Power stations without greenhouse gas emissions

So-called CO2-free power stations will be an important topic for the German EU presidency starting in January 2007. The Fraunhofer Institute for Systems and Innovation Research ISI in Karlsruhe together with the Federal Institute for Geosciences and Natural Resources (BGR) has compiled and evaluated the current state of international research. The study conducted for the Federal Environmental Agency provides answers on which methods there are for capturing CO2 from power station emissions, how the gas can be stored below ground and what economic consequences the technology has.

The Fraunhofer ISI concludes that CO2 capture is an interesting bridging technology to significantly reduce the emissions of the greenhouse gas in the next 20 to 50 years until the full portfolio of regenerative energy sources has been developed including photovoltaic and solar thermal electricity. But it is not a miracle solution: power stations with CO2 capture consume one third more coal or gas and thus do not constitute progress towards a sustainable energy supply. According to studies of the BGR, storage possibilities for CO2 are mainly to be found in northern Germany. However, the suitability and capacity of individual underground structures are still unknown.

Whether CO2-free power stations are economic depends on the standard of comparison used. In spite of the complex technology involved, they are currently much cheaper than part of the renewable energy technology portfolio such as photovoltaic and geothermal electricity. If all the costs are taken into account including the costs for capture, transport and storage, avoiding one ton of CO2 costs about 40 Euro and is thus almost double what operators of conventional power stations have to pay for emission allowances under the emissions trading scheme. However, emission certificates will probably become more expensive so that the first large CO2-free power station which RWE plans to put into operation in 2014 could be competitive by then.

It is not certain how residents will react to underground CO2 storage in their vicinity. Legal issues of CO2 capture and storage also require clarification according to Fraunhofer ISI. So far, the laws concerning underground formations such as the Federal Mining Act or the Federal Water Act do not take CO2 storage into account.