The external environmental costs saved by using green rather than fossil fuel power more than compensate for the higher -price electricity generated by renewable energy, says a new study commissioned by the federal environment ministry. Assuming a "best estimate" of the costs of climate damage by carbon emissions of EUR 70/tonne, renewables electricity saved at least EUR 2.8 billion in external costs in 2005, according to the study. The additional cost of paying a fixed premium for renewables electricity amounted to EUR 2.4 billion. In establishing the additional cost, the study assumed a market price of EUR 0.042/kWh. It was produced by the German aerospace research centre and the Fraunhofer Inst-itute for systems and innovation research.