Alternative heating: heat pump v biomass boilers

In a government survey undertaken on alternative heating methods, more respondents indicated...

As part of the Government’s strategy for the UK to achieve net-zero emissions by 2050, gas and oil boilers are expected to be phased out for newbuild properties from 2025.  A secondary stage could see gas and oil boilers being phased out altogether from 2035 and, were that to happen, boilers that failed would then need to be replaced with an alternative ‘low-carbon’ heating source.

Currently less than 2% of UK homes have a heat pump or biomass boiler installed although a shift towards alternative heat sources is already being encouraged with the Government’s Boiler Upgrade Scheme, an initiative running from 2022 to 2025 which provides upfront funding of £5,000 towards the cost and installation of an air source heat pump or biomass boiler, or £6,000 towards a ground source heat pump.  In a government survey undertaken on alternative heating methods* more respondents   indicated that they would be likely to install some form of heat pump than a biomass   boiler. The overall installation cost and space needed for a biomass boiler system were   two deterring factors.

One reason air source heat pumps are likely to be a popular choice is because they are extremely efficient, often achieving a heat output equivalent to 300-400% of the electricity consumed, which is a massive increase on the 90% efficiency that a good gas boiler can achieve.  In simple terms, heat pumps function like a refrigerator in reverse. Refrigerant liquid circulates around the system absorbing thermal energy from the outside air or ground and utilises that thermal energy either to produce warm air or to heat water inside the property via a heat exchanger.

The cost for an air to water heat pump can range from £5,000 to £18,000 whereas ground source heat pumps can typically range from £13,000 to £35,000 or higher. Whilst the front-end costs are high, the lower running costs and ongoing savings on energy bills mean these systems can represent a good longer-term investment.

Biomass boilers, on the other hand, typically burn wood fuel in the form of pellets, chips or logs to heat water via a heat exchanger which is then distributed around the building via a low-pressure water system.  There are different types of biomass boiler for use with the different fuel types.  Depending on the type of system, the fuel is fed either manually or by an automatic mechanism from a fuel storage compartment (hopper).  

An automatically-fed pellet boiler can cost between £10,000 and £20,000. These systems are particularly suited to larger properties which take longer to heat up, as the wood fuel can be more economical than gas or oil.  A domestic sized boiler would normally have an output of 45kW or less and can achieve energy efficiency in the region of 90%, so equivalent to a good gas boiler.

When it comes to the adoption of ‘low carbon’ heating sources, the UK has lagged behind many European countries for some time so, it will be interesting to see how this changes in the coming years and whether the Government’s seemingly ambitious target of 600,000 heat pumps being installed per year by 2028 can be achieved.

Remember that under our high-net-worth home products we include an Environmental Home Upgrade benefit which provides up to £10,000 (Executive Home) or £50,000 (Executive Plus) towards the cost of installing a solar, wind or geothermal electrical power-generating system (where such a system is not already installed) following a valid buildings damage claim over £20,000, as part of the repairs to the electrical, heating or water system.

* BEIS Public Attitudes Tracker: Heat and Energy in the Home Spring 2022, UK