Heat naturally emitted by the surrounding rock in closed deep underground mines could be a geothermal source for warming homes, Canadian scientists say. Researchers from McGill University say each kilometer of a typical deep underground mine could produce 150 kilowatts of heat, enough to warm 5 to 10 Canadian households during off-peak times. In a study to be published in the American Institute of Physics\' Journal of Renewable and Sustainable Energy, the researchers analyzed the heat flow through abandoned mine tunnels flooded with water, water that could be pumped to the surface to have its heat extracted then returned to the ground. The researchers have worked to develop a general model that could be used by engineers to predict the geothermal energy potential of underground mines, a university release reported Wednesday. \"Abandoned mines demand costly perpetual monitoring and remediating. Geothermal use of the mine will offset these costs and help the mining industry to become more sustainable,\" lead study author Seyed Ali Ghoreishi Madiseh said. The researchers estimate 1 million Canadians could benefit from mine geothermal energy.