Our methodology

Learn how we calculate energy savings, carbon reductions, and estimated costs for different home energy solutions.

Data sources

We use open data from the following sources:

• EPC Open Data: For property efficiency baseline statistics.
• National Grid ESO: For live and forecast carbon intensity data.
• Ofgem: For current energy price cap and tariff information.

Assumptions

Our calculators make the following standard assumptions:

• Electricity price: 24.5p per kWh (Standard Variable Tariff).
• Gas price: 6.2p per kWh.
• Average home size: 85 square metres.

Calculation updates

We update our formulas and assumptions quarterly to reflect changes in the energy market.