Petition to examine space based solar energy

On Mar 25, 2013, at 7:16 AM, sraj wrote:

> It appears that a small space based solar power system is not practical??
> Do we really need a 1Km dia transmitting antenna??..

If you use microwaves from geosynchronous, something on that order is necessary, regardless of power level. This assumes a 10 km receiver.

However, if you use higher frequencies (e.g., IR laser), a larger receiver or get closer, the diameter shrinks linearly. Since IR frequencies are around (if memory serves) 10,000x or more shorter than microwaves, the minimum size shrinks dramatically. You need something on the order of a part of a football field.