In 2014, testing will begin to determine whether it’s possible to defray the costs of carbon capture and storage by putting the stored CO2 to use in a geothermal plant.
If it works, the technology, known as carbon capture and storage (CCS), could provide both the electricity needed to pump CO2 underground as well as being a source of revenue to offset the high cost of capturing carbon dioxide at power plants, compressing it, and shipping it to storage sites. CCS, experts say, will be essential for reducing greenhouse gas emissions.
However, the cost of large-scale CCS can be astronomical, and according to the International Energy Agency, the development of the technology has been far too slow to meet climate change targets.
In conventional geothermal plants, water and steam heated by hot rocks underground drive the turbines. The water is then pumped back underground to be heated all over again. The new technology would use the conventional approach but would go one step farther and use CO2 instead of water.
This technique has several advantages. Since the need for water is eliminated, geothermal projects can be undertaken in dry areas. According to computer simulations, CO2 might produce double the amount of electricity from an area than water does.