Are plug-in solar panels worth buying in the UK? Our energy editor explains

For millions of households, the issue isn't simply whether solar panels are worth the price. It's whether installing them is even an option in the first place. Solar has traditionally been pitched as a home upgrade for people who own their property, have a suitable roof, can afford the upfront cost and are prepared to take on a full installation.

This is where plug-in solar panels come in, offering an alternative solution to a traditional rooftop setup. They’re less powerful, but smaller and cheaper, so they could help bring solar within reach of people who have largely been left out of the energy transition. For example, renters, people living in flats, households without a suitable roof and those who can't stretch to the cost of a full solar installation.

As part of a broader effort to encourage home energy generation, the government has made plug-in solar available to support cleaner power and reduce reliance on fossil-fuel markets. These smaller systems cost less than traditional rooftop solar (with prices at UK retailers ranging from £400 and £500) and can be installed without a professional, potentially making solar a more realistic option for renters and people living in flats.

But given their lower output capacity, many may be wondering whether plug-in solar panels are worth it. The answer depends on what you expect from them. If you want to power your whole home, they are unlikely to come close to meeting your needs. But if you want a relatively low-cost way to chip away at your daytime electricity use, they could be one of the most interesting home-energy products to arrive in years.

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How much do plug-in solar panels cost?

One of the first things to consider when assessing whether plug-in solar panels are worth it is their cost. These plug-and-play systems cost about £400 to £500, depending on the number of panels, their output, the inverter, mounting hardware and the retailer.

That makes them significantly cheaper than a rooftop solar installation. However, it is important to compare like with like. A full rooftop system is professionally installed, much larger, fixed to the property and capable of generating far more electricity over the course of a year.

A plug-in solar kit is cheaper because it is smaller and simpler. Its value lies in accessibility, not in replacing a full solar array.

How much could plug-in solar panels save?

Savings will vary widely, depending on the cost of your electricity, how much power the panel generates, whether you use that electricity as it is produced and whether any excess can be exported or is simply wasted.

Estimates suggest possible annual savings of around £70 to £110, depending on system size and usage. Those figures should be treated as indicative rather than guaranteed. A well-positioned panel in a household that uses electricity during the day will perform better than a shaded panel in a home that is empty during peak daylight hours, for example.

The key issue is self-consumption. The more of the electricity you use at the time it is generated, the more valuable the system becomes. If the panel is generating while nobody is home and there is no clear export arrangement, some of the benefit will be lost.

When thinking about payback, the numbers could look attractive for the right household. For example, if a plug-in solar kit costs £500 and saves £80 a year, it would take just over six years to pay for itself. If it costs £400 and saves £100 a year, the payback could be closer to four years.

Again, these are simple calculations, not guarantees. They do not account for panel degradation, product lifespan, warranty terms, installation accessories, changes in electricity prices or whether the household actually uses the power when it is generated.

How much electricity can plug-in solar panels generate?

Another important consideration is output. The electricity a plug-in solar panel can generate depends on its size, the amount of sunlight it receives, its angle, shading, location and how well it is positioned. A south-facing, unshaded panel will usually perform better than one on a shaded balcony or a wall that only receives sunlight for part of the day.

A single plug-in panel might generate a few hundred kilowatt-hours of electricity a year in favourable conditions, while a two-panel system could generate more. However, it will still be much smaller than a typical rooftop solar array.

That difference is important. A plug-in panel might help cover some of your background daytime electricity use. But it will not run an entire home, charge an electric vehicle at meaningful scale or provide the same level of annual generation as a 3kW, 4kW or 5kW rooftop system.

For homeowners with a suitable roof, traditional rooftop solar will usually remain the stronger (although more expensive) option (Getty/iStock)

The best way to think about plug-in solar is not as a replacement power station for your home, but as a modest bill-trimming device.

Who should consider plug-in solar panels?

Plug-in solar panels may be worth considering if you:

Rent your home and cannot install rooftop solar
Live in a flat with a suitable balcony or outdoor space
Own a home but do not have a suitable roof
Want a lower-cost way to try solar power
Use electricity during the day
Have an unshaded, sunny space for a panel
Want a portable system you may be able to take with you when you move

They could be particularly useful for people who work from home, retirees, households with regular daytime energy use, or anyone who can shift appliance use into daylight hours.

For example, running a washing machine, dishwasher or charging devices during sunny periods could help increase the proportion of solar electricity used in the home.

Who should avoid plug-in solar panels?

Plug-in solar panels may not be worth it if you:

Have no suitable outdoor space
Live in a heavily shaded property
Cannot get landlord or freeholder permission
Expect them to power your whole home
Rarely use electricity during daylight hours
Already have the option of installing a full rooftop system
Are considering a cheap imported kit that may not meet UK rules

They are also unlikely to be the best choice for households looking for maximum bill savings. In those cases, a properly specified rooftop solar system, potentially with battery storage, is likely to deliver far greater returns.

The bottom line: Are plug-in solar panels worth it?

Plug-in solar panels are worth considering if you have a sunny outdoor space, use electricity during the day and want a lower-cost way to generate some of your own power.

But they are not a replacement for rooftop solar. They will not run your whole home, remove your electricity bill or deliver the same savings as a full solar panel system. For many households, the financial benefit will be modest.

But judged on accessibility, they are much more interesting. A £400 to £500 plug-in kit could give renters, flat owners and lower-budget households a way into solar generation for the first time. And in a market where full rooftop systems still require thousands of pounds of upfront investment, this makes them a very intriguing option.

The best case for plug-in solar is not that it beats rooftop solar, but that it opens the door to people who were never in the rooftop solar market in the first place.