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 such as space heating and water heating. Space heating is the Heating of a space usually enclosed such as a house or room Water heating is a thermodynamic process using an energy source to heat Water above its initial Temperature. The heat is often obtained from a cogeneration plant burning fossil fuels but increasingly biomass, although heat-only boiler stations, geothermal heating and central solar heating are also used. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production A heat-only boiler station generates Thermal energy in the form of hot water for use in District heating applications Geothermal heating has been used since the time of the Roman Empire as a way of heating Buildings and Spas by utilizing sources of hot Water 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 District heating plants can provide higher efficiencies and better pollution control than localized boilers.

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. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both A heat-only boiler station generates Thermal energy in the form of hot water for use in District heating applications 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.

The combination of cogeneration and district heating is very energy efficient. Energy conversion efficiency is the Ratio between the useful output of an Energy conversion machine and the input in Energy terms A thermal power station which generates only electricity can convert less than approximately 50 % of the fuel input into electricity. A thermal power station is a Power plant in which the prime mover is Steam driven The major part of the energy is wasted in form of heat and dissipated to the environment. A cogeneration plant recovers that heat and can reach total energy efficiency beyond 90 %.

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

A cancelled Russian nuclear district heating plant in Fedyakovo, Nizhny Novgorod Oblast. Fedyakovo (Федяково is a village in Kstovsky District of Nizhny Novgorod Oblast, Russia, located just a few kilometers

Nuclear energy has been suggested to be used for district heating. The principals for a conventional combination of cogeneration and district heating applies the same for nuclear as it does for any thermal power station. A thermal power station is a Power plant in which the prime mover is Steam driven One use of nuclear heat generation was with the Ågesta Nuclear Power Plant in Sweden. In Switzerland, the Beznau Nuclear Power Plant provides heat to about 20,000 people. The Beznau Nuclear Power Plant (German Kernkraftwerk Beznau, abbreviated KKB) is located in the municipality Döttingen (canton Aargau, ^[1]

Heat distribution

Insulated pipes to connect a new building to Warwick University's campus-wide combined heat and power system. The University of Warwick is a British Campus university located on the outskirts of Coventry, West Midlands, England and is Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both

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 may be installed to even out peak load demands.

The common medium used for heat distribution is water, but also steam is used. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. The advantage of steam is that in addition to heating purposes it can be used in industrial processes due to its higher temperature. Industrial processes are procedures involving chemical or mechanical steps to aid in the Manufacture of an item or items usually carried out on a very The disadvantage of steam is a higher heat loss due to the high temperature. Also, the thermal efficiency of cogeneration plants is significantly lower if the cooling medium is high temperature steam, causing smaller electric power generation. In Thermodynamics, the thermal efficiency (\eta_{th} \ is a dimensionless performance measure of a thermal device such as an Internal combustion Electric power is defined as the rate at which Electrical energy is transferred by an Electric circuit.

At customer level the heat network is connected to the central heating of the dwellings by heat exchangers (heat substations). For the Grand Central Records albums see Central Heating (Grand Central album and Central Heating 2. A heat exchanger is a device built for efficient Heat transfer from one medium to another whether the media are separated by a solid wall so that they never mix or the media 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.

For the Norwegian district heating systems the yearly heat losses from distribution are about 10% of the total heat generated. ^[2]

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. The larger combustion units also have a more advanced flue gas cleaning than single boiler systems. Flue gas is Gas that exits to the atmosphere via a Flue, which is a pipe or channel for conveying exhaust gases from a fireplace oven Furnace, Boiler In the case of surplus heat from industries, district heating systems do not use additional fuel because they use heat (termed heat recovery) which would be disbursed to the environment.

District heating is a long-term 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 network, heat-only boiler stations, and cogeneration plants require high initial capital expenditure and financing. Only if considered as long-term investments these may 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.

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.

Europe

Since 1954, district heating has been promoted in Europe by Euroheat & Power. Year 1954 ( MCMLIV) was a Common year starting on Friday (link will display full 1954 Gregorian calendar) They have compiled an analysis of district heating and cooling markets in Europe within their Ecoheatcool project supported by the European Commission. Launched at the beginning of 2005 with support from the Intelligent Energy Europe programme the ECOHEATCOOL project carried out by Euroheat & Power, in cooperation with 13 The European Commission (formally the Commission of the European Communities) is the executive branch of the European Union. The legal framework in the member states of the European Union is currently influenced by the EU-CHP Directive. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in The Directive on the promotion of cogeneration based on a useful heat demand in the internal energy market and amending Directive 92/62/EEC, officially 2004/8/EC and popularly better known

Denmark

In Denmark district heating covers more than 60 % of space heating and water heating. The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe Space heating is the Heating of a space usually enclosed such as a house or room Water heating is a thermodynamic process using an energy source to heat Water above its initial Temperature. ^[3] In 2005 82. 4 % of this heat was produced on combined heat and power plants. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Heat recovered from waste incineration accounted for 22. Incineration is a waste treatment technology that involves the Combustion of organic materials and/or substances 9 % of the total Danish district heat production. ^[4] Most major cities in Denmark have big district heating networks including transmission networks operation 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 area operated by CTR I/S and VEKS I/S. Copenhagen (ˌkəʊpənˈheɪgən ˌkəʊpənˈhɑːgən ˈkəʊpənˌheɪgən ˈkəʊpənˌhɑːgən kʰøb̥ənˈhɑʊ̯ˀn kʰøb̥m̩ˈhɑʊ̯ˀn is the capital and largest city In central Copenhagen the CTR network covers 275. 000 households (90-95 % of the areas population) through one network of 54 km district heating distribution pipes providing a peak delivery of 663 MW. ^[5] The consumer price of heat from CTR is approximately €42 per MWh plus taxes. ^[6]

Finland

In Finland district heating accounts for about 50 per cent of the total heating market ^[7], 4/5 of which being produced from combined heat and power plants. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Over 90 per cent 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 is mostly used in areas to the south east gas pipeline network, imported coal is used in areas close to ports, and peat is used in northern areas where peat is a natural resource. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Peat is an accumulation of partially Decayed Vegetation matter. However, other renewables such as wood chips and other paper industry combustible by-products are also used, as is the energy recovered by the incineration of municipal solid waste. Incineration is a waste treatment technology that involves the Combustion of organic materials and/or substances Industrial units which generate heat as an industrial by-product may sell otherwise waste heat to the network rather than release it to the environment. In some towns, waste incineration can contribute as much as 8% of the district heating heat requirement. Availability is 99. In Telecommunications and Reliability theory, the term availability has the following meanings 1 98% and disruptions when they do occur usually reduce temperatures by only a few degrees^[8].

Germany

In Germany district heating has a market share of around 14 % in the residential buildings sector. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. 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. ^[9]

The largest district heating network is located in Berlin whereas the highest diffusion of district heating occurs in Flensburg with around 90% market share. Berlin is the capital city and one of sixteen states of Germany. Flensburg ( Danish: Flensborg, Low Saxon: Flensborg, North Frisian: Flansborj) is an independent town in

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. The Directive on the promotion of cogeneration based on a useful heat demand in the internal energy market and amending Directive 92/62/EEC, officially 2004/8/EC and popularly better known

Italy

In Italy, district heating is used in some cities (Bergamo, Brescia, Reggio Emilia, Torino). Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest Bergamo ( Bèrghem in Lombard, antiquated Wälsch-Bergen in German) is a town in Lombardy, Italy, about Brescia ( Lombard: Brèsa) is a city in the region of Lombardy in northern Italy. For the city in the southern Italy See Reggio Calabria. For the basketball club "Bipop Carire Reggio Emilia" see Pallacanestro Reggiana.

Norway

In Norway district heating only constitutes approx. Norway ( Norwegian: Norge ( Bokmål) or Noreg ( Nynorsk) officially the Kingdom of Norway, is a Constitutional 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. However, there is district heating in the major cities.

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 neighbouring city blocks. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Russian ( transliteration:,) is the most geographically widespread language of Eurasia, the most widely spoken of the Slavic languages They mostly use coal and oil-powered steam turbines for cogeneration of heat. An oil is a substance that is in a viscous Liquid state ( "oily") at ambient temperatures or slightly warmer and is A steam turbine is a mechanical device that extracts Thermal energy from pressurized Steam, and converts it into useful mechanical work Now, gas turbines and combined cycle designs are beginning to be widely used as well. A gas turbine, also called a combustion turbine, is a rotary Engine that extracts energy from a flow of Combustion gas A combined cycle is characteristic of a power producing engine or plant that employs more than one Thermodynamic cycle. 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 ^[10]. A soviet (сове́т, "council" originally was a workers' local council in late Imperial Russia. Leakage describes an unwanted loss or Leak, of something which escapes from its proper location 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

Serbia

In Serbia, district heating was used throughout the main cities, particularly in the capital, Belgrade. Serbia (Србија Srbija) officially the Republic of Serbia (Република Србија Republika Srbija) is a Landlocked Country Belgrade (Београд Beograd is the Capital and largest city of Serbia. NATO targeted one of the main DH plants, the District Heating Plant of New Belgrade (JKP "Beogradske elektrane") during the Kosovo War [1][2]. The North Atlantic Treaty The NATO bombing of Yugoslavia (code-named Operation Allied Force) was NATO 's military operation against the Federal Republic of Yugoslavia that 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. Novi Beograd or New Belgrade ( Serbian Cyrillic: Нови Београд) is one of 17 municipalities which constitute the City of Belgrade 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.

Sweden

Sweden has a long tradition for using district heating in urban areas. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. The city of Växjö has reduced its fossil fuel consumption by 30% in 1993-2006 and aims at 50% reduction in 2010. Växjö (vɛkːɧøː is a city in Småland in southern Sweden. This is to a large extent to be achieved by way of biomass fired district heating^[11]

United Kingdom

District heating accumulator tower and workshops on the 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 and impressive London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. This plant once used waste heat piped from Battersea Power Station on the other side of the River Thames. Battersea Power Station is a defunct coal-fired power station in Battersea, London, that was the first in a series of large coal-fired electrical generating The Thames ( is a major River flowing through southern England. (January 2006)

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 United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located World War II, or the Second World War, (often abbreviated WWII) was a global military conflict which involved a majority of the world's nations, including The Blitz was the sustained bombing of Britain by Nazi Germany between 7 September 1940 and 10 May 1941 in World War II. The photo (right) shows the accumulator at the Pimlico District Heating Undertaking (PDHU), just north of the River Thames. The Thames ( is a major River flowing through southern England. 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. Battersea Power Station is a defunct coal-fired power station in Battersea, London, that was the first in a series of large coal-fired electrical generating The Thames ( is a major River flowing through southern England. 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.

One of the United Kingdom's largest district heating schemes is EnviroEnergy in Nottingham. Nottingham ( is a city in the Ceremonial county of Nottinghamshire, England. Plant initially built by Boots is now used to heat 4,600 homes, and a wide variety of business premises, including the Concert Hall the Nottingham Arena, the Victoria Baths, the Broadmarsh Shopping Centre, the Victoria Centre and others. This article is about a former British company which has now merged to form Alliance Boots, as a result information on this page may be out of date The Royal Concert Hall in the English city of Nottingham, is part of the city's Royal Centre which also incorporates the Victorian Theatre Royal. The National Ice Centre ( NIC) is located in Nottingham, England. Westfield Broadmarsh (Formerly known as The Broadmarsh Shopping Centre) is the southern end Shopping centre in Nottingham England, owned by the Australian The Victoria Centre is a large Shopping centre in the city of Nottingham, England. The heat source is a Waste-to-energy incinerator. Waste-to-energy (WtE or energy-from-waste (EfW refers to any waste treatment that creates energy in the form of Electricity or Heat [3]

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. A thermostat is a device for regulating the Temperature of a System so that the system's temperature is maintained near a desired setpoint

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

Central Heat Distribution Ltd. operates a central heating plant in the downtown core of Vancouver, British Columbia. Central Heat Distribution Ltd (CHDL is a private District heating company located at 720 Beatty Street in Vancouver, Canada that provides heat to the Vancouver (vænˈkuːvɚ is a coastal In addition to building heating, 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. Enwave provides district heating and cooling within the downtown core of Toronto, including deep lake cooling technology, which circulates cold water from Lake Ontario through heat exchangers to provide cooling for many buildings in the city. Enwave is a private corporation jointly owned by the City of Toronto and the Ontario Municipal Employees Retirement System and is one of the largest district energy Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario

Many Canadian universities operate central campus heating plants.

United States

Consolidated Edison of New York (Con Ed) operates Con Edison Steam Operations, the largest commercial district heating system in the world. Consolidated Edison Inc is one of the largest investor-owned energy companies in the United States with approximately $13 billion in annual revenues and $30 billion in assets New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous The New York City steam system is a District heating system which carries Steam from central power stations under the streets of Manhattan to heat cool [4] The system has operated continuously since March 1882 and serves Manhattan Island from the Battery through 96th Street. Manhattan Island, in New York Harbor, is much the largest part of the Borough of Manhattan, one of the Five Boroughs which form the City of New York 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 [5]. Events 390 BC - Roman - Gaulish Wars Battle of the Allia - a Roman army is defeated by raiding Gauls, Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. The July 18, 2007 New York City steam explosion sent a geyser of hot steam up from beneath a busy intersection with a 40-story-high shower of mud and flying In 1989 three people were also killed in a similar event [6]. 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. The absorption refrigerator is a Refrigerator that utilizes a heat source (e The term air conditioning refers to the cooling and dehumidification of indoor air for Thermal comfort. NRG Energy Inc. also operates district systems in major cities of San Francisco, Harrisburg, Minneapolis, Pittsburgh and San Diego[7].

History

District heating traces its roots to the hot water-heated baths and greenhouses of the ancient Roman Empire. The Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial District systems gained prominence in Europe during the Middle Ages and Renaissance, with one system in France in continuous operation since the 14th century. The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere The U.S. Naval Academy in Annapolis began steam district heating service in 1853. The United States Naval Academy is an undergraduate college in Annapolis, Maryland, United States that educates and commissions officers of the United States Annapolis is the capital of the US state of Maryland, as well as the County seat of Anne Arundel County. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Year 1853 ( MDCCCLIII) was a Common year starting on Saturday (link will display the full calendar of the Gregorian Calendar (or a Common

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. New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous Year 1877 ( MDCCCLXXVII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common Birdsill Holly ( November 8, 1820 - April 27 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) lost interest in the district heating business and provided insufficient funding for maintenance, and the systems and service to customers started to deteriorate. The result was that the systems started losing customers. The reliability decreased and finally the whole system closed down. For example, in Minnesota in the 1950s there were about 40 district steam systems, but today only a few remain. [8]

Paris has been using geothermal heating from a 55-70 °C source 1-2 km below the surface since the 1970s for domestic heating. Paris (ˈpærɨs in English; in French) is the Capital of France and the country's largest city Geothermal heating has been used since the time of the Roman Empire as a way of heating Buildings and Spas by utilizing sources of hot Water ^[12]

In the 1980s Southampton began utilising combined heat and power district heating, taking advantage of geothermal heat "trapped" in the area. Southampton ( IPA /ˌsaʊθˈhæmptən/ is the largest city in the county of Hampshire, on the south coast of England The geothermal heat provided by the well works in conjunction with the Combined Heat and Power scheme. Geothermal energy provides 15-20 %, fuel oil 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. Fuel oil is a fraction obtained from Petroleum Distillation, either as a distillate or a residue Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, "Waste heat" from this process is recovered for distribution through the 11 km mains network. The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand ^{[13] [14]}

Market penetration of district heating

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 and economic and legal framework.

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. Geothermal heating has been used since the time of the Roman Empire as a way of heating Buildings and Spas by utilizing sources of hot Water In most East European countries energy planning included development of cogeneration and district heating. Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both Negative influence in The Netherlands and UK can be attributed partially to milder climate and also competition from natural gas supply. The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom, the UK or Britain,is a Sovereign state located Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane,

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. ^[16]

Figures for Sweden suggest that the average Swede using district heating receives 4500 kWh/year from the system. ^[17]

District cooling

The opposite of district heating is district cooling. District heating (less commonly called teleheating) is a system for distributing heat generated in a centralized location for residential and commercial heating requirements Working on broadly similar principles to district heating, district cooling delivers chilled water to buildings like offices and factories needing cooling. In winter, the source for the cooling can often be sea water, so it is a cheaper resource than using electricity to run compressors for cooling.

The Helsinki district cooling system uses otherwise wasted heat from summer time CHP power generation units to run condensers for cooling during summer time, greatly reducing electricity usage. In winter time, cooling is achieved more directly using sea water. The adoption of district cooling is estimated to reduce the consumption of electricity for cooling purposes by as much as 90 per cent and an exponential growth in usage is forecast. The idea is now being adopted in other Finnish cities.

Cornell University's Lake Source Cooling System uses Cayuga Lake as a heat sink to operate the central chilled water system for its campus and to also provide cooling to the Ithaca City School District. Cayuga Lake (pronounced either "kā-'yü-gə" or "kī-'yü-gə" is the longest of western New York 's glacial Finger Lakes, and is the second largest The system has operated since the summer of 2000 and was built at a cost of $55-60 million. It cools a 14,500 tons load. Units of mass There are three similar units of Mass called the ton: Long ton (simply ton in countries such as the United

In August 2004, Enwave Energy Corporation, a district energy company based in Toronto, Canada, started operating system that uses water from Lake Ontario to cool downtown buildings, including office towers, the Metro Toronto Convention Centre, a small brewery and a telecommunications centre. Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page Lake Ontario is one of the five Great Lakes of North America. The process has become known as Deep Lake Water Cooling (DLWC). Deep lake water cooling uses cold water pumped from the bottom of a lake as a Heat sink for climate control systems. It will provide for over 40,000 tons (140 megawatts) of cooling—a significantly larger system than has been installed elsewhere. Units of mass There are three similar units of Mass called the ton: Long ton (simply ton in countries such as the United The watt (symbol W) is the SI derived unit of power, equal to one Joule of energy per Second. Another feature of the Enwave system is that it is integrated with Toronto’s drinking water supply.

In Jauary 2006, PAL technology is one of the emerging project management companies in UAE involved in the diversified business of desalination plant, sewerage plant to district cooling system. More than 400,000 Tons of district cooling projects are already in the pipe line whilst negotiating other key projects in the region.

See also

• Central solar heating
• Geothermal heating
• Lists of public utilities
• New York City steam system
• Public utility
• Seasonal thermal store
• Deep lake water cooling

Footnotes

External links

• Euroheat & Power: European District Heating & Cooling Association
• District Energy Library
• Technical description of district heating and district cooling at Munich Airport, Germany
• Helsinki district cooling system
• Danish Board of District Heating: Denmark's District Heating & Cooling Organisation
• Sequoien - UK non-profit district heating