How Much Do Commercial Solar Panels Cost? (UK 2026)

How much do commercial solar panels cost in the UK in 2026?

As of mid–2026, a commercial rooftop solar system in the UK typically costs between £700 and £1,050 per kWp installed, excluding VAT — and the rate falls as the array gets larger. A modest 50kW system on a single factory roof lands near the top of that band, while a 1MW array across a large industrial estate sits near the bottom. There is no single “price of solar”; there is a price for your roof, your energy demand and your DNO region.

We are an independent, supplier–neutral service. We do not sell panels — we match UK businesses to vetted installers and give a like–for–like quote comparison, which is why we can publish real numbers rather than a headline designed to win a sale. This guide breaks down factory solar panel costs by system size, explains what pushes the price up or down, and covers the VAT and tax treatment that most quotes gloss over. If you run a manufacturing or industrial site, our full guide to solar panels for factories puts these figures in context.

Commercial solar cost by system size (2026)

The table below shows typical installed costs for turnkey commercial solar installation across the UK, all figures ex–VAT. UK arrays generate roughly 900–1,000 kWh per kWp per year, so a 100kW system produces around 90–100 MWh annually — enough to displace £18,000–£25,000 of grid power at today’s commercial rates of about 28–32p/kWh, assuming high on–site use.

Payback figures above are simple and before tax relief. Realised savings depend heavily on self–consumption: power you use on site offsets the full 28–32p/kWh grid rate, while surplus you export earns only 1–12p/kWh under the Smart Export Guarantee (or a negotiated rate under a PPA). Sites with steady daytime load — production lines, refrigeration, compressors — get the fastest returns. For a size–matched estimate, see our dedicated breakdown of commercial solar panel cost.

What pushes the price up — and down

Two quotes for the same kWp can differ by 20% or more for legitimate reasons. Understanding the drivers helps you compare commercial solar installers on a genuine like–for–like basis rather than on headline price alone.

Factors that increase cost

• Roof condition — ageing sheeting, fragile fibre–cement or asbestos may need remediation before install.
• Structural surveys and any strengthening for the added dead load.
• Complex DNO connections — every commercial array of 50kW+ needs a full G99 application, and constrained grid areas may require export limiting or reinforcement.
• Ground–mount or carport structures, which add steelwork and groundworks over a simple rooftop.
• Battery storage, optimisers, and half–hourly export metering.

Factors that reduce cost

• Scale — per–kWp rates fall sharply from 50kW to 1MW as fixed costs spread.
• A large, unshaded, south–facing roof with simple cable routes to the intake.
• Tier–1 modules (Trina, JA Solar, LONGi, Jinko, Aiko, Qcells) at competitive panel pricing.
• A single mobilisation rather than phased works.

This is exactly why comparing the best commercial solar companies side by side matters: the cheapest quote is rarely the best value once you account for panel tier, inverter brand (SMA, Huawei, SolarEdge, Fronius, Sungrow), workmanship warranty and monitoring.

VAT and capital allowances: the numbers most quotes skip

Here is where independent advice earns its keep. Two facts materially change the real cost of business solar panels, and both are routinely muddled.

VAT is 20% on commercial solar — not 0%

The 0% VAT rate you may have read about applies to residential installations only, and runs to 31 March 2027. Commercial and factory solar is charged at the standard 20% VAT rate. The good news: if your business is VAT–registered, that VAT is normally recoverable, so it is a cash–flow item rather than a permanent cost. Any installer quoting 0% VAT on a factory roof has got it wrong.

AIA gives 100% first–year tax relief

Since the Autumn Statement 2023 made it permanent, the Annual Investment Allowance (AIA) lets you claim 100% first–year relief on up to £1m of qualifying plant per year, and solar qualifies. At 25% corporation tax, a £100,000 system generates roughly £25,000 of year–one tax relief — which is what trims a 4–6 year simple payback down to about 3.5–5 years. Spend above £1m in a year? Solar is a special–rate asset, so the balance attracts the permanent 50% First–Year Allowance, then a 6% writing–down allowance on the remainder. Note that commercial solar does not qualify for full expensing, which is reserved for main–rate plant. Always confirm the treatment with your accountant.

Grants, SEG and the honest incentives picture

Let us be straight, because a lot of marketing is not: there is no broad UK cash grant for commercial solar. When people search for “solar grants”, what actually exists for businesses are the tax reliefs above plus export income. So “commercial solar grants” in practice means capital allowances, not a cheque from government. Our page on solar panel grants for business sets out the real routes:

• AIA / 50% FYA — the primary financial support, covered above.
• Smart Export Guarantee (SEG) — supplier–set export payments of about 1–12p/kWh (best rates near 12p). SEG is an income stream, not a grant, and large sites often beat it with a negotiated PPA.
• Farms only — agricultural rooftop projects may access the Improving Farm Productivity grant at 25%; this does not extend to general commercial premises.
• Public sector — schools, NHS and councils use Salix / the Public Sector Decarbonisation Scheme.

Ignore any claim of a “40% FETF solar grant” for factories — it does not apply. For a clear view of the legitimate commercial solar incentives, weigh the tax relief and export income together rather than chasing a grant that is not there.

Getting an accurate quote for your site

The bands in this guide get you to a credible budget, but only a proper roof and load assessment produces a real number. Refrigerated and chilled sites are a good example: constant compressor load makes solar for cold storage unusually well matched to on–site generation, which can shorten payback well below the typical range. A generic per–kWp figure would miss that entirely.

Because we are independent, we can put vetted commercial solar panel installers in front of you and hold their commercial solar panels quotes to the same specification — same panel tier, same inverter class, same warranty terms — so you compare value, not sales spin. If you want to see how the leading options stack up, start with our roundup of the best commercial solar panels UK buyers rely on, then request a like–for–like comparison.

There is no phone queue and no obligation. Use our free quote form to get matched to installers and receive a side–by–side comparison for your factory solar panels project — typically within a couple of working days.