IET urges households to check electrical safety before using plug-in solar products

The Institution of Engineering and Technology (IET) is urging the public to consider the electrical safety of their homes before purchasing and using emerging ‘plug-in’ solar products, as the Government moves to make these devices available in UK shops as soon as possible. 

While the IET supports the ambition to broaden access to affordable, low-carbon energy, it is essential that households understand that plug-in solar products are not typical appliances. Unlike a kettle or a phone charger, these devices introduce a new source of electricity directly into a home’s wiring system, which may not have been designed or maintained to handle this safely.

Mark Coles, Head of Technical Regulations at the IET, said:

“Before anyone buys a plug-in solar kit from a supermarket shelf, they need to be aware of the condition and capability of their home’s wiring. Many UK homes have ageing, modified or poorly maintained electrical installations. Introducing a generating source into wiring that hasn’t been checked could expose homeowners to risks that are not immediately obvious.

“Before purchasing or plugging in any off-the-shelf generation product, householders should have their electrical installation checked by a competent electrician. What may be safe in one home may pose a significant risk in another. Professional verification is the only way to be sure.”

Plug-in solar systems remain not yet legal to use in the UK, as regulators continue to assess how they can be safely integrated into domestic installations. Current reviews highlight concerns around how electricity flows through older wiring, how protective devices behave when power flows both ways, and how multiple plug-in units may interact during faults or grid outages. 

Key safety considerations include:

• Suitability of home wiring: Many installations – especially those that have not been professionally inspected for years – may contain worn components, unverified DIY alterations, or protective devices that cannot safely manage electricity being fed back into the system.
• Older RCDs may not work correctly with plug-in generation: An RCD is the safety switch that cuts the power if there’s a fault – for example, if someone cuts through a lawnmower cable it protects you against electric shock. But some older RCDs were never designed for electricity flowing back into the circuit, as can happen with plug-in solar. This can stop the RCD from tripping when it should, meaning it may not protect you during a fault. Households should check with a competent electrician whether their RCDs are suitable before plugging in any energy generation equipment.
• Compliance with Wiring Regulations: BS 7671 (the IET Wiring Regulations) sets out how electrical installations should be designed, built and verified. These regulations do not determine what consumers may plug in, placing responsibility on households to ensure that their wiring is fit for purpose before introducing any form of local generation.
• Risk of overload or back feed: Plug-in solar can create scenarios where parts of a circuit carry more current than intended, even if the circuit breaker appears to operate normally.
• Safe disconnection: Until appropriate standards are finalised, it is not guaranteed how different plug-in solar units will behave when more than one is connected, or how reliably they will disconnect during a power cut, posing a safety risk.

The IET continues to contribute its technical expertise alongside industry and standards partners to support the development of clear guidance and appropriate standards as new technologies, including plug-in solar products, emerge in the UK.

theiet.org