My apologies, I was utterly confused there.
I thought you were talking about putting this cannon on the end of a tether, thereby making it orbit to surface. I know realise that you were probably refering to the implications of the lasers, and not the tethering part, and that I am an idiot.
Kool idea but I would imagine that unless those solar panels could travel down the tether they would be rather expensive to repair and maintain. Being attached to the climber they could easily be maintained when it returns to Earth.
I hail from Saskatchewan, Canada. The general public here (farmers) could be gullible enough to believe that those newfangled bit-torrent do-hickeys are contributing to the trucking industry's troubles.