Solar potential calculator

Use this tool to estimate the amount of electricity you could generate by installing solar panels on your property. This calculation is based on average UK weather data and typical solar panel efficiency.

What you’ll need

To get a more accurate estimate, you should have the following details ready:

  • Your Postcode: This helps us estimate the annual solar irradiance (sunlight intensity) in your area.
  • Roof Orientation: Which direction does your roof face? South-facing roofs generate the most energy.
  • Roof Tilt: The angle of your roof. A 30 to 40-degree tilt is usually ideal for the UK.
  • Shading: Are there any trees, chimneys, or neighbouring buildings that cast shadows on your roof?
  • Available Space: How many panels can you fit? A typical panel is roughly 1.7m x 1m.

Key outputs

The calculator will provide estimates for:

  1. Annual Generation: The total amount of electricity (in kWh) your system is likely to produce each year.
  2. Financial Savings: An estimate of how much you could save on your energy bills.
  3. Export Income: Potential earnings from the Smart Export Guarantee (SEG).
  4. Carbon Reduction: The amount of CO2 emissions you will avoid by using renewable energy.

Methodology

Our tool uses the Standard Assessment Procedure (SAP) methodology. We assume a standard 400W monocrystalline panel and a system efficiency of 80% (accounting for losses in the inverter and wiring).

Note: This tool is for guidance only. A professional MCS-certified installer will need to perform a technical survey to provide a precise yield report for your specific property.

Interactive Calculator

Sunlight intensity varies across the UK.
A typical 4kWp system uses 10 panels. Each panel is approx 1.7m x 1m.
Which direction does the roof face?
Are there nearby trees or buildings?
Will you install a battery?