Are plug-in solar panels dangerous? Experts reveal the factors that could pose a risk to your home and how to avoid them

The benefits of solar power are now available to more people than ever before. Thanks to a legislation change, plug-in solar panels are now legal in the UK, and once on sale, are significantly more affordable than traditional rooftop solar panels.

While there are lots of differences between rooftop solar panels and plug-in versions, the installation is arguably one of the biggest. Plug-in solar panels are designed to be plugged into an electrical socket on a DIY basis, with no professional input required. But questions have been raised as to how safe that is, when not every home's electrical system is the same.

So how do you know if plug-in solar panels will be safe to use in your home? Well, I asked the experts to find out.

Are plug-in solar panels dangerous?

Plug-in solar panels themselves aren't dangerous, but there is concern that connecting a plug-in solar panel to an old or faulty socket could be.

'Plug-in solar panels, sometimes called balcony solar or Shuko solar systems, connect directly into a standard household socket,' explains John Collett, Director of Quantum Renewables. 'The primary risk arises in homes with older or faulty wiring. If the household electrical installation is not in good condition, adding any additional load including a solar panel can create a risk of overheating at plug sockets or junction points.'

'Plug-in solar panels can be safe when used correctly, but they aren’t quite the same as plugging in a standard household appliance,’ adds George Penny, Solar Panel Expert and Director at The Solar Co. ‘They introduce a new source of electricity into the home, so existing weaknesses in the wiring could create an electrical or fire risk.

'Homes with ageing wiring, worn components, previous DIY alterations, inadequate earthing or a lack of modern protective devices may require electrical work before plug-in solar can be used safely.'

But it's not just your electrical system that could prove problematic; there are other ways that plug-in solar could pose a risk to your home and safety, including improper installation. George Penny explains: 'Incorrect installation or use could also make a plug-in solar system dangerous. A typical rigid solar panel weighs around 20 to 25kg, so an 800W system containing two panels could add approximately 40 to 50kg before any mounting equipment is included.

'That weight could damage an older or weakened fence or shed roof, particularly when combined with strong winds. That’s why it’s essential to check for rot, cracks or sagging and make sure the structure and fixings can safely support both the panels’ weight and wind loading.'

Using unsuitable connectors could also pose a risk, especially if they are not designed for outdoor use.

'Sockets, cables and connectors should also be suitable for outdoor use and protected from water, dust and physical damage,' adds George. 'Never use a standard extension lead, trap a cable through a window or door, or daisy-chain multiple panels. Adding equipment that the system or household circuit isn’t designed to handle could cause components to overheat.'

It's also important to check you have the necessary permissions in place before you attempt an installation. 'Renters should also get their landlord’s permission before drilling into or attaching panels to fences, balconies, walls or sheds,' concludes George.

How to use plug-in solar panels safely

'Anyone considering a plug-in solar system should have their consumer unit and wiring checked by a qualified electrician first, particularly in properties built before the 1990s,' suggests John Collett.

You should also make sure you are only buying panels that meet the required safety standards. Those sold in this country through reputable retailers will meet those standards, but beware if you are buying online and if they look like they may be delivered from overseas. 'Only purchase systems that are certified to UK and EU safety standards,' adds John. 'Check for the CE mark and confirm the system has been tested to EN 62109 standards for inverters.'

In further buying advice, Electrical Safety First says you should only buy from reputable high street retailers and their websites, rather than through third party retailers on online marketplaces, that currently have no legal responsibility for the safety of the products they sell.

You should also make sure that you follow any installation and set-up instructions exactly. 'My advice to anyone picking one up at their local Lidl: keep expectations realistic, follow the manufacturer's instructions to the letter, and don't be tempted to daisy-chain panels or run them through extension leads,' advises George.