How Much Does Commercial Solar Cost in 2026? A UK Business Guide
Commercial solar is one of the strongest-return investments available to a UK business with roof or ground space and daytime electricity use — but the cost depends heavily on scale, roof type and how you fund it. Here’s an honest guide to what commercial solar costs in 2026, what drives the price, and the payback you can realistically expect.
Typical commercial solar costs
At commercial scale, the installed cost per kilowatt is lower than for homes — usually around £700–£1,100 per kWp, falling as the system gets bigger. As a rough guide:
- A small commercial system (~30 kWp) might cost in the region of £25,000–£35,000.
- A mid-size system (~100 kWp) often lands around £90,000–£130,000.
- A large rooftop or ground array (250 kWp+) scales from there, with the best per-kWp rates.
Get an indicative figure for your business in seconds with our commercial solar ROI calculator.
What drives the price
- System size — bigger systems cost more overall but less per kWp.
- Roof type and access — flat roofs need ballast or fixings; height and access affect scaffolding/plant.
- Electrical works — switchgear, half-hourly metering and the DNO grid connection can be significant on larger sites.
- Battery storage — optional, but can increase self-consumption and add resilience.
Payback and return
Because businesses use most of their electricity during daylight hours — exactly when panels generate — self-consumption is high, which drives the return. Typical paybacks are around 4–6 years, after which you generate largely free electricity for another 20+ years. Add protection from rising energy prices and the case is often compelling.
Tax relief: capital allowances
Commercial solar typically qualifies for capital allowances — under full expensing or the Annual Investment Allowance, much of the cost can be offset against your taxable profits, improving the effective return. The rules depend on your business structure, so confirm the position with your accountant.
No upfront cost? Consider a PPA
If the capital outlay is the sticking point, a Power Purchase Agreement (PPA) lets a funder install and own the system while you simply buy the cheaper solar electricity it generates — often with no upfront cost. See our guide to funded commercial solar.
Want exact figures for your premises? Try the commercial ROI calculator, see who we’ve worked with, or request a free commercial assessment.
