Pat Flannery writes:
Your adding a whole extra step by turning the sunlight into a electricity
and then back into light again, and that's not good from a total efficiency
point of view.

Bingo...

Far cheaper than either alternative is simply to build a larger solar power
plant on the Earth's surface and skip the very expensive space-based part of
the equation.

Which is the crux of the cost problem for all the space-based systems, solar
electric or solar thermal.

Dave