Toronto Hydro on Nov. 18 unveiled its first underwater compressed air energy storage system located in 180 feet of water about two miles off the coast of Toronto Island in Ontario.
The system, which was supplied by Toronto, Ontario-based Hydrostor, is connected to Toronto Hydro’s electricity grid under a two-year pilot study. Toronto Hydro said the system is expected to improve power quality and resiliency for island residents. Engineers will monitor its performance through a variety of tests, the company said.
Toronto Hydro President and CEO Anthony Haines said in a statement: “We’re very excited to see this new technology in action. Toronto Hydro has been very busy exploring new ways to power our grid, and I think this is the most creative project we’ve been involved in so far. Supporting innovative solutions for Toronto’s power needs will continue to be a focus for our organization.”
Toronto Hydro said it is actively exploring energy storage as a way to extend the life of some of its equipment.
The project uses compressed air and the pressure of water to run its system with zero emissions. According to Toronto Hydro, the technology works by running electricity through a compressor and converting it into compressed air. The compressed air is sent underwater where it is stored in large balloon-like structures that are made out of the same type of material used in marine lift bags to raise shipwrecks. When electricity is needed again, the weight of the water pushes the air to the surface through a large pipe and an expander converts the air back into electricity.
The company said that, at peak output, the storage unit is capable of powering approximately 330 homes (660 kW). Depending on how much power is drawn, the system can currently run for a little over an hour, and future expansion of the underwater air cavity is expected to increase that duration.
Lead image: Air bag installation 2: Hydrostor prepares to install one of the air accumulators in Lake Ontario. Credit: CNW Group/Toronto Hydro Corporation