Heating our homes in the future
Most people will be aware of the Climate Emergency, with rising temperatures and changing weather patterns. One of the major factors in driving climate change is the burning of fuels to heat our homes and offices along with powering vehicles.
Nearly all the energy used in homes is either directly or indirectly produced by the burning of fuels which generates Carbon Dioxide (CO2). Most homes are heated by fossil fuels such as mains gas, oil or LPG, although some are heated by biomass (such as wood chip/pellets), the latter still generates carbon dioxide though.
To avert the predicted dangerous temperature rises in the future the Government has stated the following:
All new homes built after 2025 should not be fitted with gas, oil or LPG boilers
By 2035 all gas, oil and LPG boilers should be phased out in existing homes
This means that most home owners will need to consider their options. The Government will be introducing a £5000 grant to encourage households to switch from gas and oil boilers to heat pumps.
So what are the options?
These work in a manner which is in essence a reverse of how a refrigerator works. Heat is generated by condensing a fluid in the heat pump. There are three types:
Air Source Heat Pump ASHP
Ground Source Heat Pump GSHP
Water Source Heat Pump WSHP
The main choice for most households will be the ASHP. These typically cost £6000 - £14000 to install so more costly than a gas boiler. There are other factors to consider though:
Heat pumps work most efficiently when emitting heat at lower temperatures, so ideally suited to underfloor heating, otherwise the option is to install larger radiators.
As the ASHP is likely to emit heat at a lower temperature than a gas boiler it is essential that the property is well insulated, this might not be the case in older (mainly solid brick and solid stone) properties. Such properties may require external (or internal) wall insulation, additionally any damp in the walls will need to be treated prior to the application of insulation.
An alternative to heat pumps is the hydrogen boiler. Burning hydrogen does not generate CO2. The hydrogen would be produced by the electrolysis of water, this still requires electricity. A great deal of research is being carried out looking at producing boiler that could be “hydrogen ready” such that they can burn mains gas in coming years and then be adjusted to burn hydrogen.
There may be a number of hydrogen fuel types:
Green hydrogen – This uses renewable electricity to electrolyse water to produce hydrogen
Blue hydrogen – This involves burning natural gas to produce electricity which in turn is used to produce hydrogen. This will use carbon capture and storage to limit (or eliminate) the carbon dioxide produced.
Grey hydrogen – this involves burning natural gas but still produces carbon dioxide that is not captured.
Purple Hydrogen – this uses nuclear energy to generate the electricity.
Electricity as a fuel
Many flats and off the gas grid houses may have electrical heaters such as storage heaters or panel heaters. The intention is that in the future there will be much less electricity generated by burning fossil fuels at power stations. The following will be required:
More wind farms (either inland or offshore)
Solar PV “farms”
a greater proportion of energy to come from nuclear power stations
With respect to the actual heating in properties, panel heaters should have both programmers and appliance thermostats to reduce unwanted heating, whilst storage heaters should ideally be replaced with High Heat Retention Storage Heaters.
Some homes have electric boilers which will be acceptable if the mains electricity is not being generated by the burning of fossil fuels.