What is district heating and why do you need to know about it?

copenhagen_district_heatingWith a new district heating project under way in Fife and further major investment in Scotland on the horizon, it is an important time to ask the question: what is district heating and why do you need to know about it?

While district heating is nothing new, gaining prominence in the UK after World War II, the importance of it has grown as issues of peak oil and sustainable energy sources become ever more important.

In brief, district heating is the process of supplying space heating and domestic hot water to a large number of buildings – be it homes or government and commercial properties – from a central source. In other words, rather than having 100 homes with 100 heat sources, district heating can allow the use of one heating source for all 100 homes.

The mechanism of providing this heating from one central energy source to a large number of properties (the largest district heating system in Copenhagen supplies 275,000 households) involves a network of insulated pipes from the point of generation to an end user.

The heat supplied can come in various energy forms including:

  • Power stations
  • Energy from waste (EfW) facilities
  • Industrial processes
  • Biomass and biogas fuelled boilers
  • Gas-fired CHP unites
  • Fuel cells
  • Heat pumps
  • Geothermal sources
  • Electric boilers
  • Solar thermal arrays

Scandinavia are leading the way when it comes to district heating with between 50 and 60 per cent of its heating coming from a centralised source. This foresight to implement an efficient, sophisticated heating system, however, may have come more from necessity, rather than perspicacity. Scandinavia has few natural resources such as coal and oil and was greatly affected by the oil crisis of the seventies.

Therefore, the geography of Scandinavia determined the need to be proactive about its energy source and usage, and the region is now widely regarded as a world leader in sustainability.

In the UK, Scotland is leading the way in terms of generating energy from district heating. It is a key component of the Scottish Government’s approach to meeting its climate change targets and securing a low carbon economy in Scotland.

Since 2011 the country has implemented its District Heating Loan fund which has provided £10million in low-interest loans. This money has helped save 220,000 tonnes of lifetime CO2 and supplied heat to over 700 homes.

And now a potential new district heating network is being developed in Fife as part of the Glenrothes Heat project which will look to use heat from a nearby RWE Markinch Biomass CHP plant, which is 90% fuelled by waste wood.

So what plans are in the insulated pipelines for the rest of the UK? The British government is trying to increase the number of households connected to district heating networks, while the Greater London Authority is aiming for 25 per cent of its energy supply to come from a centralised source in 2025.

Other cities such as Sheffield, Nottingham and Bristol are also investing in district heating with Bristol developing the local city centre enterprise zone to entice potential businesses with guarantees of lower heating bills.

So while the UK is not on a par with Scandinavia or other European countries like Germany just yet, the imperative that was laid down to Scandinavia in the seventies is now upon us. Sometimes it takes extreme circumstances to bring about improvement. And improvement in the energy supply of our heating is certainly on the horizon.

Source: Saul Bush – One