The most cost effective way forward appears to be applying for the RHI (Renewable Heating Incentive): The Domestic RHI is A government scheme to pay incentives for using renewable heat.https://www.ofgem.gov.uk/environmental-and-social-schemes/domestic-renewable-heat-incentive-domestic-rhi
Options include:
- biomass boilers (Our house is old enough to have chimneys but is in a smokeless area)
- solar water heating (Our house has solar panels fitted on the south facing roofs)
- certain heat pumps (The plot our house is on has space for either a air based heat pump or a ground based heat pump)
We will consider each in turn.
Biomass boilers:
- Burn wood or pellets which require storage :
- We have room to store fuel for a biomass boiler.
- Fuel will need to be bought in.
- Require manual feeding (CON)
- Can function on demand(PRO)
- Require tending ash disposal and cleaning (CON)
Solar water heating : Our southern facing Roofs are in use so this option is not suitable. We have out buildings that may be used but the piping and insulating of water to these locations make this problematic.
Heat Pumps :
- Air source heat pump
- Electrical power required to run pump.
- Requires suitable space away from property boundaries
- Lower Operating temperature requires resizing of radiators (CON)
- Potential for icing in cold weather (CON)
- Ground source heat pump
- Electrical power required to run pump
- Requires more space close to the house (CON)
- Lower Operating temperature requires resizing of radiators (CON)
- Heat pumps have a COP (Coefficient of performance) a good COP is anything over 3 with 4.5 being the max possible. The heating for our house for the last year required 26834.5 KWH. Assuming a COP of 3 we would need 8945 KWh of electricity to do this. About 50KWH per day in winter.