[ExI] pentagon wants orbiting solar power stations

[Eugen Leitl]

On Mon, Oct 15, 2007 at 12:23:03PM -0400, John K Clark wrote:

> > Vehicular applications are but a fraction of total energy use
> 
> But that would seem to strengthen my argument not yours.

It would seem, if you snip the rest of my post. So it would seem.
 
> > A few weeks ago I've seen an electrical scooter which was
> > recharged with  solar panels.
> 
> Yes, and people could ride to work right now on solar electrical scooters,

I just *thought* you would latch on that illustration, and ignore the
rest of my points.

> but they don't; even in the third world a bicycle is preferred. People will

Actually, the electroscooter is huge in the third world. Just not the PV-powered
scooter, but that's a cost issue. Make it cheap, and they will come.

> never want to ride to work on slow, uncomfortable, inconvenient, and
> dangerous machines unless there was absolutely no alternative. There will
> always be alternatives.

Current EVs have excellent driving characteristics. The bottleneck
is traction on the road, not performance. Ranger is not really an
issue in a commuter setting, and hybrids and DMFCs can easily beat
existing systems.
 
> There are limits to of conservation; if somebody invented a cheap gadget
> that doubled the fuel efficiency of automobiles fuel consumption would not
> be cut in half because then people would be driving bigger more muscular

I guess I'm not people. On the average, the european cars are considerably
smaller and more fuel efficient, though there has been some SUV (especially
Cayenne) creep here as well. I think the other day I've even seen the pinnacle 
of primate dominance display, a Hummer. 

Energy is apparently still way too cheap. Not enough folks hurtin'.

> cars and be taking more and longer trips. The amount of energy used by the
> human race can only go up over the years, probably dramatically, and

It will get up dramatically. But in order for it to go up dramatically, we
need solar satellites, and that's a high threshold. Meanwhile, fossil energy
is getting more and more expensive year by year. Rural US certainly seems
to be hurting, according to what I hear. Here's people with a huge commute,
and old clunkers they can't really afford.

> > Remember, 1/10000th of terrestrial insolation is enough to
> > keep current > humanity in business indefinitely
> 
> If that cryptic remark means what I think it does then I'd say it is a very
> questionable statistic indeed.

I don't see what is questionable about it. How does 0.6% of Germany sounds
like? (Germany is reasonably densely populated, most other places would be 
negligible).
 
> > This means there is no need for additional surfaces, just tiling a
> > fraction of our existing structures with PV panels.
> 
> It means finding a way to make to make PV panels that are dirt cheap, it

Right, that's the ticket.

> means PV panels that are so efficient and so durable that they produce
> more energy over their lifetime than it took to make them, and it means

That's a pretty questionable statistic. Even classical PV ROIs energetically
within a couple years, or so. It's just financially it would take some 50
years, in Germany at least. I should run the numbers again. Perhaps things
have changed meanwhile.

> figuring out what to do at night or on cloudy days. It means your use of

I don't know what you do at night, but I sleep, or sit at the computer, or
watch movies. Cloudy days are not night.

> the word "just" may not be entirely accurate.

Maybe I live in an alternative reality, but the place I rent out is heated
(and partly, powered) by geothermal, via 120 C hot water from a few km depth.
I see PV and solar collectors on every second roof, in places. I see farmer
barns covered by PV entirely -- they're making a fair money on it, thanks to
subsidy, but it's real money for them.

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