Illustrative calculator

Estimate how much solar could save your household

This calculator gives a fast, client-side estimate for generation, savings, export income, payback, and 25-year value. It is designed for research, not as financial or engineering advice.

  • No forms or data capture
  • Battery and finance scenarios
  • Optimized for mobile
System inputs

Build your estimate

Adjust the inputs below. Results update instantly and stay in your browser.

40%
5%
Add battery storage Raises self-consumption and increases installed cost.
Your estimate updates instantly using broad UK assumptions for output, degradation, export income, maintenance, and financing.
Estimated output

Your solar snapshot

Indicative only. Use this as a decision aid before comparing installers.

Estimated payback

- years to break even

Annual generation

- kWh per year

Annual bill saving

- year 1 estimate

SEG earnings

- year 1 estimate

25-year net savings

- after estimated costs

Annual ROI

- year 1 return on spend
Important: This calculator is for informational purposes only. Results are estimates, not guarantees, and can vary materially depending on roof condition, shading, orientation, region, electricity tariff, export tariff, usage patterns, finance terms, and installer pricing.
Assumptions

How the calculator works

  • Base irradiance uses 950 kWh per kWp per year as a broad UK average.
  • Output degrades by 0.5% per year.
  • Maintenance of £125 per year starts in year 3.
  • Battery storage increases self-consumption but adds system cost.
Next step

Use this estimate to compare providers

Once you have a rough savings range, move to the installer comparison page to review pricing tiers, warranties, and finance options.

Compare UK installers
FAQ

Frequently asked questions

Clear answers help users understand what the calculator can and cannot tell them before they compare providers.

What electricity rate does the calculator use?

The calculator uses a default UK household electricity rate as a starting point, but you can enter your own tariff for a more relevant estimate. Results can vary significantly depending on whether you are on a standard variable tariff, fixed tariff, or time-of-use tariff.

How accurate are these calculations?

This tool provides directional estimates rather than guaranteed outcomes. Actual results depend on roof size, roof condition, pitch, shading, orientation, regional generation levels, household usage patterns, export tariff, installation quality, and future energy prices.

Are solar panels worth it in the UK?

For many homes, solar can reduce grid electricity use and improve long-term energy costs, but the financial case varies from property to property. The most reliable answer depends on your roof suitability, consumption profile, quote price, and available export tariff.

How much do solar panels cost in the UK?

Costs vary by system size, equipment quality, roof complexity, scaffolding, inverter choice, battery setup, and installer pricing. Smaller residential systems may start from the lower thousands, while larger systems and battery packages can cost materially more.

What size solar system do I need?

The right system size depends on your annual electricity use, roof space, roof layout, and budget. Many households look at systems in the 3 kW to 6 kW range, but the correct size should be confirmed by an installer after a proper site assessment.

Are batteries worth adding?

A battery can improve self-consumption by storing electricity for later use, but whether it is worth the extra cost depends on your tariff, usage habits, and battery price. In some homes it improves payback; in others it mainly adds flexibility rather than stronger returns.

What is the Smart Export Guarantee (SEG)?

The Smart Export Guarantee pays eligible households for surplus electricity exported to the grid. Rates vary by supplier and tariff, so export income can differ materially from one household to another.

Do I need planning permission for solar panels in the UK?

Many domestic solar installations fall under permitted development, but exceptions can apply, especially for listed buildings, conservation areas, flats, or unusual roof arrangements. It is sensible to check current local rules before committing.