[extropy-chat] Nuke 'em

Damien Sullivan phoenix at ugcs.caltech.edu
Mon Oct 24 17:43:11 UTC 2005


On Mon, Oct 24, 2005 at 09:26:23AM +0200, Eugen Leitl wrote:

> http://www.eere.energy.gov/solar/pv_cell_light.html says it's about 6 kWh/m^2/month 
> insolation, for U.S. June. At 5% efficiency, a 60x60 m would be about enough for
> the average 2005 household http://www.eia.doe.gov/emeu/reps/enduse/er01_new-eng.html

Notice that's *household electricity*.  I've been budgeting for total energy
use.

> > > > And what are the thermodynamics of getting CO2 from 300 ppm to 100,000
> > > > ppm or whatever the C concentration in biomass would be?

> My point was that plants don't directly produce hydrocarbon fuels.

Eh, what are we arguing about?  My original was industrial production of
hydrocarbons.  Or other liquid fuels which we can distribute and use with
existing infrastructure.

> > > photochemistry? Why are plants not velvet black in the first place?
> > 
> > Perhaps they're already using all the energy they can limited by other
> > factors and they don't want to cook?
> 
> Can you imagine an evolutionary process resulting in a plant that can operate
> at 130 C, normal pressure?

I thought I was good at following your thought-contortions but I'm lost now.
Overheating can be a problem for animals, burn one for plants.  You asked why
they aren't black; I suggested there's no need for them to be.  Are you saying
black plants would reach 130 C in sunlight?

> > > > Which is why a solar heat engine can produce electricity better than a
> > > > photovoltaic, at least in direct light.
> > > 
> > > Uh, I'd like to see your Stirling beat 35% efficient (theoretical

I never said Stirling, just generic heat engine.  I was thinking more of
whatever they're using in California with all those mirrors focused on a
tower.

-xx- Damien X-) 



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