Injection moulding is one of the most electricity-hungry processes in UK manufacturing, and almost all of that electricity is drawn during the working day. Barrel heaters, hydraulic and electric presses, chillers, compressed air and granulator lines run through every shift, which is exactly the load profile that makes solar panels for plastics manufacturers and injection moulders such a strong commercial case: a large industrial roof sitting directly above machinery that consumes power from the moment the first press cycles.
Why plastics processing is such a strong solar load
Solar only pays its way fully when the electricity generated is used on site rather than exported at a low rate. Plastics processing sites rarely have that problem. Injection moulding machines draw continuously through their cycle – heating the barrel, holding pressure, cooling the mould and ejecting the part – and most factories run several presses in parallel across a single shift or more.
Cooling adds a second daytime load on top of the presses themselves. Water chillers and cooling towers work hardest on warm, bright days to hold mould temperatures steady, which is precisely when a rooftop array is generating at its peak. Compressed air systems, granulators and regrind lines, extrusion and blow moulding equipment, and material drying hoppers all add further consumption through working hours, and few of these processes can simply be switched off to chase a cheaper tariff.
Big industrial roofs, built for solar
Plastics manufacturing typically happens in steel-framed portal sheds with large, unshaded roofs and comparatively little rooftop plant, which makes for straightforward, efficient array design once a structural survey confirms the roof can take the load.
We saw exactly this at Scott Closures & Plastics, a Poole manufacturer of closures and plastic components. We installed 710 panels across its pitched industrial roof for a 436.65 kWp system, generating an estimated 357,976 kWh of clean electricity a year and saving an estimated 74 tonnes of CO2 annually. Plastics sites with a similar footprint can usually take a system of comparable scale, and smaller moulders on smaller roofs see the same daytime match at a smaller scale.
Realistic savings and payback
For a system sized around genuine daytime consumption rather than a rule of thumb, a 40–70% reduction in electricity bills is typical for commercial sites, with payback usually landing in the three-to-five-year range. Plastics processors with high, steady daytime demand often sit towards the better end of that band, because so little of what the array generates goes unused.
We size every system from your half-hourly meter data rather than nameplate machine ratings, because actual running patterns – how many presses run together, how long changeovers take, how drying and cooling plant cycles through the day – determine how big an array your consumption can genuinely absorb. The panels themselves are warrantied to keep performing strongly at twenty-five years, so the savings continue long after the system has paid for itself.
Where battery storage fits
Many moulders run a second or third shift into the evening, or keep presses live overnight to avoid the cost and quality risk of a full stop-start cycle. A battery lets you store midday solar surplus and use it against that evening and night-time load instead of exporting it for a fraction of its value. Storage can also help smooth the demand spikes that come from multiple presses starting together, which is worth investigating if your supply is close to its capacity or your maximum-demand charges are climbing.
We took this approach at Cowdrys Wholesale Bakery on the Ferndown Industrial Estate, pairing rooftop solar with battery storage for a food producer whose production and refrigeration run through the working day in much the same way a moulding line does.
No upfront cost: the fully funded route
Capital in a plastics business is usually earmarked for tooling, new machinery or raw material stock, not roof space. A fully funded arrangement removes that trade-off entirely: a funder pays for the system and its installation, and you buy the electricity it generates through a power purchase agreement, typically at a rate below what you currently pay the grid. There is no capital outlay, and savings start from month one.
DES delivered exactly this model for Leek Town FC: a fully funded 46.8kWp array paired with 69kWh of battery storage, at no upfront cost to the club. Manufacturing sites with steady, predictable daytime consumption – which describes most moulding operations – are exactly the kind of load a funder wants to buy against.
Installing without stopping production
A moulding line cannot easily be paused for a day of roof work. Our installation teams are directly employed rather than subcontracted, so we plan cable routes, roof access and the final connection around your shift pattern and any planned changeover or maintenance window. We handle the DNO application as part of the project, which matters on larger industrial supplies where a G99 connection is usually required.
Why choose DES Renewables
DES Renewable Energy is a commercial solar installer based in Wimborne, Dorset, working with manufacturers and processors across the South and beyond. Our installations are MCS accredited, and we hold NAPIT, RECC and City & Guilds qualifications – the credentials that matter for electrical safety, workmanship and consumer protection, and the ones funders and insurers look for. Our wider guide to commercial solar for UK businesses explains how the numbers are put together.
Find out what your site could save
The honest starting point is your bills. Our free business energy bill check reviews your current usage and costs and gives you a realistic picture of the savings and payback solar could deliver at your plastics or injection moulding site, with no obligation.
Request your free bill check online, email madeleine@desrenewables.com, or call the team on 01202 985 888. We will tell you straight whether solar suits your site, and how a fully funded option could get you there with no upfront cost.