Cape Breton studies huge geothermal project
Richard Dooley, Canwest News Service, June 07, 2008
Thousands of kilometres of unused mines in the former coal mining capital of Canada could be getting new life as a source of clean, renewable energy to heat schools and hospitals in one of the largest geothermal projects ever contemplated.
Cape Breton sits on top of 3,200 kilometres of unused underground coal mines, some stretching far out under the Atlantic Ocean. The mines once supplied Canada with half its coal requirements.
Since the last underground coal mine shut down in 2000, the mines have been allowed to flood with water – which is being warmed by the heat of the Earth. The mine water remains at a constant temperature of between 9 and 15 C, depending on the depth of the shaft.
The Cape Breton Development Corporation and Cape Breton University are now looking at ways of tapping into that warm mine water by using heat-capturing technology to warm everything from hospitals to elementary schools.
The project, which is expected to get underway later this summer, will look at mines in Glace Bay, New Waterford and Sydney Mines as potential heat sources.
“Almost every home and business in the area sits over these old workings,” said Gerard Shaw, manager of corporate legacy for the Cape Breton Development Corporation.
That makes the potential for using geothermal energy enormous in Cape Breton – to heat existing buildings and to attract builders to the area.
The development corporation, or Devco as it’s known, is already talking with a local school board about using geothermal energy to heat a new elementary school in Glace Bay.
The Cape Breton Regional Hospital is doing an engineering study to decide how to retrofit one of its facilities to utilize mine water as a heat source. Shaw says subdivision developers are also interested in the feasibility study and the pilot project, which is expected to start in September.
“We see this as a great opportunity and something we can leave as a legacy to the mining communities,” he said.
The idea is not new, but the scale being contemplated in Cape Breton is novel.
The Ropal Can Am packaging plant in Springhill N.S. is heated with geothermal power from a nearby abandoned coal mine.
Geothermal heating is used in Scotland and in northern Canada. The U.S. is taking the idea one step further by testing the feasibility of drilling deep bore holes into the crust of the Earth – six or seven kilometres deep – to tap into geothermal energy.
In Cape Breton, the geothermal energy would work in a loop. Warm water will be pumped out of the mines, circulated through heat exchangers, then returned to the mines to be re-warmed.
“It’s the same principle as the hot water heater in your basement,” Cape Breton University Dean of Research Harvey Johnstone said.
There is no shortage of water in the abandoned mine shafts. Scientists estimate there could be as much as one trillion litres of water sitting below the Cape Breton mining communities.
“So that’s part of the study, to see what the capacity is and how much energy can be extracted,” Johnstone said.
The university is so excited by the prospect of geothermal “mining” that it created a special research chair.
Other uses for the coal mines are also being contemplated.
Nova Scotia Power Inc. and Dalhousie University are researching the possibility of using old mines to store carbon dioxide emissions. Research is also underway on methods of converting geothermal energy into electricity and extracting methane from unused coal seams.
© Canwest News Service 2008