Canadian Manufacturing

Toronto firm’s battery-free, underwater energy storage technology nabs venture deal

by Staff   

Canadian Manufacturing
Sustainability Energy Solar venture capital Wind

Co-managing director of the fund says this low-cost storage option "...will disrupt global energy markets."

TORONTO—The MaRS Cleantech Fund is pleased has signed a venture deal with Toronto energy storage firm Hydrostor.

Hydrostor’s technology converts surplus electrical energy to underwater compressed air and stores it for use at peak times.

Tom Rand, co-managing director of the MaRS Cleantech Fund says this technology will allow solar and wind developers to bid on previously untouchable base-load contracts.

“This is grid-scale technology, meaning that it has the ability to store energy on a level that will significantly impact our electricity grid. If you combine Hydrostor’s technology with solar, or wind, you get cost-competitive base-load renewable power that will disrupt global energy markets,” Rand says.


Hydrostor’s anchors a low-cost air cavity to the bottom of a lake or ocean floor which stores energy for use later.

Surplus renewable electricity drives a compressor that pressurizes atmospheric air to the pressure found at the sea floor offshore. The heat produced during compression is extracted from the air and stored in an insulated thermal reservoir. The air is stored in low-cost underwater accumulators, where the weight of the water keeps it at a constant pressure until required. When needed, the system is reversed: The weight of the water forces the air back to the surface, where it collects the stored heat and drives an expander, reproducing approximately 70 per cent of the input electricity and releasing the air back into the environment.

The developer has a video on its web site explaining how the process works.

Using this technology, Hydrostor claims it can deliver grid-scale energy storage at a fraction of the price of competing technologies.

Hydrostor has two commercial projects under development. The first is in collaboration with utility host Toronto Hydro-Electric System Ltd. (Toronto Hydro) and will be located seven kilometres off the shore of Toronto in Lake Ontario, at a depth of 80 metres. The second, with the national utility of a Caribbean island, will store wind power generated at night when it can’t otherwise be used.

Early-stage venture capital is in short supply in Canada, particularly in the burgeoning global cleantech sector. The MaRS Cleantech Fund targets outsized returns by filling that gap in what is estimated to be a $2-3 trillion dollar market by 2020.


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