What solar panels cost in the UK
A 4 kW system — the most common UK size — costs roughly £6,800 installed in 2026, or about £1,700 per kW. VAT on residential solar is 0%, so that is the price you pay; there is no separate credit or rebate to claim afterwards.
There is no UK tax credit — the relief is already in the price
American solar guides talk constantly about a 30% federal tax credit claimed back on your return. Britain does not work that way. Instead, VAT on residential solar installation is zero rated, so the relief is already inside the quoted price rather than something you recover later. If a UK quote mentions a tax credit, be sceptical.
What actually moves the price
Hardware is a minority of a modern quote. Scaffolding, labour, electrical work, DNO notification and installer margin make up much of it, which is why quotes for the same roof routinely differ by thousands. A steep or complex roof, an old consumer unit needing replacement, or scaffolding on a tight terrace all move the number more than the choice of panel does.
Cost by system size
| System | Panels | Installed cost | Output, median UK |
|---|---|---|---|
| 2 kW | 5 | £3,400 | 1,688 kWh |
| 3 kW | 8 | £5,100 | 2,532 kWh |
| 4 kW | 10 | £6,800 | 3,376 kWh |
| 5 kW | 13 | £8,500 | 4,220 kWh |
| 6 kW | 15 | £10,200 | 5,064 kWh |
Note what happens past about 4 kW: output keeps rising but a typical 2,500 kWh household cannot use it, so the extra goes to export at a much lower rate. Bigger is not automatically better here.
Sunlight figures are our own measurements: the median of roughly 16 suburban rooftop samples per city from Google's Solar API, across 115 UK cities. Electricity price is the Ofgem default tariff cap unit rate, 26.11p/kWh, for 1 July – 30 September 2026 — the cap is reset on 1 October 2026 and will be restated excluding VAT, so this figure has a known expiry. Household usage is Ofgem's Typical Domestic Consumption Value of 2,500 kWh, revised down on 1 July 2026. Export is modelled at a conservative 12p/kWh. Estimates only — not a quote, and not financial advice.
Check a specific UK city
Frequently asked
How much is a 4kW solar system in the UK?
About £6,800 installed in 2026, working out near £1,700 per kW. Published ranges run from roughly £5,500 to £9,000 depending on roof complexity, scaffolding and whether your consumer unit needs upgrading. Get three quotes for the same specification — the spread is genuinely wide.
Is there VAT on solar panels in the UK?
No. Residential solar installation is zero rated for VAT in 2026, so the relief is already inside the price you are quoted rather than something you claim back afterwards. This is why UK solar has no equivalent of the American federal tax credit that so many guides reference.
Why do UK solar quotes vary so much?
Because hardware is the smaller part. Scaffolding, labour, electrical work, grid notification and margin dominate, and none of them are standardised. A complex roof or an old consumer unit can add thousands. Ask every installer to quote the same panel wattage and system size, or you are comparing different products.