Pouting Thomas

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    • Tue Jan 22nd 12:27 PM | Rating: 0 0
      Commented on:
      Whitman Departs eBay As It Becomes Less Relevant
      "During the last two years, eBay has lost about half its value."

      Half its price, anyway.
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    • Mon Dec 3rd 23:30 PM | Rating: 0 0
      Commented on:
      The Tellurium Supernova
      I am, in fact, a EE who has done work from IC layout to abstract signal analysis. I have worked with light conversion materials that cost over $1,000/gram, which tends to focus one's mind on efficient use of material.

      The comparison to indium is bogus. Indium is not widely used as a trace dopant. It is used for bulk materials like solders and semiconductor substrates, and in indium-tin-oxide transparent electrodes on LCD displays. LCDs apparently use a lot: the layers are thin, but they make 'em literally by the acre. So yeah, they zip through a ton at a time.

      By comparison, the phase-change material in memory devices is only used on small dice in an extremely thin layer.

      Incidentally, my numbers are ridiculous, but not for the reasons you think. They are way, way conservative. The market for memory devices is a lot less than US$100G/year. Memory cost will be a lot more than US$0.10/GB, at least for the next couple of years. Practical memory cells are likely to be considerably smaller than 150 nm. Only around 25% of the chip area will be covered with phase-change material; the balance being etched off and recoverable from the waste stream.

      If you disagree with the assumptions I listed, please state which ones, what you think they should be, and why. This is physics. If you're not calculating hard numbers from first principles, you're lying.

      "As for FSLR, from head to toe it started as a CdTe based company, and has no other product. There is no feasible way for it to switch to a different technology, other than liquidate all existing assets and start over again from scratch on a different technology."

      No. First Solar is a glass panel company having a fling with CdTe. All plausible high-efficiency materials will be rather fancy and expensive. To keep costs in hand, they will HAVE to be used as thin films, sandwiched between sheets of inexpensive glass for protection and mechanical strength. And First Solar has that problem SOLVED. Can they handle acres of glass? Check. Can they get the glass extremely smooth and clean? Check. Can they put electrodes on that glass that don't block too much sunlight? Check. Can they make electrodes that have acceptable electrical resistance? Check. Can they make reasonably rugged assemblies that stand up to weather? Check. Do they have a customer base and distribution channels? Check. That's no guarantee they will pull off the transition to a different film composition, but they have as good a chance as you could ask for.

      One-trick ponies like CdTe are generally regarded as a stop gap solution. It's just not plausible that any simple material will have a good match to the entire visible spectrum. To get light conversion efficiencies up in the 50-75% range will take layers of multiple materials, or a fancy structures (keep your eyes on the folks growing vertical nanotubes on surfaces). Those technologies are being developed right now and will become increasingly practical over the next 10 years. Whoever has a glass panel plant sitting around waiting for them will have tremendous first mover advantages.

      The real structural risk is that someone could invent laminated plastic PV cells that are distributed on a roll. The glass panel business would be toast.
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    • Mon Dec 3rd 04:37 AM | Rating: 0 0
      Commented on:
      The Tellurium Supernova
      Oh, dear.

      Think twice before taking physical delivery of tellurium. When even a microscopic amount gets inside the human body, the victim develops a horrific stench that can last for the rest of their life. Which tends not to be all that long due to suicide.

      I question the effect of the digital memory market on tellurium demand. Start with some absurdly conservative assumptions: that a bit cell is a 150 nanometer square, that the phase-change film contains tellurium equivalent to a 75 nanometer layer of elemental tellurium, that the memory uses 10 cells to store 8 bits, that the memory will sell for US$0.10/GB, and that sales will be US$100 billion/year. A gig of memory would contain 1.7E-11 cubic meters of tellurium, or 1.1E-7 kg. Multiply that by 1E+12 GB/year, and you get 105 tonnes/year of tellurium, or 116 U.S. tons/year. That's only half the current world production. First Solar doesn't have to worry about memory hogging the tellurium. The worry, if any, would be phase-change optical disks, which have huge bits and thick layers.

      Regarding securing supplies, CdTe compounding is a low-margin, low-volume specialty business. The compounders are contractors, CdTe creation is a minor business, and they probably have no interest in learning to be international tellurium brokers.

      "They do not need to go buy sand and pass it to their glass suppliers to make the glass."

      Oh? Where I work, we are currently having impurity problems with a specialty glass product. We would LOVE to talk sand with the production folks, instead of working our way through the layers of an international commodity distribution chain.
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