District heating (also known as heat networks or teleheating) is a system for distributing heat generated in a centralized location through a system of insulated pipes for residential and commercial heating requirements such as space heating and water heating. The heat is often obtained from a cogeneration plant burning fossil fuels or biomass, but heat-only boiler stations, geothermal heating, heat pumps and central solar heating are also used, as well as heat waste from factories and nuclear power electricity generation. District heating plants can provide higher efficiencies and better pollution control than localized boilers. According to some research, district heating with combined heat and power (CHPDH) is the cheapest method of cutting carbon emissions, and has one of the lowest carbon footprints of all fossil generation plants.
Fifth-generation district heat networks do not use combustion on-site and have zero emissions of CO2 and NO2 on-site; they employ heat transfer using electricity, which may be generated from renewable energy or from remote fossil-fuelled power stations. A combination of CHP and centralized heat pumps is used in the Stockholm multi-energy system. This allows the production of heat through electricity when there is an abundance of intermittent power production, and cogeneration of electric power and district heating when the availability of intermittent power production is low.