Tesla Megapacks Power Canada’s Largest Battery Storage Park in Ontario

A massive new energy project is now live in Haldimand County, marking a major shift in how Ontario manages its electricity. The Hagersville Battery Energy Storage Park is a joint venture between Boralex and the Six Nations of the Grand River Development Corporation (SNGRDC). It has officially begun commercial operations as the largest facility of its kind in Canada.

The site is built using 334 Tesla Megapack 2XL units. These high-capacity lithium-ion battery systems act like a giant reservoir for the provincial power grid. They can store up to 1,200 MWh of electricity. This is enough to provide full power to the grid for four continuous hours during times of high demand.

How the Tesla technology works

The Tesla Megapacks are designed to solve one of the biggest challenges in modern energy which is timing. Because wind and solar power are intermittent, the grid often has more power than it needs when it is breezy or sunny and not enough when demand spikes.

These batteries soak up excess electricity during off-peak hours and time-shift it. This allows the system to release that stored energy back into the Ontario grid when residents and businesses need it most. This process helps stabilize the electrical system and reduces the need to fire up expensive gas-burning power plants.

A landmark for Indigenous partnership

The project is more than just a technical achievement because it represents a significant economic win for the Six Nations community. As a co-developer, SNGRDC now oversees a portfolio that makes it the largest Indigenous holder of battery storage assets in North America.

Local participation was a priority throughout the build. Workers from the Six Nations community handled the primary civil works on the 30-acre site through A6N General Partnerships.

With this site and another recently launched project in Lakeshore, Boralex has become the top battery storage operator in the country. The partners are already looking ahead to a third project in Oxford County that is expected to break ground soon. A formal grand opening for the Hagersville site is scheduled for Spring 2026.