Before you sign

Questions to Ask a Solar Installer Before You Sign

Quick answer

Before you sign with a solar installer, ask who will fit the system, which panels, inverter and battery are included, how the generation estimate was worked out, what the workmanship and product warranties cover, how the deposit is protected and who to call if something goes wrong after installation. Get every answer in writing.

A good installer welcomes questions. The answers tell you more than any brochure: how carefully they design, who does the work and what happens if something goes wrong. Ask these questions, ideally by email, so you have the answers in writing.

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Last updated: 1 November 2026

Reviewed by the Scottish Energy Efficiency team.

Installer fitting a solar panel to a house roof during a Scottish home installation

Who will actually carry out the installation?

Short answer

Ask for the name of the company that will fit the system and whether it passes any of the work to another firm. Then check that company holds MCS certification for the work. Selling through one company and installing through another is common, but you should know who will be on your roof and whose name goes on the certificate.

We are open about this: systems are installed through MCS-certified partners, and the partner’s name appears on your quote. Ask every installer for the same clarity, and ask who you would call about a fault in year three.

What equipment are you quoting, exactly?

Short answer

Ask for the make and model of the panels, inverter and any battery, along with their datasheets. Named equipment lets you compare quotes properly and check warranties directly with the manufacturer. A quote that only says “premium panels” or “high-efficiency inverter” leaves too much room for a cheaper substitute later.

Ask whether any equipment could be swapped if stock runs short, and whether you would be told in advance. A fair contract says substitutes must be equal or better and agreed with you first.

Electrician installing a home battery storage unit alongside a solar system

How did you estimate how much electricity the system will generate?

Short answer

Ask to see the generation estimate and the shading assessment behind it. MCS-certified installers use a standard method based on roof direction, pitch, location and shading. The figure should be in kWh per year, and the installer should explain the assumptions behind any savings figure they show you.

Generation varies noticeably across Scotland, from the Borders to Shetland, and between a south-facing roof and an east–west split. Be cautious of any savings claim that is not based on your actual usage and tariff.

What warranties come with the system?

Short answer

Ask for every warranty in writing: panel product and performance, inverter, battery and the installer’s own workmanship warranty. Then ask whether the workmanship warranty is insurance-backed, so it is still honoured if the installer stops trading. Of all the questions here, this is one of the most important.

Ask how long each warranty lasts, what it excludes and how you would make a claim. Some manufacturer warranties only reach their full length if the product is registered, so ask whether the installer does this for you.

What happens after installation?

Short answer

Ask what paperwork you will receive, who tells your network operator about the system, and how monitoring and aftercare work. You should get an MCS certificate, an electrical installation certificate, warranty documents and a proper handover showing you how to use the system and its app.

Ask how quickly they respond to faults and whether call-outs are charged after the first year. Keep the MCS certificate safe: you need it to sign up for Smart Export Guarantee payments, and buyers will ask for it if you sell your home.

What else do homeowners ask?

Should I get the answers in writing?

Yes. Answers given by email become part of the record if there is a disagreement later. Most reputable installers will happily confirm details in writing or include them in the quote.

What deposit is reasonable?

Consumer codes limit deposits, and a modest deposit with the balance due on completion is common. Be cautious of any request for most or all of the cost upfront, and ask how your deposit is protected.

Should I ask about scaffolding and bird protection?

Yes. Scaffolding is usually needed and should be included in the price. Bird protection mesh is worth asking about in many parts of Scotland, especially where pigeons or gulls are common.

Can I speak to previous customers?

You can ask, and good installers often have customers happy to talk or local installations you can see from the street. Use this alongside independent reviews rather than relying on testimonials on the installer’s own website.

Can I spread the cost?

Interest-free credit up to £30,000, subject to status. Ask for the full terms in writing and compare the total repayable with paying from savings before you decide.

Which guide should you read next?

How to Choose an InstallerThe checks that matter, in the order that saves you the most time.Read guide Warranties ExplainedPanel, inverter, battery and workmanship cover, and who stands behind each.Read guide FAQStraight answers on quotes, finance, batteries and timescales.Read guide

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