[RightWhale]

the electricity would be beamed to Earth in low intensity microwave beams.

Not necessary. Put the smelters and factories in space, too, and right there save 1/3 of the power grid load and all the pressure.

[Sherman Logan]

Space energy or manufacturing options are not practical as long as we depend on rocketry for propulsion. When anti-gravity or something similar comes along we're in business. Until then, forget it. The cost of getting payload to orbit is just too great.