District heating is an innovative solution to the problems of domestic energy supply, a community system that removes the need for households to have their own boilers. Find out more…
District heating - also known as teleheating or heat networks - is a method of supplying homes and businesses with heating and hot water that works on a community basis rather than an individual household one.
The idea can hardly said to be new - the Romans used it to heat their baths and systems operated in medieval Europe. In the industrial age, the USA has been using district heating since the nineteenth century and it's something that was quite common in eastern Europe during the Soviet era.
District heating is, though, considered to be an innovative and forward-thinking approach. Although up-front costs can be steep, in the long term it can be a cost-efficient, environmentally friendly way of supplying domestic energy.
Denmark, for example, is held up as an example of a country that has made a success of district heating.
The country looked at this after energy shortages during the 1973 oil crisis, investing heavily in renewable energy and a vast network of pipes under its towns and cities that could capture waste heat and deliver district heating.
It's far less common in the UK where, in 2014, only about 2% of households (around 200,000 homes) were connected to district heating systems.
However, the Department for Environment and Climate Change (DECC) would like to see this percentage climb to 40% by 2050.†
This is likely to be most evident in densely populated areas like London with numerous blocks of flats; district heating is much more effective in this sort of urban landscape than in more sparsely populated regions with detached housing and business units.
In London, the Pimlico District Heating Undertaking (PDHU) has been in operation since 1950.
It used to rely on waste heat from the old Battersea Power Station, but now relies on a new energy centre to heat the water.
A district heating system is powered by a central energy centre that typically produces electricity as well as heat.
The size and scale of such a centre will vary depending on the community it serves, but such generation and storage plants can be enormous.
The way that the heat is then delivered can take many forms, but the most typical arrangement involves a network of underground, insulated pipes that deliver hot water.
This removes the need for individual households and businesses to have their own boilers; instead, they have their own Heat Interface Unit (HIU) which controls energy usage and is monitored by a heat meter or, alternatively, a water meter.
Simple economy of scale is one reason why district heating is considered an efficient and environmentally friendly option.
They're particularly well placed to make use of any natural heat that may be available in the form of geothermal energy and water.
District heating can also work well with renewable energy schemes.
One of the big problems with creating things like solar and wind power is storing excess energy for times when the wind isn't blowing or the sun isn't shining.
A large, central energy centre is able to invest in the technology to store such excess power in a way that may not currently be practical for individual households and businesses.