How we calculate our savings

£550 annual energy bill savings

Our £550 annual bill savings calculations are based on energy bill savings (as opposed to all energy-related costs). This means we compare the expenses of gas and electricity bills (including for appliances) with a boiler to electricity bills (including for appliances) for an air source heat pump (ASHP) over the course of a year. These calculations exclude the cost of the hardware. We assume an average yearly electricity consumption of 3,375 kWh with the ASHP system and 3,000 kWh allocated for your appliances, contrasted with a gas consumption of 15,000 kWh for heating and hot water.

Our calculations are based on an average gas price of 6.99 p/kWh and 32.67 p/day standing charge and an average electricity price of 27.03 p/kWh. The calculation is based on installing an Aira 8kW Heat Pump, a 100-litre all-in-one Indoor Unit, a 40-litre buffer tank and 5 new standard radiators in a semi-detached, 3-bedroom home with no loft or cavity wall insulation. In the calculation for Cosy Octopus, energy costs are compared between a boiler and a home equipped with an Aira Heat Pump connected to the Cosy Octopus smart tariff. It factors in a yearly electricity consumption of 3,375 kWh for the heat pump priced at a blended average rate of 22.07 p/kWh, which is the average from 39.79% base rate at 28.52 p/kWh, 52.51% dip rate at 13.98 p/kWh, 8% peak rate at 42.77 p/kWh. And 3,000 kWh for your appliances at 22.07 p/kWh, which is the average from 37.69% base rate at 28.52 p/kWh, 54.31% dip rate at 13.98 p/kWh, 8% peak rate at 42.77 p/kWh. DISCLAIMER 1: The comparison is an estimate of all energy-related costs over the expected lifetime of a heat pump. Gas and electricity bills are calculated using current prices as of April 2025 multiplied by 20 years, assuming constant gas and electricity costs over that period. Actual bills will vary based on variable factors, e.g. future energy consumption, future energy price caps and future tariff rates. DISCLAIMER 2: 15,000 kWh yearly gas consumption and 3,375 kWh yearly electricity consumption represent a typical Aira customer. The figures are based on Aira’s own data, comprising more than 800 costumer visits per month, and Ofgem data (between medium consumption homes – 11,500 kWh annual gas use – and high consumption homes – 17,000 kWh annual gas use).  Source of data: AIRA 2025.