IN Brief:
- NAPIT supports compliant plug-in solar where safety is equivalent to permanently connected systems.
- Government plans will create a controlled route for qualifying battery-free products using a BS 1363 plug.
- Product certification, circuit condition, anti-islanding, G98 notification, socket selection, and market enforcement remain central.
NAPIT has set out the electrical safeguards it considers necessary as the UK government advances a regulatory route for plug-in solar products.
The government intends to amend the Plugs and Sockets etc. (Safety) Regulations 1994 and introduce an interim product specification covering small solar devices designed to connect through a standard UK socket.
Qualifying products will be limited to solar equipment without integrated battery storage. Plug-in batteries and other forms of socket-connected microgeneration will remain outside the proposed route.
NAPIT supports the principle where products comply with an approved UK specification, achieve safety equivalent to permanently connected systems, carry clear instructions, follow appropriate DNO notification arrangements, and undergo independent testing and certification.
The organisation has also called for enforcement capable of preventing unsafe or non-compliant imports from reaching the UK market. Online marketplaces, second-hand sales, unclear product descriptions, and equipment designed around other national wiring systems create particular surveillance challenges.
Of the 466 responses received during consultation, 85% supported the proposed interim specification and 88% regarded a controlled BS 1363 route as a practical transitional measure. The government intends to proceed with targeted refinements before laying the necessary statutory instrument.
The final specification is expected to strengthen guidance around installation, circuit identification, mounting, prohibited uses, G98 notification, and circumstances in which professional advice should be obtained. Products will initially remain subject to the existing G98 limit of one device per household until a planned amendment permits one qualifying device per separately protected final circuit.
A familiar connection changes direction
Plug-in solar reverses the normal power flow at a standard accessory. A socket usually supplies a load, whereas a compliant solar device delivers locally generated electricity into the final circuit, requiring the product to control conversion, generation, disconnection, and protection without the procedures used for a conventional fixed PV installation.
Anti-islanding protection is essential because the device must stop energising the circuit when the network supply is lost. Without dependable disconnection, an apparently isolated installation could remain live during maintenance or emergency work.
The interim specification also addresses output limits, protective devices, and compatibility with Engineering Recommendation G98. Those provisions create a defined operating envelope around products intended for self-installation.
Condition of the existing electrical installation remains a variable that product certification cannot remove. UK properties include modern radial and ring final circuits, older wiring, mixed accessories, historic alterations, damaged sockets, and consumer units installed under several generations of requirements.
Qualified advice may therefore be needed where installation condition is uncertain. Extension leads, adaptors, damaged outlets, and unsuitable locations should not be used, while product documentation must identify acceptable socket selection, cable management, mounting, maintenance, and output limits.
RCD or RCBO protection, circuit identification, socket condition, protective-device rating, and the loading already present on the circuit will all influence safe operation. A product intended for consumer installation still operates as part of the fixed electrical installation rather than independently of it.
Microinverter design forms another important boundary. The latest European microinverter platforms incorporate conversion, communications, monitoring, and grid-support functions within conventionally installed solar systems.
Plug-in products will use a smaller and more constrained architecture, but they still require reliable conversion and disconnection. Market surveillance must distinguish equipment designed around UK wiring requirements from generic microinverter packages fitted with a physically compatible plug.
DNO notification remains necessary because small generators contribute to the total volume and behaviour of distributed generation. Accurate registration supports planning, safety, network modelling, and visibility of generation connected below conventional monitoring levels.
Where adoption becomes concentrated, aggregate output could influence local voltage and reverse power flow. Individual products will be limited, but their combined effect will depend on feeder conditions, daytime demand, property density, and existing rooftop-solar penetration.
The proposed framework is transitional while longer-term standards are developed. Sales, installation patterns, incidents, DNO notifications, and in-service performance will need to be monitored so that output limits, product rules, and installation guidance can be adjusted where evidence supports change.
Effective enforcement will be at least as important as the written specification. A compliant route can be undermined if products lacking the required protection, certification, labelling, or instructions are advertised as equivalent alternatives.
Plug-in solar is intended to widen access where conventional rooftop installations are impractical or unaffordable. Safe deployment will depend on preserving the distinction between a product engineered for UK electrical systems and a generic solar kit that happens to fit a socket.
