Solar Panel Savings Calculator
Estimate your potential energy generation, annual financial savings, and carbon footprint reduction based on your UK roof space and location.
Calculate Your Solar Potential
Enter your average electricity bill, available roof space, and region to instantly see your estimated solar energy generation and environmental impact.
Solar Estimator
Get a clear breakdown of your potential system size, generation, and savings.
How it Works
Understanding your solar potential
Roof Space Analysis
We calculate how many standard 400W solar panels (approx. 1.7m² each) can fit on your available roof space.
Regional Solar Yield
We apply UK regional solar irradiance data to estimate your annual energy generation in kilowatt-hours (kWh).
Financial Savings
We calculate savings based on 40% of energy used directly (offsetting your electricity bill) and 60% exported to the grid via the Smart Export Guarantee (SEG).
Environmental Impact
We translate your clean energy generation into kilograms of CO₂ saved, based on the current UK national grid carbon intensity.
Typical Solar System Sizes
A general overview of common residential solar panel system configurations in the UK.
| System Size | Number of Panels (400W) | Required Roof Space | Avg. Annual Generation |
|---|---|---|---|
| 2 kW System | 5 panels | ~8.5 m² | 1,700 – 1,900 kWh |
| 3 kW System | 8 panels | ~13.6 m² | 2,550 – 2,850 kWh |
| 4 kW System | 10 panels | ~17.0 m² | 3,400 – 3,800 kWh |
| 6 kW System | 15 panels | ~25.5 m² | 5,100 – 5,700 kWh |
Solar Energy FAQ
Answers to the most frequently asked questions about residential solar panels, savings, and regulations in the UK.
The average UK home requires a 3kW to 4kW solar panel system, which typically consists of 8 to 10 standard 400W panels. This requires approximately 14 to 17 square metres of unshaded roof space and can cover a significant portion of an average household’s electricity usage.
Yes, solar panels still generate electricity on cloudy days and during winter, though at a reduced capacity. They rely on daylight, not direct heat or bright sunshine, to produce power. Modern panels are highly efficient even in diffuse light conditions, and any excess summer generation can offset lower winter output.
In most cases, no. Solar panels are considered ‘permitted development’ in England, Scotland, and Wales. You do not need planning permission as long as they do not protrude more than 200mm from the roof slope and are not installed on a listed building or in a designated conservation area.
The Smart Export Guarantee (SEG) is a UK government initiative that requires energy suppliers to pay homeowners for the excess renewable electricity they generate and export back to the national grid. Rates typically range from 1p to 15p per kWh, depending on the supplier and tariff you choose.