Plug-in solar panels
How they work, what they cost and how much you could save
Plug-in solar panels are expected to hit UK shelves soon. They could be a simple way for some households to cut their energy bills. But the payback is around four to six years, and not all homes will be suitable. Here's what you need to know about how the technology works and whether it's right for you.
This is the first incarnation of this guide. We'd love to know your thoughts on plug-in solar panels, or if you've any feedback or questions we've not answered. Let us know in the Plug-in solar panels forum thread.
What are plug-in solar panels?
Plug-in solar panels are a type of lower-cost, portable solar panel that can be placed outdoors (such as on a balcony railing, garden fence, patio or shed roof). They're a cheaper, easy-to-install alternative to expensive rooftop solar panel systems. In theory, you simply plug them in to your mains electricity and they're ready to use. Plus as they're portable, you can easily take them with you if you move home.
They're a particularly good option for people in flats, where you're unlikely to able to install a full rooftop solar panel system.
Plug-in solar panels haven't been allowed in the UK so far due to safety regulations. But this will change on 27 August, and it's expected these systems will become available online and on the high street after this date (though we don't know when exactly).
How do plug-in solar panels work?
Plug-in solar panels work in the same way as rooftop solar, by generating electricity from sunlight. The panels then feed this electricity directly into your home's electrical circuit, via a standard three-pin wall socket.
Any appliance you have switched on will automatically and instantly use this free solar-generated power before importing costly electricity from the National Grid, which you pay your energy supplier for (do a full market comparison to make sure you're on the cheapest rate for you).
But if you don't use what you generate, any surplus will flow back to the National Grid. So, it's very much use it or lose it with the power you generate (at least in monetary terms, though you will be helping to feed renewable electricity into the grid).
What do you get in a plug-in solar kit?
Plug-in solar systems sold under the new rules can generate a maximum of 800W of usable power, thanks to a built-in inverter limit. That's much smaller than a typical rooftop solar setup, which is usually 4kW or more. Some kits may include solar panels with a higher combined capacity than 800W, but the microinverter ensures no more than 800W is fed into your home's electrical system at any one time.
The kit will also include a microinverter, which converts the electricity produced by the solar panels into the type of power your home uses.
Some kits should also come with mounting equipment too. However, exactly what's included may vary between manufacturers, so it's worth checking what's in the box before you buy.
How much could you save with plug-in solar panels?
Similar plug-in solar panel kits currently being sold in Europe cost about £400–£600 (before extra costs such as mounting, installing a new socket or any wiring checks).
The Department for Energy Security & Net Zero (DESNZ) says plug-in solar could save households about £70–£110 a year on energy bills.
Based on these costs and savings, the average break-even point is about four to six years.
Warning: Before getting plug-in solar panels, it's a good idea to get your house's wiring checked to make sure it's safe to plug in the panels. We've full info below on what to check.
Your break-even point will depend on size, location, energy use and weather
How much power a solar kit generates depends on the size of your panels, the direction they face and the weather.
If the panels don't regularly get direct sunlight, you won't generate as much, so your annual savings would likely be much less than what you'd get with an optimal set up and this will massively increase the payback time.
The size of the solar panels will also make a difference - the bigger the kit, the more energy it will produce. Finally, savings will also depend on when you use electricity. Households that are at home during the day and can run appliances while the panels are generating power are likely to benefit the most.
Plug-in solar could cover around a quarter of your home's electricity use
In the UK, plug-in solar panels are limited to a capacity of 800W (even if some panels or systems could be capable of producing more). An 800W plug-in solar kit, made up of two 400W panels and a microinverter, could generate roughly 500kWh to 800kWh a year, depending on efficiency, location, orientation and panel angle.
At the upper end of that range, that's around 2kWh of electricity a day on average. The average UK household uses around 7.4kWh of electricity a day, based on Ofgem's typical household use figures. So while plug-in solar is unlikely to power your entire home, it could cover around a quarter of a typical home's daily electricity use.
You can install plug-in solar yourself - but it's not always as simple as plug and play
Unlike full conventional rooftop solar panels, one of the benefits of plug-in solar is that you don't need an electrician to install them.
While you can install them yourself, before you take the plunge, make sure you first consider where you'll put them, if it's safe to install them in your home and if you're comfortable putting them together and mounting them in your chosen spot.
Step 1: Check it's safe to install plug-in solar in your home
Plug-in solar panels aren’t standard appliances. While they’re marketed as ‘plug and play’, they introduce a new source of electricity into your home – which brings electrical and fire risks. So first make sure it’s safe to plug them in.
The Institution of Engineering and Technology recommends having your wiring professionally checked first. Many UK homes have ageing wiring, worn parts or DIY alterations that could make using solar panels unsafe.
You can get an Electrical Installation Condition Report (EICR) from a qualified electrician to check the health of your electrics. Do mention you’re considering plug-in solar, as this may affect any recommended updates. These reports cost £100–£250 according to Checkatrade, which will add to the panels’ payback time.
Step 2: Find the best place to install them
Plug-in solar panels can be installed almost anywhere they’ll fit, such as a balcony, garden fence, patio, garage roof or exterior wall.
Ideally, choose a spot that gets plenty of sunlight – somewhere south-facing and unshaded for much of the day. If possible, tilt them to about a 35-degree angle to maximise sunlight exposure.
Panels can be large, so take full measurements to check they’ll fit. Also consider where you’ll plug them in. Use a weatherproof, dust-resistant outdoor socket (trailing cables through windows or doors isn’t safe or practical). According to Checkatrade, this could cost £140–£260 – again adding to the payback time.
Safety warning: DON'T use standard extension cables. Standard household extension cables are designed to send power, not receive it, so they could become dangerously hot. Always check before buying how long a cable you need and make sure the panels you buy come with a long enough cable.
There are 'MC4' extension cables available (MC4 are the standard connection for solar panels), but do make sure these are safe before using them.
Step 3: Buy your plug-in solar system and follow the manufacturer's instructions
If it’s safe, you’ve space and an unshaded area, the next step is to buy the panels and install them. We don’t yet know exactly where they’ll be sold, though the Government says it expects major high street and online retailers to stock them – see where to buy them.
Once you have the panels, you may need some DIY skills to install them. Typically, you’ll attach the panel to a mounting bracket and connect the microinverter (your system should include instructions). If mounting on a wall or balcony railing, extra steps may include securing the bracket or drilling holes.
If installing them yourself, always follow the manufacturer’s safety guidance.
Step 4: Notify your local electricity network operator within 28 days of installation
If you do get plug-in solar panels, you'll need to let your electricity Distribution Network Operator (DNO) know within 28 days of connecting them.
The Government has told us there will be a central registration website that will launch when plug-in solar becoming available on 27 August - so you may not need to know who your DNO is, depending on how the registration page works (if needed, you can find out who yours is on the Energy Networks Association's website). We'll update this section, with a link to the registration page, once it's available.
Where can I buy plug-in solar panels?
From Thursday 27 August, new rules come in that will allow plug-in solar panels to be sold widely across the UK. It's expected that the panels will become available in high street retailers such as Lidl and Iceland, as well through online retailers such as Amazon, and via solar specialist and solar panel manufacturers.
We'll update this section with details on pricing and availability as soon as stores start offering the panels for sale.
It should be as simple as buying any other off-the-shelf product, though before you take the plunge, consider how and where you'll install them.
Should I get plug-in solar panels or a rooftop solar system?
Plug-in solar panels are mainly aimed at households without space for a full conventional rooftop system. They’re relatively small and easy to install, so if you’re in a small home or live in a flat with no roof access, they can give you some solar power and help cut your electricity bill.
Even if you do have space for a full rooftop system, installation is costly – a typical 4.6kWp system costs about £7,600 to install, compared with about £400–£600 for plug-in solar. So homes of any size can benefit.
However, savings on electricity bills will be lower, and you can’t currently sell unused power back to the grid with plug-in systems. See our comparison of costs and savings below.
Cost | Annual bill savings | Annual export earnings | Time to break even | |
|---|---|---|---|---|
Plug-in solar (1) | £400-£600 | £70-£110 | None | 4 to 6 years |
Rooftop solar (2) | £7,600 | £200-£330 | £510-£590 | 9 years |
(1) Based on average potential savings from the Department of Energy Security and Net Zero, and the costs of similar plug-in systems currently sold in Europe. (2) Based on a 4.5kWp system installed in London. Cost, savings and export earnings figures from the Energy Saving Trust.
If you rent, you'll need to ask permission from your landlord
If you live in rented accommodation, you'll need permission from your landlord to install solar panels anywhere in or around your home. The Government has said it's working to ensure there is clear guidance on what tenants can and cannot do.
Quick questions
Are plug-in solar panels safe?
Yes, plug-in solar is already widely used by households across Europe.
Ensure you buy from a reputable retailer and that it meets UK product safety standards. Plug-in solar panels do have built-in safety features. Typically, the inverter will immediately shut down if it’s unplugged from the wall or if there’s a powercut. This prevents the plug pins from being ‘live’ and shocking you, as well as sending electricity back into the grid, while engineers might be working on the line.
Do make sure it's safe to plug them in to your home before you get them (see how to check) and follow all safety guidance from the manufacturer when installing them.
What happens to the electricity I generate but don't use?
Any electricity you generate with plug-in solar panels that you don't use will get sent back to the National Grid. You can't currently get paid for this - like you can with rooftop solar under the Smart Export Guarantee - scheme. That means energy you generate but don't use is essentially wasted (at least for you).
Can you export the electricity to the grid?
Yes, but you can't currently get paid for it. As above, any excess power you generate but don't use flows back to the National Grid.
If you do want to be able to make money from solar energy you generate, you'll need proper rooftop solar panels, a working smart meter and you'll need to sign up to a smart export tariff.
Can you use solar panels with a battery?
Technically, yes plug-in solar systems can be used with batteries, so you can store the electricity it generates when you're not using it to use later.
However, the current UK rules don't support batteries with plug-on solar, though they could become available in future.
In Europe, you can buy all-in-one solar and battery plug-in systems, for example. These could become available in the UK at some point in the future, though we don't know when.
How long do plug-in solar panels last?
Plug-in solar panels have a similar lifespan to rooftop systems – around 20–30 years. Microinverters usually come with a 10–12 year warranty.
Regularly clean off dirt, leaves and bird droppings to maintain efficiency and lifespan.
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