Wind energy project stores electricity in massive batteries at North Cape, P.E.I.

A $24-million demonstration wind energy storage project in North Cape, P.E.I., is not only helping Maritime Electric save money, it could ultimately change how this renewable resource is used in Canada, says a researcher.

Wind energy isn't reliable because it's only available when the wind blows, but being able to store the energy could increase how much is used.

Two years ago, the Wind Energy Institute of Canada started storing electricity from its wind turbines in two batteries the size of shipping containers using seed money from Natural Resources Canada's Clean Energy Fund.

In the colder winter months, some of that stored energy is being used when the Island's electricity demand exceeds what can be shipped over from New Brunswick.

Using stored wind energy means the utility has to burn less diesel in its Charlottetown generator, said David Watson, the institute's wind integration researcher.

"During peak periods in the wintertime the cable to New Brunswick can be at its maximum, so to avoid going over the maximum the diesel generators in Charlottetown are used, and during those periods we typically discharge the batteries to provide some of that power."

The energy can sit in the battery for weeks, with the occasional top-up.

Since mid-December, Watson and Maritime Electric have been in daily contact, looking at the wind and temperature forecast to determine when the likeliest time of highest electricity use will be.

Watson doesn't know how much diesel fuel is being saved, but he said the batteries can provide enough electricity to power 600 homes for two hours.

That's less than one per cent of Maritime Electric's customer base but Watson said it's about proving that storing and using the electricity to cut costs can be done successfully.

During non-winter months, Watson said the energy is stored overnight, when there is less demand, and then used later in the day when more electricity is needed. 

"We charge the battery from 1 a.m. typically to about 5 a.m. or 6 a.m. and then we discharge the battery during our local peak, which is between 5 p.m. and 7 p.m. when everyone gets home and starts making supper," said Watson.

"So that allows the electricity from the wind to be used when it is most valuable, because the most valuable electricity is during the peak periods."

More demonstration projects

Currently, P.E.I. gets 25 per cent of its electricity from renewable sources, mainly wind — that's the highest commitment to renewable energy in Canada. Being able to store and use wind successfully would allow for an even higher percentage of wind energy in the province. 

Watson said he believes it will be at least five to 10 years before wind energy storage becomes commonplace in Canada's electricity grids. He figures there will be many more demonstration projects before then, as the cost of wind storage slowly drops and more battery innovation makes it possible.

Maritime Electric didn't want to do an interview with CBC News at this time. A spokesperson said the utility is excited about the five-year project but is still evaluating its potential.