The University of Victoria, in British Columbia, Canada, is helping a town covert its old coal mines into a clean energy source. After 80 years, the coal mines near Cumberland, British Columbia, closed, and the abandoned shafts and tunnels have filled with water. This water remains warmer than the outside air in winter and cooler in the summer. Using the mine water as a giant heat exchanger eliminates the need for expensive, deep geothermal drilling.

The university is offering the engineering expertise to leverage the temperature differences to efficiently heat and cool a new community center, municipal buildings, affordable housing and an industrial center at a relatively low cost. Members of the town hope to attract businesses that require controlled temperatures, such as greenhouses and food processing businesses.