Re: H2-PV Makes the Right Kind of Economic Chaos

bill wrote:

The pv casting furnace is the heart of a pv plant *after* you have
99.9999% pure silicone, which is obtained from a vapor deposition
process which is painfully slow and energy intensive. All of your
other stupidity is predicated on that particular false statement. You
cannot acid wash sand, melt it and cast it and have pv grade wafers,
what you'll have will be beer bottles, roughly 98% pure. You have to
acid wash the sand, then run it through your casting process, THEN run
it through the seimens process to get the 99.999% purity that is
required for polycrystaline pv cells.

There *are* other processes for producing PV-grade silicon that don't involve the Siemens process, which I think is the basis for his point. However, while many of them produce cheaper silicon in principle, almost all of them have been either so slow, unscalable, or produce silicon of such low quality that when it come down to finished PV modules they don't produce the promised cost savings. Besides which, slicing the silicon into wafers costs more than producing the ingot in the first place, even at today's inflated silicon feedstock prices. If he really wants to cut silicon wafer costs, that's the place to focus.

For what it's worth, the first real mass production of PV-grade silicon is beginning this year. As I recall, it uses a fluidized bed process in place of the Siemens process (though I could be mistaken).
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