Really the only reasonable world wide solar plan I've ever seen is solar power satellites. There has been a lot of work done there and they beam the energy back to the planet as microwaves where it is needed into the existing grid system. But so far the cost of getting all of that material into orbit to build them is something of a deal breaker.
>At this level, our 3.6 km diameter collecting area would generate about 40 GWh of energy in a day, at an assumed reception/conversion efficiency of 70%. By comparison, a flat array of 15%-efficient PV panels occupying the same area in the Mojave Desert would generate about a fourth as much energy averaged over the year. So these beaming hotspots are not terribly more concentrated than what the sunlight provides already. Again, I find myself scratching my head as to why we should go to so much trouble.
Well, you sure can't point the power delivery beam at downtown LA either.
And the footprint of the rectenna array is enormous-- Tom assumes a 100GHz transmit antenna 30m wide, which means the downlink antenna has to be 3.6km wide! And this is the minor axis-- the solar array has to be geosynchronous orbit, which means any receiving antenna not on the equator has be an ellipse.
