The short answer
Commercial rooftop solar typically costs UK businesses £800–£1,300 per kWp installed and pays back in 4–7 years — faster for daytime-heavy operations like warehouses (2–5 years). With grid electricity at 25–30p per kWh and rooftop solar generating at an effective 5–8p, most suitable roofs are now strongly cash-positive.
Solar has quietly become one of the better returns a UK business can make on its own roof. Electricity prices sit roughly 75% above their pre-2021 level, the kit has never been cheaper, and the tax treatment is generous. Yet the market is full of installers quoting to win the job, which makes it hard to judge whether the numbers you're shown are realistic. This guide lays out the real figures, independently — we don't install anything. When you want a number for your roof, the calculator below gives you one in about a minute.
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Are solar panels worth it for a business?
For most businesses with a suitable roof and meaningful daytime electricity use, yes. The economics turn on one number: self-consumption. Every unit you generate and use yourself displaces a grid unit costing 25–30p; every unit you export earns far less. Operations that run during daylight — warehouses, factories, cold stores, offices — use most of what they generate, which is why their payback is fastest.
Across UK commercial installs, payback typically lands in the 4–7 year range, with an internal rate of return of 10–20% over the system's 25-year-plus life. That comfortably beats most infrastructure a business could otherwise invest in. The table below shows how it varies by building type.
| Building type | Typical payback | Annual ROI | Why |
|---|---|---|---|
| Warehousing / logistics | 2–5 years | 22–45% | Large roofs, daytime load, high self-consumption |
| Manufacturing | 3–5 years | 19–36% | Heavy continuous daytime demand |
| Offices | 5–7 years | 15–28% | Good daytime use, smaller roofs |
| Retail / leisure | 4–7 years | 15–30% | Varies with opening hours and roof size |
A real example: Novatech in Portsmouth installed a 404 kWp system that saves around £52,000 a year and paid back in four years — roughly £1.1m of net benefit projected over 20 years. The detail varies enormously by site, which is the whole reason a free survey (not a sales call) is the right next step. Our payback and ROI guide works through the numbers in full.
What do commercial solar panels cost?
Commercial solar is priced per kWp (kilowatt-peak) of capacity, and bigger systems cost less per unit because the fixed costs — scaffolding, design, grid paperwork — spread further. As a guide for 2026:
| System size | Typical installed cost | Roughly suits |
|---|---|---|
| 25 kWp | £32,000–£35,000 | Small unit / shop, ~£1k–£1.5k/mo bill |
| 50 kWp | £64,000–£70,000 | SME premises, ~£2k–£3k/mo bill |
| 100 kWp | £80,000–£95,000 | Larger unit / light industrial |
| 250 kWp | ~£190,000–£230,000 | Factory / mid-size warehouse |
| 500 kWp | £375,000–£425,000 | Large warehouse / distribution |
Note how the cost per kWp falls from around £1,300 on a small system to £750–£950 at scale. The headline price isn't the whole story — what matters is cost against the savings it unlocks. Our commercial solar cost guide breaks down exactly what sits inside a quote (and what inflates it).
How businesses pay for solar: buy, PPA or lease
You don't need the cash upfront. There are four common routes, each with a different trade-off between lifetime return and cashflow:
- Buy outright — best lifetime return and full tax relief; you own the asset and the savings. Payback 4–7 years.
- Power Purchase Agreement (PPA) — £0 upfront. A funder owns the system and you buy the power it generates at 10–17p per kWh, well below grid. You give up the tax benefits, which the funder claims.
- Lease — fixed monthly payments (typically £3,000–£5,000) with maintenance included.
- Roof rental — an investor pays you £10,000–£20,000 a year to put their panels on your roof.
Which one fits depends on your capital, your tenure and your appetite for ownership. Our financing guide compares all four, including what "free solar panels for business" offers really are.
Grants and tax relief in 2026
There is no universal government grant for commercial solar in the UK. The real support comes through the tax system, and it's substantial.
Myth: solar qualifies for full expensing
On top of the AIA, commercial solar is exempt from business rates in England (since April 2023), and regional grants of £5,000–£50,000 exist in places through schemes like the UK Shared Prosperity Fund and group-buying initiatives. Our grants and tax relief guide keeps a current list by nation, including Scotland, Wales and Northern Ireland.
Is your building suitable?
Most commercial roofs work, but a few things decide it quickly:
- Roof size and condition — you need clear, structurally sound roof area. Aim for a roof with at least 10 years of life left; re-roofing first is common.
- Electricity supply — most commercial systems need a three-phase supply. Single-phase premises are usually limited to small systems.
- Daytime use — the more you consume while the sun is up, the better the return.
- Tenure — owner-occupiers have the simplest path; tenants need landlord consent and enough lease left.
Different premises behave differently. We have dedicated guides for industrial units, farm buildings, offices, small businesses, retail parks, hotels and leisure and cold stores. For warehouse roofs, see our warehouse solar installers guide.
Do you need planning permission?
Usually not. Since December 2023, permitted development rights cover rooftop solar of any size on commercial buildings in England, provided the panels sit at least 1m from the roof edge and don't protrude more than 200mm on a pitched roof (or 1m on a flat roof). The main exceptions are listed buildings, scheduled monuments and conservation areas. Building regulations always apply. Full detail is on our planning permission guide.
How to choose an installer
This is where businesses most often get a bad deal. The shortlist that matters is MCS-certified, properly insured, has installed systems of your size in your sector, and puts operations-and-maintenance terms in writing. Get at least three quotes and compare them on cost-per-kWp and projected payback — never on headline price. Our quote-comparison checklist shows exactly what a good quote contains, and our guide to choosing an installer sets out how we vet the ones we match businesses with.
How long does installation take?
The panels themselves go up in days to a few weeks depending on system size. The longer part is the grid side: a G99 connection application for a system that exports to the grid typically takes 8–12 weeks for approval. End to end — survey, design, DNO approval, install, commissioning — a commercial project usually runs 5–9 months. Starting the grid application early is the single biggest thing that shortens it.
The bigger picture
Frequently asked questions
Can I buy solar panels through my business?+
Yes. A VAT-registered business buys commercial solar as a capital asset, reclaims the VAT, and can deduct up to 100% of the cost from year-one profits via the £1m Annual Investment Allowance — worth about 25% of the project back at the 25% corporation tax rate. Solar does not qualify for full expensing, but the AIA covers most SME systems in full.
What size solar system does a business need?+
Size to your daytime electricity use, not your roof. As a rule of thumb, a business spending £2,000–£3,000 a month on electricity suits roughly a 50 kWp system. Our calculator estimates the right size from your roof area, postcode and monthly bill in about a minute.
How long do commercial solar panels last?+
Panels are typically warrantied for 25–30 years and keep generating beyond that at a slowly declining output (around 0.4–0.5% a year). Inverters are the part most likely to need replacing first, usually after 10–15 years. The 25-year-plus lifespan is why payback in years 4–7 leaves a long tail of near-free electricity.
Are commercial solar panels worth it for a UK business?+
For most businesses with a suitable, unshaded roof and significant daytime electricity use, yes. Typical payback is 4–7 years and systems then generate at an effective 5–8p per kWh against grid prices of 25–30p. Warehouses, factories and other daytime-heavy operations see the fastest returns, often 2–5 years.
What happens on cloudy days or at night?+
Solar still generates on overcast days, just less — UK systems are sized on annual averages that already account for British weather. At night or when generation is low, you draw from the grid as normal. Most businesses self-consume 60–80% of what they generate; a battery can lift that further but lengthens payback.
Can tenants install solar, or only building owners?+
Tenants can, but it needs landlord consent and a lease long enough to recoup the investment — usually 10 years or more. Where the lease is short, a Power Purchase Agreement (you buy the power, a funder owns the kit) or a landlord-funded install with a rent adjustment often works better. We cover the options on our financing guide.
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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.