Safety

A compliant plug-in solar kit is engineered with several safety features built in as a condition of meeting the DESNZ Interim Product Specification. This page covers what is already handled for you, what is still worth checking yourself, and the single most important warning: never install more than one kit.

A plug-in solar kit must connect directly into a wall socket. Do not use extension leads, multi-way adaptors, travel adaptors or RCD adaptors - the Interim Product Specification requires a direct plug-to-socket connection. See Extension leads for why.

Never install more than one plug-in solar kit. The network rules (G98, amended in August 2026) allow one plug-in solar device per household, and that is the one you notify to your network operator. The product specification on its own allows one per circuit - a limit about your wiring - but the stricter household limit is the one that applies, so a second kit is not permitted on any socket. It can also put you outside your home insurance's terms. See Considerations for the ring-circuit detail and Registration for the one-per-household rule.

What is already built in

  • Anti-islanding protectionMandatory on every compliant inverter. Loss-of-mains protection, required under G98, disconnects the inverter if the grid supply fails, so it is designed not to "backfeed" a line an engineer thinks is dead. The specification adds touch-safety limits: on disconnection from the mains the inverter must switch off within 100 milliseconds, the voltage on the plug pins must fall below 34V within 100ms, and internal capacitors must discharge to 34V or less within 1 second
  • Fixed, non-rewireable plugManufacturer-fitted, moulded BS 1363 plug with a BS 1362 fuse rated at no more than 5A. If the fuse ever needs replacing, use the same rating
  • Plug markingsThe plug must be marked "one device per household circuit", with its rated current, an "observe the instructions" symbol and a warning against extension leads, multi-way adaptors and RCD adaptors
  • Hard output ceiling800VA / 3.5A AC maximum, whatever the panels are rated at - the inverter itself will not push more than that into your home's wiring
  • WeatherproofingAny part meant to be fitted outdoors must be rated at least IP55; parts meant only for indoor use must be better than IP44
  • Panel-side limitsUp to 2,000W of panels, up to four panels with no more than two in series, no more than 120V DC (open circuit) at the inverter, and no Y-connectors
  • Consumer unit labelEvery kit comes with a durable label to fix at or near your consumer unit, in a clearly visible place, so anyone working on your electrics can see a plug-in solar device is connected
  • No export payment, not "no export"If your panel briefly generates more than your home is using, the surplus can flow out onto the grid the same as any small grid-tied inverter's would - there is just no metering or tariff (like the Smart Export Guarantee) set up to pay for it from a kit like this. That is a payment gap, not a technical block, and it is a separate point from anti-islanding above, which only reacts to a lost grid connection, not to export itself

What is still worth checking yourself

  • Before you buyConfirm the exact model is on the ENA's live Type Test Register - see Certification - rather than trusting a retailer's own claim
  • Before each season / after stormsInspect the plug, cable and panel casing for cracks, discolouration or water ingress; stop using and unplug immediately if you see any
  • The socket itselfShould be in good condition, ideally on its own or a lightly-loaded circuit - see Considerations for consumer unit and ring-circuit detail
  • Your circuit's protectionThe specification says to check your installation has modern residual current protection (an RCBO), and to test it periodically by pressing its test button while the kit is generating. If you are not sure what you have, ask an electrician
  • More than 960W of panelsThe specification says to consider a professional assessment of your existing wiring before fitting a kit with more than 960W of panels
  • FixingMust use a proper rated bracket - never cable ties, rope, tape, bungees or straps alone - and never on a timber balcony or on timber or other combustible cladding - see Mounting - a panel coming loose in high wind is a genuine fall/impact hazard
  • Children and petsKeep cabling out of reach and avoid routing it across walkways where it becomes a trip hazard
  • Never attempt your own repairsIf the inverter fails, return it under warranty rather than opening the casing - there is no user-serviceable part inside and doing so can void both its compliance and the warranty

Sources

Rules last checked: 29 October 2026, against the Interim Product Specification v2 (16 July 2026), SI 2026/848 and Ofgem's G98 decision of 11 August 2026. The specification has not been updated or replaced since July 2026.

This page is informational, not electrical-safety advice for your specific home. If your consumer unit is old, your circuits are unidentified, or anything about your installation looks unusual, get a qualified, registered electrician's opinion before fitting one yourself.