District heating - cost £10,000 per dwelling

Although it is very unlikely that this is something you’re likely to do yourself (you’ll need your neighbour’s permission for a start), we thought it worth including in case you do live in a very close community.
District heating comprises a centralised boiler with a distribution network to neighbouring houses – this might be a small mixed-use development or even a whole town.
The heat and hot water is distributed to your home via pipework that might be carried above ground or buried below it – either way the pipes need to be very well insulated.
Modern DH schemes will then meter the heat/hot water that enters your home, which is likely to fill up a storage tank for use in radiators and taps as usual. You are then billed for the amount you use at a rate set by the Energy Supply Company (ESCO), which might be a co-operative or any other type of public, shared, or private organisation.
Heat metering is expensive however, and an alternative approach is to meter the water. Water meters are much cheaper than heat ones, and metering the water also encourages the consumers to extract as much heat as possible from the incoming hot water, leading to a very low return temperature. This in turn increases the efficiency of the CHP plant.
The received wisdom is that district heating plants provide higher efficiencies and better pollution control than localised boilers, and district heating using CHP (CHPDH) is the cheapest method of cutting carbon emissions.


Fuel sources

Generally CHP plants are used and the fuel is often gas or oil, although increasingly biomass is being used, largely in the form of woodchip. However, DH need not necessarily utilise a central woodchip-fired CHP unit; other district heating systems make use of geothermal heat; solar heat; heat pumps which extract heat from seawater, river or lake water, sewage, or waste heat from industrial processes; and even nuclear power plants

NB: We don’t advise that you attempt to introduce your neighbours to the idea of a small shared nuclear power plant...


Space: obviously the amount of space that your DH plant will require will wholly depend upon the total demand of the houses/buildings that it needs to serve. However, if you imagine something that would fill a shipping container, with at least as much space again for fuel storage, then you’ll be in the right proximity. Basically, it would make sense if your street was to knock down one of the houses in the middle and use the empty plot as the power station. 
Cost: district heating is a long-term commitment that unfortunately fits poorly with the modern focus on short-term returns on investment. DH requires high initial capital expenditure and financing, and only if considered as long-term investment will a scheme translate into a profitable operation.
Benefits: to the community over time include reduced energy costs, reduced investment in individual household heating equipment, and an increase in autonomy. Because of the distribution expenses, DH works best in areas of high population densities – blocks of flats over detached houses for example.
© green.co.uk 2020