How to Tell If Your Solar Quote Is Fair
Getting your first solar quote can feel like being handed an exam paper in a language you don't speak. Kilowatt-peak, MCS certification, export tariffs, panel degradation rates — and somewhere in the middle of it all, a number you're meant to decide is fair.
The honest answer is that most homeowners can't tell whether a quote is good or bad just by looking at the bottom line. Two quotes for "the same size system" can differ by thousands of pounds and still both be defensible — or one of them could be quietly overpriced, undersized, or built around inferior kit. Here's what actually matters when you're checking a quote, before you sign anything.
1. Does the system size actually match your roof and your usage?
A well-designed system starts with your roof — usable space, orientation, pitch, and any shading from chimneys, trees or neighbouring buildings — and your household's real electricity consumption, not a generic assumption about what a "typical" home uses.
Be cautious of a quote that seems to default to "as many panels as will fit" without ever asking how much electricity you actually use, when you use it, or whether you're planning to add an EV or heat pump in the next few years. Oversizing wastes money on panels you'll rarely draw full value from; undersizing means you'll still be paying peak-rate electricity for years to come. A proper design should reference your usage, not just your roof.
2. Is the installer MCS-certified?
MCS (the Microgeneration Certification Scheme) accreditation is the baseline marker of a properly regulated solar installer in the UK. It matters for more than reassurance — it's what makes your system eligible for schemes like the Smart Export Guarantee (SEG), which pays you for electricity you export back to the grid.
If MCS accreditation isn't mentioned anywhere in the quote, ask directly. It's a simple yes/no question, and a legitimate installer will have the answer ready — and usually a certificate number to prove it.
3. What's actually in the equipment spec?
Panel and inverter brand matters more than most quotes make obvious. Two systems can look near-identical on paper — same kW rating, similar panel count — and still be built from very different quality equipment underneath.
Don't accept vague descriptions like "high-efficiency panels" or "premium battery." Ask for the exact make and model of the panels, inverter, and battery, then look them up. A few minutes of searching will usually tell you whether you're looking at well-established, well-reviewed equipment or something at the budget end of the market being sold at a premium price.
4. What are the warranty terms, really?
Solar warranties come in layers, and it's easy for a quote to lead with the most impressive-sounding one while glossing over the others:
Product warranty — covers the physical panels or inverter against manufacturing defects, typically 10–15 years.
Performance warranty — guarantees a minimum level of energy output over time (commonly 25–30 years for panels), usually with a gradual, specified degradation curve.
Workmanship warranty — covers the installer's own labour and installation quality. This is often the shortest of the three and the easiest one to miss, because it's about the installer, not the manufacturer.
Ask for all three, in writing, with actual durations — not just "fully warrantied."
5. What's the deposit and cancellation policy?
Under UK consumer law, you generally have a 14-day cooling-off period for contracts signed off-premises (for example, in your home after a sales visit). A reputable installer's contract will set this out clearly, along with deposit terms, rather than burying it in small print or pressuring you to commit on the spot.
Be wary of any sales approach that leans on urgency — "this price is only valid today" is a common pressure tactic, not a reflection of genuine cost volatility.
6. Does the price reflect the spec — or just the sales pitch?
Prices vary considerably for systems that look comparable on the surface. The only reliable way to judge whether a price is fair is to weigh it against the actual, itemised spec — panel brand and count, inverter model, battery capacity, warranty terms, and scope of installation work — rather than reacting to the headline number alone.
A lower price attached to weaker equipment or a thinner warranty isn't necessarily a bargain. A higher price isn't automatically better value either. The comparison only works line by line.
If you're not sure, get a second opinion
It's a significant purchase, and every installer who quotes you is — understandably — selling their own product. That's not a criticism of installers; it's just worth remembering when you're the one trying to judge whether a specific quote, from a specific company, is genuinely fair.
If you'd like an independent read on your quote from a company that isn't trying to install it, Giants Wood Solar offers a fixed-price, independent quote review — no installer relationship, no commission, no agenda. Just a straight answer on whether your quote stacks up, before you sign.