The average price of charging an electric car on a pay-as-you go, non-subscription basis at a publicly accessible rapid charger in Great Britain has increased by 21% to 44.55p per kilowatt hour (kWh) since September, figures analysed by the RAC’s show.

The 7.81p per kWh increase, from 36.74p at the end of last summer, means that the average cost to complete an 80% rapid charge of a typical family-sized electric car such as a Kia e-Niro with a 64kWh battery has increased by £4 over this period, from £18.81 to £22.81 now. The RAC’s analysis shows that it now costs on average 10p per mile to charge at a rapid charger, up from 8p per mile last September. 

This is nearly half the cost per mile compared to filling a petrol-powered family car, the cost of which has risen from 15p per mile since the end of last September to a staggering 19p per mile now. The cost per mile for a similarly sized diesel-powered car is even higher at nearly 21p.

Charging at home remains the best value. Electrifying.com’s weekly Fuel Check analysis shows the difference in monthly cost between comparable petrol and electric cars. At the time of writing, a medium-sized family such as a Volkswagen ID.3 is would save the average motorist £73 versus an equivalent Golf. 

The average price of charging at the quickest ultra-rapid chargers – which have a power output of 100kW-plus and can deliver a charge to a compatible vehicle in as little as 20 minutes – has increased by a greater margin of 16.76p per kWh, from 34.21p per kWh in September to 50.97p in May. This means the cost to charge a vehicle to 80% has risen from £17.51 to £26.10. 

Charging an ID.3 is currently £73 per month cheaper to fuel than a Golf, but rapid charging shrinks the saving

​This, however, is still £48 cheaper than filling a petrol-powered car to 80%, although electric car drivers do not get quite as many miles from an 80% charge as drivers of petrol cars do from an equivalent fill-up of a tank.

The price increases facing drivers of electric cars using publicly accessible chargers can be explained by the rises in the wholesale cost of electricity, which itself is driven by hikes in the cost of gas – especially since a considerable proportion of the UK’s electricity is generated by natural gas-fired power stations. 

RAC electric vehicle spokesperson Simon Williams said: “Just as the price that drivers of petrol and diesel cars pay to fill up at the pumps is driven by fluctuations in the world oil price, those in electric cars are affected by gas and electricity prices. But while electric car drivers may not be immune from the rocketing price of wholesale energy – most notably gas, which in turn dictates the cost of electricity – there’s no doubting that charging an EV still represents excellent value for money compared to filling up a petrol or diesel car.

“Unsurprisingly, our analysis shows that the quickest places to charge are also the most expensive with ultra-rapid chargers costing on average 14% more to use than rapid chargers. For drivers in a hurry though, or travelling a long distance, paying this premium might well be worth it with the very fastest chargers capable of almost completely replenishing an electric car’s battery in a matter of minutes.”​

The fastest chargers have got even more expensive