Old Mines Hold Geothermal Promise


Among the lesser-known projects set to get federal funds: turning old coal mines into geothermal energy hubs, according to .

Whats going on: Abandoned coal mines generally fill with water when the mining has ceased. That water contains heat from far below the earths surface. People can drill bore holes to bring that heat to the surface, then pass it through heat exchanges and heat pumps in buildings and in homes.

  • The first such heating scheme in Great Britain recently began operation and is expected to serve more than 1,200 homes eventually.
  • While geothermal energy isnt new, taking it from abandoned coal mines is not yet common, especially in the United States.

Why its important: Geothermal energy is carbon-free and can be used to both heat and cool buildingsand mines offer storage, a sought-after characteristic in renewable energy sources.

  • Whats more, old mines are plentiful in the U.S. In Ohio, there are more than 4,000 abandoned mines, a wealth of opportunity for geothermal energy.
  • In 2007, the U.S. Department of Energy reported that the amount of water currently being discharged from underground coal mines in just the Pittsburgh coal seam could potentially be used to heat and cool roughly 20,000 homes.