Technology for capturing of CO2 is already commercially available for large CO2 emitters, such as power plants; however, capture is meaningless without storage. Storage of CO2, on the other hand, is a relatively untried concept and as yet no power plant operates with a full carbon capture and storage system.
Carbon sequestration applied to a modern power plant could reduce CO2 emissions to the atmosphere by approximately 80-90 percent. Capturing and compressing CO2 requires much energy and would increase the fuel needs of a plant by about 10-40 percent. These and other system costs are estimated to increase the cost of energy from a power plant with carbon capture and storage by 30-60 percent depending on the specific circumstances.
Storage of the CO2 is envisaged either in deep geological formations, deep oceans, or in the form of mineral carbonates. In the case of deep ocean storage, there is a risk of greatly increasing the problem of ocean acidification, a problem that also stems from the excess of carbon dioxide already in the atmosphere and oceans. Geological formations are currently considered the most promising sequestration sites.