Plug-in solar panels could save you £100 – but this is who should buy one

Plug-in solar panels will be sold in UK supermarkets “within months”, the Government has announced.

Households using the panels, which are widely used in Germany and Spain, could save between £70 and £110 per year, according to estimates from the Department for Energy Security and Net Zero.

The panels can be bought in the UK, but regulations prohibit them from being plugged into a circuit connected to the grid – including from household sockets.

Retailers including Amazon, Iceland and Lidl have confirmed they are working with the Government to update the rules to allow the panels to be connected to domestic sockets.

The i Paper revealed that Sainsbury’s, Currys and John Lewis are among companies considering plans to supply the panels in their stores if the regulations are changed.

That means the panels’ cost of about £400 could be covered within four years by the savings they generate, with any additional electricity they produce being effectively free.

How do the panels work?

To function, the panels could be plugged into household sockets and installed in outdoor areas such as balconies, rooftops, gardens and external walls.

“Plug-in solar is just like, in principle, plugging in a toaster or a microwave,” said Gareth Simkins, a spokesperson for Solar Energy UK, which represents more than 400 companies in the energy sector.

“It’s that simple. You don’t need an electrician. You don’t need a technician. You don’t need scaffolding.”

Simkins explained that the panels function by turning “the energy of light into a direct current – much like that supplied by a battery”.

He added that a “unit called an inverter turns the direct current into alternating current”, which can then flow “into the mains supply, running TVs, fridges and other devices”.

“At night, power is imported into the home as normal,” he added.

Simkins said the panels will be limited to a capacity of 800 watts – considerably less than the capacity of traditional rooftop solar panel systems, which is about four kilowatts.

If rooftop panels generate more energy than is required, it is sold to the household’s power supplier, but Simkins said that “may not be the case for plug-in systems”.

“They allow solar power generated in the day to be used or even exported to the grid in the evening, when time-of-day tariffs are most expensive,” he explained. “So far as I am aware, there are no plans to allow plug-in batteries to connect to the grid.”

Which households would the panels benefit most?

While the panels could cut around £100 off household bills each year, experts told The i Paper they work best in smaller households and high-rise flats.

Adrian Arbib, an electrician and solar installer from Oxford, told The i Paper: “Plug-in solar panels are really designed for smaller households, particularly people living in flats with balconies. They work best for single occupants or low-energy homes.”

The placement and orientation of the panels is also “critical” to how effective they can be.

“Ideally, the panels should be south, south-east or south-west facing,” he explained. “If you’re in a north-facing flat or there’s significant shading, then frankly it’s a waste of money.

“You need good, direct light for them to be effective.”

Arbib said plug-in panels have “taken off more quickly in parts of Europe because more people live in flats and high-rises with balconies”.

He said: “That’s exactly the type of home these systems are designed for, somewhere you can securely fix them, like a balcony, roof, or garage.

“They’re not something we’re trying to push onto everyone. They’re only suitable in the right conditions.”

Frankie Mayo, senior analyst at the global energy think-tank Ember, described the rollout of plug-in solar panels as a “democratising move”.

“Optimised, south-facing, rooftop solar panels will still generate more than typical plug-in panels, however this opens up cheap, immediate and clean energy to a whole new group of households,” he said.

“This unlocks, for example, self-generation opportunities to high-rise homes with balconies, those in rental properties, and even owner-occupiers thinking about moving house.”

How much could I save?

Arbib explained that a plug-in solar panel costing about £400 could save roughly £100 per year.

“By comparison, a large rooftop system costing around £10,000 can take eight to 10 years to pay back, depending on household energy use, and requires scaffolding, paperwork, and professional installation,” he added.

“I’m an installer, so naturally I might be reticent to promote these small systems, but I want to reduce carbon. The benefits outweigh any negatives.

“I can install full off-grid setups that could eliminate bills entirely, but they’re expensive and require more thinking. These plug-in systems, by contrast, are simple, relatively hassle-free, and painless – just plug-in cheap solar.”