Solar Panels for Fabrication: Cost Guide 2026

Electricity is now the biggest controllable cost a metal-fabrication shop carries after steel and labour, and industrial power prices roughly doubled between 2021 and 2024. So the first question every owner-manager asks is a blunt one: what does a rooftop solar system actually cost, and how fast does it pay for itself? This guide gives you real UK 2026 numbers by workshop size, the cost per kWp you should expect, what the Annual Investment Allowance does to those figures, and the payback range a fabrication shop realistically sees.

Fabrication earns a shorter payback than almost any other building type for one reason competitors miss: it is a single-shift, Monday-to-Friday, daytime operation, so the electrical load lands almost exactly on top of the solar generation curve. That drives 70 to 90 percent self-consumption at your full 25 to 30p import rate rather than cheap export. High self-consumption is what turns capex into a fast return.

What a fabrication solar system costs by workshop size

The single biggest driver of total cost is system size in kWp, and size is set by your daytime load, not your roof area. The table below groups the sector into small, medium and large workshops using the verified sizing bands for fabrication. Figures are illustrative and depend on roof type, height, three-phase headroom and any roof or supply remediation.

Workshop size	Typical array	Roof area	Capex (before relief)	Payback
Small welding or jobbing engineering unit	40 to 90 kWp	240 to 700 m²	£30,000 to £70,000	5 to 7 years
Medium sheet-metal, CNC or general fabrication shop	100 to 200 kWp	600 to 1,500 m²	£70,000 to £150,000	4.5 to 5.5 years
Large structural-steel, laser or powder-coating plant	250 to 500 kWp	1,500 to 3,000 m²	£150,000 to £330,000	3.5 to 4.5 years

As a rule of thumb, 1 kWp needs about 5 to 6 square metres of unshaded roof and generates 900 to 1,000 kWh a year in the UK, so a 1,000 square metre workshop roof typically supports 150 to 180 kWp. Our detailed breakdown on the cost page walks through each line item, and you can put your own roof and load into a live quote on the quote page.

Cost per kWp: why bigger is cheaper

Solar has strong economies of scale. Fixed costs, scaffolding, the DNO application, design, commissioning and a day of crane time, are spread across more panels on a bigger array, so the price per installed kWp falls sharply as the system grows.

• Small systems, roughly 40 to 100 kWp: about £700 to £810 per kWp.
• Medium systems, 100 to 250 kWp: about £600 to £740 per kWp.
• Large systems, above 250 kWp: about £520 to £700 per kWp.

This is why a large structural-steel fabrication shop with a big clear-span roof gets the best value in the whole sector, and why a small jobbing unit pays a little more per kWp but still lands a strong payback because its single-shift daytime load is so well matched to solar.

What is actually in the price

A commercial fabrication install price covers the panels, mounting system, inverters, DC and AC cabling, isolators, the G99 grid-connection works, scaffolding and access, structural survey, design and the MCS-certified commissioning that makes you eligible for export payments. On older units, budget separately for any roof remediation, an asbestos-cement roof cannot take PV directly and usually needs over-cladding, and for any three-phase supply upgrade a tired incoming supply might need. A proper survey surfaces those before you commit, not after.

How AIA cuts the real cost

The headline capex is not what a profitable company actually pays, because commercial solar qualifies for capital allowances. Solar PV is special-rate plant and machinery, so the route that applies is the Annual Investment Allowance (AIA): 100 percent year-one tax relief on the first £1m of qualifying spend, which covers the entire cost of almost every SME fabrication install.

For a company paying 25 percent corporation tax, AIA is worth up to about a quarter of the qualifying spend back in year one. On a £120,000 medium-workshop system, that is up to roughly £30,000 of corporation tax saved, bringing the effective net cost closer to £90,000.

Two things to be clear about, because the internet gets them wrong:

• Solar is special-rate expenditure (HMRC CA22335), so it is excluded from 100 percent full expensing and from the 40 percent first-year allowance, both of which are main-rate only. Do not budget on those.
• Above the £1m AIA cap, the 50 percent first-year allowance applies to the special-rate balance, then a 6 percent writing-down allowance on the remainder.

Also worth having on the ledger: on-site solar and battery plant is exempt from business rates in England to 31 March 2035, and exported power earns the Smart Export Guarantee, supplier-set and typically around 12 to 16p/kWh in 2026. These figures are illustrative and depend on your profits and tax position, so confirm the numbers with your accountant. Our grants and funding page sets out the full relief stack, and the government’s capital allowances guidance is the authoritative source.

Payback: why fabrication lands 3 to 7 years

Payback is the number that matters when solar capital competes head-on with a new fibre laser or press brake. For a UK fabrication shop on a single daytime shift, simple payback typically lands between three and seven years, faster on larger high-self-consumption sites, a little longer on small jobbing units.

The mechanism is self-consumption. Every kWh you use on site displaces grid electricity at the full commercial import rate of around 25 to 30p, whereas exported surplus only earns 12 to 16p. Because a fabrication shop runs its welders, compressor, LEV fume extraction, laser chillers and CNC coolant through the daylight hours, 70 to 90 percent of generation is self-consumed at the higher rate. A home that sits empty all day or a 24/7 plant that exports more of its midday output cannot match that.

A worked example: a 150 kWp system generating around 140,000 kWh a year, with 85 percent self-consumed at 28p and the rest exported at 14p, saves roughly £35,000 in year one. Against a net-of-AIA cost near £75,000, that is a payback comfortably inside four years, and the saving grows as grid tariffs rise.

Cash, finance or PPA

You may not need the capital at all. Most fabrication installs are funded one of three ways:

1. Cash purchase: you claim the AIA and own the asset outright, shortest overall cost.
2. Asset finance over five to seven years: usually cash-flow positive from month one, because the finance payment is smaller than the bill it replaces, leaving your capital budget free for production plant.
3. Power Purchase Agreement (PPA): zero capex, a funder owns the array and you buy the power below grid, which suits tenants and shorter leases.

We model all three against a cash purchase so you can compare like for like before spending anything.

Where costs vary most

Two site factors move the price more than anything else:

• Roof condition. Older fabrication sheds often sit on corroded, single-skin or asbestos-cement roofs. Any building from before 2000 needs an asbestos management survey, and doing the roof at the same time as the panels, which carry a 25-year warranty longer than most industrial roofs, is frequently the right call.
• Structural and supply headroom. A portal-frame roof must be assessed by a structural engineer, and on heavy structural-steel shops the EOT crane-rail and gantry dead loads are deducted from residual roof capacity before any array is added. A tired three-phase supply may also need attention.

For the fuller picture on how the roof, the load profile and the compliance overlap for your specific trade, our guide on why fabrication is such a strong fit for solar goes deeper on the load-match economics behind these paybacks.

The bottom line

Budget from around £30,000 for a small welding unit to over £320,000 for a large laser or powder-coating plant, at £520 to £810 per kWp depending on size. Knock off up to a quarter through AIA in year one, add business-rates exemption and export income, and expect the system to pay for itself in three to seven years while hedging a doubled and volatile power bill for 25 years. Every real figure should come from your own half-hourly meter data, not a rule of thumb, and we build the model from that data and share the file. Start with a free feasibility study on the quote page.