What to Look For in Solar Panels

Efficiency and output

Panel efficiency affects how much electricity you get per square metre. It matters most when roof space is limited — if you have plenty of room, a slightly less efficient panel can be better value. What counts is the estimated annual generation for your roof, which a good quote will state.

Warranties

Check three separately: the product warranty (manufacturing defects), the performance warranty (guaranteed output after 25 years) and the installer’s workmanship warranty. Long warranties are only worth as much as the company behind them.

The inverter

Often overlooked, but it is the component most likely to need replacing during the system’s life. Ask which inverter is quoted and what warranty it carries — see how the inverter fits in.

MCS certification

Use an MCS-certified installer. It is normally required for Smart Export Guarantee eligibility and is a baseline sign of accreditation.

Questions worth asking

• What annual generation do you estimate for my roof, and how did you calculate it?
• Is the price itemised — panels, inverter, battery, scaffolding, labour?
• Who handles aftercare and warranty claims?
• Are you MCS-certified?

This article is general information. Costs and savings vary by property, energy use and tariff.