How to Compare Solar Panel Quotes
Compare solar quotes on the same basis. Check the system size in kWp, the named panels and inverter, the expected yearly output, the warranty terms, the MCS certificate and what the price includes, such as scaffolding. Get at least three quotes, and check each installer’s MCS number yourself before you sign.
Why quotes are hard to compare
Two quotes for the same roof can differ by thousands of pounds. Sometimes the cheaper one is simply smaller or leaves out scaffolding. Because there is no standard layout, you need to line the items up yourself.
A fair comparison starts with the same facts. Give each installer the same bills, the same roof details and the same questions. Then compare what each one offers, because the total alone can mislead.
What every quote should include
Use this table as a checklist. If a quote leaves out an item, ask the installer to add it in writing.
| Item | What to look for |
|---|---|
| System size | Total in kWp, and the number of panels |
| Panels | Make, model and wattage |
| Inverter | Make, model and warranty length |
| Expected output | Yearly kWh, with the roof direction and shade assumptions |
| Mounting and scaffolding | Whether both are included in the price |
| Certification | MCS certificate and grid paperwork included |
| Warranties | Panels, inverter, workmanship, and who backs them |
| Payment terms | Deposit, stage payments, and what protects your deposit |
Check the installer, not just the quote
While a quote shows the price, the certificate shows the standard. Ask for the company’s MCS certificate number and search for it on the MCS website. Check that it covers solar PV and that it is current. Our page on MCS-certified installations explains what the certificate does and does not tell you.
Also ask which consumer code the firm follows, such as RECC or HIES, and check that too. Consumer codes set rules on contracts, deposits and complaints. Because protection comes mainly from the code, it matters as much as the price.
Work out the price per kWp
Divide the total price by the system size in kWp. For example, a £7,000 quote for a 3.5 kWp system works out at £2,000 per kWp. Do the same for each quote, then compare the results.
This simple sum helps you spot odd offers. A much lower figure may mean thin equipment or missing items, while a much higher one needs a good reason. Our guide to how much solar panels cost shows typical ranges.
Questions worth asking
Good installers answer these without fuss. Ask who will do the work, and whether they use subcontractors, since someone else may hold the certificate. Ask how long the installation will take and how the firm handles the roof if it rains.
Ask what happens after commissioning, because the paperwork matters. You want the MCS certificate, the Smart Export Guarantee paperwork and clear guidance on monitoring. Our guide to selling electricity back to the grid explains why the certificate matters for export income.
Red flags
Watch for pressure to sign quickly, since good offers can wait a few days. Other warning signs include prices that are valid only today, and requests for a large deposit up front. Be careful with firms that cannot show an MCS number or that refuse to put promises in writing.
Be wary of claims that sound too good, such as “free solar” or guaranteed savings. Our guide to free solar panels explains how to read such offers. Similarly, treat any promise of a fixed payback with caution, because savings depend on your use.
Think about the extras
Decide early whether you want a battery or an EV charger, because quoting them together can save scaffolding and labour. Read our guide on whether solar batteries are worth it before you add one.
Also check the grid side, since the network operator must approve the connection. Your installer should handle that paperwork, so ask which route applies to you. Our page on solar panel installation explains the steps.
Local points
Local factors can change a quote, because roof types, scaffolding access and planning rules differ between places. See our local guides to solar panels in Birmingham, solar panels in Sheffield, solar panels in London and solar panels in Nottingham.
Sources
Want comparable quotes? Use our contact form and we will pass your enquiry to MCS-certified installers who cover your area.
More solar guides from Y Solar