The UK Government has been keen to encourage district heating schemes as a way of lowering both emissions and energy costs. But what are the real benefits?
What is district heating?
District heating is where a single heat source serves more than one property, this could be an apartment block, housing estate or commercial complex. A heat interface unit (HIU) in each dwelling or building provides all of the control and functionality of a traditional boiler.
Combined heat and power (CHP) plants generate heat as a by-product of generating electricity by burning coal, oil, gas or biomass. By placing CHP plants in large building complexes or housing developments, the heat can be circulated in district heating pipes to each building or dwelling.
Another system is a heat sharing network, when a communal ground array can be accessed by each building which uses its own heat pump for heating and hot water. Buildings with excess heat can reject heat to the network, which is more efficient than venting heat as hot air.
Can district heating lower energy costs?
They key thing to remember about district heating schemes is that as they increase in size, they become more cost effective. District heating schemes can be divided up, with groups of buildings being supplied by a single heat source, saving on installation and maintenance costs.
Savings can be furthered by using a biomass boiler which can produce fuel savings of up to 75% compared with fossil fuels. Biomass also produces 96% less CO₂ than oil, making it an attractive option for new housing developments.
Using renewable sources can be an opportunity for property owners to qualify for Renewable Heat Incentive (RHI) payments. The RHI will provide finance in the form of a tariff scheme, which will be paid, usually to the owner, for up to 20 years in non-domestic and seven years in domestic buildings.
What about metering?
Landlords or property managers can easily monitor consumption in district heating systems as heat usage can be measured in each building or dwelling. By using accurate data, billing is easy and areas of high usage can be quickly identified.
There is also no need to read meters manually as data can be sent via wireless technology to a data collection and billing provider. This saves time and money as billing data can be collected without travelling to each location.
Is maintenance cheaper?
With heat combustion taking place in a central location, there is no need for annual safety checks or carbon monoxide alarms in each dwelling. This is why district heating is popular with hospitals, care homes, social housing and schools.
There are other time and cost saving benefits, such as simpler servicing and maintenance of one central boiler rather than visiting each individual dwelling.
What are the disadvantages?
Only a minority of UK buildings benefit from district heating, despite the Government investing £320 million in its Heat Network Investment Project. The main barrier to building district heating schemes is, quite simply, cost.
Establishing a CHP district heating system requires substantial investment and space for a boiler plant. It is also much more difficult, and expensive, to retro fit district heating systems to existing buildings.
Although district heating still only makes up a small part of the UK energy market, the industry has seen rapid growth in recent years and district heating seems set to become an increasingly important player in delivering energy in the future.