[ExI] The silent PV revolution

[Eugen Leitl]

On Sat, Mar 31, 2012 at 08:16:56AM -0700, Ben Zaiboc wrote:

> I'd have thought it should be fairly obvious that PV energy would be 
> best turned into hydrocarbons as soon as possible.  We have the technology 

Not all of it, and not all in higher hydrocarbons. Latter have good
volumetric energy density at normal conditions, but not everything
is for propulsion. I'd prefer hydrogen, methane and methanol, and 
more non-Carnot usage. Once methanol fuel cells work well you'll
see a lot of these in electric vehicles and electroflight.  

> and infrastructure for using them in so many ways, all we need to do is 
> recycle the CO2 produced by burning them, back into fuel using whatever 

It's easier to use just water instead of water and CO2 scrubbing. Hydrogen
would work in most locations but propulsion (outside of cryogenic
liquids in aerospace).

> energy sources we end up using, be that PV, nuclear, or whatever.

Nuclear is not going to happen anymore. It also appears stupid
to waste fissibles potentially useful for deep space uses and
propulsion.
 
> Seems stupid to me to abandon a mature, effective (and highly energy-dense - 
> probably still the densest we know of) storage medium, that we're all fully 
> geared up to use, on a global scale.  Plus they're the raw material for 
> probably about 75% of the things you see if you look around you right now, 
> and an even greater %age of the device you're reading this on.
> 
> Hydrocarbons aren't going away any time soon (if ever).  Of course, if 

I can see how advanced systems just use dynamically tracked beamed power 
and don't need fuel. 

> someone finds away to make metallic monatomic hydrogen stable at STP, 

What is wrong with gases? Methane works well enough. 

> I'll happily eat my words.