Commercial solar panels cost UK 2026 — the £/kWp guide
UK commercial solar has never been cheaper per kWp. Panel prices have fallen 40% since 2022, inverter supply has normalised and installer capacity has scaled up to meet demand. This guide gives 2026 benchmark pricing by system size, a full CapEx breakdown, what's included in a like-for-like quote, and how Full Expensing changes the net cost for a limited company.
By the Solar Britain commercial team · Published 20 July 2026.
Short answer
In 2026, commercial solar in the UK costs roughly £650–£1,100 per kWp installed before tax relief. A 100 kWp system is around £85–£98k; a 500 kWp system is £360–£410k; a 1 MWp system is £680–£780k. Full Expensing returns 25p on the £ for limited companies, taking effective net CapEx down by around 25%. Payback is typically 4–7 years at 2026 grid prices.
2026 UK commercial solar price benchmarks
Ranges below are all-in installed prices for standard rooftop installations on structurally sound commercial buildings with a simple G99 grid connection. Ground-mount, HV connections and unusual roof types are priced separately.
| System size | Installed CapEx | £/kWp | Year-1 saving | Payback |
|---|---|---|---|---|
| 50 kWp | £47,500 – £55,000 | £950 – £1,100 | £9,500 – £12,000 | 4.5 – 6 yrs |
| 100 kWp | £85,000 – £98,000 | £850 – £980 | £19,000 – £24,000 | 4 – 5.5 yrs |
| 250 kWp | £190,000 – £215,000 | £760 – £860 | £48,000 – £60,000 | 3.8 – 5 yrs |
| 500 kWp | £360,000 – £410,000 | £720 – £820 | £95,000 – £120,000 | 3.5 – 4.5 yrs |
| 1 MWp | £680,000 – £780,000 | £680 – £780 | £190,000 – £235,000 | 3.5 – 4.5 yrs |
| 2 MWp | £1.3m – £1.5m | £650 – £750 | £380,000 – £465,000 | 3.5 – 4.5 yrs |
Year-1 savings assume 70%+ daytime self-consumption at a 26p/kWh blended import rate. Use the calculator to model your own tariff and load profile.
What's inside the price — the CapEx breakdown
On a typical UK 500 kWp commercial rooftop install, the CapEx splits roughly as follows:
PV modules (panels)
30–35%Tier 1 mono-PERC or TOPCon modules from Longi, Jinko, Trina or Canadian Solar. 25–30 year linear performance warranty.
Inverters
10–12%String inverters from SMA, Huawei, Sungrow or Solis. 10–12 year warranty as standard. DC-coupled or hybrid to allow future battery add-on.
Mounting and BoS
12–15%Roof rails, clamps, DC cabling, AC cabling, isolators and monitoring hardware. Aluminium and stainless-steel components rated for 25+ years.
Structural and roof survey
2–3%Chartered structural engineer sign-off on point-load and wind uplift, plus a roof condition report to confirm 20+ years of remaining life.
Design and DNO application
3–5%Detailed electrical design, G99 (or G100 with limitation) application to the local DNO, permitted-development check.
Install labour and safety
18–22%MCS-accredited or NAPIT-registered installers, RAMS, scaffolding or MEWPs, plant hire. Typically 4–10 weeks on site for 250 kWp–1 MWp.
Commissioning and handover
2–3%DC/AC testing, DNO witness where required, monitoring portal setup, O&M pack and training.
Contingency and profit
10–15%Installer margin, contingency for grid works, temporary works and variations.
What drives the price up or down
- System size — bigger arrays get a lower £/kWp because fixed costs (scaffolding, DNO application, mobilisation) are spread over more panels.
- Roof type — standing-seam metal roofs are cheapest to fix to; fragile fibre-cement or ageing built-up-felt roofs need extra work and drive cost.
- Access — sites with easy MEWP or telehandler access install faster; awkward roofs with scaffolding requirements add 5–10%.
- Grid connection — a simple G99 to a DNO with capacity is included; a full HV connection or a new substation can add £30,000–£150,000.
- Structural upgrades — some older sheds need purlin reinforcement, which is priced separately.
- Battery storage — a co-installed battery adds roughly £400–£600/kWh of usable capacity, quoted separately.
Full Expensing — the 25% tax reduction
Full Expensing was made permanent in the 2024 Autumn Statement. A limited company installing qualifying solar plant on a commercial building deducts 100% of the CapEx from taxable profits in the year of installation. At the 25% main corporation tax rate that cuts 25p out of every £1 spent — effectively an instant discount on the sticker price.
| Gross CapEx | Tax deduction (25%) | Net cost after tax |
|---|---|---|
| £100,000 | £25,000 | £75,000 |
| £250,000 | £62,500 | £187,500 |
| £500,000 | £125,000 | £375,000 |
| £1,000,000 | £250,000 | £750,000 |
Full Expensing rules apply to limited companies. Unincorporated businesses use the Annual Investment Allowance (AIA) at £1,000,000 per year — very similar cash effect for most SMEs. Always confirm with your accountant.
Zero-upfront alternatives
If CapEx isn't right for your business, three routes remove the upfront cost entirely:
- Solar PPA — funder installs and owns the array; you buy power at a fixed 20–40% discount to grid. Read the PPA guide.
- Asset finance / lease — 5–10 year monthly repayments; you own the asset at end of term. See funding options.
- Grants — sector-specific and regional grants (SME Boost, agricultural, LCSF for public sector). Full list on the grants and funding page.
Related reading
FAQ — commercial solar pricing
How much do commercial solar panels cost in the UK in 2026?
UK commercial solar CapEx in 2026 is typically £650–£1,100 per kWp installed, before tax relief. A 100 kWp system costs around £85,000–£98,000; a 500 kWp system is £360,000–£410,000; a 1 MWp system is £680,000–£780,000. Larger systems drop below £700/kWp because fixed costs are spread over more panels.
How much do commercial solar panels cost for a business after tax relief?
Under Full Expensing, a limited company deducts 100% of qualifying CapEx from taxable profits in the year of installation. At the 25% corporation tax rate that returns 25p per £1 spent — so a £400,000 array has an effective net cost of £300,000 after tax relief.
What is included in a commercial solar quote?
A complete UK commercial solar quote should include: MCS/NAPIT-accredited design and install, Tier 1 modules and inverters, structural survey, DNO application (G99 or G100), scaffolding/MEWP hire, all AC and DC works, remote monitoring, commissioning, 25-year performance warranty on modules and 10–12 years on inverters. Anything less isn't a like-for-like quote.
How much does a 250 kWp commercial solar system cost in the UK?
A 250 kWp rooftop system typically costs £190,000–£215,000 installed in 2026, delivering roughly £48,000–£60,000 in year-one savings on a site with 70%+ daytime self-consumption. Full Expensing brings the effective net CapEx down to £145,000–£165,000 for a limited company.
What is the cost per kWh of commercial solar over its lifetime?
Lifetime unit cost — total CapEx divided by expected 25-year generation — is typically 3.5–5p/kWh for a well-sized UK commercial array. That compares to a 2025 UK non-domestic grid average of around 26p/kWh.
Can I get commercial solar with no upfront cost?
Yes. A UK commercial Power Purchase Agreement (PPA) removes all upfront cost — the funder pays 100% of the CapEx and you buy the generated power at a fixed 20–40% discount to your current grid rate for 15–25 years. Asset finance and operating leases spread the CapEx over 5–10 years of monthly repayments.
How long do commercial solar panels take to pay back in the UK?
At 2026 grid prices, most UK commercial solar systems pay back in 4–7 years. Payback shortens as system size grows, as daytime self-consumption rises and as the site's grid tariff rises. After Full Expensing, sub-5-year paybacks are typical for 250 kWp+ systems.
Are commercial solar panels cheaper than they used to be?
Yes. UK commercial solar CapEx has fallen roughly 40% since 2022, driven by cheaper Chinese module manufacturing, cheaper inverters and industry consolidation. Even with UK inflation on labour, all-in £/kWp is at a historic low.
Get an indicative price for your site
Two minutes in the calculator gives an indicative system size, CapEx range, Full Expensing relief and payback for your building.