UK Plug-In Solar: The 2026 Rules and the 27 August Go-Live
From 27 August 2026, plug-in solar can be legally connected to an ordinary UK socket. The framework is now finalised: BS 7671 Amendment 4 (in force since 15 April 2026) recognised plug-in solar in the wiring rules, and SI 2026/848 — amending the Plugs and Sockets (Safety) Regulations 1994 — makes it legal to feed power into a socket from 27 August 2026, provided the kit meets DESNZ’s Interim Product Specification, finalised on 16 July 2026. Systems are capped at 800 VA inverter output and up to 2,000 W of panels, connected through a standard BS 1363 plug with a 5 A fuse — the same framework that put over a million systems on German balconies. Here is what UK residents need to know.
What exactly is allowed
The UK rules mirror the German model almost point for point: a micro-inverter capped at 800 VA, panel capacity up to 2,000 Wp (overpaneling is explicitly fine — it improves cloudy-day output), a fused standard plug, and no requirement for an electrician for a compliant off-the-shelf kit. Two specific compliance points follow from the July 2026 rules: the kit must meet DESNZ’s Interim Product Specification, and the micro-inverter must appear on the ENA G98 Type Test Register — any kit sold for the UK market should state both.
Do you need to notify anyone?
There is no DNO pre-approval — you do not wait for permission before installing. But you must notify your local DNO under G98 within 28 days of connecting the system. G98 covers any single-phase generator under 3.68 kW, which includes every 800 W plug-in kit. The notification is a short after-the-fact form, not an approval process, but it is a legal requirement, so don’t skip it.
Why this matters more in the UK than anywhere else
Roughly one in five UK households rents, and millions more live in flats where rooftop solar was never an option. Plug-in solar is the first self-generation technology available to this group. With UK electricity among the most expensive in Europe (~26p/kWh in mid-2026), payback periods are competitive with Germany despite less sun.
Realistic UK numbers
| Setup | Annual output | Annual saving | Payback |
|---|---|---|---|
| 800 Wp south-facing, London | ~680 kWh | ~£125 | ~3.8 yrs |
| 800 Wp east/west, Manchester | ~540 kWh | ~£100 | ~4.7 yrs |
| 450 Wp single panel, south | ~380 kWh | ~£70 | ~4.2 yrs |
Assumes a £450–480 kit and 65% self-consumption. Run your own case in the payback calculator.
What to check before buying
- Interim Product Specification + G98 Type Test Register — the kit must meet the DESNZ spec and its inverter must be on the ENA G98 Type Test Register; stated in the listing, non-negotiable.
- Fused BS 1363 plug — UK-specific; kits imported from the EU with Schuko plugs need a proper UK version, not an adapter.
- Mounting — UK balcony railings vary; kits with adjustable non-drilling clamps fit most.
- Landlord/freeholder consent — the electrical rules don’t override lease terms; railing-mounted panels usually need a quick written OK.
The market right now
Because the go-live date is 27 August 2026, the legal UK market is only just opening: mostly German and Chinese brands shipping UK-plug versions verified against the new spec. Note that the 27 August rules cover solar-only kits; kits with integrated battery storage are treated separately. Expect prices to fall and choice to widen through 2026–27 as UK-specific kits launch. Our kit comparison tracks what’s actually available in the UK and is updated monthly.
Primary sources: BS 7671:2018+A4:2026; SI 2026/848 (Plugs and Sockets (Safety) Regulations 1994 amendment, in force 27 August 2026); DESNZ Plug-in Solar Interim Product Specification (finalised 16 July 2026); ENA Engineering Recommendation G98. Reviewed monthly.
Frequently asked questions
When does plug-in solar become legal in the UK?
BS 7671 Amendment 4 (15 April 2026) brought plug-in solar into the wiring standard, but connecting a kit to an ordinary socket becomes legal on 27 August 2026, when SI 2026/848 (amending the Plugs and Sockets (Safety) Regulations 1994) comes into force alongside DESNZ's Interim Product Specification, finalised 16 July 2026. Limits: up to 800 VA inverter output, up to 2,000 W of panels, connected via a fused BS 1363 plug.
Do I need to tell my energy supplier or DNO?
There is no pre-approval, but you must notify your local DNO under G98 within 28 days of installing. Make sure the kit's micro-inverter appears on the ENA G98 Type Test Register and that the kit meets the government's Interim Product Specification — reputable sellers state this.
How much can UK balcony solar save per year?
A south-facing 800 Wp system in southern England produces roughly 650–700 kWh a year. At around 26p/kWh and typical self-consumption, that is £110–150 per year, giving a 3.5–5 year payback on a £450 kit.