By Alistair Brown, CEO of LumenStream
Last updated: 31 July 2026
Replace the legacy lighting in an industrial facility with LED and you cut lighting electricity by 65 to 85% where halogen is coming out.
Where the outgoing fittings are fluorescent or high-intensity discharge, the saving is around 20% (Carbon Trust). Because lighting runs on purchased electricity, every saved kWh comes straight off your Scope 2 emissions: 0.131 kg of CO2e per kWh under the 2026 government conversion factors. And the work happens above your production line, not inside it. At Ryobi Aluminium Castings UK, one of our UK customers, the entire upgrade was installed during normal operating hours in a plant that manufactures 24/7.
This article covers how much carbon an LED upgrade removes, why lighting is usually the fastest Scope 2 cut on an industrial site, how the installation works around production, and how the result shows up in ESG and SECR reporting. It is written for the people who own a carbon target and cannot stop the plant to hit it.
How much carbon does an LED lighting upgrade actually cut?
On the UK grid, every megawatt hour of electricity an upgrade saves removes roughly 0.13 tonnes of CO2e from your Scope 2 total, using the DESNZ 2026 conversion factor of 0.131 kg per kWh.
The percentage saving depends on what you are replacing.
The Carbon Trust puts the saving from swapping halogen for LED at 65 to 85% (2014 research, still its most recent published figure), and at around 20% where the outgoing technology is compact fluorescent or high-intensity discharge. Most industrial facilities still run one of those two. Add occupancy and daylight controls and the saving grows again, because a zoned system stops lighting empty areas at full output.
Scope 2 is where the tonnes come in.
Scope 2 covers the emissions from the electricity you buy. A lighting upgrade shows up as a direct reduction in a number you already track: fewer kWh through the meter, multiplied by the published conversion factor, equals fewer tonnes. There is no modelling and no offsetting involved.
For example, at Ryobi Aluminium Castings UK, one of our UK customers, replacing 218 fluorescent fittings with LED at a high-pressure die-casting plant saves 72 MWh and 48 tonnes of CO2 a year, a 51% increase in energy efficiency.
Two conditions come with these numbers:
- The saving is relative to what comes out. A site still running metal halide, sodium or fluorescent has the most to gain; a site that fitted quality LED three years ago will not see anything like these ranges.
- The conversion factor is updated every year as the grid changes, so state a carbon saving against the factor for the reporting year in question, not the year the lights went in.
Why is lighting the fastest Scope 2 reduction available?
Because lighting is a large electricity load that can be replaced outright, in weeks, without redesigning anything else on the site.
Lighting typically consumes 20% of the electricity used in commercial and industrial buildings (Carbon Trust), and in an industrial facility that load is worked hard: high bays running full shifts, some around the clock. A percentage saved on lighting keeps paying back every hour the plant operates.
The speed comes from what the upgrade does not touch.
Cutting carbon from process heat, compressed air or a vehicle fleet means changing how the plant works, and that carries engineering risk, approval cycles and downtime. A lighting upgrade replaces the fittings above the process and leaves the process alone. No planning application, no new infrastructure, no retraining.
That is why lighting earns its place as the first project on a net zero plan: the savings it releases can help fund the harder measures that follow. We make that case in full, against solar, EV fleets and heat pumps, in Why 'Lighting First' Should Be Your Business's First Step to Net Zero.
How is an LED upgrade delivered without stopping production?
In sections, planned around your shift pattern, with no changes to your processes, machinery or building layout.
A proper installer starts from your operating constraints. There are three ways an industrial installation is usually scheduled:
- In phased sections, so one area is isolated and re-lit while the rest of the facility runs normally.
- Out of hours, where night windows or planned shutdowns exist.
- During live operating hours, with luminaires safely isolated and replaced one at a time, for sites that never stop.
The third route matters most in manufacturing.
Ryobi's die-casting plant runs 24/7, so there was no downtime window to borrow. The installation was planned in two phases, delivered during regular operating hours, and completed in a few days with no downtime.
Speed is the other half of low disruption.
For example, at Fedrigoni Self Adhesives, one of our UK customers, we replaced a first-generation LED system installed roughly ten years earlier with 232 new fittings plus motion sensors and daylight-harvesting controls. The new system saves 47 MWh and 32 tonnes of CO2 a year.
Mike Wilkins, Fedrigoni's Environmental Health & Safety Manager, said:
"Everyone was amazed at how quickly the installation was completed. The results have impressed everyone, and we've had positive feedback across departments. The spaces look brighter, clearer, and the response has been overwhelmingly positive."
If your own estate went LED a decade ago and you are wondering whether round two is due, Is Your Manufacturing LED Lighting System Due for an Upgrade? covers the warning signs.
None of this works without the survey and lighting design done before anyone touches a fitting. We cover that side of an upgrade in What Facilities Managers Need to Know About Lighting.
How does a lighting upgrade show up in ESG and SECR reporting?
As a metered fall in kWh and Scope 2 tonnes: the same numbers SECR already requires large UK companies to publish.
Under Streamlined Energy and Carbon Reporting, quoted companies and large unquoted companies and LLPs report their annual UK energy use, the associated greenhouse gas emissions, an intensity ratio, and the energy-efficiency action they have taken in the year. A lighting upgrade feeds all four lines at once.
| SECR asks for | What the upgrade gives you |
|---|---|
| Annual UK energy use | A metered kWh reduction |
| Greenhouse gas emissions | Saved kWh multiplied by the published DESNZ factor |
| Intensity ratio | A lower numerator from the same output |
| Energy-efficiency action taken | The upgrade itself, with a start date |
The reporting advantage is that lighting data is clean.
The kWh saving is metered, the conversion factor is published by DESNZ, and the project has a start date. That gives a sustainability lead a before-and-after an auditor, a customer questionnaire or a tender panel can check, with no assumptions to defend.
The same project also reads well beyond the environmental line. Better light quality on the floor is a working-conditions improvement your social reporting can point to, and auditable energy data strengthens the governance side. At Ryobi, staff had been asking for better lighting long before the carbon case was made; after the upgrade, lux levels rose to over 500, in line with UK manufacturing standards.
What does an industrial LED upgrade cost upfront?
Nothing, if it is delivered as Lighting as a Service.
With Lighting as a Service, we survey, design, fund, install and maintain the system, and you pay one fixed monthly fee out of the energy savings: fixed for the full term, zero indexation. Whether the agreement sits on your balance sheet depends on how it is structured. The accounting rules changed for periods beginning on or after 1 January 2026, so ask your accountant and see the full answer in What is Lighting as a Service?
One honest qualification.
This model is not right for every site. Very small premises, short leases, and estates already running recent, healthy LED do not generate enough saving to carry a service fee. If that is your position, the right answer is to keep your money, and we will tell you so after the survey.
