Comment by pfdietz

I'm not impressed by these arguments.

(1) Solar panels can be made much lighter in space. On Earth, panels have to withstand wind and gravity loads, flying debris, and precipitation including hail. The PV material itself doesn't have to be thick: thin film CdTe cells can be ~1 micron thick (the absorption length of the relevant photons in CdTe is something like 0.1 microns.) There has to be a protective layer to prevent solar wind ions from degrading the cells but this doesn't have to be very thick. It's not like shielding against high energy particles.

(2) Heat dissipation can be addressed by refrigeration. Yes, this takes energy, and yes that extra energy also has to be radiated. But the area of the radiator goes down as the fourth power of its absolute temperature. If you radiate 2x as much heat but at 2x the absolute temperature, the area of the radiator declines by a factor of 8. Even with inefficiencies one should be able to come out ahead by pumping the waste heat to higher temperature before radiating it.

(3) Ionizing radiation is dealt with by shielding. The amount of shielding per unit of capacity declines as you make your installation larger, by the square cube law. So this is really just a matter of scale. We're talking about potentially enormous amounts of capacity here so shielding shouldn't be a problem at scale.