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This might actually work. A lot of of the dirty work can be done in places with solar /wind power and during the peak energy producing times. Like for aluminum

This might actually work. A lot of of the dirty work can be done in places with solar /wind power and during the peak energy producing times. Like for aluminum smelting which apparently needs ~10x the energy that steel needs https://theconversation.com/the-trouble-with-aluminium-7245 https://theconversation.com/the-trouble-with-aluminium-7245

codecamper 9y ago
That might be a good use of solar actually. Smelt the aluminum right at the site, which might have poor grid connectivity. Generate your own power ultra cheap & use it directly for smelting. Save on raw material transport costs. It would be interesting to see a cost / benefit analysis here.
- mercutio2 9y ago
  Efficient aluminum smelting requires reliable, continuous power for weeks at a time. Photovoltaics are cheap, but the diurnal variation makes them singularly inappropriate for aluminum smelting.
  - SEJeff 9y ago
    And could the economics eventually work of photovoltiacs + battery storage ala a tesla powerpack?
  - codecamper 9y ago
    Why does it need to be continuous?
    - mercutio2 9y ago
      In a nutshell, allowing the aluminum to solidify gums the batch process up catastrophically. Friends who used to work at aluminum plants were surprisingly happy when the plant was snowed in: it was more economical to keep workers onsite running rotating understaffed shifts at triple pay for the duration than to let the pots solidify. From the Wikipedia page on aluminum smelting: An aluminium smelter consists of a large number of cells (pots) in which the electrolysis takes place. [...] Smelting is run as a batch process, with the aluminium metal deposited at the bottom of the pots and periodically siphoned off. [...] However power must not be interrupted for more than 4-5 hours, since the pots have to be repaired at significant cost if the liquid metal solidifies. In addition to Wikipedia, there’s a surprisingly good explanation here: https://www.ega.ae/en/operations/smelters/production-process/aluminium-smelting/ https://www.ega.ae/en/operations/smelters/production-process...
sremani 9y ago
But they can do that right next to hydro-electric plants with much more reliability.. If I am not wrong, Alcoa did shutdown their plant in central Washington (crypto-valley), so aluminum smelting is probably not that rage anyway. edit: Crypto-mining may be one alternative, you are converting energy into currency is the most straight forward fashion. Could be the way, who knows.
- adrianN 9y ago
  It's hard to build airplanes out of Bitcoin. That aluminium must be produced somewhere.
  - sremani 9y ago
    The point, If they are closing Aluminium smelting plants when they are being sold 2cents/kwh from a reliable hydro-electric plant. Wind and Solar's chances are slim to none. I am not questioning the utility of Aluminium here.
  - dx034 9y ago
    You can smelt it in remote places. Iceland has a lot of Aluminium smelting because energy is so cheap. Doesn't mean that you need to produce the aluminium products there.
- crdoconnor 9y ago
  Aluminum smelting is still popular in Germany where they are being paid to offset the variability of wind/solar there by ramping production up and down. I have a suspicion that this is being used by Germany to feed them a disguised subsidy.
csours 9y ago
https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery I'd love to see some napkin math on this.
- LeifCarrotson 9y ago
  Gasoline has an energy density of 13 000 Wh/kg. Lithium-ion rechargeable batteries have an energy density of ~250 Wh/kg, and LiMnO2 lithium primary (non-rechargeable) batteries have an energy density of about 300 Wh/kg. Let's assume energy density near the upper end of that Wikipedia page - say, 6 500 Wh/kg, we have half the energy density of gasoline, and 26x the energy density of lithium ion rechargeables. So your Tesla 100D with 540km range becomes a 14 000 km/8 500 mile range. You can get a battery swap a few times a year, a little less frequently as you'd get an oil change now. But that's still half the energy density of gas. Instead of buying 12 gallons of gas every week or two, you're now buying 720 kg of aluminum every few months. All the gas tanker trucks you see on the road right now? They're replaced with twice as many aluminum-air battery carrying trucks. All the pipelines, supertankers, rail cars, etc? Replaced with aluminum carriers. And on top of all that, gas turns into CO2 and water, disappearing into the atmosphere. With this plan, you have to ship these aluminum batteries back to the manufacturer for rebuilding! You'd have to build thousands of mostly automated battery reconditioning plants and scatter them across the country for that to work.
  - csours 9y ago
    Awesome, thanks for that.

codecamper 9y ago

That might be a good use of solar actually. Smelt the aluminum right at the site, which might have poor grid connectivity. Generate your own power ultra cheap & use it directly for smelting. Save on raw material transport costs. It would be interesting to see a cost / benefit analysis here.

mercutio2 9y ago
Efficient aluminum smelting requires reliable, continuous power for weeks at a time. Photovoltaics are cheap, but the diurnal variation makes them singularly inappropriate for aluminum smelting.
- SEJeff 9y ago
  And could the economics eventually work of photovoltiacs + battery storage ala a tesla powerpack?
- codecamper 9y ago
  Why does it need to be continuous?
  - mercutio2 9y ago
    In a nutshell, allowing the aluminum to solidify gums the batch process up catastrophically. Friends who used to work at aluminum plants were surprisingly happy when the plant was snowed in: it was more economical to keep workers onsite running rotating understaffed shifts at triple pay for the duration than to let the pots solidify. From the Wikipedia page on aluminum smelting: An aluminium smelter consists of a large number of cells (pots) in which the electrolysis takes place. [...] Smelting is run as a batch process, with the aluminium metal deposited at the bottom of the pots and periodically siphoned off. [...] However power must not be interrupted for more than 4-5 hours, since the pots have to be repaired at significant cost if the liquid metal solidifies. In addition to Wikipedia, there’s a surprisingly good explanation here: https://www.ega.ae/en/operations/smelters/production-process/aluminium-smelting/ https://www.ega.ae/en/operations/smelters/production-process...

sremani 9y ago

But they can do that right next to hydro-electric plants with much more reliability.. If I am not wrong, Alcoa did shutdown their plant in central Washington (crypto-valley), so aluminum smelting is probably not that rage anyway. edit: Crypto-mining may be one alternative, you are converting energy into currency is the most straight forward fashion. Could be the way, who knows.

adrianN 9y ago
It's hard to build airplanes out of Bitcoin. That aluminium must be produced somewhere.
- sremani 9y ago
  The point, If they are closing Aluminium smelting plants when they are being sold 2cents/kwh from a reliable hydro-electric plant. Wind and Solar's chances are slim to none. I am not questioning the utility of Aluminium here.
- dx034 9y ago
  You can smelt it in remote places. Iceland has a lot of Aluminium smelting because energy is so cheap. Doesn't mean that you need to produce the aluminium products there.
crdoconnor 9y ago
Aluminum smelting is still popular in Germany where they are being paid to offset the variability of wind/solar there by ramping production up and down. I have a suspicion that this is being used by Germany to feed them a disguised subsidy.

csours 9y ago

https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery https://en.wikipedia.org/wiki/Aluminium%E2%80%93air_battery I'd love to see some napkin math on this.

LeifCarrotson 9y ago
Gasoline has an energy density of 13 000 Wh/kg. Lithium-ion rechargeable batteries have an energy density of ~250 Wh/kg, and LiMnO2 lithium primary (non-rechargeable) batteries have an energy density of about 300 Wh/kg. Let's assume energy density near the upper end of that Wikipedia page - say, 6 500 Wh/kg, we have half the energy density of gasoline, and 26x the energy density of lithium ion rechargeables. So your Tesla 100D with 540km range becomes a 14 000 km/8 500 mile range. You can get a battery swap a few times a year, a little less frequently as you'd get an oil change now. But that's still half the energy density of gas. Instead of buying 12 gallons of gas every week or two, you're now buying 720 kg of aluminum every few months. All the gas tanker trucks you see on the road right now? They're replaced with twice as many aluminum-air battery carrying trucks. All the pipelines, supertankers, rail cars, etc? Replaced with aluminum carriers. And on top of all that, gas turns into CO2 and water, disappearing into the atmosphere. With this plan, you have to ship these aluminum batteries back to the manufacturer for rebuilding! You'd have to build thousands of mostly automated battery reconditioning plants and scatter them across the country for that to work.
- csours 9y ago
  Awesome, thanks for that.