HydoStor for Inclusion

Toronto Hydro is working with Hydrostor Inc. to analyze the electrical grid benefits of underwater compressed air energy storage (UCAES). The world’s first system has now been installed in Lake Ontario. The pilot project will focus on the unit’s ability to provide reserve power, shift load and smooth out transmission and distribution congestion.  

The system is designed to store excess electricity generated during low-demand off-peak hours by driving compressed air into a flexible wall air accumulator below the lake’s surface. When the energy is required, the system is reversed.


How it works

Compressed air stored in a fixed wall air accumulator allows for the use of electricity on-demand. When electricity is required, the weight of the water pushes the stored air from the underwater accumulators through an air feeder pipe into an expander, which drives a generator, to supply electricity back to the grid.