The MaRS Cleantech Fund has made an investment in Hydrostor, a Canadian energy storage firm. Headquartered in Toronto, Hydrostor has developed a technology that converts surplus electrical energy to underwater compressed air, storing it for peak use at a later time. The company then partners with utilities and energy producers to accelerate the large-scale deployment of energy. Its partnership with MaRS also makes sense—the Canadian venture fund focuses its investments on early stage cleantech companies.