Re: this might usher in utopia

Don Kelly wrote:

> And the conversion efficiency, as well as the effectiveness of Zinc-
> air -hydrogen process? Weight and size of cells? Cost? How is this better
> than direct conversion of solar energy to electrical energy and storing it
> in a battery of any type or sing it directly? Just some questions that need
> answering.

Is this anything?

They're claiming 45 kg Zn per hour,
on 300 kW of concentrated sunlight.
This would make the free energy in the zinc 20.4 percent
of that of the sunlight that is used, not the reported 30 percent,
unless some carbon is involved, as seems likely
since no claim to the contrary is made.

"... this solar chemistry pilot project opens the way
for an efficient thermo-chemical process whereby
the sun?s energy can be stored and transported
in the form of a chemical fuel. In this process
the zinc is combined with coal, coke or carbon biomass
which acts as a reactive agent ..."

There has long been a PSI/ETH story, which I link from
http://www.eagle.ca/~gcowan/boron_blast.html#Zn ,
about thermolysing straight ZnO. If zinc could be precipitated
from *that* mixture -- Zn(g) + (1/2) O2 --
that would be something.

But if carbon is burned, and the only liquid-zinc precipitation
that is accomplished is from Zn(g) + CO, as was the commercial
way of making zinc for about 200 years --

Nothing.

Lock up the late night bear...


--- Graham Cowan, former hydrogen fan
http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html --
boron: how individual mobility gains nuclear cachet
.