Abandoned coal mines as source for geothermal direct use for heating

Abandoned coal mines as source for geothermal direct use for heating Yellowknife, NWT/ Canada, Con Mine is the tower in the back (source: flickr/buck82, creative commons)
Alexander Richter 16 May 2012

A new study by researchers of McGill University in Montreal, Canada, might help predict how much energy can be utilized for heating collecting heat in abandoned mines, estimating that per kilometer of mine shafts heat of 150 kW could be produced.

Reported by several media outlets earlier this month and in the past, old coal mines have a potential to be used for the utilization of geothermal heat for heating above the surface. There are projects and actual existing installations, e.g. in Springhill, Nova Scotia and planned project at Yellowknife in the Northwest Territories both in Canada.

There have also been efforts by mining groups to evaluate revenue creation from abandoned mines. Now there is a “new study that might help predict how much energy could be harnessed from the heat collecting in abandoned mines.

Researchers from McGill University in Montreal stated using this kind of geothermal energy may possibly advantage as much as one million people in Canada and have even far better prospective for alot more densely populated countries such as Britain. By analysing the heat flow by means of mine tunnels flooded with water, the group has created a model that could be utilized to assess the thermal behaviour of a mine under distinct heat-extraction scenarios.

In a paper due to be published in the American Institute of Physics’ Journal of Renewable and Sustainable Energy, the researchers calculate that each kilometre of a widespread deep underground mine could produce 150kW of heat.

As with other geothermal plants, hot mine water is often pumped towards the surface, the heat extracted as well as the cool water returned to the ground. But for this to be sustainable, the heat need to not be removed a lot more easily than it might be replenished by the surrounding rock.”

This could mean a big step ahead the utilization of abandoned mines.

Source: Sustainable Energy Systemz