How much does commercial solar cost in 2026?
Real UK prices by system size, and the point most cost guides miss: the funding route decides what you actually pay upfront.
Commercial solar cost by system size
Indicative installed cost, cost per kWp and simple payback for typical commercial system sizes. Larger systems cost less per kWp. Payback shown before tax relief; the Annual Investment Allowance usually shortens it.
| System size | Typical use | Installed cost | Per kWp | Annual saving | Simple payback |
|---|---|---|---|---|---|
| 30 kWp | Small unit / small SME | £27,000 to £33,000 | ~£1,000 | £6,000 to £8,500 | 4 to 6 yrs |
| 50 kWp | SME / small warehouse | £43,000 to £52,000 | ~£950 | £10,000 to £14,000 | 4 to 6 yrs |
| 100 kWp | Warehouse / office | £78,000 to £92,000 | ~£850 | £20,000 to £27,000 | 3.5 to 6 yrs |
| 250 kWp | Mid-size industrial | £185,000 to £215,000 | ~£800 | £50,000 to £66,000 | 3.5 to 6 yrs |
| 500 kWp | Large industrial | £350,000 to £425,000 | ~£775 | £100,000 to £130,000 | 3.5 to 6 yrs |
| 1 MWp | Large / ground-mount | £650,000 to £850,000 | ~£750 | £200,000 to £260,000 | 3.5 to 6 yrs |
Indicative 2026 ranges. Assumes about 950 kWh per kWp a year and 60 to 80% self-consumption; actual figures depend on roof, orientation, shading, load profile and tariff. Savings gross of tax relief. Last updated July 2026.
The sticker cost is not what you pay upfront
That £80,000 for a 100 kWp system is the capital cost of owning it outright. How much you actually pay on day one depends entirely on the funding route. Buy outright and you pay it all, but claim up to 100% first-year tax relief and keep every saving. Finance it on hire purchase, asset finance or a green loan and you spread it over three to fifteen years while still owning the system. Or take a PPA and pay nothing upfront at all, buying the power instead.
What actually drives the cost of a commercial solar system
The figures in the cost ladder above are a useful starting point, but no two commercial installs price the same way. The headline number on a quote is built up from several moving parts, and understanding them is the difference between comparing quotes fairly and being caught out by a low sticker price that quietly balloons on site.
The main cost drivers
System size is the largest single factor, and it works in your favour as it grows. A small array carries the same design, scaffolding and commissioning overheads as a bigger one, so the cost per kWp typically falls as capacity scales up. This is why a 250 kWp system almost always prices lower per kWp than a 30 kWp one, and why sizing the array to your actual daytime demand matters as much as chasing the lowest headline rate. Beyond size, the biggest variables are:
- Roof condition and structure. An older roof may need repair or reinforcement before panels can be mounted, and a structural survey will confirm whether the building can carry the load. On a flat roof, ballasted or penetrative mounting choices change the cost too.
- The DNO connection. Any system exporting to the grid needs approval from the Distribution Network Operator. A straightforward connection is cheap, but a constrained local network can mean a connection charge or an export limit, which affects both the price and the returns.
- Inverter choice. String inverters are the standard, cost-effective option; optimisers or microinverters cost more but can be worth it on a shaded or complex roof.
- Cabling, switchgear and electrical upgrades needed to tie the array into your existing distribution board.
Hidden costs to plan for
A credible quote should account for scaffolding, the structural survey, DNO application fees, and, where relevant, a G99 protection relay for larger export. Watch also for any roof remediation flagged by the survey, and for ongoing operation and maintenance. A quote that omits these is not cheaper, it is simply incomplete, and the gap tends to appear once the installer is on the roof.
The sticker cost versus what you actually pay upfront
The capital cost is only half the picture, because the funding route decides how much of it you pay now. With a capital purchase you meet the full cost upfront and own the asset outright, which gives the strongest long-term return. With hire purchase, asset finance or a business solar loan, you spread that same cost across fixed instalments, so the upfront figure can fall close to zero while the total paid over the term is higher. A no-upfront-cost route such as a power purchase agreement removes the capital outlay entirely and you pay for the power instead. The sticker cost is the same system; the route changes the shape of the payments.
The tax that reduces your true cost
Tax relief materially lowers the net cost of an owned system. Solar PV is classed as special rate plant, so it does not qualify for 100% full expensing, which is main-rate only, nor for the 40% first-year allowance. It does qualify for the Annual Investment Allowance, giving 100% first-year relief on qualifying spend up to 1 million pounds, which covers most commercial installs. Above that cap, companies can use the 50% special-rate first-year allowance, with the balance written down at 6% a year. VAT on commercial solar is 20% and is reclaimable by VAT-registered businesses; the 0% domestic rate does not apply to commercial projects. Rooftop solar for self-consumption is 100% exempt from business rates in England from April 2022 to March 2035, and exported power can earn income under the Smart Export Guarantee. This is general information, not tax advice, so confirm your position with your accountant.
See your real numbers
We are a comparison and quote service, not a lender or financial adviser, and we connect UK businesses with vetted MCS-certified installers and funders. To turn the ladder above into figures for your building, compare the routes in how the finance options compare, and get a tailored costing at our quote page.
Up to 100%
First-year tax relief on most installs via the Annual Investment Allowance (up to £1m).
Reclaimable
The 20% VAT is reclaimable if you are VAT-registered, so it is a timing cost, not a net one.
£0 rates
Rooftop self-consumption solar is business-rates exempt in England to March 2035.
Sources and official guidance
Figures on this page are based on the following primary sources. This is general information, not tax advice.
Further reading
Cost and finance questions
Can I get commercial solar with no upfront cost?
Yes. Either a PPA, where a third party owns the system and you buy the cheaper power, or 100% finance, a green loan, hire purchase or lease repaid from your energy savings. Both aim to be cash-flow positive from day one. The trade-off is that you give up some ownership, tax relief or lifetime return in exchange for zero capex.
What tax relief can my company claim on commercial solar panels?
For most installs the Annual Investment Allowance gives 100% first-year relief up to £1m, which at 25% corporation tax returns about 25p per £1 spent in the first year. Solar is special-rate, so above the £1m cap a company can use the 50% first-year allowance with the balance written down at 6% a year. Solar does not qualify for 100% full expensing, which is main-rate only. Confirm your position with your accountant.
Who gets the tax relief and export income under a PPA?
The PPA provider, because they own the asset. You get cheaper power, not the capital allowances or the SEG export payments. If capturing the tax relief matters to you, own the system through cash, a loan or hire purchase.
Can I reclaim the VAT on a commercial solar installation?
If you are VAT-registered, yes. The 20% input VAT is reclaimable through your normal VAT return, provided the system is for business use and you hold a valid VAT invoice. The 0% domestic rate does not apply to commercial buyers, so it is a cash-flow timing item rather than a net cost.
Will commercial solar increase my business rates?
No. In England, qualifying rooftop solar for self-consumption is 100% exempt from business rates from April 2022 to March 2035, so it will not raise your rateable value in that window. Scotland and Wales have separate regimes, so check locally.
What are typical finance terms and rates for commercial solar?
It depends on the route: hire purchase and asset finance are commonly 3 to 7 years, green loans 3 to 15 years, PPAs 10 to 25 years, and operating or finance leases about 5 to 15 years. Rates are priced off the Bank of England base rate plus a credit margin, so verify live pricing, which moves with rates and your covenant strength.