Are solar panels for your warehouse a good idea?
Thinking about turning your warehouse roof into monthly pay cheques and lower electricity bills? You might be on to something: warehouses have some of the biggest, best, unshaded roofs in the country, and can create £15 to £30 per square metre of saved cost and export income, per year. The payback split is usually 89% in saved energy and 11% in export income.
I’ll go over the details here, so you can decide if it makes sense for you.
- Expect £650 to £1,200 per kW installed, before tax relief. Bigger systems cost less per kW. A 250 kW warehouse array runs roughly £200,000 to £240,000; a 500 kW system around £375,000 to £425,000, ex VAT.
- Size to daytime load, not roof area. Most warehouses use about a quarter of what their roof could generate. Match the system to what you consume on site and payback lands at 4 to 6 years. Fill the roof for export and it can stretch to 8.
- Solar is a special-rate asset, so it misses full expensing. The 100% first-year route is the Annual Investment Allowance, capped at £1m. Above that, companies get a 50% first-year allowance.
- Rooftop solar is exempt from business rates in England until 31 March 2035. A 250 kW array saves roughly £550 a year in rates on top of the energy savings.
- Grid connection is the long wait, not the install. A G99 offer can take 45 working days (65 at high voltage), and larger schemes can need substation reinforcement costing £25,000 or more. Start it early.
Why a warehouse roof is the best solar surface in Britain
Three things line up on a warehouse that rarely line up anywhere else.
The roof. A modern steel-portal distribution shed carries thousands of square metres of clear, single-plane cladding with almost nothing on it. Clip-fix mounting clamps onto standing seams with no penetration, and trapezoid profiles take short rails screwed straight into the sheet. A 5,000 sq m roof supports around 700 to 750 kW of panels.
The load profile. Warehouses draw power when the sun is up. Lighting, forklift charging, HVAC for office mezzanines, conveyor and automation systems, refrigeration in cold-chain sites, and the always-on load of CCTV, gates and IT all run through the working day. That daytime concentration is exactly what solar rewards.
Dead space becomes an asset. Warehouse roofs have historically earned nothing. Solar turns that area into roughly £15 to £30 per square metre a year in avoided cost and export income. For an owner-occupier that’s money straight off the operating line; for a landlord it lifts net income and answers the ESG questions tenants now put in tender documents.
What warehouse solar costs in 2026
Commercial pricing is quoted per kilowatt-peak (kWp) and falls as systems get bigger, because labour, mounting and connection costs don’t scale in a straight line. These are 2026 turnkey ranges, ex VAT, before any tax relief.
| System size | Cost per kW | Typical total | Roof area |
|---|---|---|---|
| 50-100 kW | £900-£1,200 | £55k-£120k | 300-700 sq m |
| 100-250 kW | £800-£1,000 | £85k-£240k | 700-1,700 sq m |
| 250-500 kW | £750-£950 | £190k-£450k | 1,700-3,400 sq m |
| 500 kW-1 MW | £700-£850 | £350k-£850k | 3,400-6,800 sq m |
| 1 MW+ | £650-£800 | £650k+ | 6,800+ sq m |
Two identical-sized systems can still differ 25 to 40% in price. Roof condition, structural headroom, access, electrical infrastructure and the DNO connection all move the number. The cleanest way to read a quote is to break it into its parts. Here’s a representative 250 kW warehouse install.
Battery storage sits outside these figures. Commercial batteries run roughly £400 to £700 per usable kWh in 2026, so a 200 kWh unit adds £80,000 to £140,000. For the full picture across every commercial building type, our guide to commercial solar panel costs shows how warehouses compare to offices, retail and manufacturing.
The sizing mistake some warehouses make
The default advice is to fill the roof. On a warehouse that’s usually the wrong call, and it’s the decision that decides whether the project pays back in four years or eight.
The reason is self-consumption. Every unit you generate and use on site is worth the full retail price you’d have paid to import it – call it 27p in 2026. Every unit you export earns the Smart Export Guarantee rate instead, which for commercial sites typically lands at 4p to 12p. That’s less than half. A warehouse with a low base load relative to its roof will send most of a roof-filling array straight to the grid at the cheap rate.
700 kW on the same roof. Over 80% of the output exports at 8p. Bigger bill saving in absolute terms, but far weaker return on the extra spend.
150 kW matched to daytime demand. Around 75% self-consumed at 27p. Less roof used, faster payback, higher return per pound.
An empty half-roof isn’t wasted money. An oversized, export-heavy array is. The exception is if you have a specific reason to export at scale – a strong power purchase deal, a plan to add electric HGV charging, or a battery to soak up the surplus. Otherwise, start from your consumption and work back.
How to size it in two steps
First, pull 12 months of half-hourly meter data and find your daytime base load – the power the site draws through operating hours. Second, size the array so that year-round it generates close to what you consume in daylight, aiming for a self-consumption ratio of 70 to 85%. As a rule of thumb, UK warehouses use 30 to 150 kWh per square metre of floor area per year, with ambient distribution at the low end and cold storage at the top.
| Floor area | Typical annual use | Load-matched size | Annual generation |
|---|---|---|---|
| 2,000 sq m | 70,000 kWh | 50-70 kW | ~52,000 kWh |
| 5,000 sq m | 175,000 kWh | 120-160 kW | ~130,000 kWh |
| 10,000 sq m | 350,000 kWh | 210-280 kW | ~240,000 kWh |
| Cold storage 5,000 sq m | 700,000 kWh | 500-650 kW | ~500,000 kWh |
Generation assumes roughly 850 to 950 kWh per kW a year across most of England, dropping toward 800 in Scotland and the far north. These are guide figures only; a PVsyst model against your roof pitch, orientation and shading gives the real number.
The payback maths, worked through
Here’s a full worked example for a mid-sized, load-matched warehouse.
The site: a chilled distribution warehouse of about 4,500 sq m usable roof, using 800,000 kWh a year on a 27p/kWh contract – an annual electricity bill of £216,000.
The system: a 600 kW array matched to daytime load, costing £480,000 at £800/kW, generating around 540,000 kWh in year one.
Year-one benefit: at 70% self-consumption, 378,000 kWh is used on site, saving £102,060 at 27p. The remaining 162,000 kWh exports at 8p for £12,960. Total benefit: £115,020.
Gross payback: 4.2 years. Deduct the £480,000 under the Annual Investment Allowance and a company at 25% corporation tax gets £120,000 of tax relief, cutting the effective cost to £360,000. The savings are taxable too, so post-tax payback stays at 4.2 years.
Across the market, load-matched warehouse systems tend to show simple paybacks of 4 to 6 years, with 25-year internal rates of return in the mid-teens to low twenties. Higher import tariffs, larger systems and stronger self-consumption all push the return up.
Tax, business rates and the grant question
Solar PV does not qualify for 100% full expensing, and it doesn’t qualify for the 40% first-year allowance introduced in January 2026. Both are main-rate reliefs. HMRC designates solar panels as special-rate expenditure. Any installer quote or business case claiming full expensing on the panels is wrong, and following it can leave you with a corporation tax underpayment that HMRC corrects with interest.
The route to 100% relief in year one is the Annual Investment Allowance (AIA), which lets a business deduct the full cost of qualifying plant and machinery from taxable profits, capped at £1m a year. Below £1m of spend, AIA gives you the full 100%, so for most single-site warehouse projects the special-rate distinction never bites.
Above the £1m cap – a 2 MW array, or a multi-site rollout in one year – the excess attracts a 50% first-year allowance, with the balance written down at 6% a year. So on £1.5m of spend you get £1m under AIA plus £250,000 under the 50% allowance: £1.25m of first-year relief, not the £1.5m a full-expensing assumption would have modelled. The mechanics, and how to split the pools, are set out in our guide to capital allowances on commercial solar.
The business rates exemption most models forget
Since April 2022, eligible rooftop solar on commercial buildings in England has been exempt from business rates, and the exemption is confirmed to 31 March 2035. In plain terms, the value the array adds to your premises doesn’t push up your rates bill. On a 250 kW warehouse array that’s worth roughly £550 a year. Install in 2026 and you get nine years of it, not the thirteen the policy started with – roughly £5,000 of extra value that rarely appears in the headline payback.
Are there grants for warehouse solar?
Mostly no, and any page promising “grants covering up to 25%” for a private warehouse is stretching it. Direct capital grants went to the public sector through the Public Sector Decarbonisation Scheme and to energy-intensive industry through the Industrial Energy Transformation Fund, and both closed to new funding in 2025. In Scotland, interest-free loan finance is available to eligible SMEs. For the typical private-sector warehouse in England, the “grant” is the combination of AIA relief and the business rates exemption, which together already remove around a quarter of the true cost.
The constraints that actually decide feasibility
Cost and payback rarely kill a warehouse project. These five things do, and each one is cheaper to check before you commit than to discover halfway through.
Structure. Large-span portal frames are engineered lean, so spare load capacity is limited. A chartered engineer’s appraisal isn’t optional at this scale and is the most common reason a system is resized.
Roof build-up. Built-up felt or single-ply needs a ballasted or bonded system, and the membrane warranty must be checked first.
Age and asbestos. On units built before 2000, a refurbishment survey is required before roof work. Asbestos cement roofs mean overcladding or removal first.
Rooflights. Industrial roofs often carry 10 to 15% rooflight coverage. That area is unusable and it fragments the array, so gross roof area always overstates what you can fit.
Fire access. Fire-service access strips, smoke vents and DC isolation cut 4 to 8% off the theoretical maximum. They’re non-negotiable for insurance and safety.
Grid connection is the long wait
Anything above 3.68 kW per phase needs a G99 connection agreement, and the DNO has up to 45 working days to issue an offer, or 65 where high-voltage works are needed. Larger systems that export can require substation reinforcement costing £25,000 to £150,000 or more, so the scoping enquiry should go in on day one. The difference between the connect-and-notify and full-application routes is set out in our explainer on the G98 and G99 connection rules.
Where reinforcement is uneconomic, the fix is usually export limitation – capping what the system can push to the grid so it stays inside the existing connection. Our guide to export limitation covers how much you tend to lose and when it makes sense. Because warehouses match generation to on-site use so well, a limited-export design often costs very little in practice.
Batteries, forklift charging and future HGV loads
A battery isn’t automatic on a warehouse. Because self-consumption is already high on a load-matched system, the surplus a battery captures is smaller than on a home. Payback on a commercial battery typically lands at 8 to 10 years against 4 to 6 for the panels alone. It earns its keep in three situations: cold-chain sites with heavy overnight refrigeration, sites on time-of-use tariffs where cheap-rate arbitrage is worthwhile, and operations that charge forklifts or vehicles into the evening after generation has tailed off.
Forklift charging is the cleanest match to solar in the sector. A mid-shift charging block sits right under the midday generation peak, and many operators now size the array specifically to cover charging plus base load through the day. Electric HGV charging is the coming question – it needs far more power, 150 to 500 kW per vehicle, and grid capacity, not roof space, is the binding constraint. If HGV charging is on your five-year horizon, size the AC infrastructure and DNO connection for it now, even if you install solar-only today. The same logic applies to depot car and van charging, and our guide to solar for EV charging covers the principles.
Best commercial solar installers for warehouses, 2026
There’s no single best installer, and any “top 10” that ranks a fixed league table is selling something. The best company for your project depends on your size, region and roof. What follows is an editorial shortlist of established commercial EPCs with a real track record on large roofs, scored on the criteria that matter for a warehouse. Treat it as a starting point, then run every firm you contact through the checklist below.
One of the UK’s longest-established commercial EPCs, with in-house design and a heavy portfolio across logistics, manufacturing and public sector. Full engineering, procurement and construction under one roof, which suits large single-site and multi-site rollouts where structural and DNO complexity is high.
Best for: 250 kW to multi-MW schemes / distribution estates / operators wanting a single accountable contractor.
A commercial specialist with a strong record on industrial and warehouse roofs, particularly across the Midlands and North. Consumption-led design and in-house delivery, with the appetite for the larger, more awkward roofs that residential-turned-commercial firms tend to avoid.
Best for: mid-to-large warehouse arrays / industrial estates / operators who want a design built around their meter data.
A commercial and agricultural specialist with in-house structural and DNO capability for 250 kW-plus schemes. Well suited to warehouses on constrained connections where getting the grid application right is half the battle, and to sites pairing solar with battery and EV charging.
Best for: connection-constrained sites / farm and rural logistics / solar-plus-storage projects.
Two more worth a quote: Solarsense, one of the longest-established EPCs in the South West with strong O&M and PPA structuring, and Spirit Energy, which installs commercial solar, storage and EV charging across the south of England.
| Installer | Warehouse track record | In-house design/DNO | Transparency | Overall |
|---|---|---|---|---|
| EvoEnergy | 4.7 | 4.6 | 4.3 | 4.5 |
| Custom Solar | 4.6 | 4.4 | 4.4 | 4.5 |
| Geo Green Power | 4.4 | 4.6 | 4.3 | 4.4 |
| Solarsense | 4.3 | 4.2 | 4.4 | 4.3 |
| Spirit Energy | 4.2 | 4.3 | 4.2 | 4.2 |
Scoring note: ratings are Solar Love editorial estimates based on published portfolios, accreditations and sector reputation as of September 2026, not laboratory testing. They’re a shortlist aid, not a substitute for your own due diligence.
The 8-point checklist before you sign
- MCS certification if the system is 50 kW or under, plus NICEIC, NAPIT or Stroma for the electrical work.
- Working-at-height tickets – IPAF and PASMA for the crew on your roof.
- A demonstrated G99 track record at your system size, with references you can call.
- Insurance-backed workmanship warranty, ideally 10 years, plus £5m or more public and professional indemnity cover.
- An itemised, fixed-price quote – not a single bundled number that hides scaffolding, DNO and civils.
- A full PVsyst yield model and a discounted cash flow showing payback, IRR and NPV.
- A chartered structural report before, not after, the contract.
- Three comparable quotes on the same size, panel tier and warranty basis, compared line by line.
Own it or sign a PPA
How you pay decides who owns the asset, and ownership decides who gets the tax reliefs.
- You own the system, so the AIA relief and business rates exemption are yours
- Asset finance over 7 to 10 years is usually cash-flow positive from month one
- The full lifetime saving stays with the business
- Best return over the 25-year life
- No upfront capital and no maintenance burden
- A third party owns the roof asset, so you lose the AIA and rates relief
- You buy the power at 10 to 40% below grid, typically over 15 to 25 years
- PPA payments are a deductible running cost, not a capital claim
Cash purchase suits cash-rich owner-occupiers. Asset finance suits operators who’d rather keep working capital free. A PPA suits multi-site 3PL operators and landlords who want a roof rolled out across an estate without touching the balance sheet – common where margins are tight and capex is constrained. Model all three; the right answer is site-specific.
The installation timeline
The physical install is fast; the paperwork isn’t.
Share 12 months of half-hourly data, roof drawings and build year. The installer models size, generation, self-consumption and payback, and submits the DNO scoping enquiry.
Structural appraisal, roof condition and electrical surveys, asbestos survey if pre-2000. The design is fixed and a fixed-price proposal issued.
Reinforcement works, if needed, extend this. It’s the step that sets the overall timeline.
Clip-fix mounting, panels, inverters, AC works and fire-integrated DC isolation. Commissioning, monitoring set-up and handover follow, then the system starts earning.
Can a warehouse roof structurally take solar panels?
Most modern steel-portal warehouses can. Clip-fix solar adds roughly 8 to 12 kg per square metre, and a post-2005 roof usually has 15 to 25 kg of reserve capacity. Older roofs may need strengthening, typically £8,000 to £25,000 on a large roof, which should be costed before you commit.
Can I install solar on a warehouse I lease?
Yes, but you need the landlord’s consent, usually a licence for alterations covering ownership of the array, the roof warranty, reinstatement at lease end and what happens if you assign the lease. Start that conversation early – it often takes longer than the DNO application. Where the remaining term is short, a landlord-funded or shared arrangement is usually the only structure that works.
The roof isn’t the constraint – the load is
The economics are strong enough that a load-matched system pays for itself in four to six years, before you count the business rates exemption running to 2035.
The mistake to avoid is filling the roof for the sake of it. Size the array to what you consume in daylight, get the grid application in early because it sets the timeline, and make sure your business case uses the correct tax treatment – Annual Investment Allowance, not full expensing. Do those three things and warehouse solar is among the most reliable capital investments a logistics business can make in 2026.
Start with 12 months of half-hourly meter data and three line-by-line quotes.
METHODOLOGY: Cost ranges cross-checked against UK commercial installer pricing published in 2026. Generation figures use approximately 850 to 950 kWh/kWp for England at a typical performance ratio. Worked examples assume a 27p/kWh import contract and an 8p/kWh export rate.
DISCLAIMER: All prices are indicative and ex VAT before tax relief; actual quotes vary by roof, access, connection and region. This is general information, not financial, tax or legal advice – confirm capital allowance treatment with your accountant and connection costs with your DNO. Installer scores are editorial estimates, not endorsements.
UPDATED & FACT-CHECKED: 9 October 2026. Reflects the AIA £1m cap, the 50% first-year allowance on special-rate assets, and the rooftop solar business rates exemption to 31 March 2035.
