As prices for conventional fuels continue to increase and prices for renewable energy steadily decrease, the renewable energy sector is expected to continue to grow. Electricity generation from renewable energies is substantially based on the German Renewable Energy Sources Act (Erneuerbare-Energien-Gesetz, EEG), which is in accordance with European policy (Directive 2001/77/EC). The share of renewable energy sources in the total energy consumption (heat, electricity and fuels) is expected to be more than 28% by 2020.
Renewables will generate an expected 47 % of the entire electricity (incl., 25% of all heating energy and 19 % of all fuels used for transportation purposes (ships, automobiles, trucks, and electricity for electric vehicles and trains).
Of all renewable energy sources, wind energy will remain the most significant. Until 2020, 25 percent, or 149 TWh, of the entire electric consumption in Germany is expected to be met by wind energy.
In 2020, bio energy will account for 54 TWh (2008: 27 TWh) or 9.1% of all electricity, 150 TWh (2208: 97 TWh) or 13% of heating energy , and 111 TWh (2008: 37 TWh) or 21% of all fuels. The major share will come from biogas, followed by solid biomass (mainly wood and plants), liquid biomass (plant oils), and sewage and landfill gas.
Photovoltaic (PV) Energy
Only about 6% of the entire suitable roofs (not considering free standing installations) are being used for solar energy purposes at present in Germany. In 2020, 39.5 GW of installed cells will generate 40 TWh (2008: TWh). PV will then generate around seven percent of the electricity used in Germany. Solar thermal heating energy is expected to increase to an annual yield of 30TWh in 2020 (2008: 4 TWh).
Most hydro power plants operating in Germany were built before the 1960s and the majority is in the 5-10 MW class. Experts state that the 31 TWh that were generated in 2008 can be increased (mainly by repowering existing plants) to over 31 TWh by 2020 and then account for 5.4% of the electric power generation in Germany. In addition to repowering, major investment is also expected for environmental protection measures for hydro power plant surrounding waterways (fish steps, re-naturalization of riverbeds, and optimization of river flow).
Industrial, deep geothermal energy: At present, total installed electrical power equals to 7 MW generating 220 Million kWh per year. It is expected that this energy form will reach as much as 6000 MW and 38 TWh by 2020. Surface geothermal energy: In 2008 alone, about 62,000 heat pumps were installed, mostly in private residences bringing the total number of heat pumps to over 350,000 units. More than half use water-to-water or brine-to-water technology for which vertical drilling or horizontal netting is required. A little less than half use air-to-air heat pump technology, which is expected to carry the highest growth potential.