2 Comments

Summary:

If land-based wind turbines are a bird’s worst nightmare, it will be interesting to see how the fish in Lake Ontario react to giant underwater “accumulators” that will store compressed air to feed back into the electric grid.

Screen Shot 2012-04-05 at 10.31.19 AM

Editor’s note: SGN Managing Editor Liz Enbysk recently participated in a smart grid media tour hosted by the Ontario provincial government. With journalists from around the world, she visited utilities, smart grid companies and research labs. This is one of her reports.

If land-based wind turbines are a bird’s worst nightmare, it will be interesting to see how the fish in Lake Ontario react to giant underwater “accumulators” that will store compressed air to feed back into the electric grid.

Toronto-based startup Hydrostor ran a pilot of its underwater compressed air energy storage (CAES) technology last summer and with partner Toronto Hydro will construct a 1MW, 4MWh demonstration facility about 7 kilometers from Toronto’s shore later this year.

As Hydrostor President Cam Lewis explains, his company’s first-of-its-kind system mechanically converts electricity from the grid to compressed air, which is captured, cooled and can be stored indefinitely in underwater accumulators. These accumulators are large, high-strength polyester bags that inflate with the air like a big balloon – no doubt producing quite an underwater show for salmon and lake inhabitants. When the grid needs the stored energy, the weight of the water pushes the air back to the surface where Hydrostor’s expander/generator system sends it back.

The idea, Lewis says, is to transmit excess electricity at night when demand is less and reverse it when demand is high. The technology offers 70 percent round-trip efficiency, he says.

Lewis sees underwater CAES as a smart choice for cities, which he says accounts for 75 percent of electricity consumed. But many find it difficult to locate generating assets close by due to NIMBYism and other issues. And that leads to higher transmission costs.

Thirty to forty percent of cities worldwide have deep enough water nearby to accommodate underwater CAES, Newton says. And as cities grow, more accumulators can be added..

There isn’t going to be a single magic bullet in energy storage, Lewis says. He believes Hydrostor’s scalable, low-cost solution makes sense for urban centers and can also play a role in the growing demand for renewables and accompanying challenges of intermittency.

“We really see our market as peak power right now,” Lewis says, noting that underwater CAES is an emerging industry with research also under way in the U.S. and U.K.

This article originally appeared on SmartGridNews.com. SmartGridNews.com is the Internet’s oldest, largest and highest-ranked smart grid site. Visit for up-to-the-minute analysis of smart grid trendssmart grid technology and smart grid companies. Sign up for the free email newsletter or follow SGN on Twitter.

  1. Bill Hewitt Friday, April 6, 2012

    This energy storage technology story is great. However, you really need to get a better perspective on bird strikes from wind turbines. They are, for all intents and purposes, a non-issue. See table 2 on page 11 here – http://www.fs.fed.us/psw/publications/documents/psw_gtr191/psw_gtr191_1029-1042_erickson.pdf – and also this article from Tree Hugger – http://www.treehugger.com/renewable-energy/common-eco-myth-wind-turbines-kill-birds.html

    Perpetuating the bird strike from wind turbine myth is singularly unhelpful.

    Share
    1. Yeah, why the hell are we quoting a self-avowed “free-market conservative think tank” on the subject of bird strikes?

      Share

Comments have been disabled for this post