On 3/12/2010 1:39 PM, Brian Gaff wrote:
If you do that you are losing energy in heating the water though.

I'd have thought a frequency more akin to microwaves would have been better
for that.

So would I; this is the first time I've heard lasers floated as a
serious proposal rather than microwaves, although the laser concept has
been discussed from time-to-time.
It's clumsy though, as it works like this: Sunlight electrical power
laser generation laser reception steam turbine electrical power.
Whereas the microwave one works like this:
Sunlight electrical power conversion into microwaves reconversion
into electricity.
Your adding a whole extra step by turning the sunlight into a
electricity and then back into light again, and that's not good from a
total efficiency point of view.
The best of all would just be to reflect the sunlight down to the
Earth's surface where it would fall onto a solar power plant's arrays
and illuminate them at night to the same degree they are lit up in
daylight, while doubling their power output during the daylight hours.
Far cheaper than either alternative is simply to build a larger solar
power plant on the Earth's surface and skip the very expensive
space-based part of the equation.
If they ever come up with superconducting power transmission cables the
whole equation shifts markedly, as then the whole world can be
electrically interconnected with power being transferred from the day
half to the night half as needed.


Of course if they want to use focussed beams they need to unearth the stuff
done in the 70s and 80s by the US Defense department on the attempted use
of lasers as weapons. The problem was that the turbulance created by the
beam defocussed it just like we see with starlight.


The blooming of the beam only occurred when it heated the air up into
plasma, I don't think they have that high of energy flux in mind for
this project.
Consider for a second what would happen if you made a conductive plasma
path clean through the Earth's atmosphere, connecting the charged
ionosphere to the surface, like shorting out a giant capacitor.
Because I suspect it would make a lightning storm look pretty mild by
comparison.

Pat