Renewable energy sources and increased energy efficiency are not only crucial for reducing greenhouse gas emissions and other negative impacts of conventional energy supply; they also hold enormous economic opportunity. Significant and dynamically growing sectors have emerged in the area of renewable energy over the last several years. In 2010, 26.6 billion euros were invested in Germany alone in renewable energy facilities. Altogether, renewable energy sources created 35.5 billion euros in demand for the German economy. Gross employment in the area of renewable energy is estimated at 367,400 persons for 2010. Likewise, the net economic balance for the expansion of renewables is positive. Model calculations conducted by DIW Berlin show that the gross domestic product is by 2.9 percent higher in 2030 in the "Expansion Scenario" than following a "Null Scenario" with no expansion. Depending on the labor market conditions, the net employment effects appear to be weak to moderate, but in any case positive. These scenario calculations also illustrate that the impact of the expansion differs across sectors. Furthermore, the transition from the current energy supply regime to one where renewable energy sources contribute a large share and energy efficiency has been substantially increased will require a structural change in business and the working world that will have to be followed closely in the future.