Electrical Contractors’ Association (ECA), Electrical Safety First (ESF), the Institution of Engineering and Technology (IET), NICEIC and SELECT are clear that public safety must be the first principle in any rollout of plug-in solar PV units. Whilst we support wider access to cheap and clean energy, these products should only enter the mass market once the necessary regulatory, technical and product safety framework is fully in place. Without that foundation, there is a serious risk of avoidable hazards in homes, uncertainty for the electricity system, and lasting damage to public confidence in the energy transition.

As organisations representing electrical safety, engineering standards and technical competence across the electrotechnical sector, we believe there are serious issues that must be addressed before any mass-market adoption. We are urging Government to proceed with caution and ensure that safety, product assurance, competence and system resilience are designed into any rollout from the outset.

Public safety cannot be treated as a secondary consideration

It remains unclear how plug-in solar panels will interact with the millions of existing electrical installations in UK homes, particularly in older properties where this wiring may have deteriorated, the operation of uni-directional RCDs (residual current device) and RCBOs (residual current circuit breaker with overcurrent protection) may be affected, and maintenance may have been inconsistent. A product marketed as simple and consumer-friendly could in practice be connected to electrical installations that were never assessed for this type of product. In such cases, there could be an increased risk of fire and danger to life due to the inability of the circuit to deal with the importation of power.

Six public safety issues: 

1. Bi-directional flow – Generating and consuming electricity isn’t the same

Plug-in solar PV units operate differently to the conventional appliance plugged into an electrical installation. Rather than just supplying power to an appliance, with plug-in PV units, the installation now has to import power, meaning that power flow is in both directions. This introduces technical issues that leave most homeowners unaware of the dangers. With electrical sources being applied to what we often refer to as the ‘load side’ of protective devices, Amendment 3:2024 to BS 7671:2024 addressed this very issue. Under certain conditions, the RCD, a key protective device in the home’s consumer unit, can be compromised. It may be possible to reset but the protective device may not operate as normal. This could be dangerous as the assumed protection with not be active. One death resulting from this lethal failure has already been reported by one Australian state, however it should be noted that this view is not shared by regulators from other Australian states.

2.    Fire risk

Over 50% of UK housing stock is more than a century old. These properties may have old, damaged or deteriorating electrical wiring, unfit to carry extra load. Without a proper electrical assessment, it is unwise to add a plug-in solar PV unit and is indeed contrary to existing British Standards, i.e. clause 5 of BS 1363-1. Plug-in solar PV units, especially multiple units, can increase the risk of localised overheating of cables. 

3.    Inconsistent and dangerous product standards 

The Government has announced that plug-in solar panels will be made available quickly, but if products reach the retail market before a robust and enforceable UK standard is fully embedded, consumers may be exposed to inconsistent quality, unclear compliance requirements and unsafe imports.

For example, some products are already being promoted with flattened cables intended to pass under doors or through openings not designed for electrical equipment. Without clear standards, testing and enforcement, such accessories could normalise unsafe practice in domestic settings and increase the risk of insulation damage and overheating, raising the potential for fire.

4.    Grid capacity is vital to network resilience

One of the central safeguards in the UK electricity system is that new electricity generating technologies are introduced in a way that network operators can monitor and manage. Industry advice has long been that new installations such as solar PV units and electric vehicle charge-points should be notified to the local Distribution Network Operator (DNO) because cumulative demand and generation affect local network capacity and stability. If plug-in solar PV units are normalised as an off-the-shelf consumer purchase without a clear notification and oversight regime, visibility of what is connected to the system will be reduced at the very point when visibility matters most. The electrical industry recommends that clear guidance is given to consumers to notify the DNO, before a device becomes operational.
The risk is not theoretical. If multiple flats in a single block were each to install plug-in solar PV units, the cumulative effect on the local network could be significant. We should be wary of treating these systems as negligible simply because each individual unit is small. At scale, small installations can produce material consequences for network planning, safety and resilience.

5.    Liability and insurance questions remain unresolved

There are also serious unanswered questions about insurance and liability. If a fire or electrical fault is linked to a plug-in solar PV unit, it is not yet clear how insurers will assess cover where the product was self-installed, not declared in advance or connected to an unsuitable electrical installation. Consumers should not be encouraged to adopt these products before they fully understand the consequences, potentially leaving landlords, leaseholders and insurers to manage the fallout.

6.    Daisy-chaining

Consumers, seeking convenience, may use extension leads, adaptors or multiple devices on the same circuit. Improvised installations significantly increase the likelihood of overheating and fire, as well as creating trip and fall hazards from trailing cables poor installations/fixings into gardens or on balconies with a risk of becoming loose or falling from height, with disastrous consequences. A particular concern if used in a high-rise building.
Additionally, rooftop solar PV has a single dedicated connection to the electrical installation through an inverter. An inverter converts the direct current (DC) generated by the solar panels to alternating current (AC) which is the type of electricity that is conventionally used to power homes and feed into the National Grid. When a power cut in the street occurs, the inverter will shut down very quickly to halt the export of power. Where multiple plug-in solar PV units are plugged in to the electrical installation through socket outlets, each has an individual connection to the installation, and it is not known how quickly multiple plug-in solar PV units will shut down in the event of a power cut.

A low upfront cost must not override safety

The appeal of plug-in solar PV units is obvious: low-cost, visible and quick to deploy. But affordability alone is not a sound basis where electrical safety is concerned. If cost becomes the dominant driver, there is a danger that quality assurance, competent installation, enforcement and consumer protection will be treated as optional rather than essential.

A poorly regulated bargain product may reduce bills in the short-term, but it can also transfer risk onto households, emergency services, insurers, network operators and, ultimately, Government. A rushed rollout could potentially weaken confidence in the energy transition.

The electrotechnical industry advocates innovation and recognise the potential role that new technologies can play in expanding access to cleaner energy. But plug-in solar PV units should not be rolled out unless and until the supporting framework is in place: clear product standards, robust enforcement, competent installation pathways, appropriate consumer guidance, and a mechanism to protect both householders and the electricity distribution network. Due diligence is not a barrier to progress. It is what makes progress safe, credible and sustainable.