This research analyzes the German experience in promoting Renewable Energy (RE) as an instrument to reduce GHG emissions. It identifies the cost of reducing CO2 emissions in the power sector through the promotion of wind and solar energy for the years 2006-2010. A RE carbon surcharge and an implicit carbon price due to the RE incentives are calculated. The RE carbon surcharge is the ratio of the net cost of the RE over the CO2 emission reductions resulting from actual RE injections into the electric power system. The implicit carbon price is the sum of the RE carbon surcharge and the EUA price. Results show that for the period analyzed both the RE carbon surcharge and the implicit carbon price of wind are on the order of tens of euro per tonne of CO2, while for solar are on the order of hundreds of euro per tonne of CO2.