The short answer
Commercial solar panels cost £800–£1,300 per kWp installed in the UK (2026). Economies of scale are steep: a 25 kWp system runs £32,000–£35,000, a 100 kWp system £80,000–£95,000, and large warehouse arrays fall to £700–£1,000 per kWp. Most systems pay back in 4–7 years.
Price is the first thing every business asks about and the easiest thing for an installer to massage. The figures below are independent UK averages for 2026 — we don't install anything, so there's no quote to win here. The single most useful number, though, is the one for your roof: the calculator below estimates your system size, savings and payback from your postcode, roof area and monthly bill in about a minute.
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How much do commercial solar panels cost?
Commercial solar is priced per kWp (kilowatt-peak) of installed capacity. The headline range is £800–£1,300 per kWp, but where you land inside it depends almost entirely on system size, because the fixed costs — scaffolding, design, grid paperwork, the survey — spread further across a bigger array. Here is the full picture for 2026:
| System size | Typical installed cost | Roughly suits |
|---|---|---|
| 10 kWp | £12,780–£15,000 | Small premises, light daytime load |
| 25 kWp | £31,950–£35,000 | Small unit / shop, ~£1k–£1.5k/mo bill |
| 50 kWp | £63,900–£70,000 | SME premises, ~£2k–£3k/mo bill |
| 100 kWp | £80,000–£95,000 | Larger unit / light industrial |
| 150 kWp | £112,500–£127,500 | Mid-size commercial / industrial |
| 500 kWp | £375,000–£425,000 | Large warehouse / distribution |
Cost per kWp explained (and why "per panel" is the wrong unit)
You will sometimes see solar quoted "per panel". Ignore it. Panel wattages differ between manufacturers, so the same roof can need a very different panel count for the same output — the per-panel figure tells you nothing comparable. The honest unit is cost per kWp, and on a like-for-like basis it falls sharply with scale:
| System band | Cost per kWp | Notes |
|---|---|---|
| 50 kWp or under | £1,278–£1,500 | Fixed costs spread over little capacity |
| 100 kWp or over | £750–£950 | Scale drives the unit price down |
| Warehouse / industrial | £700–£1,000 | Largest roofs, lowest unit cost |
This is why a 100 kWp system doesn't cost four times a 25 kWp one — and why comparing quotes on cost per kWp, rather than headline price, is the only fair test. Our quote-comparison checklist shows how to read a quote line by line.
Cost per square metre or square foot
Some buyers think in roof area rather than capacity. As a rough conversion, a commercial rooftop system needs about 6 m² of roof per kWp of panels (around 5–6 m² in practice). On the typical £800–£1,300 per kWp range, that works out at roughly £130–£215 per m² of panelled roof, or about £12–£20 per square foot — falling towards the bottom of that range on large arrays. Treat this only as a sense-check: capacity, not area, is what your bill savings track.
What's inside the price
A commercial solar price is not just panels on a roof. Understanding the anatomy helps you judge whether a quote is realistic and where a cheap one has cut corners:
| Element | Typical share / cost | What it covers |
|---|---|---|
| Hardware | 35–50% of total | Panels, inverters, mounting, cabling |
| Labour | 15–20% of total | Installation and electrical work |
| Scaffolding / access | £1,200–£3,000 | Safe roof access for the install |
| DNO connection fees | £1,000–£10,000+ | Grid operator approval and any upgrade |
| Structural survey | £500–£2,000 | Confirms the roof can carry the load |
The DNO (Distribution Network Operator) line is the one that varies most. If your local grid has little spare capacity, connection costs and any required upgrade can run to five figures — which is why two quotes for the same roof can differ widely.
What changes the price for your roof
The averages above are a starting point; your site moves the number. The main factors:
- Flat vs pitched roof — flat roofs need ballasted or framed mounting and must meet a BROOF(t4) fire rating, which can add cost.
- Asbestos — older roofs containing asbestos may need specialist handling or replacement before any install.
- Grid headroom — limited local capacity raises DNO fees and can force an upgrade.
- Access — height, fragile roofs and tight sites all push scaffolding and labour costs up.
Used or cheap commercial panels — why we'd skip them
There is real demand for second-hand or budget commercial panels, and we understand the appeal on a large array. Our honest take is that it rarely pays. Used panels usually come without a meaningful performance warranty, may have degraded unpredictably, and complicate insurance and any future claim. On a 25-year asset where the panels are only a third to a half of the cost, the saving is small against the risk. Pay for new, warrantied hardware and spend the energy instead on getting the design and installer right.
Cost vs return
The price only matters against what it saves. With grid electricity at 25–30p per kWh and rooftop solar generating at an effective 5–8p, most suitable commercial roofs pay back in 4–7 years and then run at a 10–20% internal rate of return over a 25-year-plus life. Daytime-heavy operations do best. Our payback and ROI guide works through the returns by building type, with real installations.
Cut the net cost: tax relief and grants
The figure you actually pay can be well below the sticker price. There is no universal government grant for commercial solar, but the tax treatment is generous: the £1m Annual Investment Allowance lets a business deduct 100% of the cost from year-one profits — worth about 25% of the project back at the 25% corporation tax rate — and solar is exempt from business rates in England.
Solar does not qualify for full expensing
Regional grants of £5,000–£50,000 also exist in places. Our grants and tax relief guide keeps a maintained list by nation and works through the AIA on a real example.
Frequently asked questions
What does a 50 kW commercial solar system cost?+
A 50 kWp commercial solar system costs roughly £64,000–£70,000 fully installed in 2026, or about £1,280–£1,400 per kWp. That suits a business spending around £2,000–£3,000 a month on electricity. The exact figure depends on roof type, access and grid connection — our 50 kW system guide breaks it down.
How much does solar cost for a warehouse roof?+
Large warehouse and industrial arrays fall to roughly £700–£1,000 per kWp because the fixed costs spread across far more capacity. A several-hundred-kWp roof is therefore much cheaper per unit than a small one. Warehouse-specific economics are covered in detail on our partner site Solar Grid Check rather than here.
Is commercial solar cheaper per panel than domestic?+
Per panel is the wrong unit, but yes — commercial solar is cheaper per unit of capacity. Domestic systems run higher per kWp because they are small and labour-heavy. Commercial systems benefit from scale: a 100 kWp roof can cost £750–£950 per kWp against £1,278–£1,500 for systems of 50 kWp or under.
What ongoing costs are there after installation?+
Running costs are low — typically around 1% of the system cost a year. Budget for occasional cleaning, monitoring and panel insurance, plus one inverter replacement at roughly 10–15 years. Panels themselves are warrantied for 25–30 years with no moving parts. These costs are modest against the bill savings and are factored into typical 4–7 year payback figures.
Do commercial solar prices include VAT?+
The prices quoted here are before VAT. Commercial solar installations carry VAT at the standard 20% rate — the 0% rate that applies to domestic installs does not apply to businesses. If your business is VAT-registered, you can normally reclaim that VAT, so the real net cost is the pre-VAT figure.
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Updated June 2026 · By Taro Schenker, founder of Business Solar Check. We're independent — we don't install solar. Figures are indicative UK averages; your site survey confirms the numbers for your roof.