Key takeaways
- • Plug-in solar in Great Britain is limited to a maximum output of 800W.
- • Savings depend heavily on how much electricity you use during daylight hours.
- • Permission may be required if you rent, lease or live in a managed building.
Plug-in solar (sometimes called balcony solar) is a small photovoltaic system you mount on a balcony, wall, flat roof, garden frame or shed, connected through a microinverter. It generates electricity that your home uses first, cutting the units you buy from your supplier.
How a plug-in system works
Sunlight hits one or two panels. A microinverter converts the DC output into 230V AC. That power flows into your home circuits and is consumed by whatever is running at the time — fridge, router, standby loads, kettle. Anything you do not use is exported, usually unpaid unless your setup is registered with a tariff that supports it.
The UK 800W picture
Under Great Britain's current plug-in solar framework, a compliant device may have a maximum apparent AC output of 800 VA and is designed to connect to a suitable UK mains socket using the manufacturer-supplied BS 1363 plug. The product must meet the applicable safety and technical requirements, while current G98 network requirements also apply. After installation, the relevant Distribution Network Operator must be notified under the applicable process. See our plug-in solar regulations guide, DNO notification guide and socket guide.
What it realistically saves
A well-sited 800W system in southern England typically produces 550-750 kWh a year. At 25p per kWh that is roughly £100-£160 saved, and only if you actually consume the output as it is generated. North-facing, shaded or heavily overshadowed positions can halve that.
Who it suits
Flat dwellers with a sunny balcony, homeowners who cannot justify a full rooftop array, renters who want something removable, and anyone with a south-facing fence, garage or shed wall. It is a supplement, not a replacement for rooftop solar.
Before you buy
Check the inverter rating, the mounting hardware included, the warranty term, and whether the seller documents UK compliance. Get written permission where a landlord, freeholder or managing agent is involved.
Frequently asked questions
Sources
Fact-check status: reviewed. Read our editorial policy. General information only — not electrical, legal or financial advice.