Solar installations have increased sharply across Scotland over the last two years, and so has the number of companies offering them. Some are excellent. Some are not. Here’s how to tell the difference before you commit.
1. MCS certification — non-negotiable
MCS (Microgeneration Certification Scheme) is the industry standard for solar installations in the UK. An MCS-certified installer has been assessed against quality and safety standards and is independently audited. Without MCS certification, you won’t qualify for the Smart Export Guarantee, and many finance schemes and warranties become void.
Check the MCS installer database at mcscertified.com before any conversation goes further. If they’re not listed, walk away.
2. TrustMark registration
TrustMark is a government-endorsed quality scheme for tradespeople. It’s an additional layer of accreditation that not all MCS installers have. It matters because TrustMark-registered businesses carry additional consumer protections and dispute resolution access if things go wrong.
3. Local presence and accountability
A company with a local office, local staff, and a local track record is very different from a national or online-first operation that subcontracts to whoever is available. If something needs fixing in year three, you want someone who answers the phone and can be there within a day or two — not a call centre routing you through a warranty claims process.
Ask: where are your engineers based? Who will actually be on my roof?
4. What they install — and why
Ask any installer what panels and batteries they use, and why. A confident, knowledgeable answer should cover cell technology (N-type vs P-type), degradation rates, warranty length, and low-light performance. Vague answers (“we use good quality panels”) are a warning sign.
The same applies to batteries. LFP chemistry is the standard for home storage — longer cycle life, safer chemistry, better suited to daily use. If they’re installing NMC batteries and can’t explain why, push back.
5. Detailed written quote — fixed price
Your quote should be itemised: panel make and model, battery make and model, inverter, fixings, labour, and any scaffolding costs. It should be a fixed price, not an estimate. If the quote is vague or the price is “subject to a site survey”, that’s fine — but the post-survey quote should be fully itemised and fixed.
Never pay a large deposit before receiving a detailed, fixed written quote.
6. References and reviews
Look beyond the testimonials on their own website. Check Google reviews, Checkatrade, and Trustpilot. Look for reviews that mention the quality of the installation, how issues were handled, and whether the projected savings matched reality. A pattern of complaints about communication or after-sales service is worth taking seriously even if the overall rating is decent.
7. After-sales support and monitoring
A solar and battery system should come with a monitoring app that lets you see generation, consumption, battery state, and export in real time. Ask your installer how they handle faults — what’s the response time, who carries out warranty repairs, and are they using components with UK-based technical support?
The installation is one day. The relationship is 25 years.
The honest question to ask yourself
If this company doesn’t exist in five years, what happens to my warranty and ongoing support? Installers backed by established businesses with long track records in related trades — roofing, construction, electrical — are more likely to still be around.
Speedy Solar is part of the Speedy Roofing group, which has been operating across Scotland since 2011. We’re MCS certified, TrustMark registered, and all our engineers are Scotland-based.
