Plug-in Solar in the UK: What Electricians Need to Check at the Consumer Unit
A solar panel with a plug sounds straightforward. The circuit it connects to deserves a closer look.
Since 27 August 2026, compliant plug-in solar products have been permitted in Great Britain under a new regulatory framework. These are small, single-phase systems designed to feed electricity into an existing domestic socket circuit. The government's interim product specification limits their apparent AC output to 800 VA. It applies to plug-in solar without batteries, and the current GB network rules restrict connection to one device per household.
That is a meaningful change. A homeowner can buy a generating device and connect it to a circuit that was originally designed to supply appliances. The product may be compliant, but its presence does not tell you whether the existing installation is in suitable condition or whether its protection is right for the arrangement.
The IET has advised householders to get a competent electrician to assess the installation before buying or connecting a kit. For electricians, the useful question is: what exactly needs checking?
Start with the actual product and circuit
Confirm that the exact kit is compliant with the UK interim product specification and check its status on the ENA Type Test Register. The register contains both compliant and non-compliant entries, so finding a model name is not enough. Check the manufacturer's instructions and the device's stated output and connection requirements.
Then identify the socket the customer intends to use and trace the circuit that supplies it. Establish whether it is a ring or radial, what else is connected, the circuit's condition and rating, and how the proposed generation affects its overcurrent protection. Do not assume that a small inverter makes circuit loading and protection irrelevant. The IET treats RCD performance and final circuit overcurrent protection as separate questions.
The government specification is written around connection to a suitable socket circuit through the manufacturer's supplied plug. It does not give a blanket approval for every existing socket. It rules out multiway adaptors, travel adaptors, RCD adaptors and plug converters; its warnings also prohibit extension cables. A damaged or degraded socket needs attention before a kit is connected.
Look at the RCD or RCBO, not just the board label
An RCD being present is not, on its own, proof of suitability. Identify the device protecting the relevant circuit, its residual current type, its condition and its manufacturer's instructions. Older protection may not have been assessed for this kind of connection. The IET has specifically raised concerns about some legacy RCDs and the effect that DC leakage from electronic equipment can have on their operation.
The interim product specification requires the plug-in solar device to be designed and tested so that it does not adversely affect upstream RCDs. It limits smooth DC residual current fed to the mains to 5 mA under the specified conditions. That product requirement matters, but it does not turn every existing protective device into a suitable one. The specification also requires product instructions to tell users to operate the RCBO test button periodically while the solar unit is generating and to seek an electrician's advice if it does not trip immediately.
Does plug-in solar mean every RCBO must be bidirectional?
No. Start with the circuit arrangement and the exact protective device.
A bidirectional RCBO is one its manufacturer declares suitable for a source of supply connected at either set of terminals. The fact that energy can flow towards the consumer unit does not, by itself, establish the required directionality of every device in that board. Equally, an existing RCBO should not be assumed suitable simply because it fits and operates normally with conventional loads.
Identify where the solar source connects, consider the possible supply conditions at the protective device, then verify the markings and manufacturer's technical information for that specific model. If an existing device is unsuitable for the proposed connection, select an appropriate arrangement and protective device as part of the installation assessment.
We cover this distinction in more depth in our guide to when a bidirectional RCBO is needed. Navitas Type A bidirectional RCBOs are an option where the assessed circuit calls for that functionality. Fitting one RCBO is not a substitute for checking the rest of the circuit and the kit's instructions.
A sensible handover matters
Once the arrangement has been assessed, make sure the customer knows which socket and circuit are suitable, how the system is to be connected, and why moving it to another socket or using an extension lead could change the answer. The supplied product instructions and network registration requirements also matter. A kit that can be connected by an ordinary person still needs clear information about the limits of its use.
Plug-in solar creates a new question at the consumer unit, not an automatic reason to replace it. Some installations may be suitable as they stand. Others may need a protective device changed, circuit work, or a different connection approach. The answer comes from the actual kit, actual socket circuit and actual devices installed, not from a claim printed on the front of the box.
For electricians: if you are assessing a plug-in solar installation and need details of a Navitas protective device, contact our technical team. We can provide the product information you need to make the decision on site.
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