By Debora Van Brenk
Electrical engineers at the University of Western Ontario have found a way to harness solar technology at night.
Two Ontario power companies have already signed on to use the new technology.
“Everybody wants to become green, the world over,” says Rajiv Varma, a UWO professor of electrical engineering.
But solar power has limitations — it doesn’t work efficiently under cloudy skies, and not at all at night — so its components are under-used most of the time.
Meanwhile, wind turbines tend to work best at night, but are often constrained by lower electricity demand and the power grid’s inability to manage the power generated from them.
That means solar electronics are idle precisely when wind power is peaking.
Varma’s team has come up with a way to use idle solar components as inexpensive regulators that will modulate electricity surges from wind generation, and so allow more wind power to get into Ontario’s power grid.
“This is unique because it is one renewable resource helping another renewable resource, with both making profits,” said Varma.
The UWO team is putting solar installations to work, even when the solar cells themselves are sleeping. At the same time, it enables wind producers to do their job more effectively and cost-efficiently.
Near Goderich, Ont., for example, power flows from wind turbines are regulated by statcoms — or voltage controllers — at a cost of $5 million to $10 million, Varma said.
By comparison, he said, if a solar farm were planted near a wind farm, the solar modules could be adapted to act as those statcoms and put the solar electronics to work 24 hours a day, at a cost of about $100,000.
“This is not something that is a hypothetical situation,” Varma said.
There are plans to bring the technology to a large-scale wind farm.
In similar applications, solar facilities can act as voltage controls, even apart from wind installations, where there are transmission issues or power surges that need to be reined in.
The UWO team’s development can even use solar components to add transmission capacity at a price that’s millions of dollars less than it would cost to add new transmission lines.
Varma has applied for two patents for the technology, developed in part through a $6-million research grant from the Ontario Centre of Excellence.
Bluewater Power and London Hydro both plan to use the technology at select solar sites.
Vinay Sharma, chief executive of London Hydro, said London Hydro plans to use Varma’s voltage-regulating technology at two of 14 solar installations it hopes to have running by early next spring.
“(Just) like water pressure has to be maintained, electricity has to be maintained,” Sharma said.
