Practical? With that inconvenient periodic eclipse that reduces the duty cycle to 50% (nighttime)? And solar flux in orbit is many times that on the ground. So

Practical? With that inconvenient periodic eclipse that reduces the duty cycle to 50% (nighttime)? And solar flux in orbit is many times that on the ground. So efficiency improves again. Let's skip over the objection about transmission-loss. That's estimated at 10% or 20% at most. The cheaper part is fast evaporating. Lift cost is falling geometrically with new rockets etc. Costs of eminent domain, mounting and weatherproofing are not zero. They're maybe the largest ground-based cost. Wet blankets aside, space-based has the huge, huge advantage of not requiring local planning permission to do!