

The problem is not that you need to run a single laser, but multiple lasers in order to have some form of usable working width. Then you also need to power the cooling and the computer for the plant detection. If you build some form of small scale robot it should work with solar, but any machine that is designed to get the job done relatively quick probably won’t work.
The problem with a single laser is, that, in order to achieve bigger working widths, it would have to be able to rotate very accurately, very fast and not shoot your crops at the same time. Especially the latter makes it impossible to use a single one.
You also dont have to “burn” the weeds. It is enough to destroy certain cells to stop them from growing.