Commercial solar panels for UK businesses and buildings

Commercial solar panels — also called business solar panels or solar panels for commercial buildings — are photovoltaic systems installed at scale on offices, industrial units, warehouses, retail premises and mixed-use buildings. The technology is mature and the economics are strong: with commercial electricity at roughly 24–28p per kWh in 2026, every unit a building generates and uses on site displaces grid power at full retail price, while surplus is exported under the Smart Export Guarantee. The result is a typical payback of four to eight years and a 25–30 year asset that keeps paying back long after.

What sets a commercial install apart from a domestic one is not the panels — it is the engineering around them: the half-hourly load modelling, the structural and electrical design, the G99 grid connection, and, where the building is let, the lease. That last point is where most installers stop and we begin.

How much do commercial solar panels cost?

Installed cost runs at roughly £700–£1,100 per kWp in 2026 and falls as the system scales — a megawatt array is far cheaper per unit than a 50 kWp one. All figures below are ex-VAT, because the supply and installation of commercial solar has been zero-rated for VAT since April 2022.

Payback is typically four to eight years, shortening to three to five on high-load sites, and the Annual Investment Allowance (100% first-year tax relief up to £1m) plus the business-rates exemption to 2035 sharpen the post-tax figure. Our commercial solar cost guide breaks the numbers down further, and the funding and tax page covers the reliefs.

Solar panels by commercial building type

Every commercial building generates differently. We design and install across all of them:

• Industrial and logistics property — large shed roofs, the lowest cost per kWp, ideal for 250 kWp–1 MWp arrays.
• Office buildings — Monday-to-Friday daytime demand suits solar, with the strongest green-premium evidence.
• Retail parks and retail units — daytime trading plus car-park solar canopies.
• Multi-let commercial buildings — common-parts supply and tenant power-purchase agreements.
• Mixed-use developments — blended landlord, commercial and residential supply.

Owner-occupier or landlord? It changes the economics

If your business owns and occupies its building, commercial solar is the simplest capital project you can run — you keep 100% of the saving and claim the full allowances. If you are a landlord or investor, the picture is different: under a typical lease your tenant pays the energy bills, so the value has to be engineered through the lease. That is the heart of what we do, and it is covered in full in the split incentive solved. Either way, solar lifts your building\'s EPC and protects its lettability under MEES.

How to buy commercial solar panels

The process is the same whether you fund it yourself or through a third party. We start with your half-hourly meter data and a free desk feasibility, follow with a structural and electrical survey and a fixed-price proposal, handle the Class J prior approval and G99 DNO connection, then install and commission — typically a six-to-nine-month programme end to end. We also handle the funding route, from capital purchase with full capital allowances to a third-party-funded roof lease at zero capex. See commercial solar panel installation for the full process.

Solar panels for commercial buildings: what changes by building fabric

Most guides to solar panels for commercial buildings answer the question as if every building were the same box. They are not, and the fabric of the building — not the panel — is what decides whether a scheme is straightforward or expensive. Three things about the building itself govern the outcome: what the roof is made of, how much load it can carry, and how the incoming supply is arranged.

Roof construction. A modern steel-portal unit with a profiled metal deck takes a clamped, non-penetrating system on the seams and is the cheapest case per kWp. A flat membrane roof — single-ply, felt or asphalt, typical of offices and retail — takes a ballasted array that never punctures the waterproofing, preserving the membrane guarantee. An older concrete deck may carry plenty of load but need a bonded or weighted solution. A lightweight or fragile roof (fibre cement, some older industrial sheets, or a thin composite) is where schemes fail: the deck cannot accept conventional ballast, and the honest answer is often a lightweight mounting system, a partial array on the strongest bays, or a car-park canopy instead of the roof. We survey the deck before we design anything.

Structural capacity. Every commercial array needs a structural roof-loading assessment to BS EN 1991. Ballasted flat-roof systems add weight; clamped systems add uplift. Buildings put up to older standards, or with long unsupported spans, sometimes need the array laid out to follow the purlin lines rather than filling the roof. This is also the point at which roof lifecycle matters — if the covering has under 15 years left, the right project is a re-roof and a solar install as a single programme, not solar now and a strip-and-refit later.

The electrical arrangement. Where the incoming supply sits, whether the building is single- or multi-metered, and how much headroom the main switchboard has all shape the design as much as the roof does. On a multi-let building the meter arrangement decides who can actually be sold the power — the point covered in the split incentive solved. Above roughly 50 kW every scheme also needs a G99 connection agreement with the network operator, and that, not planning, is usually the longest lead item.

The practical consequence for an owner is that two buildings with identical floor area can produce very different proposals. That is why we model from the actual roof and the actual half-hourly data rather than a per-square-metre rule of thumb, and why the roof-type guide and the owner's due-diligence guide sit alongside this page. If you want an indicative number before any of that, the commercial solar calculator will give you one in seconds.

Commercial photovoltaic panels: the specifier's vocabulary

Commercial photovoltaic panels and "commercial solar panels" describe the same hardware, but the two phrases tend to come from different people. Owners and finance directors say solar panels. Consulting engineers, building surveyors, EPC assessors and DNO application forms say photovoltaic, or PV. If you are reading a specification, a planning condition or a G99 application, it will be PV — so it is worth knowing what the terms in that document mean before you sign anything.

The module. A commercial PV module is a laminated sheet of monocrystalline silicon cells behind toughened glass, framed in aluminium, rated in watt-peak (Wp) under standard test conditions. Current commercial modules run 400–590 Wp at roughly 20–22% conversion efficiency. A specification will name the module by wattage and cell technology, and the two you will meet most are PERC (the mature mainstream) and TOPCon or HJT (newer n-type cells with slightly better efficiency and lower temperature losses). Efficiency matters less than people expect: it determines how many kWp fit on a given roof, not how much each kWp earns.

The array. Modules are wired in series into strings, and strings are combined into an array. Array size is quoted in kWp — kilowatt-peak — which is the nameplate DC rating, not what the system delivers on an average day. A UK commercial array yields roughly 950 kWh per kWp per year, so a 250 kWp array is a ~237,500 kWh-per-year asset. Any proposal quoting output should show the yield model behind it; ours are PVSyst files and we share them.

The balance of system. The inverter converts DC to AC and is the component that gets replaced once, at around 10–15 years. Mounting is either ballasted (flat roofs, no penetration) or clamped (metal-deck and pitched). Then there is the isolation, protection, metering and the DNO interface — and on anything above roughly 50 kW, the G99 connection agreement that governs how much you are allowed to export.

Commercial rooftop solar versus the alternatives. Rooftop is the default because the roof is already yours, already structurally supported and already next to the load. Ground-mount needs land and usually full planning; a solar carport costs more per kWp because you are buying a steel structure as well as an array, but it turns parking into generation and pairs with EV charging. The comparison is set out in full in rooftop vs ground-mount vs solar carport.

Whatever the document in front of you calls them, the economics are the same and they are governed by self-consumption — see the cost and payback guide, or put your own numbers into the commercial solar calculator.

The panels and inverters we install

We are independent of any single manufacturer, so the specification follows the building and the budget, not a supplier target. On panels we install tier-1 modules — typically AIKO, LONGi, REC, Trina Solar, JA Solar, Jinko and DMEGC — in the 400–590 W range at around 20–22% efficiency, with 25–30 year performance warranties. On inverters we work with SMA, Fronius, SolarEdge, Huawei and Sungrow, sized to the array and the grid connection, and we specify hybrid inverters where a battery is planned. Every proposal names the exact panel and inverter model and shares the PVSyst yield file, so any third party can check the numbers. The "best" commercial solar panel is the one that fits your roof, load and budget and is installed properly — the design and the installer matter more than the badge.

Estimate your numbers

Want a quick figure before you talk to anyone? Our commercial solar calculator estimates the cost, generation, annual saving and payback for any system size in seconds — then send us your half-hourly data and we turn it into a fixed-price proposal.

Commercial solar by sector

A commercial solar array is not a single product bolted onto any building. The economics, the roof, the load profile and the person who benefits all change by sector, and the array should be engineered around those differences rather than a generic kilowatt-per-square-metre rule.

Offices. Investment offices carry the split-incentive problem in its sharpest form: under a full repairing and insuring lease the occupier pays the electricity, so a landlord-owned rooftop array has to be routed through the common-parts supply, a tenant power purchase agreement or a green lease before it earns anything. The prize is real. JLL research on prime London offices associates a strong EPC with materially higher rent and capital value, and MEES makes the EPC a legal precondition for letting at all. See office investment property for the letting-led case.

Industrial and logistics. Large single-let sheds are the strongest fit in the portfolio: expansive flat or shallow-pitch roofs, daytime process and refrigeration loads, and often an owner-occupier or a single covenant tenant who consumes what the roof makes. High self-consumption is what drives the return, and self-consumption is highest here. See industrial and logistics property.

Retail. Retail parks and standalone units combine daytime trading hours with car parking, which opens Class OA solar canopies alongside rooftop capacity. Trading-hours demand aligns well with generation, and a retail park landlord can package the roof across several units. See retail parks and retail property.

Multi-let and mixed-use. Multi-tenanted buildings are the hardest to meter and the most rewarding to solve, because a single roof can serve landlord common parts, several tenant supplies and, in mixed-use, residential demand. The metering and lease structure decide who captures the value. See multi-let commercial buildings and, where you hold several assets, commercial property portfolios.

How commercial solar pays for a property owner

Two revenue lines exist, and they are not equal. The first is self-consumption: every kilowatt-hour the building uses on site displaces grid electricity at roughly 24 to 28p per kWh ex VAT and CCL for a typical commercial user. The second is export: surplus generation sold back under a Smart Export Guarantee tariff earns roughly 12 to 16p per kWh, set by the supplier rather than a fixed government rate. Because the saved import price is nearly double the export price, the single biggest lever on your return is how much of your own generation you use on site rather than sell.

Solar alone typically self-consumes 30 to 50 per cent of what it generates on a daytime commercial load. Adding battery storage lifts that to 60 to 80 per cent, and a genuine 24/7 operation such as cold storage or a data-adjacent facility can reach 90 to 95 per cent. That is why two identical arrays on two different buildings produce very different paybacks, and why any credible proposal models your actual half-hourly consumption rather than an annual total.

On top of the energy saving sits a tax stack that a property owner should not overlook. Solar equipment is a special-rate asset, so it does not qualify for full expensing, but it does attract 100 per cent relief in year one through the Annual Investment Allowance up to the current £1m limit. Capital allowances reduce taxable profit, so the cash benefit is approximately the qualifying spend multiplied by your tax rate. Business rates on solar are exempt to 2035, and since April 2022 the supply and installation qualifies for 0 per cent VAT. Assets bought specifically to lease follow a different route using AIA and 6 per cent writing-down allowances, so the ownership structure matters. Take professional advice on the tax position for your entity.

To size the two revenue lines against a real roof and a real bill, use the commercial solar calculator, then set the numbers against installed prices on the cost page, where system prices run from around £35,000 to £60,000 at 50kWp up to £700,000 to £900,000 for a megawatt, with payback typically between four and eight years and faster on high-load sites.

Owning vs leasing the array

How you fund the system changes who owns the asset, who claims the allowances and who carries the risk. There are three broad routes, and the right one depends on your balance sheet, your tax position and whether you occupy or let the building.

Cash plus AIA. Buying the array outright gives you every kilowatt-hour saved, the full Annual Investment Allowance relief and an asset on your balance sheet. For an owner-occupier or a cash-rich investor this produces the best lifetime return, because there is no finance cost eroding the energy saving and the capital allowance lands in year one. The trade-off is the upfront capital and the opportunity cost of that cash.

Asset finance. A lease or loan spreads the cost so the array is funded from the energy saving it creates, which protects working capital and can make the project cash-positive from the outset. The finance structure determines whether you or the lender claims the allowances, and interest reduces the net return, so the comparison is against cash rather than against doing nothing. This route suits owners who would rather deploy capital elsewhere in the portfolio.

Sell the roof. A third party funds, owns and operates the array and either pays you rent for the roof or sells power to the building under a power purchase agreement. You put in no capital and carry no maintenance risk, but you forgo the allowances and most of the energy saving. For a landlord who cannot easily reach the tenant supply, or who wants an EPC improvement without capital outlay, this can still be the sensible answer. Weigh the routes on the commercial solar finance options guide, and work through roof lease against PPA against licence in roof lease vs PPA vs licence.

Why choose a commercial property solar specialist

Commercial rooftop solar sits at the intersection of engineering, tax and property law, and the sites that go wrong tend to fail on the parts a domestic installer never has to think about. A specialist earns their place on four fronts.

Accreditation and compliance. Look for MCS certification, NICEIC or equivalent electrical registration, and RECC or TrustMark membership. These are not badges; they govern warranty validity, DNO acceptance and, on public-sector or funded work, eligibility. A G99 application to the network operator is the real bottleneck above roughly 50kW, and getting it right the first time protects the programme.

Half-hourly modelling. The difference between a four-year and an eight-year payback is self-consumption, and self-consumption can only be modelled from your half-hourly meter data, not an annual kWh figure. A specialist pulls that data, matches generation to load profile hour by hour and sizes the array, and any battery, to the demand that is actually there.

Yield engineering. Production forecasts should come from PVSyst or an equivalent modelling package that accounts for orientation, shading, panel degradation and inverter losses, not a rule of thumb. On flat roofs the design has to be ballasted to preserve the membrane warranty, and a structural survey to BS EN 1991 is a precondition, not an afterthought.

Lease engineering. For a property owner the array is only half the project; the other half is the legal structure that decides who captures the value. A specialist who understands MEES, the split incentive, green leases and power purchase agreements can engineer the lease so the roof pays, rather than leaving a landlord-owned array stranded on a tenant-metered building. That is the difference between a solar company and a commercial property solar specialist. Ready to start with your own numbers, request a quote.