This thesis examines the demand for imported steam coal in the German electricity sector. In particular, the impact of renewable energy sources such as wind, solar, hydro or biomass on conventional electricity generation from steam coal is of special interest. An econometric model supports the hypothesis that renewable energy sources, do indeed, change the structure of the electricity market and, therefore, they can be regarded as substitutes for steam coal. Especially, in the long-term renewable energy sources can contribute to a more sustainable and independent electricity market in Germany. The results indicate that institutional changes such as the introduction of the feed-in tariffs for renewable energy sources in the beginning of the 1990s and, especially, the introduction of the Renewable Energy Sources Act in 2000 are an effective and powerful instrument in transforming the electricity sector. These results give valuable advice to countries which seek to avoid increasing scarcity of natural resources and which want to decrease their dependence on foreign fuels for electricity generation.