One of the advantages of plug-in solar over rooftop systems is flexibility. You are not limited to wherever your roof happens to face. Panels can go on a balcony railing, a garden fence, a shed roof, a wall bracket or a ground-mounted frame. Each option produces different amounts of electricity and comes with its own installation considerations.
Balcony solar
Balcony solar, known in Germany as Balkonkraftwerk, is the most common setup for flat dwellers. Panels are mounted vertically on balcony railings using brackets, which is quick to install and easy to remove when you move. The trade-off is output: a vertical panel receives sunlight at a non-optimal angle, typically producing around 70 percent of what the same panel would generate at the ideal 35 to 40 degree tilt.
For a south-facing balcony in central England, a vertical 800W system might generate 450 to 550 kilowatt hours per year. That is still enough to save £125 to £150 annually at current rates. For east or west-facing balconies, output drops further to roughly 400 to 450 kilowatt hours. North-facing balconies produce too little to justify the cost of a kit.
Garden and ground-mounted solar
If you have outdoor space at ground level, a tilted ground-mounted frame can get your panels much closer to the optimal angle. This is the setup that produces the best output from a plug-in kit, since you have full control over both the tilt angle and the orientation. A south-facing 800W system at 35 to 40 degrees in central England typically generates 600 to 700 kilowatt hours per year.
Ground frames are available from most plug-in solar suppliers and typically cost £40 to £80 on top of the panel kit. The installation involves nothing more than placing the frame, attaching the panels and running a cable to the nearest socket. For homeowners with a garden, this is often the best value configuration.
Shed and flat roof solar
A shed with a south-facing roof is one of the most underused solar opportunities in UK gardens. The roof area is often ideal for a tilted panel array, the cable run to the house is short, and there are no planning considerations for a small outbuilding. A flat roof can also work well with an adjustable tilt frame.
Wall-mounted solar
Mounting panels on a south-facing wall is another option for homes without a suitable garden or balcony. Output is similar to a vertical balcony installation. The installation is slightly more involved than a railing mount, but the result is more permanent and can look neater for homeowners who do not need to move the system.
What matters most
The biggest factor in output is not where you mount the panels but which direction they face. A south-facing balcony panel will always outperform an east-facing garden frame. If you have a choice of locations, prioritise south-facing over everything else. After orientation, tilt angle is the next most important variable, which is why ground-mounted setups with adjustable frames tend to outperform balcony railings when properly positioned.