News

Carbon Dioxide to be used for making geothermal projects more efficient

Alexander Richter 4 Jan 2010

Carbon Dioxide, as a more efficient fluid than water, could be used to capture heat from geothermal systems, as highlighted in recent research from the University of Minnesota.

A recent article on Discovery News looks into how carbon dioxide could be pumped into geothermal reservoirs making those projects more efficient.

According to the article, “This combined system could double the efficiency of geothermal energy capture, while also making carbon storage projects more feasible.

“I think it’s really exciting because one of the big problems with most geothermal energy and carbon capture and sequestration seems to be that the economics of either doesn’t quite work unless there’s some sort of subsidy on the geothermal side, or some tax on carbon on the carbon capture and sequestration side,” said Grant Ferguson of St. Francis Xavier University in Antigonish, Nova Scotia, who is not a part of the research.

Typical geothermal energy systems pump water deep underground in geologic hot spots. The water soaks up heat emanating from Earth’s core and brings it back to the surface. The hot water is then used to generate electricity.

However, it turns out that high-pressure, high-temperature carbon dioxide is a more efficient fluid than water for capturing heat from geothermal systems.

Martin Saar and Jimmy Randolph of the University of Minnesota, Twin Cities, propose that sites where carbon dioxide will be sequestered deep underground could do double duty as geothermal energy production projects by bringing a small fraction of the high-pressure CO2 back to the surface and using it like hot water to generate electricity. The CO2 would be pumped back down after the heat was extracted.”

For the full article see link below.

Source: Discovery News