Air source heat pumps use electricity to help with the heating process. Every pump has its own coefficient of performance (COP) which basically shows how much electricity is consumed in order to deliver a certain amount of heat.
This means that in order for an ASHP to stay financially viable, you will require an electricity tariff that is as low as possible. This is becoming increasingly concerning as it’s getting more and more difficult to find electricity providers in the United Kingdom that offer rates under 15p/kWh. The higher the tariff, the more costly it becomes to heat homes that use heat pumps.
Comparative oil and gas prices are lower than electricity at 15p/kWh. When you start to look at tariff rates above this price point, heating homes and properties can become prohibitively expensive. Let’s take a look at a simple chart to illustrate this, and assume that an average house consumes 1,000kWh to drive its air source heat pump over a cold winter month.
|Fixed Tariff||Cost on 1,000 kWh consumption|
At time of writing this article, we could not find a single electricity provider that offered a rate of 14p/kWh, and the cheapest rates we could find, for the West Midlands, was 15p/kWh. Most tariffs were 17-18p/kWh (and there were many that were over 20p). What makes this significant is that two years ago, you could easily secure a rate of 12-13p/kWh.
Smart meters with agile tariffs are probably the best way forward to use the cheapest rates to heat homes if you can be flexible enough to manoeuvre your way around peak electricity times (16:30-19:30). From our research, even flexible tariffs averaged out at about 15p/kWh during January and February 2021.