Commercial Solar Panel Installers in the UK
Choosing the right commercial solar installer matters more than choosing the right panel. The UK has over 4,000 MCS-certified solar companies, but only a fraction have genuine commercial experience with three-phase systems, G99 grid applications and structural engineering. This guide shows you how to find and compare commercial solar companies, what to check before you sign, and lists MCS-certified installers in every UK county.
Quick Answer
To find a reliable commercial solar installer in the UK, shortlist MCS-certified companies with a commercial portfolio, check RECC or HIES membership and G99 experience, and compare at least 2-3 like-for-like quotes. Solar Info UK lists MCS-certified installers in all 109 UK counties.
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How to choose a commercial solar company: 6-point checklist
1. MCS certification
MCS (or Flexi-Orb) certification is the baseline. It is required for Smart Export Guarantee payments and most commercial funding. Check the company, not just an individual engineer, is certified. See our MCS certification guide.
2. Commercial portfolio
Ask for 3+ completed commercial projects of similar size to yours, with references you can call. A photo gallery of domestic rooftops is not evidence of commercial capability.
3. G99 / DNO experience
Commercial systems need a G99 application to your Distribution Network Operator before connection. Experienced commercial installers manage this for you and know how to handle export limits and grid constraints.
4. Structural sign-off
A professional commercial installer arranges a structural engineer's report before quoting a final price. Be wary of any company willing to load 15+ tonnes onto your roof without one.
5. Insurance and warranties
Check public liability (£5m+ for commercial), employer liability, and what happens to your workmanship warranty if the company ceases trading. Insurance-backed guarantees via HIES or RECC protect you.
6. In-house team
Ask whether design, installation and electrical work are done in-house or subcontracted. In-house teams give you one point of accountability if something goes wrong.
Questions to ask every commercial solar installer
- How many commercial systems of this size have you installed in the last two years?
- Who handles the G99 application, and is DNO approval a condition of the contract?
- Is a structural survey included in the quote, and who carries out the report?
- What are the product, performance and workmanship warranty terms, and are they insurance-backed?
- What is the projected annual generation, and is it based on a site-specific shading analysis?
- Can you model the savings against our actual half-hourly electricity data?
- Do you offer or arrange funding options (capital purchase, lease, power purchase agreement)?
Commercial solar installers by county
We list MCS-certified solar installers in all 109 UK counties. Pick your county to see commercial solar guidance and installers working in your area.
Commercial solar by building type
Costs, payback and practicalities differ by sector. See our dedicated guides:
Commercial solar installer FAQ
How do I find commercial solar panel installers near me?
Start with the MCS register of certified installers, then shortlist companies with a commercial portfolio (not just domestic work). Solar Info UK lists MCS-certified installers in all 109 UK counties, so you can compare companies working in your area and request quotes from several at once.
What certifications should a commercial solar company have?
Look for MCS certification (or Flexi-Orb), membership of RECC or HIES, experience with G99 DNO applications for larger systems, and appropriate insurance including public liability of £5m+ for commercial work. For roof work, check CHAS, SafeContractor or Constructionline accreditation.
How many quotes should I get for commercial solar?
Get at least 2-3 quotes from installers with commercial experience. Commercial projects vary far more than domestic ones, so quotes can differ by 20-30% for the same roof. Make sure each quote covers the same system size, panel brand and warranty terms so you can compare like for like.
Do commercial solar installers handle planning and grid applications?
A competent commercial installer manages the G99 grid application to your DNO and advises on planning. Most commercial rooftop solar falls under permitted development, but listed buildings, conservation areas and ground-mounted systems above 9 m2 need planning permission.
What is the difference between a domestic and commercial solar installer?
Commercial installers work at a different scale: three-phase systems, G99 grid applications, structural engineering sign-off, CDM regulations for construction safety, and commercial financing options like power purchase agreements. A company that only fits 4 kW domestic systems is rarely equipped for a 100 kWp warehouse project.
Related guides
- Commercial solar panels UK: the complete guide
- Commercial solar panel costs
- Commercial solar battery storage
- Best solar installers UK
John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He researches every battery and inverter brand against manufacturer datasheets, MCS and Ofgem data, and feedback from the MCS-certified installers in our directory before publishing.
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