Solar quotes vary far more than most homeowners expect. Two installers can look at the same roof and come back £3,000 apart — usually because they are quoting different equipment, not because one is ripping you off.
Typical 2026 prices
- 3 kW — around £5,000 to £7,000. Suits a smaller home or a one-to-two person household.
- 4 kW — around £6,000 to £8,500. The most common size for a three-bed semi.
- 5-6 kW — around £8,000 to £11,000. Larger homes, heat pumps or EV charging.
- Adding a battery — add roughly £3,000 to £6,000 depending on capacity.
What actually moves the price
Panel brand and wattage, inverter type (string, hybrid or micro-inverters), roof pitch and access, scaffolding, the number of storeys, and whether the installer is MCS certified all change the number at the bottom of the quote.
A cheap quote is not automatically a bad one — but ask what panels and inverter are being used, and how long the workmanship warranty runs.
How to compare quotes properly
Line the quotes up on four things: total installed price, system size in kW, estimated annual generation in kWh, and warranty length. If one quote is much cheaper, it is almost always smaller, using unbranded kit, or excluding scaffolding.
Get at least three quotes. Prices for identical work genuinely differ by thousands between installers, and there is no way to know your number without someone assessing your roof.