Solar panels, inverters and batteries explained

A home solar system has several parts that need to work together. Your installer should explain what each one does and why they have chosen it for your roof.

Solar panels

Panels turn daylight into electricity. Compare the number of panels, their size and power rating, and how they fit on your roof.

Ask about both warranties: the product warranty covers faults, while the performance warranty describes how output is expected to hold up over time. Check what labour and replacement costs are covered.

The inverter

The inverter converts electricity from the panels into the type your home uses. It needs to suit the panels and any battery.

Ask where it will be fitted, how long its warranty lasts and who will help if it fails. It may need replacing before the panels.

Optimisers and microinverters

These devices work with individual panels and can help with some roof layouts or shading problems. They add cost and equipment, so ask what benefit they would bring to your particular roof and how a faulty unit would be replaced.

A battery

A battery stores electricity for later. Ask how much electricity you can use from it, how much power it can supply at once and whether it works during a power cut.

Compare the price with and without a battery. Our battery guide explains what to look for.

The roof fixings

The frames and fixings must hold the panels securely and keep the roof weatherproof. Ask how the roof will be checked and who is responsible if the installation causes a leak.

The monitoring app

An app can help you see what the panels are generating and how the battery is being used. Ask whether it costs extra, whether you will own the account and how you can get support. Check what happens if the app service closes.

Get these details in writing

• The exact panel, inverter and battery models.
• A roof layout and explanation of how the equipment works together.
• The full fitted price, including any app or monitoring charges.
• Product and installation warranties, including labour.
• Who handles repairs and how to contact them.
• Instructions for normal use, shutdown and maintenance.

Use our quote checklist before agreeing to the installation.