Commercial solar panels in the UK — what they cost, what they pay back, and how to fund them now.
UK commercial solar PV is now a £540–£1,100 per kWp installed asset class with 4–6 year payback after the active 2026 funding stack. This guide is the operator-facing reality check: live capex benchmarks, sector-by-sector system sizing, the funding routes that still work after IETF and PSDS closed, and what to ask installers before signing.
We are an independent commercial-solar funding specialist — we take no installer commission and sell no panels or export tariffs, so the cost, payback, SEG and grant tables below are honest cross-market data, not a pitch. Every figure is indicative UK 2026; confirm specifics for your site before signing.
What "commercial solar panels" actually means in the UK in 2026
"Commercial solar panels" usually means a Tier 1 mono-crystalline silicon photovoltaic module — typically 440–460Wp — mounted on the roof or land of a commercial property and connected to the building's electrical supply via inverters and a G99 DNO connection. The dominant module manufacturers in the UK commercial market in 2026 are Trina Solar, JA Solar, Jinko Solar and Longi, all selling Tier 1 modules with 25–30 year linear performance warranties at module-level pricing of around 9–12p per Wp ex-works.
What separates a "commercial" install from a domestic one is the project scale, the connection requirements, the financial structure and the regulatory regime. Commercial systems are typically 50kWp+ (often 250–500kWp for a mid-sized business), require a G99 application to the local DNO instead of the simpler G98 process, qualify for different grants and tax allowances, and are normally designed to MCS commercial standards (MCS 020 and equivalent) rather than the residential MCS 002. The financial case is also different — commercial sites generally have stronger daytime self-consumption, exposing more of the generation to displacement of higher-priced grid electricity rather than lower-paying SEG export.
Cost benchmarks — May 2026
Based on our last six months of UK commercial solar projects:
- 50 kWp — £42,500–£55,000 (£850–£1,100/kWp) — small office, agricultural barn, retail unit
- 100 kWp — £75,000–£95,000 (£750–£950/kWp) — medium SME, small school, hotel
- 250 kWp — £165,000–£210,000 (£660–£840/kWp) — mid factory, large school, hospital ward
- 500 kWp — £295,000–£380,000 (£590–£760/kWp) — large factory, multi-academy trust, NHS site
- 1 MWp — £540,000–£720,000 (£540–£720/kWp) — major industrial, large NHS trust, distribution centre
- 2 MWp+ — £525–£700/kWp — heavy industry, large logistics hub, ground-mount
These are turnkey numbers including panels, inverters, mounting, DNO connection, design, install, commissioning and insurance-backed warranty. They exclude battery storage (£350–£550/kWh), EV charging integration, and any remediation works (asbestos, structural reinforcement, roof replacement). For the full cost-stack breakdown see the cost guide.
How much do commercial solar panels cost in 2026?
The table below benchmarks commercial solar panels cost in 2026 by system-size band — the £/kWp installed rate, total turnkey install cost, the roof area you need and indicative annual generation. This is the single figure most quotes bury; we publish it openly because we sell no panels. Note the economy of scale: £/kWp roughly halves between a 10kWp and a 1MWp system. Generation assumes ~900 kWh per kWp per year for a well-oriented UK roof.
| System size (kWp) | Typical £/kWp installed | Total install cost range | Roof area needed | Indicative annual generation | Typical fit |
|---|---|---|---|---|---|
| 10 kWp | £900–£1,150 | £9,000–£11,500 | ~25 m² | ~9,000 kWh | Small office / retail unit |
| 30 kWp | £850–£1,050 | £25,500–£31,500 | ~75 m² | ~27,000 kWh | Shop, small workshop |
| 50 kWp | £850–£1,100 | £42,500–£55,000 | ~125 m² | ~45,000 kWh | Office, agricultural barn |
| 100 kWp | £750–£950 | £75,000–£95,000 | ~250 m² | ~90,000 kWh | Medium SME, small school, hotel |
| 250 kWp | £660–£840 | £165,000–£210,000 | ~625 m² | ~225,000 kWh | Mid factory, large school |
| 500 kWp | £590–£760 | £295,000–£380,000 | ~1,250 m² | ~450,000 kWh | Large factory, NHS site |
| 1 MWp+ | £540–£720 | £540,000–£720,000 | ~2,500 m²+ | ~900,000 kWh | Heavy industry, logistics hub |
Indicative UK 2026 turnkey figures (panels, inverters, mounting, DNO connection, design, install, commissioning, IBW). Excludes battery storage, remediation and grid-reinforcement charges. After Full Expensing (25% effective tax saving) and 0% VAT, effective capex is roughly 60% of the headline total. Confirm a costed figure for your roof via our cost calculator or a free funding review.
Commercial solar payback — a worked example
Octopus and the supplier pages mention payback but show no maths. Here is a transparent build-up for a 100kWp commercial solar system on a daytime-load site, with every line shown so you can swap in your own numbers:
Indicative worked example for illustration. Assumes a UK-incorporated, corporation-tax-paying company able to use Full Expensing, 65% self-consumption, a 24p/kWh import price and a 12p SEG export rate. Real payback typically lands at 4–6 years once you allow for O&M, inverter replacement, lower self-consumption or a lower SEG rate. Send half-hourly data for a site-specific model.
Commercial solar modules — panel types & specs explained
The commercial solar modules on a 2026 UK rooftop are Tier 1 silicon, but the cell technology drives both the wattage and the lifetime yield. Competitors treat panels as a black box; the table below compares the four module types a commercial buyer actually chooses between, with commercial wattages, efficiency, degradation/warranty and best-fit roof.
| Module type | Commercial wattage | Efficiency | Degradation / warranty | Best-fit roof |
|---|---|---|---|---|
| Mono-PERC | 450–550W | 20–21.5% | ~0.55%/yr, 25yr | Pitched & flat rooftop — the volume default |
| TOPCon (n-type) | 480–620W | 21.5–23% | ~0.40%/yr, 30yr | Premium rooftop — best £/kWh over life |
| Bifacial | 500–620W | 21–23% (front) | ~0.40%/yr, 30yr | Flat roof, carport & ground-mount (rear gain) |
| Thin-film | 350–450W | 13–16% | ~0.50%/yr | Lightweight / low-load roofs where weight is the constraint |
Indicative 2026 commercial module specs. TOPCon n-type now leads new commercial specs on lifetime £/kWh; bifacial adds 5–15% rear-side gain on reflective flat roofs, carports and ground-mount. Mounting choices — flat-roof ballast, pitched, ground-mount and solar carport — affect panel count and yield as much as the cell type.
The 2026 funding stack for commercial solar
This changed materially during 2024–2026. The major direct grants — IETF Phase 3 for manufacturing, PSDS Phase 4 for public sector, UKSPF for SMEs — all closed to new applications. The remaining active stack:
- Full Expensing — 100% first-year tax relief on solar plant for any UK incorporated company, effective 25p of corporation tax saved per £1 of capex. No application required. Always available.
- 0% VAT on commercial solar — extended from domestic to commercial, applied at quote stage by the installer.
- Smart Export Guarantee (SEG) — pays for surplus exports at 5–18p/kWh standard tariffs, 25–40p/kWh peak on dynamic tariffs.
- Power Purchase Agreements (PPA) — zero capex, third-party-funded, 6–9p/kWh below grid prices.
- REPF — for rural businesses, council-administered, up to 40% capex.
- Local Growth Fund — 11 Mayoral Authority areas only, replaces UKSPF.
- Salix interest-free loans — public sector, repaid from energy savings.
- Scottish IETF — Scottish manufacturers only.
Stacked properly — typically Full Expensing + 0% VAT + SEG, with a PPA layered for zero-capex sites — this delivers 4–6 year payback for most UK commercial solar projects.
2026 commercial solar funding & grants — what's open vs closed
There is no single national commercial solar grant, and the much-repeated "FETF 40%" figure is a myth — that scheme never funded commercial solar. The honest 2026 picture is a capital-allowance-led stack worth 25–40% by nation, with a handful of genuine grants that are nation-specific. We can publish this straight because we take no commission and don't need to pretend a closed scheme is still open. Internally link through to the commercial solar panel grants hub and the nation pages for application detail.
| Scheme | Nation | Type | %-of-capex / relief value | Open in 2026? |
|---|---|---|---|---|
| Full Expensing | UK-wide | Capital allowance | 100% FYA — 25% effective tax saving | Open — no application |
| Annual Investment Allowance (AIA) | UK-wide | Capital allowance | 100% relief up to £1m/yr | Open — no application |
| 0% VAT on commercial solar | UK-wide | Tax relief | ~17% of inc-VAT cost saved | Open — applied at quote |
| REPF (Rural England Prosperity Fund) | England (rural) | Grant | Up to 40% of capex | Open — council-administered |
| Local Growth Fund | England (Mayoral areas) | Grant | Varies by authority | Open — 11 areas only |
| Business Energy Scotland SME loan | Scotland | Interest-free loan + cashback | Loan + up to 75% cashback (capped) | Open |
| SIETF (Scottish IETF) | Scotland | Grant | Project-specific | Open — manufacturers |
| Development Bank of Wales / Welsh decarbonisation | Wales | Loan / grant | Project-specific | Open |
| Invest NI | Northern Ireland | Grant / support | Project-specific | Open |
| Salix interest-free loans | UK public sector | Interest-free loan | Repaid from energy savings | Open — public sector only |
| English IETF | England | Grant | Was up to 30% | CLOSED to new applications |
| PSDS Phase 4 | England public sector | Grant | Was up to 100% | CLOSED to new applications |
Indicative 2026 position; scheme windows and values change — confirm before relying on any figure. England commercial solar funding is Full Expensing / AIA-led, not FETF. REPF supports rural businesses up to 40%. English IETF and PSDS Phase 4 are closed to new applications; Salix covers public-sector bodies. We prepare and lodge the application for you.
2026 SEG export rates compared
Surplus generation is sold under the Smart Export Guarantee. Suppliers with 150,000+ customers must offer a tariff above 0p, the system must be MCS-certified and under 5MW, and you need half-hourly export metering. Because we sell no tariffs, here is the independent named-supplier comparison Octopus can't publish (it only pitches its own). See our EDF SEG, Octopus SEG and British Gas SEG deep-dives for detail.
| Supplier / tariff | Export rate (p/kWh) | Dynamic / peak | Customer required? |
|---|---|---|---|
| Octopus Outgoing Fixed | 15p flat | Flux peak ~30p | Octopus import required |
| Octopus Outgoing Agile | 14–18p avg (dynamic) | Peaks 25–40p | Octopus import required |
| EDF Export Standard | 12p flat | Variable 12–18p banded | SEG-only available — no import switch |
| ScottishPower SmartGen+ | ~12p | — | ScottishPower import required |
| British Gas Export & Earn Plus | 6.4p | — | British Gas import required |
| E.ON Next Export | ~5.5p | — | E.ON import required |
| OVO SEG | ~5p | — | OVO import required |
| Shell Energy | ~3.5p | — | Open — no account needed |
Indicative 2026 SEG rates for comparison; confirm current figures with each supplier before switching. Top fixed rates are usually gated behind that supplier's import contract; EDF Export Standard is the highest-paying rate available SEG-only without an import switch. See the full SEG comparison.
Commercial vs domestic solar — what's different
Commercial solar panels use the same silicon modules as a home array but sit inside a different connection, metering, tax and planning regime. The differences below are the buyer-education gap none of the supplier pages cover:
- Three-phase supply — commercial sites are usually three-phase, so inverter selection and balancing differ from a single-phase domestic install.
- DNO G99 application — commercial systems (50kWp+) require a G99 connection application to the local DNO, not the simpler domestic G98 notification; this is the long pole at 60–110 working days.
- Half-hourly export metering — commercial export is settled on half-hourly metering rather than the deemed-export estimate common on small domestic systems.
- VAT & business rates — 0% VAT applies to commercial installs; rooftop solar is generally exempt from a business-rates uplift, unlike a standalone generating station.
- Capital allowances — businesses fund through Full Expensing and the AIA rather than household incentives; the asset is depreciated against corporation tax.
- Permitted development — most commercial rooftop solar is permitted development, but listed buildings, conservation areas, airport glint-and-glare zones and ground-mount over 1MW need planning.
How to fund commercial solar: cash vs lease vs PPA vs roof rental
The ownership decision changes who pays upfront, who owns the asset, who keeps the SEG income and what your payback looks like. The sellers won't lay this out neutrally — we will:
| Model | Upfront cost | Who owns the asset | Who gets SEG income | Payback impact |
|---|---|---|---|---|
| Cash purchase | Full capex upfront | You own the asset | You keep all SEG income | Best lifetime return; 4–6yr post-funding |
| Asset finance / lease | Low / nil deposit | You own at term end (lease/HP) | You keep SEG; finance cost offsets | Cash-flow positive from day one; higher total cost |
| Commercial PPA | Zero capex | Third party owns the system | Funder keeps SEG; you buy power at 6–9p below grid | No payback — you pay per kWh used |
| Roof rental | Zero capex (you receive rent) | Third party owns & operates | Operator keeps generation & SEG | Rental income only; no energy bill saving |
Cash purchase gives the best lifetime return for tax-paying companies that can use Full Expensing; a PPA suits zero-capex sites willing to forgo asset ownership. We model all four against your balance sheet before recommending one.
How to apply for commercial solar funding — step by step
As independent funding specialists this is the part we handle for clients: we identify every allowance and grant you qualify for, then prepare and lodge the applications. The process runs in a predictable order.
- Establish eligible spend and demand profile — pull 12 months of half-hourly meter data and confirm your business structure so we can size the array and match funding.
- Apply the capital-allowance stack — claim Full Expensing or the AIA on the solar plant and confirm 0% VAT at quote stage; these need no separate application and provide most of the funding.
- Identify and apply for nation-specific grants — REPF (rural England), Business Energy Scotland or SIETF (Scotland), Welsh decarbonisation funding, Invest NI, or Salix (public sector) — submitted before the scheme window closes.
- Choose the ownership model — cash, asset finance/lease, commercial PPA or roof rental, based on your cash-flow and balance-sheet position.
- Submit the DNO G99 application and install — lodge G99 early (60–110 working days), then install, commission and register for the SEG to monetise export.
Sector-by-sector commercial solar economics
UK commercial solar economics vary by sector because demand profiles, electricity unit rates, roof inventory and grant eligibility all differ:
- Manufacturing — 300–2,000 kWp typical, IETF closed but Full Expensing + PPA + SEG remain. Strong daytime self-consumption.
- Farms & agriculture — 100–800 kWp, REPF still active, 5–7 year payback.
- Schools & academies — 100–350 kWp per school, PSDS closed, Salix loans + LCSF remain.
- NHS & healthcare — 250 kWp – 3 MWp, PSDS closed, Salix loans + PPAs remain active.
- Hotels — 100–600 kWp, Full Expensing + PPA dominant.
- Warehousing & logistics — 500 kWp – 5 MWp, dominant PPA market.
- Retail parks & stores — 200 kWp – 1.5 MWp, PPA + Full Expensing + solar canopies.
- Offices & business parks — 100–500 kWp, BREEAM credit value drives the case.
What to ask any commercial solar installer before signing
Five questions that catch most overpriced or undersized quotes:
- What is the panel + inverter line on your quote, separately from BOS? Together these should be 50–55% of total quote. Higher than that, you're being marked-up.
- Have you submitted the G99 application yet? If not, ask for written confirmation of expected DNO costs before contracts. UK DNO non-contestable charges have hit £8k–£180k unexpectedly — always quoted up front by responsible installers.
- Is 0% VAT applied to the install? Some installers default to 20% VAT on commercial — explicit ask required.
- Is the system size matched to my actual half-hourly demand profile? Generic installer "fill the roof" quotes often oversize, collapsing self-consumption. Ask to see the modelled self-consumption rate.
- What does the Insurance-Backed Warranty cover? IBW is required for grant-funded routes and is a quality signal even outside grants. Should be a separate line on the quote.
Battery storage with commercial solar
Adding battery storage to a commercial solar system typically adds £350–£550 per kWh of capacity to capex but lifts self-consumption by 15–25 percentage points. For sites with strong evening peaks (hotels, retail, offices) or 24/7 process loads (refrigeration, manufacturing), the battery-augmented economics often pay back faster than solar alone. For weekend-empty sites (schools, weekday-only offices), the battery economics are weaker. See our battery storage analysis for the sector-by-sector view.
For the full £/kWp breakdown by system size, see the commercial solar installation cost guide. For sector-by-sector payback benchmarks with and without the 2026 grant stack, see the commercial solar payback period guide.
Related commercial solar guides
Commercial solar panel FAQs
How much do commercial solar panels cost in the UK?
What is the typical payback period for commercial solar panels?
Are commercial solar panels worth it now that IETF and PSDS are closed?
How big a commercial solar panel system do I need?
Do I need planning permission for commercial solar panels?
How long does it take to install commercial solar panels?
How much do commercial solar panels cost in 2026?
Are commercial solar panels worth it for a business?
What size commercial solar panel system does my business need?
What is the difference between commercial and domestic solar panels?
How many solar panels can a commercial roof hold?
How long do commercial solar panels last?
Is there a grant for commercial solar panels in 2026?
Operators who have run the numbers and proceeded.
Real comments from operators we have funded. Names and roles published with consent; some company names withheld where the project is in active grant clawback period or pending public announcement.
"Daniel and the team rebuilt our solar project as an integrated decarbonisation package and walked us through the IETF scoring before we wrote a line. The £142k grant award was the difference between an internal hurdle miss and a board-approved capex. Honest, technical, and zero fluff."
"Priya understood public sector procurement better than our framework consultants. We secured 100% PSDS funding across six schools with no trust capex contribution — exactly what the bursary team needed to see. They came in early enough to do the HDP properly, and that bought the award."
"The REPF productivity narrative they wrote was a different category from anything I'd seen from other consultants. They turned a generic decarbonisation pitch into a jobs-and-contract-drying story that the council's economic development team scored top of pile. £62k of grant on a project I assumed wasn't fundable."
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