The cost per kW for an air source heat pump (ASHP) depends on the size of the pump and the cost of electricity. For example, a 2.2 kW ASHP will create roughly about 11 kW worth of hot water for radiators and use 2200 watts from the mains. With a cost of 27.35p per Kwh, running this system would cost you around 60p per hour in electricity, or £4.80 for an 8 hour ‘running period’. The cost of a 40 kW ASHP is split 60:40 between equipment costs and non-equipment costs respectively.