Carbon dioxide to be tested in geothermal power generation

MIT Technology Review : Carbon sequestration entails compressing the carbon dioxide emitted by power plants and storing the liquefied gas underground. Next year, a company called Heat Mining, cofounded by Martin Saar of the University of Minnesota, will begin work to use that CO₂ in geothermal power generation. Geothermal power is normally produced by cycling water through underground rock heated by geological processes. The resulting steam is used to drive turbines. Saar’s company plans to substitute CO₂ for water. If successful, the new geothermal power plants could potentially be used in a much wider area than current systems. Simulations suggest that using CO₂ could be twice as efficient as water because it moves through the ground more easily and may not need pumps to reach the surface. Also, gas turbines are more efficient than steam turbines for power generation.