[ExI] pentagon wants orbiting solar power stations

[Eugen Leitl]

On Sat, Oct 13, 2007 at 04:09:57PM -0400, John K Clark wrote:

> And I'm not dissing insulation or solar heating or getting rid of
> incandescent light bulbs, but as you say all these things are very small

They're only small if you're considering them isolated. In terms
of existing public momentum they're huge. In terms of ROI solar satellites
made from current launchers are ridiculous, even using Ukrainian
launchers, which are 7.5 k$/kg for LEO. There will be no solar 
satellites unless the launch costs have dropped by 2 orders of 
magnitude.

Space elevators don't exist. It is not obvious they will ever exist.
They certainly won't exist within next 10-20 years, by which time
renewable energy sources will have radically shrunk the fraction of
fossil and nuclear energy sources in our global budget.

> and if you want to get away from dead dinosaurs somebody is going to
> have find something HUGE. It would take 84 square miles of photovoltaic

Remember, suburbia would be net energy producer. There would be no longer
need for gas stations, or the electric grid (you'd use a local smart grid,
which would load-level among local demand cells). Industry would have to 
care to their own, unless residential surplus will be exported as hydrogen.

> cells to equal the energy of one gas station according to the CEO of Exxon.

Vehicular applications are but a fraction of total energy use, and personally
there's nothing in the physics of transporting 75-90 kg primates which requires
several tons worth of metal, plastic, and an ICE. A few weeks ago I've seen
an electrical scooter which was recharged with solar panels. The panels were
integrated into the vehicle, and unfolded in the back. Effectively, the 
additional space demand is zero. I don't see why a very performant residential
EV vehicle would need more than 1-2 l/100 km diesel equivalent.

> In the USA alone there are about 20,000 gas stations.

Great, we can get rid of 20 k gas stations, and the infrastructure
to supply them. Tankers, refineries, and we can actually use dead dinos
for chemistry, not burning them.
 
> It seems to me that the only technology able to take a significant chunk out
> of oil right now is nuclear fission. Fusion maybe someday, although from
> the 1950's it's always been 30 years away.

I'm using fusion right now. It's called PV and solar.

Remember, 1/10000th of terrestrial insolation is enough to
keep current humanity in business indefinitely. This means there
is no need for additional surfaces, just tiling a fraction of our
existing structures with PV panels.

-- 
Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org
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