Why flat commercial roofs are well-suited to solar

Flat roofs give the flexibility that pitched roofs don't, because panels can be mounted pointing south regardless of how the building is oriented. That's why retail units, warehouses, factories and commercial properties with large flat roofs tend to generate substantial energy throughout the day.

Many commercial buildings have flat roof spaces that aren't being used for anything. Solar turns them into something that pays back within a few years and continues generating for decades after that.

A real flat-roof example

Ashley is currently designing a system for a carpet and interior design warehouse in Bolton with a large flat roof. They spend £700 a month on electricity. His 50-panel flat-roof design takes that to zero with a three-year payback. A larger 115-panel option, covering both the flat roof and the pitched sections, pays back in four years.

That's the typical pattern: most commercial installations reduce monthly costs by 70-100%, with payback within 3-4 years and 20+ years of low-cost energy after that.

Who you'd be hiring

Ashley Merritt is the named director of Renegade Solar. He's been an electrician for 20+ years, ten of those on commercial projects, including electrical work on industrial sites such as the Jersey Recycling Centre.

For a commercial flat-roof job, the practical implication is that the person who walks your roof, the person who quotes the job and the person on site for the install are all the same person. Ashley personally surveyed the Bolton roof and personally designed both the 50-panel and 115-panel options for that client. The same approach applies to your job.

Why flat roofs work brilliantly

The advantages compared to pitched roofs:

• Panels point south regardless of how the building is oriented, because they're mounted on tilted frames at the optimum angle, so a building running east-west still produces like one running north-south
• System design tends to be simpler, since large unobstructed flat roofs can take bigger arrays
• Access for installation and any future maintenance is easier
• Visual impact is lower, because panels on a flat roof typically aren't visible from ground level

For commercial solar on the right building, that combination is hard to beat.

What kinds of buildings work

Ashley typically designs flat-roof commercial systems for:

• Warehouses and distribution buildings, which are usually owner-occupied with large roofs and daytime electricity use (dedicated page)
• Retail units such as cash-and-carry, furniture stores, carpet warehouses and supermarkets
• Factories and industrial units with three-phase supplies and high consumption (dedicated page)
• Hotels and hospitality properties where kitchens, heating and laundry run through the day (dedicated page)
• Owner-occupied office buildings

What about pitched roofs?

If you have pitched roofs as well as flat ones, those can usually be incorporated. The Bolton job is a good example, with the larger design using both flat and pitched sections to maximise generation.

What you need to qualify

The main requirement is that you own the building. You'll also need high enough electricity consumption to give a strong return (the more you spend, the faster the payback) and a plan to keep the property long-term.

Because commercial properties consume electricity during the day when solar generation is at its peak, you use nearly every kilowatt-hour your panels produce, so you don't need battery storage to make the numbers work. That dramatically improves the return on investment.

Credentials

• MCS-certified installer (NAP-66870)
• Octopus Energy Trusted Partner
• 20+ years' experience as an electrician, including 10 years on commercial projects
• 9.85/10 on Checkatrade from 105+ verified reviews

Coverage across Greater Manchester

Based in Prestwich, Ashley designs and installs flat-roof commercial solar throughout Greater Manchester and the wider North West.

Contact Ashley for a free flat-roof commercial solar survey and a financial breakdown.