however I think they are overly optimistic. I work in a group that researches fuel cells and they admit that there is no way that solar (or indirectly) solar power can be used. I (occasionally) work in a microfabrication cleanroom with silicon, and the chemicals that are used to create silicon solar cells are extremely unfriendly. The same for rare-earths. The issue is the shear amount of raw materials and fabrication required to gather enough energy because it is very low density. Most wind turbines are made out of aluminum and composites which are also not very environmentally friendly.
From the article:
Enough concrete and steel exist for the millions
of wind turbines, and both those commodities
are fully recyclable. The most problematic
materials may be rare-earth metals such as neodymium
used in turbine gearboxes. Although the
metals are not in short supply, the low-cost sources
are concentrated in China, so countries such
as the U.S. could be trading dependence on Middle
Eastern oil for dependence on Far Eastern
metals. Manufacturers are moving toward gearless
turbines, however, so that limitation may become
moot.
Photovoltaic cells rely on amorphous or crystalline
silicon, cadmium telluride, or copper indium
selenide and sulfi de. Limited supplies of
tellurium and indium could reduce the prospects
for some types of thin-fi lm solar cells, though
not for all; the other types might be able to take
up the slack. Large-scale production could be restricted
by the silver that cells require, but fi nding
ways to reduce the silver content could tackle
that hurdle. Recycling parts from old cells could
ameliorate material diffi culties as well.
There is a lot of vaporware in this section that is not easily solved.
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