Re:Nasa’s ambitious plan to save Earth from a supervolcano
by elihu on Tuesday October 31, 2017 @07:39PM
(#15597702)
Presumably any process that can use the heat directly rather than converting to electricity would be more cost-effective, as you lose most of the energy in that conversion.
I assume 350C isn't hot enough for aluminum which melts around 660C, but maybe there are other industrial processes that could take advantage of the heat. Maybe using the heat to kiln-dry wood or cure autoclaved aerated concrete blocks or something like that.
Re:Nasa’s ambitious plan to save Earth from a supervolcano
by mirimir on Tuesday October 31, 2017 @10:10PM
(#15598399)
In aluminum production, the electricity is used for electrolytic reduction, not melting. It's the waste heat from that which keeps the cell hot enough.
Re:Nasa’s ambitious plan to save Earth from a supervolcano
by xyzzyz on Tuesday October 31, 2017 @11:45PM
(#15598673)
> Presumably any process that can use the heat directly rather than converting to electricity would be more cost-effective, as you lose most of the energy in that conversion.
All practical electricity generation technologies do it through heating water just the same, and they produce hot water as a waste product too. So, if your industrial process can use heat directly, it might as well use waste heat from existing power plants.
Re:Nasa’s ambitious plan to save Earth from a supervolcano
by jopsen on Wednesday November 01, 2017 @12:40AM
(#15598816)
And some places this is how entire cities are heated...
Well, usually they run out of excess heating in the winter.
Perhaps, Yellowstone and Iceland ought to have some heavy industry.
Re:Nasa’s ambitious plan to save Earth from a supervolcano
by njarboe on Wednesday November 01, 2017 @02:21AM
(#15599159)
Iceland has some large aluminum smelters and aluminum is 40% of their export income[1]. They do heat their homes with geothermal. It's basically free and when I was there the lowest setting for the heat in my apartment was 22.4C (72F).
Re:Nasa’s ambitious plan to save Earth from a supervolcano
by lostlogin on Wednesday November 01, 2017 @03:54AM
(#15599481)
Interesting link. 800,000 mtpy is a lot of aluminium. While the ‘zero environmental imapct’ claim is controversial, the environment impact is definitely lower than many other producers.
You can put it into aluminum production, for example, though at $0.10/kWh it's going to be an unprofitable business.
> If only 5% of your transmitted energy actually makes it to your buyer, without congestion, you're spending $0.10 / kWh but your buyer is paying $2.00 / kWh where the difference all goes to line losses.
You might get 95% loss if you wrapped your line around the globe, but for practical length of 1000 km, you can get as little as 3% with high voltage DC. Check out the Pacific DC Intertie, which is 50 years old instalation with over 800 miles of conductor spanning from Columbia River to Los Angeles.