The government’s decision to legalise plug-in solar in the UK in 2026 was partly driven by a very specific group of people: flat dwellers. Around five million UK homes are flats. Most have no access to a suitable roof. Rooftop solar has always been someone else’s technology for these households. Plug-in solar changes that, but the options available to you depend heavily on what outdoor space your flat actually has.
South-facing balcony: the ideal setup
A south-facing balcony is the best-case scenario for a flat-dwelling plug-in solar user. Panels mount on the railing using clamp brackets that require no drilling and leave no permanent marks. The cable runs from the microinverter through the balcony door to an indoor socket. Setup takes a couple of hours and the whole system can be removed in under an hour when you leave.
The output from a vertical balcony-mounted panel is around 70 percent of what the same panel would generate at an optimal 35 to 40 degree tilt. For a south-facing position this is still a worthwhile amount — a typical 800W two-panel setup generates 450 to 550 kilowatt hours per year in central England, saving around £125 to £150 annually.
If your balcony has a solid concrete or brick parapet rather than a railing, you can still mount panels using specialist parapet clamp brackets or adjustable tilting stands that sit on the balcony floor.
East or west-facing balcony
An east-facing balcony gets morning sun; west-facing gets afternoon sun. Neither is as good as south, but both are workable. East and west-facing panels produce around 60 to 70 percent of south-facing output. For a two-panel 800W system that means roughly 350 to 450 kilowatt hours per year, saving £100 to £125 annually.
One advantage of east or west-facing panels is they can better match household usage patterns. East-facing panels generate more electricity in the morning when you are making breakfast and getting ready. West-facing panels generate more in the afternoon and evening when you return from work. Neither is optimal for pure generation, but either can suit specific household routines better than south-facing.
North-facing balcony: not worth it
North-facing balconies generate too little solar electricity in the UK to justify the cost of a kit. The sun is in the southern half of the sky throughout the year at UK latitudes, and north-facing panels are effectively pointing away from it for almost all usable daylight hours. If your only outdoor space faces north, plug-in solar is not the right option for your current home.
Terrace or shared outdoor space
Some ground-floor flats have a small terrace or garden. If the space has a south-facing fence, wall or area of paving, a ground-mounted frame can get your panels to a proper tilt angle and often generates more than a balcony mounting because of better orientation flexibility. You need to check with your landlord or freeholder that you can use the space and that a ground frame will not obstruct shared access.
A window ledge or windowsill
Technically possible for very small panels, though practical challenges make it unusual. A standard 400W monocrystalline panel is roughly 1.7 metres by 1 metre — too large for a typical UK windowsill. Smaller 200W or 300W panels exist and could theoretically sit on a wide south-facing window ledge, but output is modest. More practically, some people prop a portable panel against a south-facing window temporarily when at home and store it inside otherwise. This is not a permanent installation and does not require any permissions, but it is not something to leave unattended.
What if you have no suitable outdoor space at all?
If you genuinely have no south-facing outdoor space, plug-in solar is not practical for your current home. No amount of creative positioning compensates for a fundamentally unsuitable building orientation. The better approach in this situation is to look for a property with better solar potential when you next move, or to consider whether battery storage paired with a time-of-use tariff can reduce your electricity costs without generation.
For more detail on specific mounting setups, our balcony vs garden solar guide covers each option with practical advice. And for the full picture on renters’ rights, see our renters guide.