Free Tool

Solar Panel ROI Calculator

Adjust the sliders to match your home and see your estimated savings, payback period, and 25-year return — instantly, no email required.

£40£400
2 kWp12 kWp
Estimated annual savings
£820
8.2Year payback
£20,50025-year savings
£95SEG export/yr
1.3TCO₂ avoided/yr
Yr 5Yr 10Yr 15Yr 20Yr 25
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Estimates only, based on average UK solar irradiance, current electricity prices (~28p/kWh) and typical Smart Export Guarantee rates. Your real quote depends on your specific roof survey, panel choice, and local conditions.

How We Calculate

The numbers behind your estimate

Our calculator uses standard UK solar yield assumptions (approximately 850-950 kWh per kWp installed per year for a well-oriented system), current average electricity prices, and typical Smart Export Guarantee rates to estimate your savings.

It assumes roughly 50% self-consumption without a battery, rising to 70-85% with battery storage — meaning more of your generated electricity is used directly rather than exported.

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This calculator gives a strong estimate, but only an in-person survey can confirm your roof's exact shading, orientation, and structural suitability.

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