Guide
Commercial solar panel costs in the UK, broken down
Two quotes for the same roof can differ by thirty percent and both be honest. The difference is nearly always scope. Here is what sits inside a commercial solar price and which parts can be funded.
The short version
- Panels are often less than half the installed cost on a commercial roof.
- Access, roof condition and cable runs drive more price variation than panel brand.
- Almost all of an installed system can be funded, including labour and commissioning.
- Get the survey done before comparing prices seriously.
The cost lines that matter
Ask every installer to price the same list. If one is missing an item, the comparison is meaningless.
- Panels, with the warranty term and degradation guarantee stated.
- Inverters, and whether the design is string, central or micro.
- Mounting system, ballast or fixings, and any roof penetration detail.
- DC and AC cabling, containment, isolators and the distribution board works.
- Access: scaffolding, mewps, edge protection or a mansafe system.
- Roof survey, structural report and any strengthening required.
- G99 or G98 application, witness testing and commissioning.
- Monitoring platform and any recurring fee attached to it.
What drives the variation
On a like for like scope, the biggest price movers are physical rather than commercial. A single storey unit with clear access and a short cable run to the switch room prices very differently from a three storey building with a long DC run and a fragile roof.
Asbestos cement roofing, in particular, changes both the method and the cost, and needs identifying at survey rather than after the order.
What can be financed
Almost all of an installed array can sit inside an asset finance facility, including the labour element, which surprises businesses who assume finance only covers hardware.
- Normally fundable: panels, inverters, mounting, cabling, access equipment, commissioning and the monitoring hardware.
- Assessed case by case: significant roof strengthening or recovering, because it is a building improvement.
- Usually outside the facility: DNO charges, planning fees and ongoing monitoring subscriptions.
Where this applies
FAQs
Common questions
The questions that come up most often on this subject.
What is the cost per kWp for commercial solar in the UK?
Indicatively, £800 to £950 per kWp for small systems under 50 kWp, £700 to £850 between 50 and 250 kWp, and £600 to £750 above that. Access difficulty, roof type and cable runs move these figures more than panel choice does.
Why is one solar quote much cheaper than another?
Usually excluded scope. Common omissions are scaffolding or access, the structural survey, roof remediation, distribution board works and commissioning. Compare the itemised lines and the warranties, not the total.
Can the installation labour be included in solar finance?
Yes. On energy projects funders expect a significant labour and works element and will fund it as part of the installed asset, provided the scope is clearly itemised on the invoice or contract.
Do I need a structural survey before financing solar?
For a rooftop array, effectively yes. The installer will need it for the design and a funder wants comfort that the roof will carry the system for the length of the term.