Despite not being able to buy plug-in solar panels myself as I live in a first-floor flat with no outdoor space, I've been looking into them for months now as part of my job. As a result, I've learnt some key facts I think are worth sharing.
It's easy to jump on the bandwagon, assuming that as they are only a plug-in item you won't have any problem installing them, but cut through the noise and it's clear they aren't for everyone.
From planning rules to plug sockets, here's what you need to consider before you hand over your hard-earned cash for plug-in solar panels.
1. Mounting plug-in solar on timber will require planning permission
Although legally certified plug-in solar panels shouldn't be a risk to your home, where you mount them is still subject to restrictions.
Permitted development is often sufficient for solar panels, including plug-in ones, but since they have been legalised, the Town and Country Planning Act has been updated to reflect some new conditions. It now states that it does not apply: "in the case of plug-in solar, where any part of the plug-in solar would be installed on a wooden wall, balcony or enclosure or on any part of the exterior of a dwellinghouse where that part is clad in timber."
And it's for good reason too, explains Jon Skinner, founder of home energy company Glow Homes. “A sunny garden fence might look like the perfect home for a solar panel, but that does not mean it is safe or permitted. Timber cladding, timber balconies and other wooden surfaces can present fire, structural and planning issues, so this is not the place for a weekend DIY experiment.
“The mounting system is just as important as the panel," he continues, it must be designed for that particular product and capable of dealing with years of rain, frost and strong winds. If your plan involves spare brackets, a few screws from the shed and crossed fingers, stop and get proper advice.”
And, if your garden wall forms part of your boundary, there's also a risk you could face neighbour disputes if your panels cause a disturbance or damage to your wall – something every homeowner would rather avoid.
Jon Skinner is the founder of Glow Homes, a Surrey-based, but UK-wide residential energy company created to make home electrification clearer, better designed and easier to live with. Glow Homes takes a “home before hardware” approach, designing complete energy systems around each property, household and long-term ownership plan rather than simply selling individual products. Jon founded Glow Homes after experiencing the challenges of electrifying his own property and recognising the need for more joined-up advice. His approach brings solar panels, battery storage, inverter capacity, grid interaction, EV charging and future technologies into one considered system. With Glow Homes, he is building a premium, service-led business focused on careful design, quality installation and ongoing support throughout the lifetime of the home.
2. Rooftop solar and plug-in solar are not pieces of Lego
Think you can boost your energy efficiency and add some floor-mounted plug-in solar panels to your garden, as well as benefiting from the ones on your roof? Don't bother say experts – for several reasons.
“If you already have rooftop solar panels, you cannot assume that you can simply plug in another panel and carry on. Solar systems are not pieces of Lego. Your existing installation is already generating electricity and interacting with both the house and the wider network," explains Jon Skinner.
“Speak to your original installer and local network operator before spending any money. Plug-in solar is primarily designed to open the door for households that cannot have a conventional rooftop system, not as a casual bolt-on for homes that already have one," he expands.
How will anyone know? Even though plug-in panels are a temporary, rather than permanent fixture, you're still legally bound to report them to your local Distribution Network Operator (DNO). If you aren't sure how to do this, then going with an existing energy supplier, such as the plug-in panels being offered by Octopus might be a good idea as they can help guide you through the process.
3. Don't underestimate the size of the panels
While you can't try plug-in solar before you buy, you should absolutely size before you buy them as some models are bigger than you might expect. How do I know given I can't have them? When our content editor, Megan Milstead, was sent some to review, the photo she shared of them unpacked in her living room was met with gasps from myself and the rest of the team.
When the new technology was first announced, many referred to it as balcony solar, meaning it's perhaps easy to understand the confusion.
“People hear ‘plug-in’ or ‘balcony solar’ and picture something the size of a laptop," picks up Jon Skinner. "In reality, some products use panels much closer in size to those seen on rooftops. That can be quite a shock when a very large box arrives at the front door.
“Measure the space, the access route and the panel itself," he recommends. "Then consider whether you can position and secure it without blocking doors, windows or escape routes. A panel that technically fits but takes over half of a small garden is not a sensible installation."
Shop for plug-in solar panels
A compact model with with a hybrid mount for walls or floors
Double up with this dual panel kit from Argos that comes with a floor mount
This pre-built unit is ready to set-up on your patio or in your garden
4. The socket you plug into matters more than you think
Plug-in solar panels work in a similar way to rooftop solar but differ in that they come with a micro solar inverter which allows you to plug them directly into a socket. Phil Steele, future technologies evangelist at Octopus Energy explains more.
"The panels generate DC (direct current) electricity from sunlight. A micro-inverter then converts this into AC (alternating current) electricity – the type of electricity used by households and the electricity grid.
"The system automatically synchronises with the household’s electricity supply. Customers plug the system into a standard three-pin socket, and the electricity then flows into the home’s electrical circuit to help power appliances like fridges or TVs."
However, the type of socket you plug into holds a lot of importance.
“If the supplied cable does not reach the socket, an extension lead is not the answer," starts Jon Skinner. "Plug-in solar must use the manufacturer-supplied plug and connect directly to a suitable socket. Multi-way adaptors, travel adaptors and improvised cable arrangements are also out.
“For an outdoor connection, both the plug and outdoor socket need the correct protection against the British weather. If the right socket is not already in the right place, ask an electrician to install or assess one. Moving the socket is safer than trying to stretch the solar system towards it,” he advises.
Secondly, make sure that socket isn't old as well, adds Jon. “The solar technology may be brand new, but the socket it is connected to could be decades old. A loose, cracked, discoloured or damaged socket needs attention before a plug-in solar system goes anywhere near it," he warns.
“If you have older wiring, an ageing consumer unit or any uncertainty about the electrical condition of the property, get an electrician to take a look. Plug-in solar is meant to make generating electricity simpler. It does not make tired household wiring young again.”
Phil Steele is passionate about home tech and joined Octopus Energy in 2018. His role focuses on what Octopus can do with technology, how energy markets work, and how Octopus can make technology work within those energy markets.
5. Don't view them as a stand-alone energy source
Any energy savings you can make are of course a bonus, but as Jon Skinner states, you should think of plug-in solar panels as a gateway introduction, rather than a one-stop solution.
"Plug-in solar panels are a bit like using an umbrella during a rain shower: they are useful, affordable and accessible, but should not be mistaken for a permanent solution. An umbrella works. It keeps most of the rain off you, it is affordable and you can use it immediately. But you wouldn’t mistake it for properly weatherproofing your house," he expands.
“Plug-in solar is similar. It can be genuinely useful in its own right and a very good introduction to renewable energy, but it isn’t the same as designing permanent energy infrastructure around a home.
“The important thing is that we don’t confuse an introduction to solar with a complete long-term home energy system," he continues. "Both can have value, but they serve different purposes.”
Jon Skinner's final advice? A UK plug is not a UK safety certificate to installing plug-in solar panels without any comeback.
“Homeowners will inevitably find cheap plug-in solar kits on overseas marketplaces, but the presence of a three-pin plug does not prove that the system is approved for use in Britain. Look for clear UK compliance information, proper instructions and an approved, type-tested inverter so that you buy legally approved plug-in solar panels.
“This is a small power station connected directly to your home’s electrical system. Saving a little money on an unverified product is a poor trade if the instructions are vague, the certification cannot be checked or the seller disappears the moment something goes wrong," he warns. And, when the rules surrounding plug-in solar and home insurance are also yet to be completely defined, it's wise to start on the right foot so you don't encounter any problems in the future.
