Manufacturing Plants: Solar Panels for Manufacturing

A general manufacturing plant is close to the ideal customer for commercial solar because its electricity demand is high, continuous and weighted to the working day. High continuous daytime load gives strong self-consumption, so most of what the array generates is used on site rather than exported cheaply. Process loads such as compressors, conveyors and machining absorb the peak midday generation exactly when a rooftop array produces the most, and 24/5 or 24/7 shift patterns align well with the PV generation curve across the year. Many plants also have existing HV and LV infrastructure that simplifies grid integration. Put together, this load profile lets a correctly sized array offset a meaningful share of grid import, hedge against tariff volatility, and produce the Scope 2 evidence that customer sustainability audits increasingly demand. That is why solar tends to pay back faster on a working manufacturing site than on a low-occupancy commercial building.

Sizing solar for general manufacturing plants

Manufacturing PV is sized to daytime baseload, not to roof area. For a general manufacturing plant the system typically lands between 250 kW and 800 kW, using roughly 460 to 1,500 panels across around 1,500 to 4,500 square metres of unobstructed roof. A system in that range generates in the order of 230,000 to 740,000 kWh a year in UK conditions, a large part of which is consumed on site because the plant is drawing power throughout daylight hours.

We do not guess at any of this. We size the array from 12 months of half-hourly meter data, modelling your load profile shift by shift rather than as a single annual average. The working rule is to install enough capacity to cover a high proportion of peak daytime demand so self-consumption stays high and you avoid spilling generation onto a low export tariff. Where a night shift runs, where DUoS red-band charges are heavy, or where you want to trade flexibility, we model battery storage alongside the PV so you can see whether it earns its place.

Costs and payback

A general manufacturing solar project usually costs between £190,000 and £680,000 fully installed, with cost per kW falling as system size rises. Simple payback for a plant of this type is typically around 6 years, driven by the high self-consumption a daytime load delivers. The capital is normally fully expensed in year one under the Annual Investment Allowance, which improves the effective payback further for a corporation-tax-paying business. The figures below summarise the representative range for a general manufacturing plant.

Figure	Typical range for a manufacturing plant
System size	250 kW to 800 kW
Panels	460 to 1,500
Roof area required	1,500 to 4,500 square metres
Annual generation	230,000 to 740,000 kWh
Project value (installed)	£190,000 to £680,000
Typical simple payback	Around 6 years

These are representative figures, not a quote. Your actual payback depends on your baseload, your import tariff, and how much of the generation you consume directly, which is precisely why we model it from your own meter data before you commit anything.

Compliance and regulation

A general manufacturing install carries a clear set of compliance requirements, and we handle each one as part of the project rather than leaving it to you.

• MCS commercial certification is required for Smart Export Guarantee eligibility, so the install must be delivered by an MCS-certified contractor if you want to claim export income.
• A G99 application is needed for connections above 17 kW per phase, which covers effectively every plant-scale system. We submit the DNO application early because the connection is usually the longest single item in the programme.
• CDM 2015 applies to any install above 30 person-days, so the project is run with the correct principal-designer and principal-contractor duties in place.
• A roof structural survey is mandatory. Most pre-2000 industrial roofs need engineer sign-off before any ballast or rail loading is added, and we arrange this at the feasibility stage so there are no surprises later.

Alongside these, rooftop PV on a manufacturing building is generally covered by Permitted Development Rights under Class A Part 14 of the GPDO 2015, subject to size limits and provided the building is not listed or in a conservation area. Insurers increasingly expect SPF1981 fire-safety design as standard, and we build to that specification rather than treating it as optional.

A representative project

Consider a general manufacturing plant running a 24/5 shift pattern, with compressors, conveyors and machining lines drawing a steady daytime load. The site has around 3,000 square metres of usable trapezoidal metal roof and a healthy grid supply already in place. From its half-hourly data we size a 500 kW array of roughly 950 panels, which generates in the region of 470,000 kWh a year. Because the plant is drawing power throughout the working day, a high share of that generation is self-consumed rather than exported.

At a project value inside the £190,000 to £680,000 band for this system size, and with the capital expensed in year one under the Annual Investment Allowance, the site is on track for a simple payback of around 6 years. Beyond the bill reduction, the array gives the plant a verifiable Scope 2 figure to put in front of customer sustainability audits. This is a representative scenario built from the typical figures for a general manufacturing plant, not a specific named client, and your own numbers will differ once we model them.

Funding the project

Not every plant funds solar from its own capital budget, and it rarely needs to. Options range from a power purchase agreement with zero capex, through asset finance spread over 7 to 15 years, to a straight cash purchase that captures every pound of saving. Several grant and tax routes also apply to manufacturing, including the Industrial Energy Transformation Fund and 100 percent first-year capital allowances. You can compare the funding routes on our grants and funding page, and see the full breakdown of system costs and payback drivers on our cost page.

When you are ready, request a sized and priced proposal through our quote page, or run your own numbers first with the savings calculator. If your site sits in a more specialised part of manufacturing, we also cover food and beverage manufacturing and engineering and metalworking in dedicated detail.