District heating (also known as heat networks) 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 Water heating is a heat transfer process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water include cooking, cleaning, bathing, and space heating. In industry, hot water and water heated t ...

. The heat is often obtained from a

cogeneration Cogeneration or combined heat and power (CHP) is the use of a heat engine or power station to generate electricity and useful heat at the same time. Cogeneration is a more efficient use of fuel or heat, because otherwise- wasted heat from elec ...

plant burning

fossil fuels A fossil fuel is a flammable carbon compound- or hydrocarbon-containing material formed naturally in the Earth's crust from the buried remains of prehistoric organisms (animals, plants or microplanktons), a process that occurs within geologica ...

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

, but

heat-only boiler station A heating plant, also called a physical plant, or steam plant, generates thermal energy in the form of steam for use in district heating applications. Unlike combined heat and power installations which produce thermal energy as a by-product ...

s, geothermal heating,

heat pump A heat pump is a device that uses electricity to transfer heat from a colder place to a warmer place. Specifically, the heat pump transfers thermal energy using a heat pump and refrigeration cycle, cooling the cool space and warming the warm s ...

s and central solar heating are also used, as well as heat waste from factories and

nuclear power Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by ...

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. District heating is ranked number 27 in Project Drawdown's 100 solutions to

global warming Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes ...

History

District heating traces its roots to the hot water-heated baths and greenhouses of ancient times, perhaps today most known in the

Roman Empire The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...

. A hot water distribution system in Chaudes-Aigues in France is generally regarded as the first real district heating system. It used geothermal energy to provide heat for about 30 houses and started operation in the 14th century. The U.S. Naval Academy in

Annapolis Annapolis ( ) is the capital of the U.S. state of Maryland. It is the county seat of Anne Arundel County and its only incorporated city. Situated on the Chesapeake Bay at the mouth of the Severn River, south of Baltimore and about east o ...

began

steam Steam is water vapor, often mixed with air or an aerosol of liquid water droplets. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Saturated or superheated steam is inv ...

district heating service in 1853.

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

began

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

-fired

district heating in 1916 when it moved to

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...

. Although these and numerous other systems have operated over the centuries, the first commercially successful district heating system was launched in Lockport, New York, in 1877 by American hydraulic engineer Birdsill Holly, considered the founder of modern district heating.

Generations of district heating

Generally, all modern district heating systems are demand driven, meaning that the heat supplier reacts to the demand from the consumers and ensures that there is sufficient temperature and water pressure to deliver the demanded heat to the users. The five generations have defining features that sets them apart from the prior generations. The feature of each generation can be used to give an indication of the development status of an existing district heating system.

First generation

The first generation was a steam-based system fueled by

and was first introduced in the US in the 1880s and became popular in some European countries, too. It was state of the art until the 1930s. These systems piped very high-temperature steam through concrete ducts, and were therefore not very efficient, reliable, or safe. Nowadays, this generation is technologically outdated. However, some of these systems are still in use, for example in New York or Paris. Other systems originally built have subsequently been upgraded.

Second generation

The second generation was developed in the 1930s and was built until the 1970s. It burned coal and oil, and the energy was transmitted through pressurized hot water as the heat carrier. The systems usually had supply temperatures above 100 °C, and used water pipes in concrete ducts, mostly assembled on site, and heavy equipment. A main reason for these systems was the primary energy savings, which arose from using combined heat and power plants. While also used in other countries, typical systems of this generation were the Soviet-style district heating systems that were built after WW2 in several countries in Eastern Europe.

Third generation

In the 1970s the third generation was developed and was subsequently used in most of the following systems all over the world. This generation is also called the "Scandinavian district heating technology", because many of the district heating component manufacturers are based in Scandinavia. The third generation uses prefabricated, pre-insulated pipes, which are directly buried into the ground and operates with lower temperatures, usually below 100 °C. A primary motivation for building these systems was security of supply by improving the energy efficiency after the two oil crises led to disruption of the oil supply. Therefore, those systems usually used coal, biomass and waste as energy sources, in preference to oil. In some systems,

geothermal energy Geothermal energy is thermal energy extracted from the crust (geology), crust. It combines energy from the formation of the planet and from radioactive decay. Geothermal energy has been exploited as a source of heat and/or electric power for m ...

and

solar energy Solar energy is the radiant energy from the Sun's sunlight, light and heat, which can be harnessed using a range of technologies such as solar electricity, solar thermal energy (including solar water heating) and solar architecture. It is a ...

are also used in the energy mix. For example, Paris has been using geothermal heating from a 55–70 °C source 1–2 km below the surface for domestic heating since the 1970s. Especially in the former

Eastern Bloc The Eastern Bloc, also known as the Communist Bloc (Combloc), the Socialist Bloc, the Workers Bloc, and the Soviet Bloc, was an unofficial coalition of communist states of Central and Eastern Europe, Asia, Africa, and Latin America that were a ...

nuclear energy Nuclear energy may refer to: *Nuclear power, the use of sustained nuclear fission or nuclear fusion to generate heat and electricity *Nuclear binding energy, the energy needed to fuse or split a nucleus of an atom *Nuclear potential energy, the pot ...

has been used for district heating and new systems keep being installed in China. The source of the heat of nuclear district heating is virtually always waste heat from power reactors, but proposals to build dedicated heating reactors or to use the waste heat from repurposed

spent fuel pool Spent fuel pools (SFP) are storage pools (or "ponds" in the United Kingdom) for spent fuel from nuclear reactors. They are typically 40 or more feet (12 m) deep, with the bottom 14 feet (4.3 m) equipped with storage racks designed to hold ...

s have been brought forth.

Fourth generation

Currently, the fourth generation is being developed, with the transition to fourth generation already in process in

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

. The fourth generation is designed to combat climate change and integrate high shares of variable renewable energy into the district heating by providing high flexibility to the electricity system. According to the review by Lund et al. those systems have to have the following abilities: # "Ability to supply low-temperature district heating for space heating and domestic hot water (DHW) to existing buildings, energy-renovated existing buildings and new low-energy buildings." # "Ability to distribute heat in networks with low grid losses." # "Ability to recycle heat from low-temperature sources and integrate renewable heat sources such as solar and geothermal heat." # "Ability to be an integrated part of smart energy systems (i.e. integrated smart electricity, gas, fluid and thermal grids) including being an integrated part of 4th Generation District Cooling systems." # "Ability to ensure suitable planning, cost and motivation structures in relation to the operation as well as to strategic investments related to the transformation into future sustainable energy systems". Compared to the previous generations the temperature levels have been reduced to increase the energy efficiency of the system, with supply side temperatures of 70 °C and lower. Potential heat sources are waste heat from industry, CHP plants burning waste, biomass power plants, geothermal and solar thermal energy (central solar heating), large scale

s, waste heat from cooling purposes and

data center A data center is a building, a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems. Since IT operations are crucial for busines ...

s and other sustainable energy sources. With those energy sources and large scale thermal energy storage, including

seasonal thermal energy storage Seasonal thermal energy storage (STES), also known as inter-seasonal thermal energy storage,is the storage of heat or cold for periods of up to several months. The thermal energy can be collected whenever it is available and be used whenever need ...

, fourth generation district heating systems are expected to provide flexibility for balancing

wind Wind is the natural movement of atmosphere of Earth, air or other gases relative to a planetary surface, planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heatin ...

and

solar power Solar power, also known as solar electricity, is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power. Solar panels use the photovoltaic effect to c ...

generation, for example by using heat pumps to integrate surplus electric power as heat when there is much wind energy or providing electricity from biomass plants when back-up power is needed. Therefore, large scale heat pumps are regarded as a key technology for smart energy systems with high shares of

renewable energy Renewable energy (also called green energy) is energy made from renewable resource, renewable natural resources that are replenished on a human lifetime, human timescale. The most widely used renewable energy types are solar energy, wind pow ...

up to 100% and advanced fourth generation district heating systems.

Fifth generation/cold district heating

A fifth generation district heating and cooling network (5GDHC), also called ''cold district heating'', distributes heat at near ambient ground temperature: this in principle minimizes heat losses to the ground and reduces the need for extensive insulation. Each building on the network uses a heat pump in its own plant room to extract heat from the ambient circuit when it needs heat, and uses the same heat pump in reverse to reject heat when it needs cooling. In periods of simultaneous cooling and heating demands this allows waste heat from cooling to be used in heat pumps at those buildings which need heating. The overall temperature within the ambient circuit is preferably controlled by heat exchange with an aquifer or another low temperature water source to remain within a temperature range from 10 °C to 25 °C. While network piping for ambient ground temperature networks is less expensive to install per pipe diameter than in earlier generations, as it does not need the same degree of insulation for the piping circuits, it has to be kept in mind that the lower temperature difference of the pipe network leads to significantly larger pipe diameters than in prior generations. Due to the requirement of each connected building in the fifth generation district heating and cooling systems to have their own heat pump the system can be used both as a heat source or a heat sink for the heat pump, depending on if it is operated in heating or cooling mode. As with prior generations the pipe network is an infrastructure that in principle provides an open access for various low temperature heat sources, such as ambient heat, ambient water from rivers, lakes, sea, or lagoons, and waste heat from industrial or commercial sources. Based on the above description it is clear that there is a fundamental difference between the 5GDHC and the prior generations of district heating, particularly in the individualization of the heat generation. This critical system has a significant impact when comparing the efficiencies between the different generations, as the individualization of the heat generation moves the comparison from being a simple distribution system efficiency comparison to a supply system efficiency comparison, where both the heat generation efficiency as well as the distribution system efficiency needs to be included. A modern building with a low-temperature internal heat distribution system can install an efficient heat pump delivering heat output at 45 °C. An older building with a higher-temperature internal distribution system e.g. using radiators will require a high-temperature heat pump to deliver heat output. A larger example of a fifth generation heating and cooling grid is Mijnwater in Heerlen, the Netherlands. In this case the distinguishing feature is a unique access to an abandoned water-filled coal mine within the city boundary that provides a stable heat source for the system. A fifth generation network ("Balanced Energy Network", BEN) was installed in 2016 at two large buildings of the London South Bank University as a research and development project.

Heat sources

District heating networks exploit various energy sources, sometimes indirectly through multipurpose infrastructure such as combined heat and power plants (CHP, also called co-generation).

Combustion of fossil or renewable fuels

The most used energy source for district heating is the burning of

hydrocarbons In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may b ...

. As the supply of renewable fuels is insufficient, the fossil fuels coal and gas are massively used for district heating. This burning of fossil hydrocarbons usually contributes to

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

, as the use of systems to capture and store the CO₂ instead of releasing it into the atmosphere is rare. In the case of a cogeneration plant, the heat output is typically sized to meet half of the peak winter heat load, but over the year will provide 90% of the heat supplied. Much of the heat produced in summer will generally be wasted. The boiler capacity will be able to meet the entire heat demand unaided and can cover for breakdowns in the cogeneration plant. It is not economic to size the cogeneration plant alone to be able to meet the full heat load. In the New York City steam system, that is around 2.5 GW. Germany has the largest amount of CHP in Europe. A simple

thermal power station A thermal power station, also known as a thermal power plant, is a type of power station in which the heat energy generated from various fuel sources (e.g., coal, natural gas, nuclear fuel, etc.) is converted to electrical energy. The heat ...

can be 20–35% efficient, whereas a more advanced facility with the ability to recover waste heat can reach total energy efficiency of nearly 80%. Some may approach 100% based on the lower heating value by condensing the flue gas as well.

Nuclear fission

The heat produced by

nuclear chain reaction In nuclear physics, a nuclear chain reaction occurs when one single nuclear reaction causes an average of one or more subsequent nuclear reactions, thus leading to the possibility of a self-propagating series or "positive feedback loop" of thes ...

s can be injected into district heating networks. This does not contaminate the district pipes with radioactive elements, as the heat is transferred to the network through

heat exchanger A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contac ...

s. It is not technically necessary for the nuclear reactor to be very close to the district heating network, as heat can be transported over significant distances (exceeding 200 km) with affordable losses, using insulated pipes. Since nuclear reactors do not significantly contribute to either

air pollution Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles li ...

, they can be an advantageous alternative to the combustion of fossil hydrocarbons. However, only a small minority of the nuclear reactors currently in operation around the world are connected to a district heating network. These reactors are in Bulgaria, China, Hungary, Romania, Russia, Slovakia, Slovenia, Switzerland and Ukraine. The Ågesta Nuclear Power Plant in Sweden was an early example of nuclear cogeneration, providing small quantities of both heat and electricity to a suburb of the country's capital between 1964 and 1974. The Beznau Nuclear Power Plant in Switzerland has been generating electricity since 1969 and supplying district heating since 1984. The Haiyang Nuclear Power Plant in China started operating in 2018 and started supplying small scale heat to the Haiyang city area in 2020. By November 2022, the plant used 345 MW-thermal effect to heat 200,000 homes, replacing 12 coal heating plants. Recent years have seen renewed interest in small modular reactors (SMRs) and their potential to supply district heating. Speaking on the Energy Impact Center's (EIC) podcast, '' Titans of Nuclear'', principal engineer at GE Hitachi Nuclear Energy Christer Dahlgren noted that district heating could be the impetus for the construction of new nuclear power plants in the future. EIC's own open-source SMR blueprint design, OPEN100, could be incorporated into a district heating system.

Natural underground heat

History Geothermal district heating was used in

Pompeii Pompeii ( ; ) was a city in what is now the municipality of Pompei, near Naples, in the Campania region of Italy. Along with Herculaneum, Stabiae, and Villa Boscoreale, many surrounding villas, the city was buried under of volcanic ash and p ...

, and in Chaudes-Aigues since the 14th century. Denmark Denmark has one geothermal plant in operation in Thisted since 1984. Two other plants are now closed, located in Copenhagen (2005-2019), and Sønderborg (2013-2018). Both suffered issues with fine sand and blockages The country's first large-scale plant is being developed near Aarhus, and by the end of 2030, it is expected to be able to cover approximately 20% of the district heating demand in Aarhus. United States Direct use geothermal district heating systems, which tap geothermal reservoirs and distribute the hot water to multiple buildings for a variety of uses, are uncommon in the United States, but have existed in America for over a century. In 1890, the first wells were drilled to access a hot water resource outside of Boise, Idaho. In 1892, after routing the water to homes and businesses in the area via a wooden pipeline, the first geothermal district heating system was created. As of a 2007 study, there were 22 geothermal district heating systems (GDHS) in the United States. As of 2010, two of those systems have shut down. The table below describes the 20 GDHS currently operational in America.

Solar heat

Use of solar heat for district heating has been increasing in Denmark and Germany in recent years. The systems usually include inter

for a consistent heat output day to day and between summer and winter. Good examples are in

Vojens Vojens () is a railway town in Denmark with a population of 7,424 (1 January 2025).Dronninglund Dronninglund is a town with a population of 3,688 (1 January 2025)Drake Landing Solar Community has achieved a world record 97% annual solar fraction for heating needs, using solar-thermal panels on the garage roofs and thermal storage in a borehole cluster.

Low temperature natural or waste heat

In Stockholm, the first heat pump was installed in 1977 to deliver district heating sourced from IBM servers. Today the installed capacity is about 660 MW heat, using treated sewage water, sea water, district cooling, data centers and grocery stores as heat sources. Another example is the Drammen Fjernvarme District Heating project in Norway which produces 14 MW from water at just 8 °C, industrial heat pumps are demonstrated heat sources for district heating networks. Among the ways that industrial heat pumps can be used are: # As the primary base load source where water from a low grade source of heat, e.g. a river, fjord,

, power station outfall, sewage treatment works outfall (all typically between 0 ˚C and 25 ˚C), is boosted up to the network temperature of typically 60 ˚C to 90 ˚C using heat pumps. These devices, although consuming electricity, will transfer a heat output three to six times larger than the amount of electricity consumed. An example of a district system using a heat pump to source heat from raw sewage is in Oslo, Norway that has a heat output of 18 MW(thermal). # As a means of recovering heat from the cooling loop of a power plant to increase either the level of flue gas heat recovery (as the district heating plant return pipe is now cooled by the heat pump) or by cooling the closed steam loop and artificially lowering the condensing pressure and thereby increasing the electricity generation efficiency. # As a means of cooling flue gas scrubbing working fluid (typically water) from 60 ˚C post-injection to 20 ˚C pre-injection temperatures. Heat is recovered using a heat pump and can be sold and injected into the network side of the facility at a much higher temperature (e.g. about 80 ˚C). # Where the network has reached capacity, large individual load users can be decoupled from the hot feed pipe, say 80 ˚C and coupled to the return pipe, at e.g. 40 ˚C. By adding a heat pump locally to this user, the 40 ˚C pipe is cooled further (the heat being delivered into the heat pump evaporator). The output from the heat pump is then a dedicated loop for the user at 40 ˚C to 70 ˚C. Therefore, the overall network capacity has changed as the total temperature difference of the loop has varied from 80 to 40 ˚C to 80 ˚C–x (x being a value lower than 40 ˚C). Concerns have existed about the use of

hydrofluorocarbon Hydrofluorocarbons (HFCs) are synthetic organic compounds that contain fluorine and hydrogen atoms, and are the most common type of organofluorine compounds. Most are gases at room temperature and pressure. They are frequently used in air condit ...

s as the working fluid (refrigerant) for large heat pumps. Whilst leakage is not usually measured, it is generally reported to be relatively low, such as 1% (compared to 25% for supermarket cooling systems). A 30-megawatt heatpump could therefore leak (annually) around 75 kg of R134a or other working fluid. However, recent technical advances allow the use of natural heat pump refrigerants that have very low

global warming potential Global warming potential (GWP) is a measure of how much heat a greenhouse gas traps in the atmosphere over a specific time period, relative to carbon dioxide (). It is expressed as a multiple of warming caused by the same mass of carbon dioxide ( ...

(GWP). CO₂ refrigerant (R744, GWP=1) or ammonia (R717, GWP=0) also have the benefit, depending on operating conditions, of resulting in higher heat pump efficiency than conventional refrigerants. An example is a 14 MW(thermal) district heating network in

Drammen Drammen () is a city and municipality in Buskerud county, Norway. The port and river city of Drammen is centrally located in the south-eastern and most populated part of Norway. Drammen municipality also includes smaller towns and villages such ...

, Norway, which is supplied by seawater-source heatpumps that use R717 refrigerant, and has been operating since 2011. 90 °C water is delivered to the district loop (and returns at 65 °C). Heat is extracted from seawater (from depth) that is 8 to 9 °C all year round, giving an average

coefficient of performance The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required. Higher COPs equate to higher efficiency, lower energy ( ...

(COP) of about 3.15. In the process the seawater is chilled to 4 °C; however, this resource is not used. In a district system where the chilled water could be used for air conditioning, the effective COP would be considerably higher.Hoffman, & Pearson, D. 2011
Ammonia heat pumps for district heating in Norway 7 – a case study
. Presented at Institute of Refrigeration, 7 April, London. In the future, industrial heat pumps will be further de-carbonised by using, on one side, excess renewable electrical energy (otherwise spilled due to meeting of grid demand) from wind, solar, etc. and, on the other side, by making more of renewable heat sources (lake and ocean heat, geothermal, etc.). Furthermore, higher efficiency can be expected through operation on the high voltage network.

Heat accumulators and storage

Increasingly large heat stores are being used with district heating networks to maximise efficiency and financial returns. This allows cogeneration units to be run at times of maximum electrical tariff, the electrical production having much higher rates of return than heat production, whilst storing the excess heat production. It also allows solar heat to be collected in summer and redistributed off season in very large but relatively low-cost in-ground insulated reservoirs or borehole systems. The expected heat loss at the 203,000m³ insulated pond in

Vojens Vojens () is a railway town in Denmark with a population of 7,424 (1 January 2025).Power-to-X Power-to-X (also P2X and P2Y) are electricity conversion, energy storage, and reconversion pathways from surplus renewable energy. Power-to-X conversion technologies allow for the decoupling of power from the electricity sector for use in other ...

) is regarded as a key factor for energy systems with high shares of renewable energy.

Heat distribution

Pre-installation insulated underground pipes for district heating

After generation, the heat is distributed to the customer via a network of insulated pipes. District heating systems consist of feed and return lines. Usually the pipes are installed underground but there are also systems with overground pipes. The DH system's start-up and shut downs, as well as fluctuations on heat demand and ambient temperature, induce thermal and mechanical cycling on the pipes due to the thermal expansion. The axial expansion of the pipes is partially counteracted by frictional forces acting between the ground and the casing, with the

shear stress Shear stress (often denoted by , Greek alphabet, Greek: tau) is the component of stress (physics), stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross secti ...

es transferred through the PU foam bond. Therefore, the use of pre- insulated pipes has simplified the laying methods, employing cold laying instead of expansion facilities like compensators or U-bends, being so more cost effective. Pre-insulated pipes sandwich assembly composed of a steel heat service pipe, an insulating layer (

polyurethane Polyurethane (; often abbreviated PUR and PU) is a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term ...

foam) and a

polyethylene Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging (plastic bags, plastic films, geomembranes and containers including bott ...

(PE) casing, which are bonded by the insulating material. While polyurethane has outstanding mechanical and thermal properties, the high toxicity of the diisocyanates required for its manufacturing has caused a restriction on their use. This has triggered research on alternative insulating foam fitting the application, which include polyethylene terephthalate (PET) and polybutylene (PB-1). Within the system heat storage units may be installed to even out peak load demands. The common medium used for heat distribution is water or superheated water, but steam is also used. The advantage of steam is that in addition to heating purposes it can be used in

industrial processes Industrial processes are procedures involving chemical, physical, electrical, or mechanical steps to aid in the manufacturing of an item or items, usually carried out on a very large scale. Industrial processes are the key components of heavy ...

due to its higher temperature. The disadvantage of steam is a higher heat loss due to the high temperature. Also, the

thermal efficiency In thermodynamics, the thermal efficiency (\eta_) is a dimensionless performance measure of a device that uses thermal energy, such as an internal combustion engine, steam turbine, steam engine, boiler, furnace, refrigerator, ACs etc. For ...

of cogeneration plants is significantly lower if the cooling medium is high-temperature steam, reducing

electric power Electric power is the rate of transfer of electrical energy within a electric circuit, circuit. Its SI unit is the watt, the general unit of power (physics), power, defined as one joule per second. Standard prefixes apply to watts as with oth ...

generation. Heat transfer oils are generally not used for district heating, although they have higher heat capacities than water, as they are expensive and have environmental issues. At customer level the heat network is usually connected to the

central heating A central heating system provides warmth to a number of spaces within a building from one main source of heat. A central heating system has a Furnace (central heating), furnace that converts fuel or electricity to heat through processes. The he ...

system of the dwellings via

s (heat substations): the working fluids of both networks (generally water or steam) do not mix. However, direct connection is used in the

Odense Odense ( , , ) is the third largest city in Denmark (after Copenhagen and Aarhus) and the largest city on the island of Funen. As of 1 January 2025, the city proper had a population of 185,480 while Odense Municipality had a population of 210, ...

system. Typical annual loss of thermal energy through distribution is around 10%, as seen in Norway's district heating network.

Heat metering

The amount of heat provided to customers is often recorded with a

heat meter A heat meter attached to a heat exchanger in a District heating substation in a residential neighborhood. Right in white-blue: the calculator; in the center in bronze: the ultrasonic flow meter A heat meter, thermal energy meter or energy meter ...

to encourage conservation and maximize the number of customers which can be served, but such meters are expensive. Due to the expense of heat metering, an alternative approach is simply to meter the water – water meters are much cheaper than heat meters, and have the advantage of encouraging consumers to extract as much heat as possible, leading to a very low return temperature, which increases the efficiency of power generation. Many systems were installed under a

socialist Socialism is an economic ideology, economic and political philosophy encompassing diverse Economic system, economic and social systems characterised by social ownership of the means of production, as opposed to private ownership. It describes ...

economy (such as in the former

) which lacked heat metering and means to adjust the heat delivery to each apartment. This led to great inefficiencies – users had to simply open windows when too hot – wasting energy and minimising the numbers of connectable customers.

Size of systems

District heating systems can vary in size. Some systems cover entire cities such as

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

Flensburg Flensburg (; Danish language, Danish and ; ; ) is an independent city, independent town in the far north of the Germany, German state of Schleswig-Holstein. After Kiel and Lübeck, it is the third-largest city in Schleswig-Holstein. Flensburg's ...

, using a network of large 1000 mm diameter primary pipes linked to secondary pipes – e.g. 200 mm diameter, which in turn link to tertiary pipes that might be of 25 mm diameter which might connect to 10 to 50 houses. Some district heating schemes might only be sized to meet the needs of a small village or area of a city in which case only the secondary and tertiary pipes will be needed. Some schemes may be designed to serve only a limited number of dwellings, of about 20 to 50 houses, in which case only tertiary sized pipes are needed.

Pros and cons

District heating has various advantages compared to individual heating systems. Usually district heating is more energy efficient, due to simultaneous production of heat and electricity in combined heat and power generation plants. This has the added benefit of reducing

greenhouse gas emissions Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide (), from burning fossil fuels such as coal, petroleum, oil, and natural gas, is the main cause of climate chan ...

. The larger combustion units also have a more advanced flue gas cleaning than single boiler systems. In the case of surplus heat from industries, district heating systems do not use additional fuel because they recover heat which would otherwise be dispersed to the environment. District heating requires a long-term financial commitment that fits poorly with a focus on short-term returns on investment. Benefits to the community include avoided costs of energy through the use of surplus and wasted heat energy, and reduced investment in individual household or building heating equipment. District heating networks, heat-only boiler stations, and cogeneration plants require high initial capital expenditure and financing. Only if considered as long-term investments will these translate into profitable operations for the owners of district heating systems, or combined heat and power plant operators. District heating is less attractive for areas with low population densities, as the investment per household is considerably higher. Also it is less attractive in areas of many small buildings; e.g. detached houses than in areas with a fewer larger buildings; e.g. blocks of flats, because each connection to a single-family house is quite expensive.

Ownership, monopoly issues and charging structures

In many cases large combined heat and power district heating schemes are owned by a single entity. This was typically the case in the old Eastern bloc countries. However, for many schemes, the ownership of the cogeneration plant is separate from the heat using part. Examples are Warsaw which has such split ownership with PGNiG Termika owning the cogeneration unit, the Veolia owning 85% of the heat distribution, the rest of the heat distribution is owned by municipality and workers. Similarly all the large CHP/CH schemes in Denmark are of split ownership. Sweden provides an alternative example where the heating market is deregulated. In Sweden it is most common that the ownership of the district heating network is not separated from the ownership of the cogeneration plants, the district cooling network or the centralized heat pumps. There are also examples where the competition has spawned parallel networks and interconnected networks where multiple utilities cooperate. In the United Kingdom there have been complaints that district heating companies have too much of a monopoly and are insufficiently regulated, an issue the industry is aware of, and has taken steps to improve consumer experience through the use of customer charters as set out by the Heat Trust. Some customers are taking legal action against the supplier for Misrepresentation & Unfair Trading, claiming district Heating is not delivering the savings promised by many heat suppliers.

National variation

Since conditions from city to city differ, every district heating system is unique. In addition, nations have different access to primary energy carriers and so they have a different approach on how to address heating markets within their borders.

Europe

Since 1954, district heating has been promoted in Europe by Euroheat & Power. They have compiled an analysis of district heating and cooling markets in Europe within their Ecoheatcool project supported by the

European Commission The European Commission (EC) is the primary Executive (government), executive arm of the European Union (EU). It operates as a cabinet government, with a number of European Commissioner, members of the Commission (directorial system, informall ...

. A separate study, entitled Heat Roadmap Europe, has indicated that district heating can reduce the price of energy in the European Union between now and 2050. The legal framework in the member states of the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

is currently influenced by the EU's CHP Directive.

Cogeneration in Europe

The EU has actively incorporated cogeneration into its energy policy via the CHP Directive. In September 2008 at a hearing of the European Parliament's Urban Lodgment Intergroup, Energy Commissioner Andris Piebalgs is quoted as saying, "security of supply really starts with energy efficiency." Energy efficiency and cogeneration are recognized in the opening paragraphs of the European Union's Cogeneration Directive 2004/08/EC. This directive intends to support cogeneration and establish a method for calculating cogeneration abilities per country. The development of cogeneration has been very uneven over the years and has been dominated throughout the last decades by national circumstances. As a whole, the European Union currently generates 11% of its electricity using cogeneration, saving Europe an estimated 35 Mtoe per annum. However, there are large differences between the member states, with energy savings ranging from 2% to 60%. Europe has the three countries with the world's most intensive cogeneration economies: Denmark, the Netherlands and Finland. Other European countries are also making great efforts to increase their efficiency. Germany reports that over 50% of the country's total electricity demand could be provided through cogeneration. Germany set a target to double its electricity cogeneration from 12.5% of the country's electricity to 25% by 2020 and has passed supporting legislation accordingly in "Federal Ministry of Economics and Technology", (BMWi), Germany, August 2007. The UK is also actively supporting district heating. In the light of UK's goal to achieve an 80% reduction in carbon dioxide emissions by 2050, the government had set a target to source at least 15% of government electricity from CHP by 2010. Other UK measures to encourage CHP growth are financial incentives, grant support, a greater regulatory framework, and government leadership and partnership. According to the IEA 2008 modelling of cogeneration expansion for the G8 countries, expansion of cogeneration in France, Germany, Italy and the UK alone would effectively double the existing primary fuel savings by 2030. This would increase Europe's savings from today's 155 TWh to 465 TWh in 2030. It would also result in a 16% to 29% increase in each country's total cogenerated electricity by 2030. Governments are being assisted in their CHP endeavors by organizations like COGEN Europe who serve as an information hub for the most recent updates within Europe's energy policy. COGEN is Europe's umbrella organization representing the interests of the cogeneration industry, users of the technology and promoting its benefits in the EU and the wider Europe. The association is backed by the key players in the industry including gas and electricity companies, ESCOs, equipment suppliers, consultancies, national promotion organisations, financial and other service companies. A 2016 EU energy strategy suggests increased use of district heating.

Austria

The largest district heating system in Austria is in

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

(Fernwärme Wien) – with many smaller systems distributed over the whole country. District heating in Vienna is run by Wien Energie. In the business year of 2004/2005 a total of 5,163 GWh was sold, 1,602 GWh to 251,224 private apartments and houses and 3,561 GWh to 5211 major customers. The three large municipal waste incinerators provide 22% of the total in producing 116 GWh electric power and 1,220 GWh heat. Waste heat from municipal power plants and large industrial plants account for 72% of the total. The remaining 6% is produced by peak heating boilers from fossil fuel. A biomass-fired power plant has produced heat since 2006. In the rest of Austria the newer district heating plants are constructed as biomass plants or as CHP-biomass plants like the biomass district heating of Mödling or the biomass district heating of Baden. Most of the older fossil-fired district heating systems have a district heating accumulator, so that it is possible to produce the thermal district heating power only at that time where the electric power price is high.

Belgium

Belgium has district heating in multiple cities. The largest system is in the Flemish city

Ghent Ghent ( ; ; historically known as ''Gaunt'' in English) is a City status in Belgium, city and a Municipalities of Belgium, municipality in the Flemish Region of Belgium. It is the capital and largest city of the Provinces of Belgium, province ...

, the piping network of this power plant is 22 km long. The system dates back to 1958.

Bulgaria

Bulgaria has district heating in around a dozen towns and cities. The largest system is in the capital

Sofia Sofia is the Capital city, capital and List of cities and towns in Bulgaria, largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain, in the western part of the country. The city is built west of the Is ...

, where there are four power plants (two CHPs and two boiler stations) providing heat to the majority of the city. The system dates back to 1949.

Czech Republic

The largest district heating system in the

Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...

is in Prague owned and operated by Pražská teplárenská, serving 265,000 households and selling c. 13 PJ of heat annually. Most of the heat is actually produced as

waste heat Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...

in 30 km distant

Mělník Mělník (; ) is a town in the Central Bohemian Region of the Czech Republic. It has about 20,000 inhabitants. The historic town centre is well preserved and is protected as an Cultural monument (Czech Republic)#Monument zones, urban monument zon ...

. There are many smaller central heating systems spread around the country including waste heat usage,

municipal solid waste Municipal solid waste (MSW), commonly known as trash or garbage in the American English, United States and rubbish in British English, Britain, is a List of waste types, waste type consisting of everyday items that are discarded by the public. ...

incineration Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high ...

and .

Denmark

In Denmark district heating covers more than 64% of space heating and

. In 2007, 80.5% of this heat was produced by combined heat and power plants. Heat recovered from waste incineration accounted for 20.4% of the total Danish district heat production. In 2013, Denmark imported 158,000 ton waste for incineration. Most major cities in Denmark have big district heating networks, including transmission networks operating with up to 125 °C and 25 bar pressure and distribution networks operating with up to 95 °C and between 6 and 10 bar pressure. The largest district heating system in Denmark is in the

Copenhagen Copenhagen ( ) is the capital and most populous city of Denmark, with a population of 1.4 million in the Urban area of Copenhagen, urban area. The city is situated on the islands of Zealand and Amager, separated from Malmö, Sweden, by the ...

area operated by CTR I/S and VEKS I/S. In central Copenhagen, the CTR network serves 275,000 households (90–95% of the area's population) through a network of 54 km double district heating distribution pipes providing a peak capacity of 663 MW, some of which is combined with

district cooling A district is a type of administrative division that in some countries is managed by the local government. Across the world, areas known as "districts" vary greatly in size, spanning regions or counties, several municipalities, subdivisions ...

. The consumer price of heat from CTR is approximately €49 per MWh plus taxes (2009). Several towns have central solar heating with various types of thermal energy storage. The Danish island of

Samsø Samsø (Anglicized: "Samso" or "Samsoe") is a Denmark, Danish island in the Kattegat off the Jutland Peninsula. Samsø is located in Samsø municipality. The community has 3,724 inhabitants (2017) (January 2010:4,010) called ''Samsings'' and is ...

has three straw-fueled plants producing district heating.

Finland

In Finland district heating accounts for about 50% of the total heating market, 80% of which is produced by combined heat and power plants. Over 90% of apartment blocks, more than half of all terraced houses, and the bulk of public buildings and business premises are connected to a district heating network.

Natural gas Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium ...

is mostly used in the south-east gas pipeline network, imported coal is used in areas close to ports, and

peat Peat is an accumulation of partially Decomposition, decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, Moorland, moors, or muskegs. ''Sphagnum'' moss, also called peat moss, is one of the most ...

is used in northern areas where peat is a local resource. Renewables, such as wood chips and other paper industry combustible by-products, are also used, as is the energy recovered by the incineration of

. Industrial units which generate heat as an industrial by-product may sell otherwise waste heat to the network rather than release it into the environment. Excess heat and power from

pulp mill A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or ...

recovery boiler Recovery boiler is the part of kraft process of wood pulp, pulping where chemicals for white liquor are recovered and reformed from black liquor, which contains lignin from previously processed wood. The black liquor is burned, generating heat, whi ...

s is a significant source in mill towns. In some towns waste incineration can contribute as much as 8% of the district heating heat requirement.

Availability In reliability engineering, the term availability has the following meanings: * The degree to which a system, subsystem or equipment is in a specified operable and committable state at the start of a mission, when the mission is called for at ...

is 99.98% and disruptions, when they do occur, usually reduce temperatures by only a few degrees. In Helsinki, an underground

datacenter A data center is a building, a dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems. Since IT operations are crucial for business ...

next to the President's palace releases excess heat into neighboring homes, producing enough heat to heat approximately 500 large houses. A quarter of a million households around

Espoo Espoo (, ; ) is a city in Finland. It is located to the west of the capital, Helsinki, in southern Uusimaa. The population is approximately . It is the most populous Municipalities of Finland, municipality in Finland. Espoo is part of the Helsi ...

are scheduled to receive district heating from datacenters.

Germany

In Germany district heating has a market share of around 14% in the residential buildings sector. The connected heat load is around 52,729 MW. The heat comes mainly from cogeneration plants (83%). Heat-only boilers supply 16% and 1% is surplus heat from industry. The cogeneration plants use natural gas (42%), coal (39%), lignite (12%) and waste/others (7%) as fuel. The largest district heating network is located in Berlin whereas the highest diffusion of district heating occurs in

with around 90% market share. In

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

about 70% of the electricity produced comes from district heating plants. District heating has rather little legal framework in Germany. There is no law on it as most elements of district heating are regulated in governmental or regional orders. There is no governmental support for district heating networks but a law to support cogeneration plants. As in the European Union the CHP Directive will come effective, this law probably needs some adjustment.

Greece

Greece has district heating mainly in the province of

Western Macedonia Western Macedonia (, ) is one of the thirteen Regions of Greece, administrative regions of Greece, consisting of the western part of Macedonia (Greece), Macedonia. Located in north-western Greece, it is divided into the regional units of Greece ...

, Central Macedonia and the Peloponnese Province. The largest system is the city of Ptolemaida, where there are five power plants (thermal power stations or TPS in particular) providing heat to the majority of the largest towns and cities of the area and some villages. The first small installation took place in Ptolemaida in 1960, offering heating to Proastio village of Eordaea using the TPS of Ptolemaida. Today District heating installations are also available in Kozani, Ptolemaida,

Amyntaio Amyntaio (, before 1928: Σόροβιτς – ''Sorovits''; Macedonian: Суровичево, Сорович), is a town and municipality in the Florina regional unit of Macedonia, Greece. The population of Amyntaio proper is 4,348, while that o ...

, Philotas, Serres and

Megalopolis A megalopolis () or a supercity, also called a megaregion, is a group of metropolitan areas which are perceived as a continuous urban area through common systems of transport, economy, resources, ecology, and so on. They are integrated enough ...

using nearby power plants. In Serres the power plant is a Hi-Efficiency CHP Plant using natural gas, while coal is the primary fuel for all other district heating networks.

Hungary

According to the 2011 census there were 607,578 dwellings (15.5% of all) in Hungary with district heating, mostly panel flats in urban areas. The largest district heating system located in

Budapest Budapest is the Capital city, capital and List of cities and towns of Hungary, most populous city of Hungary. It is the List of cities in the European Union by population within city limits, tenth-largest city in the European Union by popul ...

, the municipality-owned ''Főtáv Zrt.'' ("Metropolitan Teleheating Company") provides heat and piped hot water for 238,000 households and 7,000 companies.

Iceland

93% of all housing in Iceland enjoy district heating services – 89.6% from

, Iceland is the country with the highest penetration of district heating. There are 117 local district heating systems supplying towns as well as rural areas with hot water – reaching almost all of the population. The average price is around US$0.027 per kWh of hot water. The Reykjavík Capital Area district heating system serves around 230,000 residents had a maximum thermal power output of 830 MW. In 2018, the average annual heating demand in the Reykjavik area was 473MW. It is the largest district heating system in Iceland and is operated by Veitur. Heat is supplied from the Hellisheiði (200MWth) and Nesjavellir (300MWth) CHP plants, as well as a few lower temperature fields inside Reykjavik. Heating demand has increased steadily as the population has grown, necessitating enlargement of thermal water production in the Hellisheiði CHP plant. Iceland's second largest district heating system is on the Reykjanes peninsula, with the Svartsengi CHP plant providing heating to 21,000 homes including Keflavik and Grindavik, with a thermal power output of 150 MW.

Ireland

The Dublin Waste-to-Energy Facility will provide district heating for up to 50,000 homes in Poolbeg and surrounding areas. Some existing residential developments in the North Docklands have been constructed for conversion to district heating – currently using on-site gas boilers – and pipes are in place in the Liffey Service Tunnel to connect these to the incinerator or other waste heat sources in the area.

Tralee Tralee ( ; , ; formerly , meaning 'strand of the River Lee') is the county town of County Kerry in the south-west of Republic of Ireland, Ireland. The town is on the northern side of the neck of the Dingle Peninsula, and is the largest town in ...

, County Kerry has a 1 MW district heating system providing heat to an apartment complex, sheltered housing for the elderly, a library and over 100 individual houses. The system is fuelled by locally produced wood chip. In

Glenstal Abbey Glenstal Abbey is a Catholic Church, Catholic Order of St. Benedict, Benedictine monastery of the Congregation of the Annunciation located in Murroe, County Limerick, Ireland. It is dedicated to Saint Joseph and Saint Columba. In July 2024, Col ...

, County Limerick there exists a pond-based 150 kW heating system for a school. A scheme to use waste heat from an

Amazon Web Services Amazon Web Services, Inc. (AWS) is a subsidiary of Amazon.com, Amazon that provides Software as a service, on-demand cloud computing computing platform, platforms and Application programming interface, APIs to individuals, companies, and gover ...

datacentre in Tallaght is intended to heat 1200 units and municipal buildings

Italy

In Italy, district heating is used in some cities (

Bergamo Bergamo ( , ; ) is a city in the Alps, alpine Lombardy region of northern Italy, approximately northeast of Milan, and about from the alpine lakes Lake Como, Como and Lake Iseo, Iseo and 70 km (43 mi) from Lake Garda, Garda and Lake ...

Brescia Brescia (, ; ; or ; ) is a city and (municipality) in the region of Lombardy, in Italy. It is situated at the foot of the Alps, a few kilometers from the lakes Lake Garda, Garda and Lake Iseo, Iseo. With a population of 199,949, it is the se ...

Cremona Cremona ( , , ; ; ) is a city and (municipality) in northern Italy, situated in Lombardy, on the left bank of the Po (river), Po river in the middle of the Po Valley. It is the capital of the province of Cremona and the seat of the local city a ...

Bolzano Bolzano ( ; ; or ) is the capital city of South Tyrol (officially the province of Bolzano), Northern Italy. With a population of 108,245, Bolzano is also by far the largest city in South Tyrol and the third largest in historical Tyrol. The ...

Verona Verona ( ; ; or ) is a city on the Adige, River Adige in Veneto, Italy, with 255,131 inhabitants. It is one of the seven provincial capitals of the region, and is the largest city Comune, municipality in the region and in Northeast Italy, nor ...

Ferrara Ferrara (; ; ) is a city and ''comune'' (municipality) in Emilia-Romagna, Northern Italy, capital of the province of Ferrara. it had 132,009 inhabitants. It is situated northeast of Bologna, on the Po di Volano, a branch channel of the main ...

Imola Imola (; or ) is a city and ''comune'' in the Metropolitan City of Bologna, located on the river Santerno, in the Emilia-Romagna region of northern Italy. The city is traditionally considered the western entrance to the historical region Romagna ...

Modena Modena (, ; ; ; ; ) is a city and ''comune'' (municipality) on the south side of the Po Valley, in the Province of Modena, in the Emilia-Romagna region of northern Italy. It has 184,739 inhabitants as of 2025. A town, and seat of an archbis ...

Reggio Emilia Reggio nell'Emilia (; ), usually referred to as Reggio Emilia, or simply Reggio by its inhabitants, and known until Unification of Italy, 1861 as Reggio di Lombardia, is a city in northern Italy, in the Emilia-Romagna region. It has about 172,51 ...

, Terlan,

Turin Turin ( , ; ; , then ) is a city and an important business and cultural centre in northern Italy. It is the capital city of Piedmont and of the Metropolitan City of Turin, and was the first Italian capital from 1861 to 1865. The city is main ...

Parma Parma (; ) is a city in the northern Italian region of Emilia-Romagna known for its architecture, Giuseppe Verdi, music, art, prosciutto (ham), Parmesan, cheese and surrounding countryside. With a population of 198,986 inhabitants as of 2025, ...

, Lodi, and now

Milan Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...

). The district heating of Turin is the biggest of the country and it supplies 550.000 people (62% of the whole city population).

Latvia

In Latvia, district heating is used in major cities such as

Riga Riga ( ) is the capital, Primate city, primate, and List of cities and towns in Latvia, largest city of Latvia. Home to 591,882 inhabitants (as of 2025), the city accounts for a third of Latvia's total population. The population of Riga Planni ...

Daugavpils Daugavpils (see also other names) is a state city in southeastern Latvia, located on the banks of the Daugava River, from which the city derives its name. The parts of the city to the north of the river belong to the historical Latvian region ...

Liepāja Liepāja () (formerly: Libau) is a Administrative divisions of Latvia, state city in western Latvia, located on the Baltic Sea. It is the largest city in the Courland region and the third-largest in the country after Riga and Daugavpils. It is an ...

, Jelgava. The first district heating system was constructed in Riga in 1952. Each major city has a local company responsible for the generation, administration, and maintenance of the district heating system.

Netherlands

District heating is used in

Rotterdam Rotterdam ( , ; ; ) is the second-largest List of cities in the Netherlands by province, city in the Netherlands after the national capital of Amsterdam. It is in the Provinces of the Netherlands, province of South Holland, part of the North S ...

Amsterdam Amsterdam ( , ; ; ) is the capital of the Netherlands, capital and Municipalities of the Netherlands, largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the City Re ...

Utrecht Utrecht ( ; ; ) is the List of cities in the Netherlands by province, fourth-largest city of the Netherlands, as well as the capital and the most populous city of the Provinces of the Netherlands, province of Utrecht (province), Utrecht. The ...

, and

Almere Almere () is a Planned community, planned List of cities in the Netherlands by province, city and List of municipalities of the Netherlands, municipality in the Provinces of the Netherlands, province of Flevoland, Netherlands across the IJmeer fro ...

with more expected as the government has mandated a transition away from natural gas for all homes in the country by 2050. The town of Heerlen has developed a grid using water in disused coalmines as a source and storage for heat and cold. This is a good example of a 5th generation heating and cooling grid

North Macedonia

District heating is only available in Skopje. Balkan Energy Group (BEG) operates three DH production plants, which cover majority of the network, and supply heat to around 60,000 households in Skopje, more than 80 buildings in the educational sector (schools and kindergartens) and more than 1,000 other consumers (mostly commercial). The three BEG production plants use natural gas as a fuel source. There is also one cogeneration plant TE-TO AD Skopje producing heat delivered to the Skopje district heating system. The share of cogeneration in DH production was 47% in 2017. The distribution and supply of district heating is carried out by companies owned by BEG.

Norway

In Norway district heating only constitutes approximately 2% of energy needs for heating. This is a very low number compared to similar countries. One of the main reasons district heating has a low penetration in Norway is access to cheap hydro-based electricity, and 80% of private electricity consumption goes to heat rooms and water. However, there is district heating in the major cities.

Poland

In 2009, 40% of Polish households used district heating, most of them in urban areas. Heat is provided primarily by combined heat and power plants, most of which burn hard coal. The largest district heating system is in Warsaw, owned and operated by Veolia Warszawa, distributing approx. 34 PJ annually.

Romania

The largest district heating system in

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

is in

Bucharest Bucharest ( , ; ) is the capital and largest city of Romania. The metropolis stands on the River Dâmbovița (river), Dâmbovița in south-eastern Romania. Its population is officially estimated at 1.76 million residents within a greater Buc ...

. Owned and operated by RADET, it distributes approximately 24 PJ annually, serving 570 000 households. This corresponds to 68% of Bucharest's total domestic heat requirements (RADET fulfills another 4% through single-building boiler systems, for a total of 72%).

Russia

In most Russian cities, district-level combined heat and power plants () produce more than 50% of the nation's electricity and simultaneously provide hot water for neighbouring city blocks. They mostly use coal- and gas-powered

steam turbine A steam turbine or steam turbine engine is a machine or heat engine that extracts thermal energy from pressurized steam and uses it to do mechanical work utilising a rotating output shaft. Its modern manifestation was invented by Sir Charles Par ...

s for cogeneration of heat. Now, combined cycle gas turbines designs are beginning to be widely used as well.

Serbia

Serbia , image_flag = Flag of Serbia.svg , national_motto = , image_coat = Coat of arms of Serbia.svg , national_anthem = () , image_map = , map_caption = Location of Serbia (gree ...

, district heating is used throughout the main cities, particularly in the capital,

Belgrade Belgrade is the Capital city, capital and List of cities in Serbia, largest city of Serbia. It is located at the confluence of the Sava and Danube rivers and at the crossroads of the Pannonian Basin, Pannonian Plain and the Balkan Peninsula. T ...

. The first district heating plant was built in 1961 as a means to provide effective heating to the newly built suburbs of

Novi Beograd New Belgrade (, ) is a Subdivisions of Belgrade, municipality of the city of Belgrade. It was a Planned community, planned city and now is the central business district of Serbia and South East Europe. Construction began in 1948 in a previously un ...

. Since then, numerous plants have been built to heat the ever-growing city. They use natural gas as fuel, because it has less of an effect on the environment. The district heating system of Belgrade possesses 112 heat sources of 2,454 MW capacity, over 500 km of pipeline, and 4,365 connection stations, providing district heating to 240,000 apartments and 7,500 office/commercial buildings of total floor area exceeding 17,000,000 square meters.

Slovenia

The first district heating network in Slovenia and Yugoslavia began to be implemented on November 29, 1959 from the newly built network fed from the

Velenje Velenje (; ''Leksikon občin kraljestev in dežel zastopanih v državnem zboru,'' vol. 4: ''Štajersko''. 1904. Vienna: C. Kr. Dvorna in Državna Tiskarna, p. 272.) is the List of cities and towns in Slovenia, sixth-largest city of Slovenia, and t ...

Thermal Power Plant for the needs of the new city center of Velenje. In Slovenia, coverage with district heating systems is 22%, or only 47 out of 210 municipalities have district heating systems. The largest coverage with the district heating system and the lowest price is in Velenje, where all city facilities are connected, so there are no local or individual fireplaces. The prices of MWh of district heat in Slovenia in 2010 ranged between EUR 25 and EUR 93. The largest district heating systems in Slovenia are in Velenje - Šalek Valley and

Ljubljana {{Infobox settlement , name = Ljubljana , official_name = , settlement_type = Capital city , image_skyline = {{multiple image , border = infobox , perrow = 1/2/2/1 , total_widt ...

. The total Slovenian installed production and distribution thermal power of all heating systems amounts to 1.7 GW.

Slovakia

Slovakia's centralised heating system covers more than 54% of the overall demand for heat. In 2015 approximately 1.8 million citizens, 35% of the total population of Slovakia, were served by district heating. The infrastructure was built mainly during the 1960s and 1980s. In recent years large investments were made to increase the share of renewable energy sources and energy efficiency in district heating systems. The heat production comes mostly from natural gas and biomass sources, and 54% of the heat in district heating is generated through cogeneration. The distribution system consists of 2800 km of pipes. Warm and hot water are the most common heat carriers, but older high-pressure steam transport still accounts for around one-quarter of the primary distribution, which results in more losses in the system. In terms of the market structure, there were 338 heat suppliers licensed to produce and/or distribute heat in 2016, of which 87% were both producers and distributors. Most are small companies that operate in a single municipality, but some large companies such as Veolia are also present in the market. The state owns and operates large co-generation plants that produce district heat and electricity in six cities (Bratislava, Košice, Žilina, Trnava, Zvolen and Martin). Multiple companies can operate in one city, which is the case in larger cities. A large share of DH is produced by small natural gas heat boilers connected to blocks of buildings. In 2014, nearly 40% of the total DH generation was from natural gas boilers, other than co-generation.

Sweden

Sweden has a long tradition for using district heating (fjärrvärme) in urban areas. In 2015, about 60% of Sweden's houses (private and commercial) were heated by district heating, according to the Swedish association of district heating. The city of

Växjö Växjö () is a city and the seat of Växjö Municipality, Kronoberg County, Sweden. It had 71,282 inhabitants (2020) out of a Municipalities of Sweden, municipal population of 97,349 (2024). It is the administrative, cultural, and industrial ce ...

reduced its emissions from fossil fuels by 34% from 1993 to 2009. This was to achieved largely by way of biomass fired district heating. Another example is the plant of

Enköping Enköping is a locality and the seat of Enköping Municipality, Uppsala County, Sweden with 30,000 inhabitants in 2018. Geography Enköping is situated near Lake Mälaren, about 78 km west of Stockholm. A comparably large number of S ...

, combining the use of short rotation plantations both for fuel as well as for phytoremediation. 47% of the heat generated in Swedish district heating systems are produced with renewable

bioenergy Bioenergy is a type of renewable energy that is derived from plants and animal waste. The Biomass (energy), biomass that is used as input materials consists of recently living (but now dead) organisms, mainly plants. Thus, Fossil fuel, fossil fu ...

sources, as well as 16% in

waste-to-energy Waste-to-energy (WtE) or energy-from-waste (EfW) refers to a series of processes designed to convert waste materials into usable forms of energy, typically electricity or heat. As a form of energy recovery, WtE plays a crucial role in both wa ...

plants, 7% is provided by heat pumps, 10% by flue-gas condensation and 6% by industrial waste heat recovery. The remaining are mostly fossil fuels: oil (3%), natural gas (3%),

(2%), and coal (1%). Because of the law banning traditional

landfill A landfill is a site for the disposal of waste materials. It is the oldest and most common form of waste disposal, although the systematic burial of waste with daily, intermediate and final covers only began in the 1940s. In the past, waste was ...

s, waste is commonly used as a fuel.

Ukraine

United Kingdom

In the United Kingdom, district heating became popular after World War II, but on a restricted scale, to heat the large residential estates that replaced dwellings destroyed by the Blitz. In 2013 there were 1,765 district heating schemes, with 920 based in London alone. In total around 210,000 homes and 1,700 businesses are supplied by heat networks in the UK. The Pimlico District Heating Undertaking (PDHU) in London first became operational in 1950 and continues to expand to this day. The PDHU once relied on waste heat from the now-disused

Battersea Power Station Battersea Power Station is a decommissioned coal-fired power station located on the south bank of the River Thames in Nine Elms, Battersea in the London Borough of Wandsworth. It was built by the London Power Company (LPC) to the design of ...

on the south side of the

River Thames The River Thames ( ), known alternatively in parts as the The Isis, River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the Longest rivers of the United Kingdom, s ...

. It is still in operation; the water is now heated locally by a new energy centre which incorporates 3.1

MWe The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named in honor o ...

/ 4.0 MWth of gas fired CHP engines and 3 × 8 MW gas-fired boilers. One of the United Kingdom's largest district heating schemes is EnviroEnergy in

Nottingham Nottingham ( , East Midlands English, locally ) is a City status in the United Kingdom, city and Unitary authorities of England, unitary authority area in Nottinghamshire, East Midlands, England. It is located south-east of Sheffield and nor ...

. The plant, initially built by

Boots A boot is a type of footwear. Most boots mainly cover the foot and the ankle, while some also cover some part of the lower calf. Some boots extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearl ...

, is now used to heat 4,600 homes, and a wide variety of business premises, including the

Concert Hall A concert hall is a cultural building with a stage (theatre), stage that serves as a performance venue and an auditorium filled with seats. This list does not include other venues such as sports stadia, dramatic theatres or convention ...

, the Nottingham Arena, the Victoria Baths, the Broadmarsh Shopping Centre, the Victoria Centre, and others. The heat source is a

incinerator.

Sheffield Sheffield is a city in South Yorkshire, England, situated south of Leeds and east of Manchester. The city is the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire and some of its so ...

's district heating network was established in 1988 and is still expanding today. It saves an equivalent 21,000 plus tonnes of CO₂ each year when compared to conventional sources of energy – electricity from the national grid and heat generated by individual boilers. There are currently over 140 buildings connected to the district heating network. These include city landmarks such as the Sheffield City Hall, the Lyceum Theatre, the

University of Sheffield The University of Sheffield (informally Sheffield University or TUOS) is a public university, public research university in Sheffield, South Yorkshire, England. Its history traces back to the foundation of Sheffield Medical School in 1828, Fir ...

Sheffield Hallam University Sheffield Hallam University (SHU) is a public research university in Sheffield, South Yorkshire, England. The university is based on two sites; the City Campus is located in the city centre near Sheffield station, Sheffield railway station, whil ...

, hospitals, shops, offices and leisure facilities plus 2,800 homes. More than 44 km of underground pipes deliver energy which is generated at Sheffield Energy Recovery Facility. This converts 225,000 tonnes of waste into energy, producing up to 60 MWe of thermal energy and up to 19 MWe of electrical energy. The Southampton District Energy Scheme was originally built to use just geothermal energy, but now also uses the heat from a gas-fired CHP generator. It supplies heating and

to many large premises in the city, including the Westquay shopping centre, the De Vere Grand Harbour hotel, the Royal South Hants Hospital, and several housing schemes. In the 1980s

Southampton Southampton is a port City status in the United Kingdom, city and unitary authority in Hampshire, England. It is located approximately southwest of London, west of Portsmouth, and southeast of Salisbury. Southampton had a population of 253, ...

began to use combined heat and power district heating, taking advantage of geothermal heat "trapped" in the area. The geothermal heat provided by the well works in conjunction with the Combined Heat and Power scheme. Geothermal energy provides 15–20%,

fuel oil Fuel oil is any of various fractions obtained from the distillation of petroleum (crude oil). Such oils include distillates (the lighter fractions) and residues (the heavier fractions). Fuel oils include heavy fuel oil (bunker fuel), marine f ...

10%, and natural gas 70% of the total heat input for this scheme and the combined heat and power generators use conventional fuels to make electricity. "Waste heat" from this process is recovered for distribution through the 11 km mains network. Scotland has several district heating systems. The first in the UK was installed at

Aviemore Aviemore (; ) is a town and tourist resort, situated within the Cairngorms National Park in the Highlands of Scotland. It is in the Badenoch and Strathspey committee area, within the Highland council area. The town is popular for skiing and ...

, and others followed at

Lochgilphead Lochgilphead (; ) is a town and former burgh in Argyll and Bute, Scotland, with a population of around 2,300 people. It is the administrative centre of Argyll and Bute Council. The village lies at the end of Loch Gilp (a branch of Loch Fyne) an ...

, Fort William and Forfar. Lerwick District Heating Scheme in Shetland is of note because it is one of the few schemes where a completely new system was added to a previously existing small town. ADE has an online map of district heating installations in the UK. ADE estimates that 54 percent of energy used to produce electricity is being wasted via conventional power production, which relates to £9.5 billion ($US12.5 billion) per year.

Spain

North America

In North America, district heating systems fall into two general categories. Those that are owned by and serve the buildings of a single entity are considered institutional systems. All others fall into the commercial category.

Canada

District Heating is becoming a growing industry in Canadian cities, with many new systems being built in the last ten years. Some of the major systems in Canada include: * Calgary: ENMAX currently operates the Calgary Downtown District Energy Centre which provides heating to up to of new and existing residential and commercial buildings. The District Energy Centre began operations in March 2010 providing heat to its first customer, the City of Calgary Municipal building. *

Edmonton Edmonton is the capital city of the Provinces and territories of Canada, Canadian province of Alberta. It is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Central Alberta ...

: The community of Blatchford, which is currently being developed on the grounds of Edmonton's former City Centre Airport, is launching a District Energy Sharing System (DESS) in phases. A geo-exchange field went online in 2019, and Blatchford's energy utility is in the planning and design phase for a sewage heat exchange system. *

Hamilton Hamilton may refer to: * Alexander Hamilton (1755/1757–1804), first U.S. Secretary of the Treasury and one of the Founding Fathers of the United States * ''Hamilton'' (musical), a 2015 Broadway musical by Lin-Manuel Miranda ** ''Hamilton'' (al ...

, ON has a district heating and cooling system in the downtown core, operated by HCE Energy Inc. * Montreal has a district heating and cooling system in the downtown core. *

Toronto Toronto ( , locally pronounced or ) is the List of the largest municipalities in Canada by population, most populous city in Canada. It is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a p ...

: ** Enwave provides district heating and cooling within the downtown core of

, including deep lake cooling technology, which circulates cold water from Lake Ontario through heat exchangers to provide cooling for many buildings in the city. ** Creative Energy is constructing a combined-heat-and-power district energy system for the Mirvish Village development. *

Surrey Surrey () is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Greater London to the northeast, Kent to the east, East Sussex, East and West Sussex to the south, and Hampshire and Berkshire to the wes ...

: Surrey City Energy owned by the city, provides district heating to the city's

City Centre A city centre, also known as an urban core, is the Commerce, commercial, Culture, cultural and often the historical, Politics, political, and geographic heart of a city. The term "city centre" is primarily used in British English, and closely e ...

district. *

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

: ** Creative Energy's Beatty Street facility has operated since 1968 and provides a central heating plant for the city's downtown core of

. In addition to heating 180 buildings, the Central Heat Distribution network also drives a

steam clock A steam clock is a clock which is fully or partially powered by a steam engine. Only a few functioning steam clocks exist, most designed and built by Canadians, Canadian horology, horologist Raymond Saunders (clockmaker), Raymond Saunders for di ...

. Work is currently underway to move the facility from natural gas to electric equipment. ** A large scale district heating system known as the Neighbourhood Energy Utility in the South East False Creek area is in initial operations with natural gas boilers and serves the 2010 Olympic Village. The untreated sewage heat recovery system began operations in January 2010, supplying 70% of annual energy demands, with retrofit work underway to move the facility off its remaining natural gas use. * Windsor, Ontario has a district heating and cooling system in the downtown core. * Drake Landing Solar Community, AB, is small in size (52 homes) but notable for having the only central solar heating system in North America. * London, Ontario and Charlottetown, PEI have district heating co-generation systems owned and operated by Veresen. * Sudbury, Ontario has a district heating cogeneration system in its downtown core, as well as a standalone cogeneration plant for the Sudbury Regional Hospital. In addition, Naneff Gardens, a new residential subdivision off Donnelly Drive in the city's Garson neighbourhood, features a geothermal district heating system using technology developed by a local company, Renewable Resource Recovery Corporation. * Ottawa, contains a significant district heating and cooling system serving the large number of federal government buildings in the city. The system loop contains nearly of chilled or heated water at any time. * Cornwall, Ontario operates a district heating system which serves a number of city buildings and schools. *

Markham, Ontario Markham () is a city in Regional Municipality of York, York Region, Ontario, Canada. It is approximately northeast of Downtown Toronto. In the Canada 2021 Census, 2021 Census, Markham had a population of 338,503, which ranked it the largest in ...

: Markham District Energy operates several district heating sites: ** Warden Energy Centre (c. 2000), Clegg Energy Centre and Birchmount Energy Centre serving customers in the Markham Centre area ** Bur Oak Energy Centre (c. 2012) serving customers in the Cornell Centre area Many Canadian universities operate central campus heating plants.

United States

, approximately 2,500 district heating and cooling systems existed in the United States, in one form or another, with the majority providing heat. *

Consolidated Edison Consolidated Edison, Inc., commonly known as Con Edison (stylized as conEdison) or ConEd, is one of the largest investor-owned energy companies in the United States, with approximately $12 billion in annual revenues as of 2017, and over $62 ...

of New York (Con Ed) operates the New York City steam system, the largest commercial district heating system in the United States. The system has operated continuously since March 3, 1882 and serves

Manhattan Island Manhattan ( ) is the most densely populated and geographically smallest of the five boroughs of New York City. Coextensive with New York County, Manhattan is the smallest county by area in the U.S. state of New York. Located almost entire ...

from the Battery through 96th Street. In addition to providing space- and water-heating, steam from the system is used in numerous restaurants for food preparation, for process heat in laundries and dry cleaners, for steam sterilization, and to power absorption chillers for

air conditioning Air conditioning, often abbreviated as A/C (US) or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior temperature, and in some cases, also controlling the humidity of internal air. Air c ...

. On July 18, 2007, one person was killed and numerous others injured when a steam pipe exploded on 41st Street at Lexington. On August 19, 1989, three people were killed in an explosion in Gramercy Park. *

Milwaukee Milwaukee is the List of cities in Wisconsin, most populous city in the U.S. state of Wisconsin. Located on the western shore of Lake Michigan, it is the List of United States cities by population, 31st-most populous city in the United States ...

Wisconsin Wisconsin ( ) is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest of the United States. It borders Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michig ...

has been using district heating for its

central business district A central business district (CBD) is the Commerce, commercial and business center of a city. It contains commercial space and offices, and in larger cities will often be described as a financial district. Geographically, it often coincides wit ...

since the Valley Power Plant commenced operations in 1968. The air quality in the immediate vicinity of the plant, has been measured with significantly reduced ozone levels. The 2012 conversion of the plant, which changed the fuel input from coal to natural gas, is expected to further improve air quality at both the local César Chavez sensor as well as

Antarctic The Antarctic (, ; commonly ) is the polar regions of Earth, polar region of Earth that surrounds the South Pole, lying within the Antarctic Circle. It is antipodes, diametrically opposite of the Arctic region around the North Pole. The Antar ...

sensors The Wisconsin power plants double as breeding grounds for

peregrine falcon The peregrine falcon (''Falco peregrinus''), also known simply as the peregrine, is a Cosmopolitan distribution, cosmopolitan bird of prey (raptor) in the family (biology), family Falconidae renowned for its speed. A large, Corvus (genus), cro ...

s. * Denver's district steam system is the oldest continuously operated commercial district heating system in the world. It began service November 5, 1880, and continues to serve 135 customers. The system is partially powered by the Xcel Energy Zuni Cogeneration Station, which was originally built in 1900. *

NRG Energy NRG Energy, Inc. is an American energy company, headquartered in Houston, Texas. It was formerly the wholesale arm of Northern States Power Company (NSP), which became Xcel Energy, but became independent in 2000. NRG Energy is involved in energ ...

operates district systems in the cities of San Francisco,

Harrisburg Harrisburg ( ; ) is the List of capitals in the United States, capital city of the Commonwealth (U.S. state), U.S. commonwealth of Pennsylvania and the county seat, seat of Dauphin County, Pennsylvania, Dauphin County. With a population of 50, ...

Minneapolis Minneapolis is a city in Hennepin County, Minnesota, United States, and its county seat. With a population of 429,954 as of the 2020 United States census, 2020 census, it is the state's List of cities in Minnesota, most populous city. Locat ...

Omaha Omaha ( ) is the List of cities in Nebraska, most populous city in the U.S. state of Nebraska. It is located in the Midwestern United States along the Missouri River, about north of the mouth of the Platte River. The nation's List of United S ...

Pittsburgh Pittsburgh ( ) is a city in Allegheny County, Pennsylvania, United States, and its county seat. It is the List of municipalities in Pennsylvania#Municipalities, second-most populous city in Pennsylvania (after Philadelphia) and the List of Un ...

, and

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

. * Seattle Steam Company, a district system operated by Enwave, in Seattle. Enwave also operates district heat system in

Chicago Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...

Houston Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...

Las Vegas Las Vegas, colloquially referred to as Vegas, is the most populous city in the U.S. state of Nevada and the county seat of Clark County. The Las Vegas Valley metropolitan area is the largest within the greater Mojave Desert, and second-l ...

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

New Orleans New Orleans (commonly known as NOLA or The Big Easy among other nicknames) is a Consolidated city-county, consolidated city-parish located along the Mississippi River in the U.S. state of Louisiana. With a population of 383,997 at the 2020 ...

, and Portland along with additional Canadian cities. * Detroit Thermal operates a district system in

Detroit Detroit ( , ) is the List of municipalities in Michigan, most populous city in the U.S. state of Michigan. It is situated on the bank of the Detroit River across from Windsor, Ontario. It had a population of 639,111 at the 2020 United State ...

that started operation at the Willis Avenue Station in 1903, originally operated by Detroit Edison. * Citizens Energy Group in

Indianapolis Indianapolis ( ), colloquially known as Indy, is the List of capitals in the United States, capital and List of municipalities in Indiana, most populous city of the U.S. state of Indiana and the county seat of Marion County, Indiana, Marion ...

Indiana Indiana ( ) is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Lake Michigan to the northwest, Michigan to the north and northeast, Ohio to the east, the Ohio River and Kentucky to the s ...

, operates the Perry K. Generating Station, a

gas-fired power plant A gas-fired power plant, sometimes referred to as gas-fired power station, natural gas power plant, or methane gas power plant, is a thermal power station that burns natural gas to generate electricity. Gas-fired power plants generate almost a ...

that produces and distributes steam to about 160 downtown Indianapolis customers. * Lansing Board of Water & Light, a municipal utility system in

Lansing, Michigan Lansing () is the List of capitals in the United States, capital city of the U.S. state of Michigan. The most populous city in Ingham County, Michigan, Ingham County, parts of the city extend into Eaton County, Michigan, Eaton County and nort ...

operates a steam and chilled water system with the steam coming from the natural gas-fired REO Cogeneration Plant and the chilled water coming from the dedicated Roy E. Peffley Chilled Water Plant. * Cleveland Thermal operates a district steam (since 1894) from the Canal Road plant near The Flats and district cooling system (since 1993) from Hamilton Avenue plant on the bluffs east of downtown. * Veresen operates district heating/co-generation plants in Ripon, California, and

San Gabriel, California San Gabriel (Spanish language, Spanish for "Gabriel, St. Gabriel") is a city located in the San Gabriel Valley of Los Angeles County, California. At the 2020 United States census, 2020 census, the population was 39,568. San Gabriel was founded ...

. * Veolia Energy, a successor of the 1887 Boston Heating Company, operates a district system in

Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

and

, and also operates systems in Philadelphia PA, Baltimore MD, Kansas City MO, Tulsa OK, Houston TX and other cities. * District Energy St. Paul operates the largest hot water district heating system in North America and generates the majority of its energy from an adjacent biomass-fueled combined heat and power plant. In March 2011, a 1 MWh thermal solar array was integrated into the system, consisting of 144 20' x 8' solar panels installed on the roof of a customer building, RiverCentre. * The California Department of General Services runs a central plant providing district heating to four million square feet in 23 state-owned buildings, including the State Capitol, using high-pressure steam boilers. * BPU of Jamestown NY operates a second generation water district heating system. It was put into operation in 1984, runs from the BPU electrical plant and provides heat to the business district at Fahrenheit. Historically, district heating was primarily used in urban areas of the US, but by 1985, it was mainly used in institutions. A handful of smaller municipalities in

New England New England is a region consisting of six states in the Northeastern United States: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. It is bordered by the state of New York (state), New York to the west and by the ...

maintained municipal steam into the 21st century, in cities like

Holyoke, Massachusetts Holyoke is a city in Hampden County, Massachusetts, United States, that lies between the western bank of the Connecticut River and the Mount Tom Range. As of the 2020 United States census, 2020 census, the city had a population of 38,247. Loca ...

and

Concord, New Hampshire Concord () is the capital city of the U.S. state of New Hampshire and the county seat, seat of Merrimack County, New Hampshire, Merrimack County. As of the 2020 United States census the population was 43,976, making it the List of municipalities ...

, however the former would end service in 2010 and the latter in 2017, attributing aging infrastructure and capital expenses to their closures. In 2019, Concord replaced a number of remaining pipes with more efficient ones for a smaller steam system heating only the State House and State Library, mainly due to historic preservation reasons rather than a broader energy plan. BGSU Heating Plant Interior

District heating is also used on many college campuses, often in combination with district cooling and electricity generation. Colleges using district heating include the

University of Texas at Austin The University of Texas at Austin (UT Austin, UT, or Texas) is a public university, public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 stud ...

;

Rice University William Marsh Rice University, commonly referred to as Rice University, is a Private university, private research university in Houston, Houston, Texas, United States. Established in 1912, the university spans 300 acres. Rice University comp ...

;

Brigham Young University Brigham Young University (BYU) is a Private education, private research university in Provo, Utah, United States. It was founded in 1875 by religious leader Brigham Young and is the flagship university of the Church Educational System sponsore ...

;

Georgetown University Georgetown University is a private university, private Jesuit research university in Washington, D.C., United States. Founded by Bishop John Carroll (archbishop of Baltimore), John Carroll in 1789, it is the oldest Catholic higher education, Ca ...

;

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

, which also employs deep water source cooling using the waters of nearby Cayuga Lake;

Purdue University Purdue University is a Public university#United States, public Land-grant university, land-grant research university in West Lafayette, Indiana, United States, and the flagship campus of the Purdue University system. The university was founded ...

;

University of Massachusetts Amherst The University of Massachusetts Amherst (UMass Amherst) is a public land-grant research university in Amherst, Massachusetts, United States. It is the flagship campus of the University of Massachusetts system and was founded in 1863 as the ...

; University of Maine at Farmington;

University of Notre Dame The University of Notre Dame du Lac (known simply as Notre Dame; ; ND) is a Private university, private Catholic research university in Notre Dame, Indiana, United States. Founded in 1842 by members of the Congregation of Holy Cross, a Cathol ...

;

Michigan State University Michigan State University (Michigan State or MSU) is a public university, public Land-grant university, land-grant research university in East Lansing, Michigan, United States. It was founded in 1855 as the Agricultural College of the State o ...

;

Eastern Michigan University Eastern Michigan University (EMU, EMich, Eastern Michigan or simply Eastern) is a public university, public research university in Ypsilanti, Michigan, United States. Founded in 1849 as the Michigan State Normal School, it was the fourth normal ...

;

Case Western Reserve University Case Western Reserve University (CWRU) is a Private university, private research university in Cleveland, Ohio, United States. It was established in 1967 by a merger between Western Reserve University and the Case Institute of Technology. Case ...

;

Iowa State University Iowa State University of Science and Technology (Iowa State University, Iowa State, or ISU) is a Public university, public land-grant university, land-grant research university in Ames, Iowa, United States. Founded in 1858 as the Iowa Agricult ...

;

University of Delaware The University of Delaware (colloquially known as UD, UDel, or Delaware) is a Statutory college#Delaware, privately governed, state-assisted Land-grant university, land-grant research university in Newark, Delaware, United States. UD offers f ...

;

University of Maryland, College Park The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public university, public Land-grant university, land-grant research university in College Park, Maryland, United States. Founded in 1856, UMD i ...

University of Wisconsin–Madison The University of Wisconsin–Madison (University of Wisconsin, Wisconsin, UW, UW–Madison, or simply Madison) is a public land-grant research university in Madison, Wisconsin, United States. It was founded in 1848 when Wisconsin achieved st ...

University of Georgia The University of Georgia (UGA or Georgia) is a Public university, public Land-grant university, land-grant research university with its main campus in Athens, Georgia, United States. Chartered in 1785, it is the oldest public university in th ...

University of Cincinnati The University of Cincinnati (UC or Cincinnati, informally Cincy) is a public university, public research university in Cincinnati, Ohio, United States. It was founded in 1819 and had an enrollment of over 53,000 students in 2024, making it the ...

North Carolina State University North Carolina State University (NC State, North Carolina State, NC State University, or NCSU) is a public university, public Land-grant university, land-grant research university in Raleigh, North Carolina, United States. Founded in 1887 and p ...

, University of North Carolina Chapel Hill, Duke University, and several campuses of the

University of California The University of California (UC) is a public university, public Land-grant university, land-grant research university, research university system in the U.S. state of California. Headquartered in Oakland, California, Oakland, the system is co ...

. MIT installed a cogeneration system in 1995 that provides electricity, heating and cooling to 80% of its campus buildings. The

University of New Hampshire The University of New Hampshire (UNH) is a Public university, public Land-grant university, land-grant research university with its main campus in Durham, New Hampshire, United States. It was founded and incorporated in 1866 as a land grant coll ...

has a cogeneration plant run on

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The abundance of methane on Earth makes ...

from an adjacent landfill, providing the university with 100% of its heat and power needs without burning oil or natural gas. North Dakota State University (NDSU) in Fargo, North Dakota has used district heating for over a century from their coal-fired heating plant.

Asia

Japan

87 district heating enterprises are operating in Japan, serving 148 districts. Many companies operate district cogeneration facilities that provide steam and/or hot water to many of the office buildings. Also, most operators in the Greater Tokyo serve district cooling.

China

In southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

(south of the Qinling–Huaihe Line), there are nearly no district heating systems. In northern China, district heating systems are common. Most district heating systems are just for heating by burning

hard coal Anthracite, also known as hard coal and black coal, is a hard, compact variety of coal that has a submetallic lustre. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highe ...

instead of CHP. Since

air pollution in China Pollution in China is one aspect of the broader topic of environmental issues in China. Various forms of pollution have increased following the industrialisation of China, causing widespread environmental and health problems. Jared Diamond, '' ...

has become quite serious, many cities gradually are now using natural gas rather than coal in district heating system. There is also some amount of geothermal heating and sea heat pump systems. In February 2019, China's State Power Investment Corporation (SPIC) signed a cooperation agreement with the

Baishan Baishan ( zh, s=白山 , p=Báishān), is a prefecture-level city in southeastern Jilin province, in the Northeast China, Dongbei (northeastern) part of China. "" literally means "White Mountain", and is named after Changbai Mountain ( zh, s=长 ...

municipal government in

Jilin ) , image_skyline = Changbaishan Tianchi from western rim.jpg , image_alt = , image_caption = View of Heaven Lake , image_map = Jilin in China (+all claims hatched).svg , mapsize = 275px , map_al ...

province for the Baishan Nuclear Energy Heating Demonstration Project, which would use a China National Nuclear Corporation DHR-400 (District Heating Reactor 400 MWt). Building cost is 1.5 billion yuan ($230 million), taking three years to build.

Turkey

Geothermal energy in Turkey provides some district heating, and residential district heating and cooling requirements have been mapped.

Market penetration

Penetration of district heating (DH) into the heat market varies by country. Penetration is influenced by different factors, including environmental conditions, availability of heat sources, economics, and economic and legal framework. The

aims to develop sustainable practices through implementation of district heating and cooling technology. In the year 2000 the percentage of houses supplied by district heat in some European countries was as follows: In Iceland the prevailing positive influence on DH is availability of easily captured geothermal heat. In most Eastern European countries, energy planning included development of cogeneration and district heating. Negative influence in the Netherlands and UK can be attributed partially to milder climate, along with competition from natural gas. The tax on domestic gas prices in the UK is a third of that in France and a fifth of that in Germany.

Footnotes

External links

UK's Information Portal on Decentralised and District Energy

District Energy Library

Technical description of district heating and district cooling at Munich Airport, Germany

Geothermal District Heating, Iceland

* ttp://www.maxfordham.com/news/publications/a-case-against-the-widespread-use-of-district-heating-and-chp-in-the-uk Max Fordham argues against use of CHP District Heating
Energy Hub – EU funded FP7 Project – District heating, cooling and power aiming for 100% on-site renewable energy at Leuven, Belgium

* ttp://www.benuk.net A Balanced Energy Network integrates heat pumps, demand side response and distributed heat storage in a district heat sharing network.
Heat Interface UnitsThe Celsius Toolbox – Information on district energy solutions and energy transition.
{{DEFAULTSORT:District heating American inventions Energy conservation Residential heating