Commercial Property Solar: 2026 Cost & Payback

What solar panels for commercial property actually cost in 2026

If you own or manage commercial stock, the first question is almost always the same: what will solar panels for commercial property cost, and how long before the roof pays for itself? This guide sets out the 2026 numbers, and it separates the two financial lenses that matter for property, the owner-occupier who pays the electricity bill, and the landlord whose return shows up in EPC band, lettability and asset value rather than in a lower bill.

The headline is that a commercial install in the UK runs from roughly £20,000 for a small office array of around 25 kW to about £225,000 for a large light industrial roof near 250 kW. The single most useful number is cost per installed kilowatt, because it lets you scale a quote to your own roof. Below 100 kW that figure typically sits at £900 to £1,300 per kW, and on larger roofs above 200 kW it falls toward £750 to £950 per kW. In other words, a bigger roof buys cheaper generation, which is why a portfolio owner should think in terms of the whole estate rather than one building at a time.

Why cost per kW falls as the roof gets bigger

The fixed costs of a commercial project, access and scaffold, the DNO application, design and modelling, commissioning and certification, are broadly similar whether you fit 30 kW or 200 kW. Spread them across more panels and the per-kW figure drops, while the variable costs of panels, mounting and cabling scale roughly linearly. For a landlord weighing several units, this is the argument for a coordinated rollout: the larger industrial roof effectively subsidises the smaller office array next door.

Worked illustrative examples by building type

These are illustrative figures drawn from typical UK commercial projects, not quotes. Your own numbers depend on roof, load profile, tariff and lease structure.

• Office, 30 to 150 kW. Project value in the region of £30,000 to £150,000, generating roughly 27,000 to 138,000 kWh a year. Daytime occupancy lines up well with generation, so self-consumption is healthy, though quiet weekends push payback a little longer than a round-the-clock site.
• Light industrial unit, 50 to 250 kW. Project value around £45,000 to £225,000, generating roughly 46,000 to 230,000 kWh. Broad steel-portal roofs suit clip-fix mounting and the high daytime baseload from process loads, HVAC and EV charging means strong self-consumption.
• Mixed-use commercial, 40 to 200 kW. Project value around £36,000 to £180,000. The complication here is multiple meters and multiple tenants, which we cover under funding and leases below.

If you want to size a system against your own annual spend rather than guess from these bands, our savings calculator gives a quick first-pass estimate, and the full cost guide sets out worked numbers in more detail.

Payback: the number that depends on who you are

Simple payback for most UK commercial buildings lands at 5 to 8 years, and where you sit in that range is driven almost entirely by your load shape. A daytime-heavy, high-baseload unit such as a manufacturer or busy showroom uses most of what the roof makes on site, where each kilowatt-hour is worth four or five times more than exported power, so it sits at the faster end. An office that empties at weekends self-consumes less and pushes payback toward 7 to 9 years.

Adding battery storage changes the picture. A battery typically extends simple payback by two to three years because of the upfront cost, but it can lift annual savings by 25 to 40% by shifting daytime generation into evening and weekend use. For buildings with meaningful night or weekend baseload it can be worth it, and even where it is not justified today, every system should be designed to be battery-retrofittable so the decision can wait for a year of real generation data.

The landlord and tenant split

For commercial property, the crucial subtlety is who actually captures the saving. In an owner-occupied building the answer is simple: the occupier pays the bill and banks the reduction, so payback is a clean cash calculation. On a let building it is not. If the tenant pays the electricity and the landlord funds the panels, the bill saving flows to the tenant while the cost sits with the owner, unless the lease is structured to share it. This is why solar on let property is as much a leasing question as an engineering one, and why a green-lease addendum or a service-charge mechanism usually needs to sit alongside the install. We return to this under funding.

What the landlord gets instead of a bill saving

A landlord who cannot capture the bill saving directly still has a strong case, because the return shows up in the asset rather than the energy account. Solar lifts the EPC rating, commonly moving a building from a band D to a C or a C to a B. That matters under Minimum Energy Efficiency Standards, which already bar the letting of the worst-rated non-domestic property and are set to tighten toward band C by 2027 and band B by 2030. A building that cannot meet the standard cannot be let, and a building that cannot be let has lost value, so the panels protect both the income stream and the capital value. On top of that, commercial premises with PV installed commonly see an illustrative 5 to 15% uplift in value, and the array improves kerb appeal and the ESG story that institutional buyers and corporate tenants increasingly ask about.

The tax lever that changes the real cost

The biggest single influence on what a commercial array really costs is not the quote, it is the tax treatment. Since an array counts as plant and machinery, a profitable company can use the 100% Annual Investment Allowance to offset the entire capital cost against the taxable profit of the purchase year, with the allowance’s generous annual ceiling comfortably exceeding what most commercial installs cost.

For a profitable limited company, the illustrative effect is a saving worth roughly a quarter of the project value against current corporation tax rates. On an £80,000 install that is in the region of £20,000 of relief, taking the effective net cost to about £60,000, a discount funded by HMRC rather than the installer. Sole traders and partnerships on the cash basis can access similar reliefs. These figures are illustrative because the benefit depends on your profit, entity type and structure, so our finance team confirms the right route with your accountant. You can read the detail in HMRC’s guidance on capital allowances, and the funding routes are set out in full on our grants and funding page.

Don’t forget export income

Whatever the building does not use is exported, and the Smart Export Guarantee pays for it at rates in the 4 to 15p per kWh range as of 2026. That income is modest compared with the value of self-consumed power, but it matters most for exactly the buildings with the longer paybacks, offices and retail that empty at weekends and export 25 to 45% of what they generate. Folding export income into the model can shave several months off the payback on those assets.

How the numbers come together

Put the pieces in order and the real cost of solar panels for commercial property is rarely the headline quote. Start with the per-kW figure for your roof size, apply the Annual Investment Allowance to find the net-of-tax cost, then set that against a bill saving driven by your self-consumption, with a modest export income on top. For an owner-occupier the result is a 5 to 8 year payback and decades of cheaper power behind it. For a landlord the bill saving may sit with the tenant, but the EPC uplift, MEES compliance and the protection of lettable value and asset price make the case in their own right.

The honest answer to “what will it cost” is that it depends on your building, which is why every credible figure should come from your own half-hourly meter data and a real roof assessment. To explore building-type specifics, our light industrial units page goes deeper on the fastest-payback commercial roofs. When you are ready, run a first pass on the savings calculator and then request a free feasibility modelled from your meter data.