jonathan wrote:
[snip]


Considering virtually NO money has been spent of SSP research, and
yet some are already presenting concepts where directly solar pumped
lasers replace microwaves, and rectenna sizes as small as three
meters, about the size of a car. If some real research money were
dedicated who knows what advances might happen?

The world has a population of several billion people so giving every
one their own SSP satellite would require several billion satellite,
that is not going to happen. Consequently SSP satellites have to be
city sized.

The solar power collected by the SSP satellite needs converting for
downloading. On the Earth a gigantic receiver is needed - the size
of a city. (A small receiver on every roof is still the size of a city,
it just has wasteful holes in it.) That receiver will be lucky to get
as much power as solar cells at the same location.

The advantage SSP has over Earth solar cells and solar thermal is
that it works at night. Pity we use less electricity at night.
(Offices and factories close at night.)

If you want to help the world build wind farms, solar power towers,
terrestrial solar electric panels and add a solar thermal water heating
system to your roof. Forget SSP.

Andrew Swallow