Cleantech startup Hydrostor designed and is now partnering with Toronto Hydro to operate “the world’s first-ever underwater compressed air energy storage system”. The first facility has been set up in Lake Ontario near Toronto, with a series of underwater balloons containing compressed air are submerged under 55 meters of water and connected to Hydrostor’s power facility via a pipe. Currently, the facility currently is being used to store excess energy from Toronto’s existing power grid during non-peak times. It can also be adapted to store energy from renewable energy sources such as wind or solar power, providing the ability to store energy during peak energy generation times to compensate for the occasional downtimes. The company says its solution can last twice as long as the best batteries we have today, and at a much lower cost. The idea of using compressed air to store energy is not new at all though. “Compressed air’s been around for 40 years,” Hydrostor CEO Curtis VanWalleghem told Canadian Manufacturing. “It’s finding places to store the air that’s been the problem [and] why it hasn’t been massively adopted. We open it up to thousands more sites because we use hydrostatic water pressure.”
The material used by the underwater balloons, known as accumulators, are made of material that is currently used to raise sunken ships from the bottom of lakes and oceans, and are connected to the power plant with pipes. Excess electricity is converted into compressed air at the energy facility and transferred to the balloons for storage. When needed, mostly during peak hours, the compressed air is pushed out of the balloons under the natural pressure of the lake water, and sent to a compressed air-powered turbine to produce electricity for the grid. The balloons in Lake Ontario are capable of providing 660 kilowatts of power, which is enough to hold energy to power 330 homes. The technology is scalable and, unlike competing battery storage solutions, does not use any toxic substances. “We’re now focused on commercialising this technology globally to bring our green energy storage solution to countries around the world,” Vsaid VanWalleghem. “The G20 is talking about getting off fossil fuel by 2050. To do that, our electricity system has to incorporate storage so we don’t need as much backup diesel and natural gas capacity – that’s what this can do.” Hydrostor hopes to expand its operations globally and is already working with Aruba to build a system similar to the one operating in Toronto.
