Heat pumps use electricity to make low temperature heat energy from the air or ground into useful higher temperature energy that can heat your home. How do they compare with other types of home heating for running costs?
The graph shows the cost in pence to provide 1 kWh of heat into your home for different types of heating: electric, gas, oil, air source heat pump and ground source heat pump.
Pretty obvious electric heating is not a great choice. The graph is based on average price cap unit (kWh) figures from Oct 22 – that’s 34p for electricity, 10p for gas, 8.4p for oil (based on 87p/litre – there’s no price cap on oil so this price could change quite a bit). Then the unit cost is divided by the efficiency of the heating system to get a cost per kWh of useful heat.
There’s two costs shown for each heating type. The higher cost is based on old systems – they just aren’t as efficient as newer equipment – or on new equipment that’s not set up well. The lower cost is for new systems, e.g. condensing boilers, that are set up to work efficiently. A new system that is not well set up may not perform much better than older equipment – equally true for modern condensing boilers and heat pumps.
Efficiency figures used – amount of heat output per unit of energy input
- Electric 100%
- Gas and Oil 70%- 90%
- ASHP 250% – 420%
- GSHP 300% – 500%
If you are interested in why even modern condensing gas and oil boilers can be only 70% efficient there’s a great piece here: https://www.theheatinghub.co.uk/why-our-condensing-boilers-do-not-condense
An average* house in the UK uses 12,000 kWh of heat per year – multiply the numbers in the graph by 12,000 to get:
| Yearly cost of heating | |
| Electric | £3,400 |
| Gas | £1,330 – £1,710 |
| Oil | £1,100 – £1,440 |
| ASHP | £971 – £1,632 |
| GSHP | £816 – £1,360 |
A properly set up modern heat pump has running costs lower than gas or oil boilers – if it’s not set up sensibly it can be more expensive than gas or oil. What does set up sensibly mean? Check out making-your-heat-pump-work-great
* Yes I know averages can be really misleading – I didn’t even state if it was mean or median. It doesn’t really matter – pick a number you are happy with and get multiplying. A good place to look for a realistic number for your property is the EPC certificate which gives a figure for the annual heat demand – look for ‘Estimated energy used to heat this property – Space heating’
So what’s the takeaway?
A heat pump can have similar or lower running costs to a modern gas or oil boiler (at current energy prices). It needs to be set up for efficient operation or costs can be higher than oil or gas – although oil and gas boilers can also be set up inefficiently increasing their costs.