🚀 go-pugleaf

John DeFiore wrote:

> Perhaps, but Mr. Waltz is correct when he points out that it takes more
> energy to make a solar cell, using current technology, than it can
> return in it's [sic] entire life.

This is bullshit.  (And often repeated bullshit, so let's hose it off.)

Consider: 1 square meter of 20% efficient cells can typically produce,
in ten years, 3500 kWh of electricity.  Let's see your argument that
it takes 3.5 *megawatt-hours* to sputter a 5 micron layer of amorphous
silicon, or to lay down a 50 micron layer of polycrystalline silicon.

(As I understand it, typical *crystalline* cells have a net energy
payback time of 1-2 years; newer technology is much less.)

> Also, the cells do not last forever.  They are degraded by the
> UV exposure, weather, oxygen, etc.

Of course; nothing lasts forever.  However, commercial cells have
typical service life guarantees of ten and twenty years, with no reason
to expect prompt failure at the end of that time.

> The cost to fabricate and maintain a 1000 square kilometer expanse
> of solar cells would be prohibitive, let alone 100,000.

This is mere unquantified opinion; what cost is "prohibitive"?
(Typical prices for electricity from current crystalline cells are
$0.25 to 0.50; while this is [obviously] not economically competitive
at current prices, there is both good reason and historical evidence
to believe that PV prices are far from their long-run real minimum.) 

> Granted that improvements in
> technology may eventually let the solar cell produce a net energy gain
> in it's [sic] lifetime, but still, let's be practical.

Granted that solar cells *now* produce net energy gain, and that obvious
and significant improvements in technology, production, and packaging are
likely, perhaps you will reconsider your position.


Barry Smith, Blue Sky Research
barry@bluesky.com