Calculate your exact savings and payback period for 2025
UK solar panels typically pay for themselves in 8-12 years and provide a 150-200% return on investment over 25 years. The average UK household saves £900-£1,400 per year with a 4-6kW system at current electricity rates (27.03p/kWh). Our Pro calculator often shows faster payback with location-specific data. Use our calculator below for your exact figures.
Free gives you estimates. Pro gives you a financial plan.
Using Met Office sunshine data, MCS installation standards, and current Ofgem electricity rates
Calculating your personalised results...
Based on current Ofgem rates and conservative assumptions
| UK Region | Average ROI | Payback Period | 25-Year Savings |
|---|---|---|---|
| South England | 175% | 6-7 years | £28,000 |
| Midlands | 160% | 7-8 years | £26,000 |
| North England | 150% | 8-9 years | £24,000 |
| Scotland | 145% | 8-9 years | £23,000 |
| Wales | 155% | 7-8 years | £25,000 |
We use the current Ofgem price cap rate of 27.03p/kWh (April-June 2025). From July 2025, this drops to 25.73p/kWh. If you're on a smart tariff like Octopus Agile (averaging ~19p) or have Economy 7, you can input your actual rate for more accurate calculations.
We use conservative estimates: 30% self-consumption (you export 70%), 0.5% annual panel degradation, inverter replacements at years 10 and 20 (£1,500 each), and average UK sunshine hours. Most users report actual savings 10-20% higher than our estimates.
Batteries enable 'time-shifting' - charging at cheap overnight rates (e.g., 7p on Octopus Go) and using that power during expensive peak times (27p). This can save £500-800 annually, separate from solar savings. They also store excess solar for evening use. Our Pro calculator shows exact battery ROI for your usage.
System size depends on your electricity usage and roof space. Typical sizes: 3kW for 1-2 bed homes (£4,500), 4kW for 2-3 beds (£5,500), 6kW for 3-4 beds (£7,500). Our Pro calculator recommends the optimal size based on your specific usage patterns and roof area.
Yes! Solar panels work on daylight, not just sunshine. The UK receives 60% of the solar radiation of the equator. Germany, with similar weather, has one of the world's largest solar industries. Even Scotland sees excellent returns with 8-9 year payback periods.
The Smart Export Guarantee (SEG) pays you for electricity exported to the grid. Rates vary: Octopus offers up to 15p/kWh, while others pay 4-8p. We use 12p as a current market average. Higher export rates significantly improve your ROI - our Pro calculator optimises for different tariffs.
📋 Important Disclaimer: This calculator provides estimates only for educational purposes. Results are not guaranteed and should not be used as the sole basis for investment decisions. Actual results will vary based on your specific circumstances. Always consult MCS certified installers and qualified financial advisors before making investment decisions. We accept no liability for decisions made based on these calculations.