There are two factors, which present obstacles that must be overcome if solar energy conversion is ever to be practical and widespread:
- The limitations on the availability and/or production of the natural resources needed to manufacture the best currently known technologies, and
- The comparative economics of “solar” energy conversion and all other alternate energy conversion technologies.
It’s official: a peer-reviewed scientific journal with the word “environmental” in its title, “Environmental Science & Technology,” will shortly publish an article repeating what I have been saying for years to my own peers in the natural resources production industry: there is not enough cadmium, tellurium, indium, gallium, or selenium available or producible, annually, in a reasonable time frame or scale, to make “solar” energy conversion devices, critically based on any combination of them, abundant enough or cheap enough to be anything more than a niche alternative to fossil fuels or nuclear.
A recent Popular Mechanics article on the subject of photovoltaics was not written by a well-informed person, nor edited by anyone who bothered to check or understand the facts of “solar grade” polycrystalline silicon mass production development. The article says that
“While silicon is the second most abundant element in the earth’s crust, it requires enormous amounts of energy to convert into a usable [for solar energy conversion] form. This is a fundamental thermodynamic barrier that will keep silicon costs comparatively high.”
and continues cluelessly.
The writer and editors of Popular Mechanics do not seem to have ever heard of upgraded metallurgical grade silicon (UMGSi), upon the development of which, dozens of companies are working and which development, as a commercial process, at least 6 of the well capitalized metallurgical grade silicon producers have said they have now accomplished. If even one of them has achieved mass production of UMGSi, then the cost of producing a wafer-based silicon solar cell will decline dramatically.
I would also like to point out that people who refer to an element’s concentration in the earth’s crust as a measure of its availability are completely ignorant of mining and geology. I call such people the “Earth Fundamental” crowd, and I have previously written about this nonsense recently.
There is simply not enough of the critical raw materials for thin-film solar energy conversion cells, for any technology not based on silicon to make a difference.
First Solar’s share price and market capitalization are ridiculous as even the peer-reviewed literature has found out at last.
The production of metallurgical grade silicon is today routine; globally there are 1.5 million metric tons a year produced for use by the steel industry as an additive. If 10% of that capacity could be converted to the production of UMGSi for solar cell production, it would spell the end of cadmium telluride and copper indium gallium diselenide as the basis for economical solar energy conversion technologies. There is no doubt that the probability of this UMGSi mass production occurring in the next 10 years is high, whereas the probability of increasing global production of cadmium, tellurium, indium, gallium, and selenium beyond the all time highs that were achieved in 2007 is vanishingly small.