We got solar powered string lights for our balcony. The solar panel only came with a spike to stick in the dirt. Since we are several stories up that didn't really work and we didn't want to just tape it to the railing. The part that connected to the spike was a little circular bit with a couple holes for screws so I designed a little mount for it in CAD and 3D printed it and so far it works great. It fits the railing and the solar panel perfectly.