Is commercial solar worth it for a manufacturer, warehouse or cold store?

What goes wrong, and what does it cost?

The common mistake is judging solar by sector or roof size instead of by when the site uses power, which leads to systems that are too large and savings that are overstated.

The board is asked to approve a system because "factories always benefit" or because the roof is huge. Neither is a reason.

• Sizing to the roof, not the load. Power used on site avoids the import price. Power exported earns far less. A system that fills the roof but exports much of its output pays back more slowly than the headline suggests.
• Believing a self-consumption claim nobody tested. One AI engine quoted "95%+" for cold storage. We found no primary source for it. The vendor page we could open says 60 to 80% ².
• Quoting a survey headline as a quote. A Cushman & Wakefield survey of 60+ stakeholders reports payback "as short as 5.5 years" and IRR "up to 18%" ³. Those are best-case survey figures, not a price for your roof.
• Ignoring the roof and the lease. DESNZ notes that most commercial leases put repair duties on tenants and complicate installs ⁴. A tired roof may need work before panels go on. See is my site suitable for commercial solar.

Each mistake costs the same thing: a payback figure the site never reaches. The fix is twelve months of half-hourly data, which shows when the site actually uses power.

Which types of site get the most from rooftop solar?

Sites with high, steady daytime demand, such as 24/7 manufacturers, get the most from rooftop solar, while sites with small or evening-heavy loads relative to their roof get the least.

The table groups site types by daytime demand. The percentages are vendor and installer ranges, not measurements of your site. Your half-hourly data replaces them.

The ranges come from SurgePV, a design-software vendor, and EvoEnergy, an installer. Both have a commercial interest. Treat them as a screen, then test the site and compare bids on one basis (see how to compare commercial solar quotes). For the maths behind payback, see solar payback and ROI.

What does the evidence say about warehouses and cold storage?

Public sources say warehouse and cold-store roofs have large potential, but CH Group has no published case study in either sector, so the figures below are third-party and unverified against a real tender.

The UK Warehousing Association, using Delta-EE analysis from 2022, estimates that solar could cut warehouse electricity costs by 40 to 80%. DESNZ repeated this and a 15 GW rooftop potential across the UK's largest 20% of warehouses in its Solar Roadmap on 30 June 2025 ⁴. The data is from 2022 and the original report was not available to us.

Cold stores run refrigeration around the clock, which gives a flat, high base load. SurgePV says compressors take about 55 to 65% of a cold store's electricity and demand tends to peak on hot summer afternoons, when solar output is also high ².

The same source warns that cold-store roofs may need a structural review and fire setbacks, and that a roof with under about 15 years of remaining life may justify re-roofing first. It is a vendor claim, so ask your installer to confirm it for your roof.

Warehouses have a different problem. A 2024 guest article on the Solar Energy UK site, by InRange, says a tenant's demand can be as low as 5% of a roof's potential ⁶. A large roof does not make a large saving if the building uses little power.

How many kWp fits on a factory or warehouse roof, and what does it cost?

EvoEnergy, an installer, plans on 8 to 10 m2 of usable roof per kWp, so a 10,000 sq ft roof (929 m2) takes roughly 93 to 116 kWp, and EvoEnergy's indicative warehouse costs run from £450 to £900 per kWp depending on size.

The 8 to 10 m2 figure is EvoEnergy's planning rule for warehouse roofs ⁵. SurgePV gives lower figures for flat roofs, 5.5 to 6.5 m2 per kWp on usable area, and notes that 20 to 35% of gross roof area is lost to setbacks and obstacles ⁷. The survey decides which applies.

EvoEnergy's 2025 indicative fully installed prices for warehouse systems are:

• 100 kWp: £600 to £900 per kWp
• 250 kWp: £560 to £800 per kWp
• 500 kWp: £500 to £760 per kWp
• 1 MWp: £450 to £650 per kWp

These are one installer's ranges. For the full cost picture, see how much commercial solar costs in the UK. Ask whether each price includes VAT. Commercial solar is normally standard-rated at 20%; check the treatment with your accountant.

What have CH Group's manufacturing projects projected?

CH Group's four published case studies (two manufacturers, a diesel engine repair business and a plant hire business) project annual savings of £3,038 to £44,746 and paybacks of 2.8 years to 6 years.

All figures are projected, not achieved. Savings depend on each site's energy use, tariff and system. Merlin Diesel Systems (engine repair) and Kelston Sparks (plant hire) are industrial sites rather than strict manufacturers.

The spread in payback is the point. Same technology, different sites. Merlin's project also combined the solar with a major roof upgrade, 41,000 sq ft of full roof over-cladding. See all four projects.

Who should not expect much from rooftop solar?

Sites that use little power in daylight, tenants without landlord consent, and buildings with roofs near the end of their life should not expect a strong return from rooftop solar.

• Mostly evening or night load. Panels generate in daylight. A site that runs mainly at night exports most of the output, and export pays far less than avoided import.
• Tenants without consent. A lease usually needs landlord agreement, and DESNZ says leases complicate installs ⁴.
• Weak credit and no capital. DESNZ says behind-the-meter finance is hard for businesses without strong credit ⁴. See funding options.
• Buyers who already hold comparable quotes. Solar may still pay, but a managed tender adds little for a small, simple system with a trusted installer.