UK Regulations

The 800W inverter limit

The governing figure for plug-in solar in the UK is the rated alternating-current output of the inverter. A system whose inverter is rated at or below 800W is the category this site covers. Panel capacity may exceed that figure, because the inverter caps what actually reaches your circuits, but the inverter rating is what counts.

Products advertised by panel wattage alone should be treated with caution. Ask the seller for the inverter's rated AC output in writing before buying.

Notifying your network operator

Generation equipment connected to the UK distribution network falls under connection standards administered by Distribution Network Operators. The prudent assumption is that your DNO must be notified, and that notification is either handled by the manufacturer, the installer, or you.

Requirements and forms differ by operator, and the position on small plug-in generation has been actively debated. Confirm the current requirement with your own DNO rather than relying on a seller's marketing copy.

Wiring, sockets and safety

Plugging a generator into a socket circuit is not the same as plugging in an appliance. The circuit's protective devices, the condition of the socket, and whether other loads share the circuit all matter. A qualified electrician should assess the intended socket before installation.

Grid-tied microinverters must disconnect automatically when the mains supply is lost. Do not attempt to use a plug-in system as backup power, and do not connect one via an extension lead or multi-way adaptor.

Product conformity

Equipment sold for use in Great Britain must carry appropriate conformity marking and documentation, and be supplied with UK-standard plugs and instructions. Imported kits bought from overseas marketplaces frequently arrive with continental plugs and documentation that does not reference UK standards — a strong signal to walk away.

Permission, planning and insurance

• Renters need written landlord permission for anything fixed to the building or railings.
• Leaseholders usually need freeholder or managing-agent consent for changes to the exterior or common parts.
• Listed buildings and conservation areas have additional constraints, and visible external panels can require consent.
• Tell your home insurer. A fixed external installation is a material change and non-disclosure can affect a claim.

What is genuinely unsettled

The regulatory treatment of plug-in solar in the UK is less mature than in parts of continental Europe. Guidance has changed and may change again. Where we cannot verify a requirement against a recorded source, we say so rather than filling the gap with a confident guess.

This is not legal advice

PlugInSun publishes general information. It is not electrical, legal or financial advice, and it does not replace a qualified electrician, your DNO, your insurer or your landlord.