing area.
Willis Battery Storage is operated by New York Power Authority according to the EIA generator inventory. Reporting membership does not by itself establish ultimate ownership.
Willis Battery Storage reported 683 MWh 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, Willis Battery Storage ranks #407 of 1,061 operating plants of the same technology nationally. It ranks #2 of 53 in NY.