District heating is a convenient way to space heating and warm tap water. In many processes, for example when electricity is generated or waste is burned, large parts of the energy are set free in the form of surplus heat. The fundamental idea behind modern district heating is to recycle this surplus heat which otherwise would be wasted: from electricity production, from fuel and biofuel-refining, and from different industrial processes. Furthermore, district heating can make use of the many kinds of renewables (biomass, geothermal, solar thermal).
District heating means a system supplying heat produced centrally in one or several locations to a non-restricted number of customers. It is distributed on a commercial basis by means of a distribution network using hot water or steam as a medium. As district heat is produced centrally, its use allows central removal of harmful substances, which leads to a better overall environmental protection level.
District heating systems can vary substantially in size, from systems supplying just a few buildings to systems that supply entire capital cities. Connected to a district heating network, CHP can provide heat and power to multiple customers in city centres, towns, villages, industrial zones and other built environments with a dense ‘heat load’, meaning high concentrated demand for heat.
An international study co-financed by the European Commission confirms the possibility of saving an extra 400 million tons of CO2 yearly (corresponding to a 9.3% CO2 emission reduction – thus more than the whole Kyoto target!) with more District Heating and Cooling across 32 European countries.
These days, district heating is available throughout the world: in Western and Eastern Europe, North America, and in Japan, Korea, China and Mongolia. In Europe, there are over 5,000 district heating systems, and the market share of district heat is about 10% of the heating market. More than 50% of the European district heating market can be found in the Northern & Eastern part of Europe (Germany, Denmark, Poland, Czech Republic, Finland, Russia and Romania).