Despite this summer bringing hours of sunshine, many Britons have been unable to cash in on free electricity generated by the sun. Rooftop solar panels are usually out of the question if you live in a flat or rent your home, and the cost has made them prohibitive to many more households.
However, this could be about to change because next week the first wave of low-cost “plug-in” solar panels will go on sale in Great Britain.
Also known as “plug‑and‑play” or “balcony” solar, the clue to what makes them different is in the name: you can fix them to a balcony or garden wall, then plug them in like a toaster.
The mini solar systems are a familiar sight on balconies in Spain and in Germany, where they are known as a Balkonkraftwerk (balcony power plant), but until a recent change in the law, they were not permitted in Britain.
Matt Parry from the Renewable Energy Association, a trade body for renewable energy, says the kits are a gamechanger. “It democratises solar and gives everyone the chance to get it,” he says.
How the kits work
Unlike traditional rooftop solar panels, which require a professional to install, balcony solar kits – which commonly include one or two panels – can be plugged in to a three-prong wall socket.
You can fix them on a balcony railing, shed roof or garden wall – anywhere with good sun exposure and safe access.
When sunlight hits the solar panels, they generate a direct current. The microinverter then converts this to an alternating current, which flows into your home’s electrical system, reducing the amount you draw from the grid.
Previously, rules around the installation of solar were what was holding people back. But last year the government announced it would make it possible for plug-in solar to be used in this country.
To make this a reality, it has updated wiring regulations to allow households in Great Britain to connect plug-in solar panels capable of generating up to 800 watts of power into the mains without the need for an electrician. (The rules are different in Northern Ireland.)
Buying panels
Big names including B&Q, Currys, Lidl, Wickes and Amazon are lining up to sell plug-in solar.
Given the size (and weight) of these devices, it is expected that many will be bought online.
Although you may have already come across plug-in solar panels for sale, industry experts suggest waiting until the regulations take effect on 27 August before making a purchase.
Electrical Safety First, the consumer safety charity, is urging shoppers to stick to reputable high street retailers and their websites to ensure the device complies with the rules.
Luke Osborne, the charity’s technical director, advises people to “avoid buying these devices from third-party sellers on online marketplaces. These platforms are now not legally responsible for the safety of goods sold via their sites, exposing people to substandard versions that may put you and your home at risk.”
Andrew Moore, the founder of the British solar panel brand UKSOL, says: “We are working towards making the initial products available from 27 August.”
His company will initially sell 460W and 890W kits, starting at £599 and £999 respectively, and it plans to launch another four models in late September, with prices starting from £499.
Sizewise, plug-in solar setups are usually smaller than rooftop options, but sizes vary. The UKSOL 460W single panel kit measures 1,762mm x 1,134mm x 30mm and weighs 25.5kg. The 890W kit comprises two panels.
Setting up
The official guidance suggests that it will take about an hour to set up your system. It estimates 15-25% of people will need professional support mounting the panels, and about 15% will need minor electrical works. UKSOL suggests it takes two people to handle and position the panels, as each one weighs 25kg.
Osborne says plug-in solar systems should not be connected via extension leads, cable reels, multiway adaptors, travel adaptors or plug-in RCD adaptors. “These accessories can overheat, become overloaded and create additional safety risks,” he says.
There is also some other housekeeping. The owner has to tell their distribution network operator that they are using them (there should be a form in the box). You can find out who it is by inputting your postcode on the Energy Networks Association website. You will also be able to consult the ENA’s Connect Direct site for a list of approved devices, which is a good place to start before you buy.
Savings
Plug-in systems are about a fifth of the size of a typical residential rooftop solar system, which means they will not provide enough energy to power a home on their own – but they could cut your bill.
One drawback is that you need to be home to use the power generated because without a battery it is not being stored for later, so flows back to the grid.
However, the adoption of balcony solar could, in time, pave the way for plug-in batteries in British homes, too. If paired with a plug-in solar system, households could store their own renewable electricity during the day and use it to run their appliances in the evenings. The government is reportedly considering plans to bulk-buy the devices and distribute them to low-income homes.
A basic plug-in solar system costs about £400. Parry says it will “give you back, at worst, £40 a year, and at the best about £110. If it’s the worst-case scenario, it’s going to pay for itself in 10 years, but at the best-case scenario, it’s four.
“If you’ve just got 800W, it’s only at its very peak that it will give you that.”
He adds: “The slight downside is that plug-in solar is hitting the markets as the summer’s coming to an end. It’s going to be more use in May next year.”
Moore says that the level of saving is affected by a number of things, including the system size, location, orientation and actually being home to use the power.
He expects the 460W system his company will be selling to save a typical household about £80-£120 a year, “while the 890W system could save more”.
He adds: “The greatest savings are achieved when households use appliances during daylight hours, as this increases the proportion of generated electricity used within the home.”
You can buy a more expensive 2,000W kit (the inverter will only allow 800W through) to maximise your power-generating capacity, but these are more expensive.
Staying safe
Although there is no obligation to do this, before buying a kit, some experts think you should get your home electrics checked by a professional. That is because this is the first time that British residential wiring circuits will take power in via a three-point socket rather than simply being used to distribute electricity.
Electrical Safety First is concerned about the impact on residual current devices, or RCDs, which sit in a household electricity box and cut off the power if someone drills through a wire or runs their lawnmower over a power cord. Electricians are concerned they may burn out when plug-in solar panels start adding electricity to the circuit.
A Department for Energy Security and Net Zero spokesperson says: “Plug-in solar panels will be available to buy this summer, and stringent verification and registration checks are already in place. They are a transformative technology that can save people hundreds of pounds on their bills.”
Box] Renters
Plug-in solar should make it easier for tenants to take advantage of renewable energy, as any kit they buy can be moved from place to place.
But if you are renting, you should ask permission from your landlord before you invest in any panels.
The rules on what you can do with regard to fixing brackets to hold them, for example, may vary depending on what your tenancy agreement says.
There’s “no reason” why your landlord should be against the idea, Parry says. “He or she can look at the information and know it’s super, super safe.”
Meera Chindooroy, the deputy director of campaigns, public affairs and policy at the National Residential Landlords Association, says that while the organisation supports the “principle of tenants benefiting from plug-in solar panels … landlords would first need to be satisfied that the panels meet all required safety standards”.
She adds: “It would not be right for landlords to be held responsible for the safety of equipment they were not asked about in the first place.”
