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.
Balconies are the classic plug-in solar location, and also the one with the most rules attached.
Assess the balcony first
Note the direction it faces, how many hours of unshaded sun it gets between 10am and 4pm, the railing type and whether you are above the second floor. South and west facing balconies perform best; north facing is rarely worth the money.
Mounting choices
Railing clamps are quickest and avoid drilling. Vertical mounting loses roughly a quarter to a third of annual output compared with a 35 degree tilt, but tilt brackets that overhang the rail may not be permitted. Balustrade-mounted panels must be secured against wind uplift with fixings rated for the job.
Permission
Balcony structures are usually retained by the freeholder even in an owned flat. Get written consent, and expect questions about appearance and safety from a managing agent.
Electrical connection
A compliant Great Britain plug-in solar device can connect to a suitable mains socket using the manufacturer-supplied plug. Do not run extension leads through doors or windows or improvise an outdoor connection. If a new outdoor socket, circuit alteration or assessment of older wiring is required, use an appropriately qualified electrician. See our socket guide and safety checklist.
Realistic expectations
A vertical 800W balcony system in the Midlands typically produces 380-500 kWh a year, saving roughly £70-£110 depending on how much you consume live.
Frequently asked questions
Sources
Fact-check status: reviewed. Read our editorial policy. General information only — not electrical, legal or financial advice.