Energy calculator methodology

SaveWatt calculators estimate household energy scenarios using the numbers entered by the user. They are designed to help with planning, comparison and understanding trade-offs.

Common inputs

Inputs may include electricity unit price, standing assumptions, kWh use, vehicle efficiency, annual mileage, solar installation cost, battery size, expected savings and heat pump efficiency.

What can change results

Energy estimates are sensitive to tariff changes, weather, driving style, property insulation, installation quality, export rates, time-of-use pricing and how much solar energy is used at home.

How to use results

Use the results as a first comparison, then check supplier tariffs, installer quotes, warranty terms and your actual usage data before making a purchase decision.