3 ms·

This is nice for soaking up and making good use of peaks, but it does nothing for the lows, the aluminium can't give back the electricity, so you'd still need c

by tinco 12y ago

This is nice for soaking up and making good use of peaks, but it does nothing for the lows, the aluminium can't give back the electricity, so you'd still need coal plants to complement the wind/solar farms when they're down. That said, even if we could reduce the need for coal plants that would be a huge win of course.

danieltillett 12y ago
They can help by improving the financial viability of intermittent power sources like wind by acting as soak for excess production. This allows you to invest greater amounts in wind farms and hence reduce overall coal use. It is possible that doing this might have the opposite effect if the wind farms are making most of their profit from the price spikes. In this case putting power back into the system by lowering usage in peak times might make wind less financially viable.
- raverbashing 12y ago
  The price spikes exist regardless, because those are from high-usage hours (basically day hours) and at a longer range, at summers and winters (depending on where you are) because of heating and a/c. A lot of factories already use more energy in the evening/mornings, because electricity is cheaper at those times. Storage technologies are a huge potential to be explored.
audunw 12y ago
> but it does nothing for the lows, the aluminium can't give back the electricity Actually, it seems they might be doing precisely that. See the information in the other comments. It's hard to say for sure, even the primary sources seem fuzzy. But this graphic seems to indicate that they are indeed extracting electric energy from the molten aluminum: http://images.bwbx.io/cms/2014-11-26/tech_aluminumgraphic49_630.jpg http://images.bwbx.io/cms/2014-11-26/tech_aluminumgraphic49_... This presentation also shows the energy arrow pointing from the aluminum plant to the consumer: http://www.innovationsforum-energiewende.de/wp-content/uploads/2013/11/Thomas-Flesch-Trimet.pdf http://www.innovationsforum-energiewende.de/wp-content/uploa... The most confusing thing about all of this is that they say that they only adjust their own power consumption by +/- 25%, which seems to contradict the statement that they're giving energy back. But as far as I can understand, this +/-25% is the long term average. Of course they need to consume a positive net amount of energy during the day to keep the plant running. But it seems that they are able to pump energy back into the grid for a short amount of time, which would be during the hours when solar/wind power is at a minimum.
- graycat 12y ago
  Maybe they are just giving back the energy to the grid in two respects, (1) energy they contracted for today they do not consume but sell back to the grid and (2) the energy was to come via the grid to them but, in not consuming that energy, the energy flows to homes, etc. instead and, thus, at least is redirected in the grud or, if you will, flows from the aluminum plant to the homes. At one point, they do say virtual. The losses involved are from some somewhat inefficient use of the grid and, there, losses flowing the energy through the grid.
nhaehnle 12y ago
It is misleading to claim that this does nothing for the lows, because everything that's happening here is symmetric. Let's say that aluminium production currently draws a permanent base load of 1GW. Let's say that the minimum acceptable overall level of electricity production given the status quo is 20GW. If aluminium producers manage to adapt their production so that they can temporarily operate on only 0.5GW, then the minimum acceptable overall level of electricity production is now 19.5GW. Unlike what the article misleadingly says, this is not magic that can somehow generate electricity when all other sources fail. But it does shift the line of when low levels of production become critical.

by tinco 12y ago

danieltillett 12y ago

They can help by improving the financial viability of intermittent power sources like wind by acting as soak for excess production. This allows you to invest greater amounts in wind farms and hence reduce overall coal use. It is possible that doing this might have the opposite effect if the wind farms are making most of their profit from the price spikes. In this case putting power back into the system by lowering usage in peak times might make wind less financially viable.

raverbashing 12y ago
The price spikes exist regardless, because those are from high-usage hours (basically day hours) and at a longer range, at summers and winters (depending on where you are) because of heating and a/c. A lot of factories already use more energy in the evening/mornings, because electricity is cheaper at those times. Storage technologies are a huge potential to be explored.

audunw 12y ago

> but it does nothing for the lows, the aluminium can't give back the electricity Actually, it seems they might be doing precisely that. See the information in the other comments. It's hard to say for sure, even the primary sources seem fuzzy. But this graphic seems to indicate that they are indeed extracting electric energy from the molten aluminum: http://images.bwbx.io/cms/2014-11-26/tech_aluminumgraphic49_630.jpg http://images.bwbx.io/cms/2014-11-26/tech_aluminumgraphic49_... This presentation also shows the energy arrow pointing from the aluminum plant to the consumer: http://www.innovationsforum-energiewende.de/wp-content/uploads/2013/11/Thomas-Flesch-Trimet.pdf http://www.innovationsforum-energiewende.de/wp-content/uploa... The most confusing thing about all of this is that they say that they only adjust their own power consumption by +/- 25%, which seems to contradict the statement that they're giving energy back. But as far as I can understand, this +/-25% is the long term average. Of course they need to consume a positive net amount of energy during the day to keep the plant running. But it seems that they are able to pump energy back into the grid for a short amount of time, which would be during the hours when solar/wind power is at a minimum.

graycat 12y ago
Maybe they are just giving back the energy to the grid in two respects, (1) energy they contracted for today they do not consume but sell back to the grid and (2) the energy was to come via the grid to them but, in not consuming that energy, the energy flows to homes, etc. instead and, thus, at least is redirected in the grud or, if you will, flows from the aluminum plant to the homes. At one point, they do say virtual. The losses involved are from some somewhat inefficient use of the grid and, there, losses flowing the energy through the grid.

nhaehnle 12y ago

It is misleading to claim that this does nothing for the lows, because everything that's happening here is symmetric. Let's say that aluminium production currently draws a permanent base load of 1GW. Let's say that the minimum acceptable overall level of electricity production given the status quo is 20GW. If aluminium producers manage to adapt their production so that they can temporarily operate on only 0.5GW, then the minimum acceptable overall level of electricity production is now 19.5GW. Unlike what the article misleadingly says, this is not magic that can somehow generate electricity when all other sources fail. But it does shift the line of when low levels of production become critical.