Solar thermal systems use the sun's energy to heat water and support the heating system. This method of energy generation is used by the outdoor swimming pools in Rüppurr and Wolfartsweier as well as the Rheinstrandbad Rappenwörth. There are also many private solar plants of this type in Karlsruhe. The Office for Waste Management also operates such a system.
In addition to thermal solar systems, photovoltaic systems are also operated in Karlsruhe. Solar cells are used to convert solar energy directly into electricity. In this way, electricity is generated on the roof of the Center for Art and Media Technology (ZKM) on an area of 1000 m², which flows directly into the direct current network of the streetcar. The 100 KW plant is the most powerful plant in the city. Stadtwerke Karlsruhe also has a so-called solar roof with an area of 475 m² and an output of 50 KW. Numerous schools in Karlsruhe operate photovoltaic systems. Solar energy is also generated at the Karlsruhe-West landfill site and in numerous private systems operated by companies.
The city of Karlsruhe already operates some plants in this sector as well. Bioenergy is generated by landfill gas, biowaste fermentation, wood combustion and sewage sludge incineration. Landfill gas is produced by rotting waste. This produces combustible gases inside the landfill, which can then be used to generate hot water and electricity. This form of energy generation is used, for example, by the Karlsruhe-West and -Ost landfills. Biowaste fermentation generates energy by adding process water to biowaste. This then produces a pumpable suspension. The fermentation produces biogas, which is burned together with the landfill gas. Energy is also generated at the East landfill via a wood incineration plant by burning residual wood from the urban area. Through sewage sludge incineration, sludge is dried at the Karlsruhe sewage treatment plant and thus used to generate electricity.
Hydroelectric power plant
In Karlsruhe, two plants produce electricity from hydropower. One is the Appenmühle run-of-river power plant in Daxlanden on the Alb River, which has an output of around 40 KW. The other is the Naturfreundehaus Obermühle in Karlsruhe-Durlach, which is located directly on the Pfinz River. There, up to 45 KW of energy is generated with an old-style run-of-river wheel.
Geothermal energy can be used to generate electricity with hot water from great depths or with water passed through hot rock layers via a heat exchanger. In addition, it is possible to use geothermal energy for heating as well as cooling. In near-surface geothermal energy, the natural heat of the earth is extracted by means of the heat exchanger water and brought to the desired heating temperature with a heat pump. At present, there is no "deep geothermal energy" plant in Karlsruhe. However, the Rhine Graben already offers economically interesting heat deposits at a depth of 2,500 - 4,000 m, which should definitely be used. Geothermal energy is absolutely CO2 - neutral, base load capable and therefore the most environmentally friendly type of renewable energy. In contrast to other energy sources, such as solar or wind power, geothermal energy is not subject to seasonal fluctuations. In addition, it is absolutely emission-free compared to biomass and biogas. Another positive effect is the low land consumption in relation to the output. For the reasons mentioned above, it is imperative to fully exploit the existing opportunities in the region.
There are now four wind turbines in Karlsruhe with a total output of 3.11 MW.
Electricity has been generated by wind turbines in Germany for a quarter of a century. Wind speeds of 4 m/s are required for the plants to operate economically.
The Karlsruhe plant on the Windmühlenberg can even use wind speeds of 5 m/s.
In total, two 750 KW wind turbines and one 1500 KW turbine generate electricity at this site, which is fed into the supply network of the Karlsruhe municipal utility. The 1500 KW turbine is the largest wind turbine in the region. The turbines are operated by Windmühlenberg Windkraftanlage GmbH & Co.KG.