alt Hacker NewsIt sounds like you're mistaking PV for a thermal system.
In a PV cell, you have a semiconductor. Semiconductors have this thing called a "band gap", which is the energy needed to get an electron from the valence band to the conduction band: https://en.wikipedia.org/wiki/Band_gap
The limits to efficiency of a solar panel is that sunlight has photons of many energy levels; the photons with energy less than the band gap do nothing, those with more, waste the excess.
A laser can have energy tuned to this band gap, at which point the PV part becomes ~99.9% efficient. (The laser part is not close to that efficiency).
I'm not talking about a thermal system, I'm talking about having to deal with the thermals of your inefficiencies. That energy that doesn't get converted to electricity is converted to heat. And you have to deal with it.
The type of laser based PV that you're taking about that's highly tuned is at maximum 27% efficient. Not 99%.
That's a 73% waste you have to manage