UK Solar Savings Checker
See what solar could realistically save your household — in about 20 seconds, with no contact details needed.
How this is calculated: we estimate your usage from your bill at ~27p/kWh, size a system to your consumption (capped 2.5–6kWp), and model generation at ~950kWh per kWp adjusted for your region and roof direction. Savings combine avoided import at 27p/kWh with Smart Export Guarantee income at ~15p/kWh exported; costs assume ~£1,500 per kWp installed at 0% VAT; the 20-year figure allows for panel degradation. Ranges show ±15%. Estimates only — your quotes will reflect your actual roof and usage.
How the solar savings checker works
The checker estimates what a correctly sized solar system would save your household per year, using your electricity bill, region, roof direction and daytime occupancy. It multiplies your annual usage by the share a typical system offsets (35–55% without a battery, depending on how much you’re home in daylight), then adds Smart Export Guarantee income for the electricity you sell back. It deliberately errs conservative — installers confirm exact figures with a survey, and we’d rather you were pleasantly surprised than oversold.
The UK figures behind the numbers (July 2026)
| Input | Value used |
|---|---|
| Electricity unit price | ~27p/kWh (price-capped average) |
| Typical 3-bed system | 3.5–4.5 kWp (9–12 panels) |
| Installed cost, 2026 | £5,500–£8,000 (0% VAT applied) |
| Self-consumption without battery | 35–55% of generation |
| Smart Export Guarantee | up to ~15p/kWh on the best tariffs |
| Typical payback | 6–12 years; panels warrantied 25+ |
What actually changes your saving
Roof direction matters less than folklore says: east- or west-facing roofs deliver roughly 80–85% of a south roof’s output, and an east–west split often matches daily usage better. Daytime occupancy matters more — working from home lets you use cheap solar power directly instead of exporting it. Shading from chimneys or trees is the silent killer; a good installer designs around it with optimisers. And a battery can lift self-consumption to 70–90%, though it adds £2,500–£5,000 and its own payback maths.
From estimate to real quotes
Treat the number here as your benchmark. When quotes arrive, anything promising dramatically more should explain exactly why (bigger array? battery? generous export tariff assumptions?). Quotes for the same roof routinely differ by £2,000+, which is why we match you with up to three top-ranked MCS installers rather than one — and why our quote red-flag checker exists for anything you’ve been handed already.
Common questions
Why is your estimate lower than some ads I’ve seen?
Ads often assume you use 90–100% of what you generate — real UK homes without batteries use 35–55%. We model the realistic case and let your installer’s survey improve on it.
Do I need planning permission?
Almost never — rooftop solar is permitted development for most UK houses. Listed buildings and some conservation areas are the exceptions.
Is my data collected when I use the checker?
No — the checker runs entirely in your browser. We only receive details if you choose to request installer quotes afterwards.
What about the 0% VAT?
Residential solar installations are zero-rated for VAT in Great Britain until 2027 — it’s already reflected in the installed-cost figures above and applied automatically to quotes.