District heating is a form of heat supply in which buildings are supplied with space heating and often also hot water via underground, insulated pipelines. Users of district heating no longer need their own heating system. Heat is generated in one or more central generation plants by, for example, burning biomass, coal, gas, waste, or by combined heat and power (CHP), in which electricity and heat are generated in parallel. The district heating network supplies the connected buildings. Hot water or steam enters the internal heating system underground with little heat loss via a heat exchanger. The cooled water is then returned to the generation plant to be reheated. According to the consumer advice center, district heating is particularly profitable when a large number of users are connected to the heating network. This can put the high costs of network expansion into perspective. The extent to which heating with district heating can be considered environmentally friendly depends on several factors. A large part of the energy mix in Germany currently still consists of fossil fuels. Around 30 percent is generated by renewable energies such as geothermal energy. Depending on the energy source, district heating can provide a very efficient since centralized, space-saving and also sustainable heat supply.
