The number everyone wants
How much does air conditioning cost to run?
Enter the electrical input from your unit label, how long you expect to run it and your own tariffs. The solar result includes export income you give up, not just avoided grid imports.
Your setup
What it costs
Per hour
£0.23
Per day
£1.41
Per summer
£126.89
kWh / summer
486
With solar covering 50% of cooling
£75.6
The net figure counts the electricity you still import and the export payment you give up by using solar at home. It assumes every solar kWh shown would otherwise have been exported. A battery and other household loads can change that result.
How the maths works
Running cost is electrical input in kilowatts multiplied by hours and your unit rate. The calculator starts at 26.11p/kWh, the Ofgem average capped unit rate for 1 July to 30 September 2026. Your tariff and the unit's real draw may differ. Inverter systems also vary their input as the room approaches the set temperature.
Solar coverage is not fixed. Daytime use, clear weather and a larger unshaded array raise it. Evening use, cloud and shade lower it. Net energy cost is remaining grid import plus the export payment forgone on solar used for cooling. Other household loads and a battery can change how much would otherwise have been exported.
Source: Ofgem energy price cap ↗
Ask an installer to model the whole system
Use the calculator as a first pass, then request an assessment of the room load, roof, solar generation and electrical supply.
No obligation. Final cost and performance require a property assessment.