The MaRS Cleantech Fund has completed a venture deal with Toronto-based energy storage firm Hydrostor, whose technology converts surplus electrical energy to underwater compressed air and stores it for use at peak times.
‘Our fund targets technologies that change the energy game, and low-cost storage is at the top of our list,’ says Tom Rand, co-managing director of the MaRS Cleantech Fund. ‘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.’
According to the companies, the technology uses surplus renewable electricity to drive 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 underwater accumulators, where the weight of the water keeps it at a constant pressure until required.
When demand for electricity is again high, the companies continue, 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% of the input electricity and releasing the air back into the environment.
Hydrostor has two commercial projects under development. The first is in collaboration with utility host Toronto Hydro-Electric System Ltd. The second, with the national utility of a Caribbean island, will store wind power generated at night when it cannot otherwise be used.