If you’ve ever driven through the flat, open landscape of southwestern Ontario you may have marvelled at the sight of massive wind turbines dotting the horizon.
At night, these graceful giants are harder to see, but they go on spinning, turning wind into electricity long after most people have turned off their lights and TVs.
“When the wind blows between 2 a.m. and 6 a.m., those turbines generate a lot of electricity that can’t be used. We need to find better ways of harnessing it,” says Rupp Carriveau, an associate professor in civil and environmental engineering at the University of Windsor.
His surprising solution is to store that power once more in air.
Working with the energy company Hydrostor, Carriveau has been testing a system that converts energy into compressed air, storing it at the bottom of a lake in “flexible accumulators” — large bags like those used in marine salvage operations to bring heavy objects to the water’s surface — and piping it to the surface to regenerate electricity when demand requires.
“The market is screaming” for efficient storage systems for wind and solar power, says Hydrostor president Cameron Lewis. He says compressed air energy storage not only helps solve that problem but also decreases transmission line congestion.
“Cariveau’s team has been invaluable,” says Lewis, who used to manufacture oil-field equipment in Alberta. “I was told that he worked a lot with compressed air and was very involved with renewable energy. They’ve been great to work with.”
The team has already tested scale models of their system in the university’s swimming pool as well as a full-sized version in Lake Ontario. If all goes well, a commercial system could be up and running by fall 2013.
“Energy storage is going to be critical in enabling high levels renewable energy penetration across North America,” Carriveau says. Carriveau, who also studies the feasibility of storing compressed air in underground cavities such as abandoned mines, is helping Ontario become a leader in the increasingly important area of renewable energy storage.
**Major funders of this project are Hydrostor Inc. and The Ontario Centres of Excellence.