Slashdot Mirror

← Back to Stories (view on slashdot.org)

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."

3 of 122 comments (clear)

  1. This is great by Fengpost · · Score: 4, Interesting

    However, it would more impressive if someone can recycle the waste of LCD substrate. The LCD generates huge amount of waste as well.

    --
    The purpose of writing is to inflate weak ideas, obscure poor reasoning, and inhibit clarity....Calvin
  2. Re:How Much? by Doc+Ruby · · Score: 4, Interesting

    Another way to calculate it is about 777.6Kj:Kg, which is 18.624Gj for the 8" wafer, in the range of what we ran down.

    I left out the only 20% efficiency solar -> DC conversion factor, so the cells I described produce only about 50Gj in their lifetime, or 37% total energy inefficiency from manufacturing. Seems like a lot.

    I'm not sure we'd have to put the silicon into space. I saw reports of a NASA demo a few years ago of a lunar robot making solar cells from lunar dust. There's about 20 trillion square meters of Moon facing the Sun at any time, getting about 1.3KW:m^2, or 26 petawatts. Even at 1% conversion/transmission/conversion efficiency, that's 260TW, or 17x total human energy consumption. Which means well under 6%, perhaps even 0.6%, of the Moon's surface would replace all Earth power generation. Of course, orbiting solar platforms could offer even larger energy return. And consider the amount of energy wasted on war and fuel distribution that could be saved. If the space "factories" are productive enough, the energy budget balances well in favor of doing it.

    --

    --
    make install -not war

  3. Question about solar power by Entropius · · Score: 4, Interesting

    Aren't there ways to get solar power without futzing with photovoltaics?

    What sort of efficiency can we get out of focusing sunlight on water (using cheap Fresnel lenses), making steam, and using it to turn a turbine? Is this cheaper per watt of generating capacity to build?

    Seems like if you did this on seawater (on a big barge or similar), you could extract the water once the steam recondensed and getting desalination for free. If desalination becomes necessary to supply freshwater this might be worth it.