Flexible solar panels compared

Flexible panels usually consist of cells on a plastic backing layer with an ETFE or PET surface. A 200 Wp panel often weighs just a few kilograms. That makes them attractive for balconies with limited load capacity, for rented flats where drilling isn't allowed, and for motorhome roofs.

On the other hand, they generally age faster than glass panels, because heat and UV light put more strain on the plastic layers. Performance warranties are often shorter. If the panel lies directly on a surface without rear ventilation, it gets hotter and delivers less power.

With flexible panels, it pays to take a close look at the datasheet:

For balcony power plants, there are flexible kits with four panels of 200 to 240 Wp each, which together reach the usual 800 to 960 Wp. They can be attached to the railing with cable ties. Make sure the panels don't flap or rub in the wind – over time, this damages the cells. The legal situation is the same as for glass panels: 800 watts of feed-in and registration in the Market Master Data Register.

Go for flexible panels if weight, a ban on drilling or curved surfaces are the deciding factors – for example on a motorhome roof, a boat deck or a lightweight railing. If you have a sturdy mounting option and enough space, glass panels are usually the more economical choice over their lifetime, because they age more slowly and are often cheaper per Wp. In both cases, compare the performance warranty and the temperature coefficient.