The uptake of heat pumps across the UK has been uneven, with some regions embracing the technology far more than others. This got me thinking: how much do running costs and savings vary around the country, and could financial incentives be driving the unusually high adoption in the South West? To find out, I decided to take a closer look at how regional differences in energy prices and climate impact the economics of heat pumps compared to gas boilers.
I took a typical house, the latest (price cap) gas and electricity prices and 85 years of weather data for a random house in each postcode area (e.g. PL, G, SW, etc.) of the country. The mapping isn’t perfect – some postcode areas straddle different DNOs or gas regions.
I then compared the cost of heating the house (I excluded hot water) in each area of the country with a gas boiler (90% efficient) and an air source heat pump with oversized radiators. You can think of it as a travelling heat pump.
The running costs vary regionally for two reasons:
- Variations in relative gas and electricity prices (the spark gap). These vary from a high of about 4.1 in the South East and North Wales/Merseyside – the least favourable for heat pumps to a low of 3.7 in the South West (which has unusually high gas prices rather than particularly cheap electricity). In the analysis I also included the benefit of avoiding gas standing charges as well – as heat pump owners rarely need a gas connection any more.
- Variations in climate – lower winter temperatures hit heat pump efficiency and the median winter temperature varies from 7.6C (Truro) and 2.9C (Perth). The vast majority actually cluster between 4-5C. There is a pretty strong correlation between the average temperature and savings.
Put it all together, and the biggest savings on the cost of heating a home with a heat pump are around Truro, Torquay, Plymouth, Bournemouth and Taunton – where savings are 40-45%.
The smallest savings are in Caithness/Orkney, Oldham, Oxford and Luton (25%) – Perth is a bit of an outlier at 7% savings. There’s a pocket of inland Southern England that’s quite prone to frosts and cold weather.
So, to return to my hunch, the South West is unusually favourable for heat pumps due to climate and relative (gas vs. electricity) prices. I wonder if we need to think targeting incentives regionally going forward?
Written by Ben from Kilowatts.io.
