How to Choose a Solar Installer
The most important step in choosing a solar installer is confirming they hold current MCS certification - the quality standard required for your installation to qualify for the Smart Export Guarantee and government incentives. Beyond that, the key is getting at least three quotes, asking the right questions, and knowing which red flags to walk away from. The solar market includes excellent installers and poor ones; the process below helps you tell them apart.
Start With MCS Certification
MCS - Microgeneration Certification Scheme - certification is non-negotiable. Verify any installer’s current certification status at mcscertified.com before agreeing to a survey or quote. Certification can lapse, so check it yourself rather than taking an installer’s word for it.
Get at Least Three Quotes
Prices for the same system can vary by £1,500 or more between installers. Getting multiple quotes also reveals differences in system design recommendations - if one installer proposes a 3 kWp system and another proposes 4 kWp, asking why tells you how thoroughly each has assessed your home. For context on what a system should cost, see our costs guide.
No reputable installer will pressure you to commit before you have had time to compare. If you feel rushed, walk away.
Questions to Ask Every Installer
Ask these questions of every installer you invite to quote:
- What system size are you recommending, and why?
- Have you assessed shading at different times of day and year?
- How will you handle the DNO - Distribution Network Operator, your regional grid company - notification process, and is that included in the quote?
- What warranties come with the panels, inverter, and installation workmanship?
- What monitoring and aftercare do you offer once the system is commissioned?
A good installer will answer these clearly and without hesitation. Vague answers on warranties or DNO process are worth probing further. A thorough roof suitability assessment should be part of every site survey.
Red Flags to Watch For
Walk away from any installer who:
- Cannot or will not provide proof of current MCS certification
- Quotes without a site visit
- Offers a price that seems significantly below the market range without explanation
- Pressures you to sign on the day of the survey
- Cannot clearly explain what warranties cover and for how long
Frequently Asked Questions
How many solar installer quotes should I get?
Get at least three quotes. Prices for identical-sounding systems vary significantly between installers, and comparing quotes also reveals differences in system design recommendations and proposed equipment. There is no obligation to accept any quote, and no reputable installer will pressure you to commit before you are ready.
What does a site survey involve?
A site survey typically involves an installer visiting your home to assess your roof orientation, pitch, and condition; identify any shading from trees, chimneys, or neighbouring buildings; review your electricity consumption data; and discuss your priorities - whether payback speed, output maximisation, or battery storage. A proper survey takes 30-60 minutes. Be wary of installers who quote without visiting.
What warranties should a solar installation include?
A complete installation should include: panel performance warranty, typically 25 years; panel product warranty, typically 10-12 years; inverter warranty, typically 5-10 years, with extensions available; and installer workmanship warranty, typically 1-2 years but varying significantly. Confirm each warranty in writing before signing. Understand who you contact if the manufacturer of any component ceases trading.
Is a cheaper quote always worse?
Not necessarily - a lower quote may reflect lower overheads rather than lower quality. However, a quote significantly below the market range without a clear explanation is a warning sign. Check that the quote includes everything: scaffolding, DNO notification, commissioning, and all warranties. A low headline price that excludes these items may not be as competitive as it appears.
Should I use a national company or a local installer?
Both can be excellent. National companies offer standardised processes and established after-sales support structures. Local installers often have lower overheads and stronger reputations to protect in their immediate area. The most important factors are MCS certification, clear answers to your questions, and positive verified reviews - not company size.