Solar panels cost £6,500 to £8,500 for a typical 4kW system fully installed in the UK in 2026, with an average of roughly £7,500. Adding battery storage brings the total to £10,000–£14,000. All eligible residential installations carry 0% VAT until 31 March 2027.
The honest answer is that “average” hides more than it reveals, because system size varies enormously by household. The useful figure is cost per kilowatt, which sat at roughly £1,750–£1,900 per kW installed for 4–10kW systems as of mid-2026.
Applied to the sizes most UK homes actually buy:
7–10
12–16 m²
1-2 bed, lower usage
£5,000 - £6,500
~2,500 kWh
4kW
8–14
13–22 m²
3 bed (most common)
£6,500 - £8,500
~3,400 kWh
5kW
12–16
20–26 m²
3-4 bed (higher usage)
£7,000 - £9,500
~4,250 kWh
6kW
14–20
24–32 m²
4+ bed or EV owner
£8,500 - £11,000
~5,100 kWh
4kW + Battery
8–14
13–22 m²
Evening/overnight usage
£10,000 – £14,000
~3,400 kWh
Prices include 0% VAT and cover panels, inverter, mounting hardware, scaffold, labour, DNO notification and Part P certification. Output figures assume a south-facing roof at 30–45°; Scotland and Northern Ireland typically run 10–15% below these figures, southern England slightly above.
Sources: MCS installation cost data; PVGIS output modelling. Verified August 2026.
Homeowners often assume they are mostly paying for panels. They are not.
Panel
~30%
£2,25
Inverter
~15%
£1,125
Labour
~30%
£2,250
Scaffold
~10%
£750
Mounting, cabling, DNO, certification, admin
~15%
£1,125
Two consequences follow, and they explain most of what confuses people about quotes:
One: Because more than half the cost is labour, scaffold and logistics rather than hardware, two quotes specifying identical panels can differ by well over £1,000 on entirely legitimate grounds — a three-storey terrace needs more scaffold than a bungalow.
Two: Upgrading to better panels costs less than most people expect. Moving from budget to premium panels on a 4kW system might add £600–£900 to a £7,500 job, because you are only uplifting 30% of the total. That is usually the best-value upgrade available on a solar quote.
A battery adds £3,000–£6,500 depending on capacity, brand and whether it is fitted at the same time as the panels. A 4kW system with a 5kWh battery typically lands at £10,000–£12,000; larger batteries push toward £14,000.
Fitting a battery at the same time as the panels is meaningfully cheaper than retrofitting later, because you avoid a second scaffold hire and a second electrical visit.
A battery does not automatically improve payback. It raises how much of your own generation you use rather than exporting — self-consumption typically moves from 30–50% up to 60–80% — but it also raises the capital outlay. It makes clear financial sense if you are out during the day and use most of your electricity in the evening, and much less if you are home during daylight hours.
Yes, though less than people expect. Wales and Northern Ireland averaged just over £7,000 for a 4kW system in mid-2026, broadly in line with the UK as a whole.
Three regional factors move the number:.
Eligible residential solar panel and battery installations in the UK currently carry 0% VAT rather than the standard 20%. The relief applies until 31 March 2027, after which it rises to 5% from 1 April 2027.
On a £7,500 installation, that concession is worth roughly £1,500. It applies to panels, batteries fitted alongside them, and — under current rules — batteries retrofitted to an existing system. It is applied by the installer at the point of quotation, so it should already be reflected in any 2026 quote you receive rather than appearing as a separate line.
Nine to thirteen years for most UK households, with the tighter end of that range going to homes with high daytime electricity use and a good export tariff.
Payback is driven by four variables:
Panels are warranted to produce at least 80–87% of rated output at year 25, so a system that pays back in year 11 delivers a decade or more of effectively free generation after that.
Not necessarily — but it needs explaining. A quote significantly below £6,000 for a 4kW system should prompt three questions: which panel brand and model, which inverter and what warranty, and what is excluded from the price.
The most common way a quote gets cheap is not inferior panels. It is exclusions — scaffold billed separately, DNO notification charged afterwards, consumer unit upgrade “if required” left unpriced. A £5,800 quote that becomes £7,400 after extras is not cheaper than a £7,200 all-inclusive quote.
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A 4kW system — the most common size for a three-bedroom home — costs £6,500 to £8,500 fully installed in 2026, averaging around £7,500. Smaller 3kW systems start near £5,000 and larger 6kW systems reach £11,000. All figures include 0% VAT, which applies to eligible residential installations until 31 March 2027.
A 4kW solar system with a 5kWh battery typically costs £10,000 to £14,000 installed. The battery alone accounts for £3,000 to £6,500 depending on capacity and brand. Fitting the battery at the same time as the panels costs less than retrofitting later, because it avoids a second scaffold hire and a second electrical visit.
Because more than half the installed cost is labour, scaffold, access and administration rather than hardware. Roof height, access difficulty, installer overhead and travel distance all move the figure legitimately. Quotes for the same property commonly differ by 20–40%, which is exactly why comparing three is worthwhile.
For most homes with a suitable roof, yes. Typical payback is 9–13 years against a system warranted to still produce 80–87% of its rated output at year 25. The economics are strongest for households with high daytime electricity use, a south-facing or east–west unshaded roof, and access to a competitive export tariff.
Not currently. Eligible residential solar and battery installations carry 0% VAT until 31 March 2027, after which the rate becomes 5%. On a typical £7,500 installation the relief is worth roughly £1,500, and it should already be built into any quote you receive rather than added separately.
