Laser & Plasma Cutting: Solar panels for fabrication

Why laser and plasma profiling is one of the strongest solar fits in fabrication

Laser and plasma cutting is the profiling backbone of modern metal fabrication, and it is also, quietly, one of the very best-matched building types for rooftop solar in the UK. The reason is the load profile. A common misconception is that a fibre laser is a spiky, occasional draw, on when the beam fires and off in between. The opposite is true. On a fibre-laser or CO2 profiling line, the beam source itself is only part of the demand, and rarely the largest part. The chiller that holds the laser resonator and optics at a stable temperature runs continuously whenever the machine is powered, the servo drives that move the cutting head and the sheet run all shift, and the assist-gas compressor or high-pressure nitrogen system that clears the cut runs almost without pause. Together these form a large, steady daytime baseload that sits underneath the cutting itself, and that baseload is exactly what a solar array feeds most profitably.

Profiling houses also cut long hours. A sub-contract laser or plasma bureau is typically the busiest single machine centre in the building, kept running through the working day to earn back a capital-intensive machine that may have cost as much as a house. Because that demand is concentrated in daylight, Monday to Friday, it lands almost perfectly on the solar generation curve. The practical consequence is that almost every kilowatt-hour an array generates is consumed on site, at the full commercial import rate of roughly 25 to 30p per unit, rather than exported cheaply at the Smart Export Guarantee rate. High self-consumption is what makes solar pay, and a laser and plasma cutting operation has it built in. That is why this trade sits at the fast end of the fabrication payback range, with typical simple paybacks around 4 years.

The load that actually sizes the array

The single most important design point for a profiling operation is this: a fibre laser draws far more for its chiller, drives and assist-gas compressor than it does for the beam itself, so the array is sized against the modelled baseload, not the laser's nameplate rating. Read a 6kW fibre laser's headline figure and you would badly under-size the system. Model the chiller cycling to reject heat, the drives holding position and accelerating the head, the compressor holding line pressure for the assist gas and the general plant, and the real, continuous daytime demand is several times higher and far smoother. We build that picture from your actual half-hourly meter data, which shows the true shape of the load rather than a plate rating, and size the array to it. Plasma adds its own wrinkle: heavy plasma cutters need dedicated circuits and can require a supply or breaker upgrade, which we check as part of the electrical survey before anything is designed.

A typical laser and plasma cutting install

A representative profiling operation on a modern industrial unit takes an array in the region of 100 to 400 kW, which is roughly 220 to 880 panels occupying 600 to 2,400 square metres of roof. As a rule of thumb, one kilowatt-peak of panels needs about 5 to 6 square metres of clear, unshaded roof and generates 900 to 1,000 kilowatt-hours a year in the UK, so a large single-span profiling shed comfortably carries a system at the upper end of that range. Because profiling houses tend to occupy newer, high-power-dense units with big, clean roofs, they can justify a larger array against real load than most fabrication trades, and the economics reward it.

Project values fall in the £70,000 to £285,000 band depending on system size, roof type and any electrical works, with a typical payback of around four years driven by the combination of high self-consumption and a big, cheap roof. The design method is always the same: pull twelve months of half-hourly consumption data, identify the steady baseload the chiller, drives and compressor create, and size the array so annual generation covers roughly 70 to 90 percent of daytime consumption. That captures the maximum value at the full import rate while spilling little onto low-value export. The continuous laser-chiller and compressor load means self-consumption on these sites routinely lands in the mid-80s as a percentage, among the highest of any building type we work with. You can model your own figures on our savings calculator before you speak to anyone.

A costed illustrative scenario

Consider an illustrative sub-contract profiling bureau running two fibre lasers, a high-definition plasma bed and a nitrogen generation plant on a single day shift, in a 1,600 square metre modern portal-frame unit. Its half-hourly data shows a smooth, high daytime demand anchored by the laser chillers, servo drives and a large rotary-screw compressor feeding the assist gas and general plant. A 240 kW array of around 530 panels is modelled to match that load, generating in the region of 216,000 kilowatt-hours a year.

With around 85 percent of that generation used on site, displacing grid electricity at roughly 27p per unit, and the modest balance exported under the Smart Export Guarantee, the array would be expected to cut the electricity bill by something in the order of £48,000 to £52,000 in year one, before any grid-price rises are counted. At a project value near the middle of the range, that puts simple payback close to four years, after which the system continues to generate for the balance of its 25-year-plus warranted life. Figures like these are illustrative and depend entirely on your tariff, load shape and roof, which is precisely why we model from your data rather than a rule of thumb. A full breakdown of what a system like this costs sits on our cost page.

Compliance and design for a profiling operation

Laser and plasma cutting brings a specific set of technical and regulatory points that a generalist installer will miss, and getting them right up front is what keeps a project on programme.

Three-phase supply, G99 and power quality

Profiling machines are heavy three-phase loads on a 415V supply, so two things have to be checked before design. First, the supply must have enough headroom to add behind-the-meter generation, and any inverter output above 16A per phase, roughly 3.68kW single-phase or 11kW three-phase, needs a G99 application to the local Distribution Network Operator before it can connect. A commercial profiling array is always G99 territory, and we submit that application on day one, alongside the structural survey, because the DNO connection is usually the longest single item in the programme. Second, laser resonators, servo drives and plasma power supplies produce transients and can be sensitive to power quality, so we consider harmonics and specify power-factor correction where the transient loads are heavy, protecting both the grid connection and the machines that share the supply. Where export capacity is constrained, G100 export limitation or a battery keeps the design within the DNO's terms.

Roof, structure and fire safety

Before any panel goes up, the roof is surveyed. A portal-frame steel roof must be assessed by a structural engineer, because a framed array adds roughly 15 to 25 kg per square metre of dead load plus wind uplift. Modern profiling units are usually well suited to this, but any pre-2000 building needs an asbestos management survey first, as asbestos-cement roofs cannot take rooftop PV directly and must be over-clad or replaced. Rooftop-PV fire safety follows the RC62 Joint Code of Practice from RISCAuthority, MCS and Solar Energy UK, which covers DC-side fire risk, installation quality and maintenance; insurers increasingly make RC62-compliant design, annual inspection and an updated fire risk assessment a condition of cover, so we notify your property insurer and obtain sign-off before install. Planning is rarely an obstacle: most rooftop PV on industrial buildings in England is Permitted Development under Class A of Part 14 of the GPDO 2015, and the previous 1MW cap was removed in December 2023, so even a large profiling array generally needs no planning application, subject to the sloping-roof 200mm and flat-roof 600mm projection limits and the listed-building and conservation-area exceptions.

Fume, extraction and shared-shop duties

Plasma cutting generates significant fume and particulate, and most profiling beds run downdraught or side-draught extraction that penetrates and vents through the same roof as the array; that ductwork and its discharge stacks have to be designed into the panel layout so the PV never blocks an extraction route. Where a profiling bureau shares a building with welding bays, the wider HSE welding-fume duty applies: Safety Bulletin STSU1-2019 treats all welding fume, including mild steel, as a carcinogen and requires Local Exhaust Ventilation for all indoor welding, so any weld-fume stacks are planned around the array too. A rooftop install is also construction work under CDM 2015, which makes you the Client with duties to provide pre-construction information and, where more than one contractor is involved, to appoint a Principal Designer and Principal Contractor in writing. We carry those duties on your behalf as part of a properly run project.

An illustrative case scenario

To show how this comes together, consider a representative profiling house on a trading estate in the North West, running a fibre laser, a plasma bed and a small bank of press brakes on a single day shift under a tired incoming supply. The owner had watched the electricity bill roughly double since 2021, and power had become the largest controllable cost after steel and consumables, eating directly into the margin on competitively-tendered plate-cutting work. An automotive customer had also begun asking for Scope 2 emissions data inside its supplier scorecard.

Half-hourly data confirmed what the trade profile suggested: a smooth, high daytime load dominated by the laser chiller, drives and compressor rather than the beam itself, making the site an ideal high-self-consumption candidate. A roughly 200 kW array was modelled against that load, with the plasma bed's extraction penetrations and the existing roof services mapped into the panel layout so nothing was blocked. The G99 application went in alongside the structural survey so the connection clock started immediately, and the project was funded through asset finance spread over the system life, cash-flow positive from the first month because the finance payment came in below the bill it replaced. The illustrative outcome was self-consumption in the mid-80s as a percentage, a bill cut of the order of £40,000 in the first year, and an on-site renewable line item the owner could report straight into the customer's Scope 2 disclosure, protecting a preferred-supplier position at the next tender. This scenario is representative of the profiling installs we deliver, not a named client.

How we work

We are MCS-certified fabrication solar specialists, and we design every profiling system around the load your machines actually create, not a plate rating or a rule of thumb. The process starts with your twelve months of half-hourly meter data and a site survey covering the roof structure, the incoming three-phase supply, the extraction and any asbestos, so you get an honest feasibility picture before you spend anything. We submit the G99 application and the structural survey together on day one, model cash purchase against asset finance and a zero-capex Power Purchase Agreement side by side, and set out the capital allowances and other relief available on our grants and funding page. Solar is special-rate plant, so the Annual Investment Allowance gives most SMEs 100 percent year-one tax relief up to £1m; all figures are illustrative and worth confirming with your accountant. If your operation runs more welding than profiling, our welding and engineering workshops page covers the fume-extraction detail in depth, and you can read the HSE's own guidance on welding-fume health risks for the underlying duty. When you are ready for numbers built around your machines and your roof, request a fixed-price quote and we will turn a feasibility study around quickly.