District heating pipe in Tübingen, Germany

District heating (less commonly called teleheating) is a system for distributing heat generated in a centralized location for residential and commercial heating requirements. The heat is often obtained from a cogeneration plant, although dedicated facilities called heat-only boiler stations are also used. A district heating plant can provide higher efficiencies and better pollution control than localized boilers. Image File history File links Size of this preview: 234 × 598 pixelsFull resolution (632 × 1616 pixel, file size: 538 KB, MIME type: image/jpeg)   Description: district-heating-pipeline in Tübingen, Germany. ... Image File history File links Size of this preview: 234 × 598 pixelsFull resolution (632 × 1616 pixel, file size: 538 KB, MIME type: image/jpeg)   Description: district-heating-pipeline in Tübingen, Germany. ... Cogeneration (also combined heat and power or CHP) is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat. ... A heat-only boiler station generates thermal energy in the form of hot water for use in district heating applications. ...

Heat generation

The core element of a district heating system is usually a cogeneration plant (also called combined heat and power, CHP) or a heat-only boiler station. Both have in common that they are typically based on combustion of primary energy carriers. The difference between the two systems is that, in a cogeneration plant, heat and electricity are generated simultaneously, whereas in heat-only boiler stations - as the name suggests - only heat is generated. Cogeneration (also combined heat and power or CHP) is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat. ... Cogeneration (also combined heat and power or CHP) is the use of a power station to simultaneously generate both heat and electricity. ... A heat-only boiler station generates thermal energy in the form of hot water for use in district heating applications. ...

The combination of cogeneration and district heating is very energy efficient. A steam-electric power plant which generates only electricity can convert only up to 47% of the fuel input into electricity. The major part of the energy is wasted in form of heat and dissipated to the environment. A cogeneration plant recovers that heat and thus has a degree of efficiency of around 90%. A steam-electric power plant is a power plant in which the prime mover is steam driven. ...

Other heat sources for district heating systems can be geothermal heat, solar power and surplus heat from industrial processes.

Heat distribution

After generation, the heat is distributed to the customer via a network of insulated pipes. District heating systems consists of feed and return lines. Usually the pipes are installed underground but there are also systems with overground pipes. Within the system heat storages are in place to cover peak load demands and store heat which is generated but is not needed at the moment.

The common medium used for heat distribution is water, but also steam is used. The advantage of steam is that it can be used in industrial processes as well as for heating purposes. The disadvantage is the high corrosive characteristic.

At customer level the heat network is connected to the central heating of the dwellings by heat exchangers (heat substations). The water (or the steam) used in the district heating system is not mixed with the water of the central heating system of the dwelling.

National variation

Since conditions from city to city differ, every district heating system is uniquely constructed. In addition nations have different access to primary energy carriers and so they have a different approach how to address the heating market within their borders. This leads not only to a different degree of diffusion but also to different district heating systems in general throughout the world.

Russia

In most Russian cities, district-level combined heat and power plants (Russian: ТЭЦ, Тепло-электро централь) produce more than 50% of the nation's electricity and simultaneously provide hot water for neighboring city blocks. They mostly use coal and oil-powered steam turbines for cogeneration of heat. Now, gas turbines and combined cycle designs are beginning to be widely used as well. A Soviet-era approach of using very large central stations to heat large districts of a big city or entire small cities is fading away as due to inefficiency, much heat is lost in the piping network because of leakages and lack of proper thermal insulation ^{[verification needed]}. Cogeneration (also combined heat and power or CHP) is the use of a power station to simultaneously generate both heat and electricity. ... Coal Coal (IPA: ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... Synthetic motor oil An oil is any substance that is in a viscous liquid state (oily) at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water, literally water fearing) and lipophilic (miscible with other oils, literally fat loving). This general definition includes compound classes with otherwise unrelated... A rotor of a modern steam turbine, used in a power plant A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into useful mechanical work. ... This machine has a single-stage centrifugal compressor and turbine, a recuperator, and foil bearings. ... In a combined cycle power plant, or combined cycle gas turbine (CCGT) plant, a gas turbine generator generates electricity and the waste heat from the gas turbine is used to make steam to generate additional electricity via a steam turbine, this last step enhances the efficiency of electricity generation. ... Soviet redirects here. ... The term leakage has numerous definitions: In normal usage, leakage is the diffusion of energy or matter out of a container. ... Thermal insulation on the Huygens probe The term thermal insulation can refer to materials used to reduce the rate of heat transfer, or the methods and processes used to reduce heat transfer. ...

Scandinavia

Scandinavian homes also use district heating for their hot water and heating needs. Scandinavia is a historical and geographical region centered on the Scandinavian Peninsula in Northern Europe and includes the three kingdoms of Denmark, Norway and Sweden. ...

Denmark

In Denmark district heating covers more than 60% of space heating including hot water demand. Most major cities in Denmark have big district heating networks including transmission networks operation with up to 125 °C and 25 bar (2.5 MPa) pressure and distribution networks operating with up to 95 °C and between 6 and 10 bar (600 to 1000 kPa) pressure. The heat comes mainly from waste incineration and combined heat and power plants. The efficiency of the powerplants can be raised to nearly 100% if supplying heat along with electricity compared to 30% when producing electricity only. The largest system in Denmark is in the metropolitan area operated by CTR I/S and VEKS I/S The megapascal, symbol MPa is an SI unit of pressure. ... The pascal (symbol Pa) is the SI unit of pressure. ...

District heating accumulator tower and workshops on the Churchill Gardens Estate, Pimlico, London. This plant once used waste heat piped from Battersea Power Station on the other side of the River Thames. (January 2006)

Image File history File links Download high resolution version (504x640, 177 KB) Summary District heating accumulator tower, Churchill Gardens Estate, Pimlico, London. ... Image File history File links Download high resolution version (504x640, 177 KB) Summary District heating accumulator tower, Churchill Gardens Estate, Pimlico, London. ... Pimlico is a small area of central London in the City of Westminster that is primarily residential and well known for its collection of small hotels. ... This article is about the capital of England and the United Kingdom. ... Battersea Power Station viewed from the north bank of the River Thames at Pimlico. ... The Thames is a river flowing through southern England, and one of the major waterways in England. ...

United Kingdom

In the United Kingdom, district heating also became popular after World War II, but on a restricted scale, to heat the large residential estates that replaced areas devastated by the Blitz. The photo (right) shows the accumulator at the Pimlico District Heating Undertaking (PDHU), just north of the River Thames. The PDHU first became operational in 1950 and continued to expand up till about 1960. The PDHU once relied on waste heat from the now-disused Battersea Power Station on the South side of the River Thames. It is still in operation, the water now being heated locally by a new energy centre which incorporates 3.1 MWe/4.0 MWTh of CHP engines and 3 x 8 MW gas fired boilers. Many other such heating plants still operate on estates across Britain. Though they are said to be efficient, a frequent complaint of residents is that the heating levels are often set too high - the original designs did not allow for individual users to have their own thermostats. Combatants Allied powers: China France Great Britain Soviet Union United States and others Axis powers: Germany Italy Japan and others Commanders Chiang Kai-shek Charles de Gaulle Winston Churchill Joseph Stalin Franklin Roosevelt Adolf Hitler Benito Mussolini Hideki Tōjō Casualties Military dead: 17,000,000 Civilian dead: 33,000... Heinkel He 111 German bomber over the Surrey Docks, Southwark, London (German propaganda photomontage). ... The Thames is a river flowing through southern England, and one of the major waterways in England. ... Battersea Power Station viewed from the north bank of the River Thames at Pimlico. ... The Thames is a river flowing through southern England, and one of the major waterways in England. ... Bi-metallic thermostat for buildings A thermostat is a device for regulating the temperature of a system so that the systems temperature is maintained near a desired setpoint temperature. ...

Serbia

In Serbia, district heating was used throughout the main cities, particularly in the capital, Belgrade. NATO targeted one of the main DH plants, the District Heating Plant of New Belgrade (JKP "Beogradske elektrane") during the Kosovo War [1][2]. This plant was deemed the beginning of the centralized heating supply to Belgrade, built in 1961 as a means to provide effective heating to the newly built suburbs of Novi Beograd. The district heating system of Belgrade possesses 112 heat sources of 2,454 MW capacity and by way of the pipelines more than 500 km long and 4365 connection stations, providing district heating to 240,000 apartments and 7,500 office/commercial buildings of the total floor area exceeding 17,000,000 square meters. Anthem Serbia() on the European continent() Capital (and largest city) Belgrade Official languages Serbian 1 Recognised regional languages Hungarian, Croatian, Slovak, Romanian, Rusyn 2 Albanian 3 Government Semi-presidential republic  -  President Boris Tadić  -  Prime Minister Vojislav KoÅ¡tunica Establishment  -  Formation 9th century   -  First unified state c. ... Location of Belgrade within Serbia Coordinates: Country Serbia District City of Belgrade Municipalities 17 Government  - Mayor Nenad Bogdanović (DS) (since 2004)  - Ruling parties DS/DSS/G17+ Area  - City 3,222. ... NATO 2002 Summit in Prague. ... Combatants NATO Federal Republic of Yugoslavia, various militias and paramilitaries, as well as international volunteers [1] Commanders Wesley Clark (SACEUR), Javier Solana (Secretary General of NATO) Slobodan MiloÅ¡ević (Supreme Commander of the Army of Yugoslavia), Vojislav Å eÅ¡elj, Dragoljub Ojdanić (Chief of Staff), Svetozar Marjanović (Deputy Chief of Staff... Coat of Arms of Novi Beograd Novi Beograd (Нови Београд, New Belgrade) is a part of Belgrade located on the left bank of Sava river. ...

Italy

In Italy, district heating is used in some towns (Bergamo, Brescia, Reggio Emilia, Torino ). Small street (via della Noca) leading to città alta. ... For the Italian administrative area, see Province of Brescia. ... Country Italy Region Emilia-Romagna Province Reggio Emilia (RE) Mayor Graziano Delrio (from July 1, 2004) Elevation 58 m Area 231 km² Population  - Total 141,383  - Density 612/km² Time zone CET, UTC+1 Coordinates Gentilic Reggiani Dialing code 0522 Postal code 42100 Frazioni see list Patron San Prospero  - Day... Torino or Turin is a major industrial city in north-western Italy, capital of the Piedmont region, located mainly on the west bank of the Po River. ...

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.^[1] The largest district heating network is located in Berlin whereas the highest diffusion of district heating occours in Flensburg with around 90 % market share. This article is about the capital of Germany. ... Flensburg (Danish: Flensborg, Low Saxon: Flensborg, North Frisian: Flansborj) is an independent town in the North of the German state Schleswig-Holstein. ...

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. Consolidated Edison of New York (Con Ed) operates Con Edison Steam Operations, the largest commercial district heating system in the United States. [3] The system has operated continuously since March 1882 and serves Manhattan Island from the Battery through 96th Street. While operating smoothly for most of its time in service, incidents have occurred, On July 18, 2007 one person was killed and numerous others injured when a steam pipe exploded on 41st Street and Lexington [4]. In 1989 three people were also killed in a similar event [5]. In addition to providing space and water heating, steam from the system is used in numerous restaurants for food preparation, process heat in laundries and dry cleaners, as well as to power absorption chillers for air conditioning. North America North America is a continent [1] in the Earths northern hemisphere and (chiefly) western hemisphere. ... Consolidated Edison, Inc. ... NY redirects here. ... The New York City steam system carries steam from central power stations under the streets of Manhattan to heat, cool, or supply power to high rise buildings and businesses. ... For other uses, see Manhattan (disambiguation). ... is the 199th day of the year (200th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... Rising steam from the explosion Photo of the cloud of steam from the roof of a building on 34th St. ... To meet Wikipedias quality standards and make it easier to understand, this article or section may require cleanup. ... Note: in the broadest sense, air conditioning can refer to any form of heating, ventilation, and air-conditioning. ...

Europe

Since 1954, district heating has been promoted in Europe by Euroheat & Power. They have recently compiled analysis of district heating and cooling markets in Europe within their Ecoheatcool project supported by the European Commission. [6] Year 1954 (MCMLIV) was a common year (link will display full calendar) of the Gregorian calendar. ... World map showing the location of Europe. ... World map showing the location of Europe. ... Launched at the beginning of 2005 with support from the Intelligent Energy Executive Agency European Commission programme, the ECOHEATCOOL project carried out by Euroheat & Power, in cooperation with 13 partners across Europe was concluded at the end of December 2006. ... The Commission seat in Brussels The European Commission (formally the Commission of the European Communities) is the executive body of the European Union. ...

District heating substations

Energy plants produce and sell district heat to end clients. House owners need district heating substations to distribute heat in their buildings. Factory-made substations are the best way to connect buildings to the district heating network. One of the main manufacturers of these substations is Oy GST Group Ltd in Finland.

History

District heating traces its roots to the hot water-heated baths and greenhouses of the ancient Roman Empire. District systems gained prominence in Europe during the Middle Ages and Renaissance, with one system in France in continuous operation since the 14th century. Across the Atlantic, the U.S. Naval Academy in Annapolis began steam district heating service in 1853. Motto Senatus Populusque Romanus (SPQR) The Roman Empire at its greatest extent. ... World map showing the location of Europe. ... The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times, beginning with the Renaissance. ... The Renaissance (French for rebirth, or Rinascimento in Italian), was a cultural movement in Italy (and in Europe in general) that began in the late Middle Ages, and spanned roughly the 14th through the 17th century. ... This 14th-century statue from south India depicts the gods Shiva (on the left) and Uma (on the right). ... Teamwork: Fourth Class Midshipmen lock arms and use ropes made from uniform items as they brace themselves climbing the Herndon Monument The United States Naval Academy, or USNA, is an institution for the undergraduate education of officers of the United States Navy and the United States Marine Corps. ... City nickname: Americas Sailing Capital Location in the state of Maryland Founded 1649 Mayor Ellen O. Moyer (Dem) Area  - Total  - Water 19. ... It has been suggested that this article be split into articles entitled steam and water vapor, accessible from a disambiguation page. ... 1853 was a common year starting on Saturday (see link for calendar). ...

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. Lockport is the name of several places In Canada: Town of Lockport, Manitoba. ... NY redirects here. ... 1877 (MDCCCLXXVII) was a common year starting on Monday (see link for calendar). ... Birdsill Holly (November 8, 1820 _ 27 April 1894) was an inventor. ...

The future of many of these systems are in doubt; the same kind of problems many district heating operations in former Soviet Union and Eastern Europe have today, many North American steam district heating systems began to experience in the 1960s and 1970s. In North America, the owners, in many cases power utilities, completely lost interest in the district heating business and did not provide sufficient funding for maintenance of the systems. The systems and the service to the customer started to deteriorate. The result was that, after some years, the systems started to lose customers; the reliability for heat supply went down and finally the whole system closed down. For example, in Minnesota in the 1950s there were about 40 district steam systems; today only a few remain.[7]

Paris has been using groundwater from 1-2 kilometre's depth at 55°-70 °C since the 1970's for domestic heating.[8] In the 1980s Southampton began utilising 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 between 15-20% of the total heat-input into 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.[9][10]. City flag City coat of arms Motto: Fluctuat nec mergitur (Latin: Tossed by the waves, she does not sink) The Eiffel Tower in Paris, as seen from the esplanade du Trocadéro. ... Southampton is the largest city[1] on the south coast of England. ...

Diffusion of district heating

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

In the year 2000 the percentage of houses supplied by heat from district heating in some European countries was as follows:

Iceland 95%, Estonia 52%, Poland 52%, Denmark 51%, Sweden 50%, Slovakia 40%,

Finland 49%, Hungary 16%, Austria 12.5%, Germany 12%, Netherlands, 3%, UK 1%

Source: Sabine Froning (Euroheat & Power): DHC/CHP/RES a smile for the environment, Kiev 2003

On Iceland the prevailing positive influence on DH is availability of easily captured geothermal heat. In most East 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 and also to stiff competition from natural gas supply. Geothermal heating is a method of heating and cooling a building. ... Cogeneration (also combined heat and power or CHP) is the use of a heat engine or a power station to simultaneously generate both electricity and useful heat. ... Natural gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. ...

Energy consumption

According to Helsingin Energia, consumption of energy by district heating in Helsinki since 1970 peaked in 1971, at 67 kWh/m³/year, falling to 43 kWh/m³/year in 1997, since when it has not fluctuated greatly.^[2]

Figures for Sweden suggest that the average Swede using district heating receives 4500 kWh/year from the system.^[3]

District cooling

The opposite of district heating is district cooling. Working on broadly similar principles to district heating, district cooling delivers chilled water to buildings like offices and factories that need to be cooled. In winter-time, the source for the cooling can often be sea water, so it is a cheaper resource than using electricity to run compressors to generate the cooling effect. Helsinki has a district cooling system based on these principles and the idea is now being adopted in other Finnish cities.

In August 2004, Enwave Energy Corporation, a district energy company based in Toronto, Canada, started operation of an innovative system that uses water from Lake Ontario to cool a variety of downtown buildings, including office towers, the Metro Toronto Convention Centre, a small brewery and a telecommunications centre. The process has become known as Deep Lake Water Cooling (DLWC). It will provide for over 40,000 tons (refrigeration) (140 megawatts) of cooling—a significantly larger system than has been installed elsewhere. Another unique feature of the Enwave system is that it is integrated with the city of Toronto’s system for local drinking water supply, bringing benefits to the city in terms of improved drinking water supply. Lake Ontario, bounded on the north by the Canadian province of Ontario and on the south by Ontarios Niagara Peninsula and by New York State, USA, is one of the five Great Lakes of North America. ... Deep lake water cooling uses cold water pumped from the bottom of a lake as a heat sink for climate control systems. ... Look up ton in Wiktionary, the free dictionary. ... The megawatt (symbol: MW) is a unit for measuring power corresponding to one million (106) watts. ...

Footnotes

1. ^ AGFW-Branchenreport 2006 (Frankfurt, 2007)
2. ^ Figures supplied by email to Alaric Hall, 28.5.2007.
3. ^ Chris Goodall, How to Live a Low-Carbon Life: The Individual's Guide to Stopping Climate Change (London: Earthscan, 2007), p. 85.

See also

• Central solar heating
• Geothermal heating
• Lists of public utilities
• Public utility
• Seasonal thermal store
• 2007 New York City steam explosion

Central solar heating is the provision of central heating and hot water from solar energy by a system in which the water is heated centrally by arrays of solar thermal collectors (central solar heating plants - CSHPs) and distributed through district heating pipe networks (or block heating systems in the case... Geothermal heating is a method of heating and cooling a building. ... These are lists of public utilities. ... A public utility is a company that maintains the infrastructure for a public service. ... A seasonal thermal store (also known as a seasonal heat store or inter-seasonal thermal store) is a store designed to retain heat deposited during the hot summer months for use during colder winter weather. ... Rising steam from the explosion Photo of the cloud of steam from the roof of a building on 34th St. ...

External links

• Euroheat & Power: European District Heating & Cooling Association
• District Energy Library
• Towards Local Energy Systems: Revitalizing District Heating and Co-Generation in Central and Eastern Europe
• Technical description of district heating and district cooling at Munich Airport, Germany
• Helsinki district cooling system
• The Enwave Deep Lake Water System
• GST Group's homepage
• Sequoien - Non-profit district heating