Solar for UK manufacturers: how to cut energy costs without stopping the line
Updated: Oct 19
Ask a UK finance director what keeps them awake and, in my experience, energy will be on the list, usually somewhere between employment costs and the order book. It is the one major cost they cannot forecast with any confidence, and it sits underneath every investment they want to make next. Ask an operations director about solar and the worry changes completely: what happens to production while it goes in?
Both are fair questions, and a good solar project answers them together. Eden Sustainable has worked through them on more than 300 installations since 2014, including aerospace machining in Derby, energy engineering at GE Vernova, insulation manufacturing and furniture making across three sites, and the lesson is always the same. The panels are the easy part. The outcome depends on who delivers them.
If you are heading to Advanced Engineering at the NEC on 4 and 5 November, I will be out and about at the show with our Co-Managing Directors, Justin Leger and Jamie Brimblecombe. Book time with us for a coffee and a chat, or get in touch whenever suits you.
Key takeaways
For finance directors, a Power Purchase Agreement (PPA) means no upfront cost and a fixed rate, typically 30 to 40% below grid prices, for 25 years, so capital stays with production.
For operations directors, the installation is planned around your shifts, with one agreed shutdown to energise the system.
The saving comes from electricity you use on site during the working day, not from covering every square metre of roof.
The partner you choose decides the result, because the survey, modelling, legal work, grid consent and 25 years of maintenance all sit with them.
What does factory solar mean for a finance director?
Predictability, and capital left where it belongs. Make UK reports that 90% of manufacturers have seen energy bills rise since 2022, and the Make UK and PwC Executive Survey 2026 found two-thirds expect prices to rise again. A PPA fixes the price of a large share of your daytime electricity for 25 years without spending any capital.
That matters because the cash is already spoken for. The same survey found 68% of manufacturers have firm plans to increase investment in new product development and 60% in digital technology, AI and automation, and Make UK's From Crisis to Stability report found 87% would invest more if their electricity costs came down. Solar is competing with new lines and robots for the same budget, and under a PPA it does not have to.
Our Co-Managing Director Jamie Brimblecombe, a chartered accountant, has watched that view change: "Capex still wins where cash is genuinely spare, but for most manufacturers, keeping capital for their core business is the more commercial decision."
The Senator Group chose to self-fund its rollout across three sites, which is the right call when the cash is there. For most of the manufacturers I speak to, it is not.
What does factory solar mean for an operations director?
Continuity. The installation is scheduled around your operations and permits, connection works go on maintenance days rather than live shifts, and the only stoppage is one planned shutdown at an agreed time to energise the system.
Justin Leger, our other Co-Managing Director, describes it from the site: "We have energised during a planned Saturday shutdown, meaning the lines started on Monday morning running on solar, with no lost production time. That's what planned around production means: the factory keeps making things." Our engineers work under your own permit to work and safety rules, and your operations manager knows exactly what is happening and when.
Why does on-site usage matter more than how much you generate?
Because electricity you use on site is worth far more than electricity you export. Factories run through daylight hours, so a system sized to what your lines, compressors and lighting draw during the day replaces power you would otherwise buy at full commercial rates. That high self-consumption is where the 30 to 40% saving comes from.
The instinct is to cover the whole roof, and it is usually wrong. The right system is sized from your half-hourly consumption data, matched to your shift patterns, with room to add more as production grows. Xtratherm Unilin is the clearest example: the insulation manufacturer started with a 500 kW system in 2016 and has grown it to 2.13 MW, now saving around £500,000 a year.
Get the sizing right and the funding follows. The saving comes from units your production would have bought from the grid anyway, which is what lets a PPA cut costs from the first day without any capital outlay.
What results have UK manufacturers seen?
Eden's manufacturing clients save between £41,000 and £500,000 a year. The sizes differ, but each one solved the same brief: heavy daytime demand, capital needed elsewhere and production that could not stop.
Gardner Aerospace: machining, sheet metal and surface finishing made electricity one of its biggest costs in Derby. A zero-capital PPA delivered a saving of around 40% on energy prices, and Gardner came back to us for a second site at Consett.
GE Vernova: a 399 kWp system at Whetstone, funded through a PPA and designed with GE's facilities team, now saving £41,000 a year.
The Senator Group: a self-funded rollout across three furniture manufacturing sites, saving £434,000 a year.
Why does the right partner matter more than the panels?
British manufacturing is an absolute marvel. Behind closed doors, incredible efforts go into making our everyday simple, and that work takes time, resource and energy. No two sites are the same, and understanding the nuances of each one is what delivers a project that meets the brief on time and on budget.
The mistake I see most often is solar being treated like any other construction project, with one stakeholder leading and putting their own function's priorities first. Solar touches finance, legal, operations, procurement and ESG all at once. If every stakeholder's needs are not considered from the start, the project runs out of energy before a contract is drawn up.
The right partner brings those people together early and gives each of them what they need to say yes.
In practice, that means a partner who will:
model savings from your half-hourly data and actual tariff, with panel degradation included, rather than from a rule of thumb
handle the grid application, including a G100 export limitation where the network caps export
keep the legal side simple, so a 25-year agreement does not mean months of back and forth
plan the installation around your production, down to the hour you switch on
own and maintain the system for 25 years under a PPA, earning only when it generates
tell you when solar is the wrong answer, such as a lease with only a few years left or a site that runs mostly at night
That last point matters more than it sounds. Under a PPA, the team that designs your system has to live with it for 25 years, which is a stronger guarantee than any warranty document. Repeat business is the proof: Gardner returned for a second site and Xtratherm has quadrupled its system, and neither would have done that if the first project had cost them production.
Five questions to ask any solar partner
Will you model our savings from our half-hourly data and actual commercial tariff?
Who carries the risk if the system underperforms?
How will the installation fit around our production schedule?
Who handles the grid application and any export limit?
Can we speak to a manufacturer you have worked with?
Meet the team at Advanced Engineering 2026
We are not exhibiting this year, so Justin, Jamie and I will be out and about at Advanced Engineering, NEC Birmingham, on 4 and 5 November, meeting manufacturers across the show. Book time with us for a coffee and a chat, and bring your last 12 months of electricity bills and a rough site plan if you have them; that is enough for a first view of what your roof could save.
Can't make the show, or would rather talk at a time that suits you? Book a free site assessment whenever you like on +44 (0)203 405 4896, email enquiries@edensustainable.co.uk, or visit edensustainable.co.uk/manufacturing.
Frequently asked questions about solar for manufacturers
Will installing solar interrupt production?
No. Eden schedules the installation around your operations, and the only stoppage is one planned shutdown at a time you agree, at the end of the project, to energise the system.
How much can a UK manufacturer save with solar?
It depends on your consumption and tariff, but manufacturers typically save 30 to 40% on the electricity the system supplies. Eden's manufacturing clients save between £41,000 and £500,000 a year.
Do we have to pay anything upfront?
Not under a Power Purchase Agreement. Eden funds, installs, owns and maintains the system, and you buy the electricity it generates at a fixed rate below grid prices for 25 years. If you prefer to own the system, a self-funded option is available.
What happens if we expand production?
Systems are designed with room to grow. Xtratherm Unilin started at 500 kW in 2016 and has expanded to 2.13 MW.
Does solar help with net zero targets and customer carbon requests?
Yes. On-site solar cuts the emissions from the electricity you buy and gives you measured generation data for carbon reporting, which helps when an OEM or larger customer asks about your emissions.
What if our grid connection limits how much we can export?
That is common and manageable. The system is designed so most of its output is used on site, and where the network operator caps export, a G100 export limitation keeps the system compliant.
