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IBM Recycles Waste CPU Wafers Into Solar Panels

Posted by kdawson on from the trash-to-power-revisited dept.

Luyseyal writes "IBM has developed a process for scrubbing waste silicon wafers clean, allowing the otherwise highly secret waste to be sold. The silicon quality usually necessary for solar production is very high and the cost of solar panels reflects it. Recycling this waste should help bring down the cost in the long run and add a new profit vector for chip manufacturers. The article notes that IBM has such a high profile in the chip business that this recycling tech should spread rapidly."

7 of 122 comments (clear)

  1. As the 8th Most Common Element (by Mass)... by Anonymous Coward · · Score: 1, Insightful

    in the Universe. Do we really need to worry about recycling?

    http://en.wikipedia.org/wiki/Silicon

    1. Re:As the 8th Most Common Element (by Mass)... by dwywit · · Score: 5, Insightful

      I think it's got more to do with the "energy debt" that silicon wafers acquire during their manufacture. Anything is better than starting from scratch.

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    2. Re:As the 8th Most Common Element (by Mass)... by weirdcrashingnoises · · Score: 2, Insightful

      "The silicon quality usually necessary for solar production"

      apparently u couldn't even bother to RTFS

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      sigs... don't talk to me about sigs....
    3. Re:As the 8th Most Common Element (by Mass)... by dbIII · · Score: 4, Insightful
      It's the same as with Aluminium, common as dirt but if we want to use it as something other than dirt that takes a lot of effort. Once it's in a usable form it's an incedible amount easier to use the metal than it is to turn the mined material into metal all over again.

      With Silicon you have the added problem that you want really big crystals since you do not want a grain boundary halfway across your electronic component. The wafers are cut from a single large crystal and it takes a lot of effort to grow this crystal. Silicon is very hard so cutting it into wafers is not that easy either.

    4. Re:As the 8th Most Common Element (by Mass)... by Mark_MF-WN · · Score: 5, Insightful
      I remember reading about how the entire concept of "recycling" started with aluminum -- because the difference between refining new aluminum from bauxite and reprocessing existing aluminum is so incredibly great. Even iron is recycled to an extraordinary degree. And they say that 99% of all the gold that has ever been mined is still in use. There are even a few companies that believe that they can profitably recover platinum from the dust on America's highways left behind by catalytic converters!

      Is it any surprise that silicon, being so expensive to purify, would ultimately start to see at least some measure of waste recovery?

  2. Re:How Much? by Doc+Ruby · · Score: 2, Insightful

    I understand the process. But what is the actual quantity of energy required to make a square meter of PV? How many joules to produce a 15%, or for a 20%, or a 23%, or even the new (not just silicon) 42% PVs?

    And how much is saved by using these IBM "scrubbed chips" instead of starting from scratch, for what %efficiency?

    You say about 20% of the energy the PV will produce is consumed in construction and installation - 10% in manufacturing the silicon. A square meter of PV will last maybe 30 years, getting maybe an average (across weather/night/season/daytime) of 300W, for 248Gj. Does making the silicon really consume 25Gj? The rest of the deployment takes the equivalent of 193 gallons of 34Mj:L gasoline to deploy? Somehow that seems off by 10x or more. Do PV actually take more like only 1-2% of their lifetime output to deploy? And with this new IBM process, does recycling them at the end of their life mean grinding them back to sand, or some other energy input to return them to useful PV?

    FWIW, even if the 20% number is correct, it sounds to me like we should be making and deploying these things in space, where there's vast energy to exploit, and probably the costs (including the deferred costs of "pollution" byproducts) are lower, once the process is in place. Considering the benefits (like 3-5x the reliable insolation, nearly unlimited capture area, and putting us firmly in profitable space industries poised for further exploitation), the investment in launching the "factories" seems like an excellent risk.

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  3. nano solar is the way to go by Anonymous Coward · · Score: 1, Insightful

    print solar panels on any kind of thin film. http://www.kqed.org/quest/television/view/399