For a manufacturing business, electricity is part of the cost of making every product. When production runs through the day, rooftop solar can supply some of that demand as it happens, reducing the amount of electricity the business needs to buy.
Our projects for English Pewter and Daver Steels illustrate why solar panels for factories deserve a closer look. Both connect available roof space with the electricity needs of a working production site.
Why daytime production matters
The value of a commercial solar installation depends partly on when a business uses electricity. A factory operating during daylight hours may be able to use a substantial share of its solar generation directly.
This is called self-consumption: the proportion of solar electricity used on site instead of exported. It is different from the proportion of the factory’s total electricity demand supplied by solar. A business can use nearly all the electricity its panels generate while still buying additional power from the grid.
That distinction matters when assessing a proposal. The useful question is how much purchased electricity the system could replace across the working week, including quieter periods and shutdowns.
English Pewter: solar matched to production demand
For English Pewter, we installed a 106 kWp solar PV system across rooftop and flat roof areas. The project figures estimate annual generation of around 80,000 kWh, with approximately all of that electricity used on site.
At an assumed electricity value of 25p per kWh, that represents approximately £20,000 a year in avoided electricity purchases. These are project estimates, rather than a promise of savings for another factory.
The lesson is the close relationship between generation and consumption. Where production can absorb solar output during the day, the roof can make a direct contribution to reducing operating costs.
Daver Steels: a larger array serving a working steel business
Our Daver Steels project uses a 220 kWp solar PV installation across rooftop and flat roof areas. The project figures estimate around 174,000 kWh of annual generation, with approximately 95% consumed on site.
Using the same 25p per kWh assumption, that equates to roughly £41,300 a year in avoided electricity purchases before any export income. Actual savings depend on generation, consumption and the electricity tariff in place.
Daver Steels also describes rooftop solar as part of its wider environmental work, alongside changes to its vehicle fleet. Read Daver Steels’ account of its solar investment.
What should manufacturers check before installing solar?
Start with electricity data. Half-hourly consumption records help show how production shifts, weekends and seasonal changes line up with potential solar generation.
The building matters too. Roof condition, structural capacity, shading and access all influence the design. If roof repairs are approaching, it makes sense to consider them alongside the solar project.
Installation planning should also account for deliveries, production areas and any electrical shutdowns. These details belong in the project plan from the outset.
Finally, ask for the assumptions behind the financial forecast. A useful proposal separates generation, on-site use and exports, and shows the electricity prices used to calculate savings.
Could solar work for your factory?
English Pewter and Daver Steels demonstrate the opportunity for manufacturing businesses with suitable roofs and daytime electricity demand. Your system should be assessed against your own production schedule and energy use.
Speak to ComSol Energy about your site and explore how commercial rooftop solar could reduce your factory’s electricity costs.
