The Oneida Energy Storage (OES) project is a planned 250MW/ 1,000MWh energy storage development in Haldimand County, Ontario. (Credit: Northland Power Inc.)
The total cost for the project is approximately $800m. (Credit: Sandia National Laboratories/ Wikipedia)
Oneida Energy Storage project will begin full commercial operations in 2025. (Credit: Enyavar/ Wikipedia)

The Oneida Energy Storage (OES) project is a 250MW / 1,000MWh grid-connected lithium-ion battery storage facility being developed in Ontario, Canada.

Northland Power, which owns a 72% stake in the facility, will lead the construction, financing, and operation of the project.

The other partners of the project are NRStor, Six Nations of the Grand River Development Corporation (SNGRDC) and Aecon Group.

The total cost for the project is approximately $800m. The construction works are expected to begin in 2023, with full commercial operations slated to begin in 2025.

Once operational, OES will be the largest clean energy storage project in Canada and will deliver critical capacity to Ontario’s energy grid.

Oneida Location Details

The energy storage project will be located in Jarvis, Haldimand Country in Ontario. The site is around 21.1km from Grand River at nearest point and 16.9km from Six Nations community boundary.

The project will be located adjacent to the existing Jarvis Transformer Station and the Hydro One Transmission Corridor.


A memorandum of understanding (MoU) was signed by SNGRDC and NRStor in November 2018 regarding the battery project.

Oneida Energy Storage LP, a special purpose limited partnership, was formed in November 2019.

SNGRDC and NRStor started engaging with the Independent Electricity System Operator (IESO) and the Government of Ontario to evaluate different pathways to get investment for the OES Project.

In 2020, detailed design and engineering work along with site selection process began.

In July 2020, Interconnection Applications, including Connection Impact Assessment (CIA)/System Impact Assessment (SIA) work with Hydro One and the IESO were submitted.

The project’s Electricity Storage Licence was issued in April 2021. It will be valid for 20 years until April 2041. The term of the licence may be extended by the Ontario Energy Board in the future.

In May 2021, the OES Project received support from the SNGRDC Elected Council following the review and acceptance of the Community Investment Review Final Report.

In May 2023, Northland announced that the Oneida Energy Storage Project reached a financial closure, signifying that the project has secured all necessary funding.

Oneida Energy Storage Project details

The development of Oneida Energy Storage Project was planned to stabilise Ontario’s electricity sector by storing renewable energy during off-peak phases and releasing it during peak demand periods.

The lithium-ion battery modules of the Oneida Energy Storage will be installed on a 10-acre plot of land owned by a provincial crown agency Infrastructure Ontario.

The project will reduce greenhouse gas emissions by 4.1 million tonnes, which is equivalent of taking 40,000 cars off the road annually.

It will also more than double the amount of energy storage on Ontario’s clean electricity grid from approximately 225MW to approximately 475MW.

Key Contractors

US-based automotive and energy company Tesla has signed a battery supply agreement for the Oneida Energy Storage Project. The project has also finalised a long-term service agreement with Tesla for the supply of key components and services.

Construction firm Aecon Group secured the $141m Engineering, Procurement, and Construction (EPC) contract for the battery storage facility.

Under the contract, Aecon will be responsible for designing the facility, procuring balance of plant facility equipment, installing equipment foundations, electrical houses, battery transformers, switchgear, underground cabling, and high voltage substation, as well as the commissioning and startup activities.

Torys is acting as counsel in the development, construction, and financing of the 250MW/ 1000 MWh energy storage project, including advice on governance arrangements, financing, and material contracts.

Offtake Agreement

In February 2023, Northland announced an Energy Storage Facility Agreement (ESFA) with the Independent Electricity System Operator (IESO), an electric power transmission company for the Oneida Energy Storage Project.

Under the 20-year agreement, the partners of the Oneida will provide electricity storage services to the IESO and receive fixed availability payments. The remaining capacity of the project will be sold into the wholesale market.