6 ms·

From what I understand, the big hurdle for 100% renewable is not replacing the power stations that provide base load power, but rather replacing peak load power

From what I understand, the big hurdle for 100% renewable is not replacing the power stations that provide base load power, but rather replacing peak load power stations. Hydro is often used for that, but in the Midwest the peaker stations are almost entirely run with natural gas. Replacing those often involves some way of storing energy that you've generated in a renewable fashion. The issue is that storing large amounts of energy is not easy, especially when you live in an area that could be described as flatter than flat.

Robotbeat 9y ago
Storing energy for a few hours isn't that hard. I have no doubt we can store for 4 or even 8 hours of average load to replace all the peaker plants. It's the multiple-day cloudy spells during the winter when you really need that last 20% of power capability. It's not feasible to store energy like that for 200-1000+ hours (there are ways, but they're very, very difficult and generally inefficient... deep sea hydrogen storage, for instance). Since we have decent short-term storage tech, it's not the peaker plants I worry about but the constant baseload. Peakers will be replaced by utility-scale storage.
- deleted 9y ago
  [deleted]
Diederich 9y ago
Mr. Musk said that the world would need about 100 gigafactories in order to produce enough batteries to level out solar production off hours. One factory is producing batteries now, and Tesla is announcing three or four new gigafactory locations by the end of the year. It's a start.
- ogrisel 9y ago
  The first factory is not complete yet. According to Wikipedia: Tesla held a grand opening on July 29, 2016 of the operational facility, having only three of the final 21 "blocks" of the gigafactory built out, or approximately 14 percent of the final factory size expected by 2020. By September 2016 Tesla had spent $608 million on Gigafactory.
  - Jweb_Guru 9y ago
    By those numbers it would take only about $425.6 billion to manufacture all 100 factories, which I think is probably an estimate that's off by orders of magnitude in the wrong direction. And of course time and materials are a large factor as well. I still feel like the reluctance to invest in pumped storage is ultimately going to be what does us in.
    - Robotbeat 9y ago
      Pumped storage at ~$150/kWh (for a large installation) is about half the Musk price of large scale battery storage ($250/kWh). I think there's room for both, as you can put batteries just about anywhere and at nearly any scale, while pumped hydro works best for large scale. Gigawatt-level for ~10 hours at a time potentially... Largest facility is 3GW for about 10-12 hours, about the same as the yearly battery production the completed Gigafactory will have: https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Station https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta... I do think the difference between pumped and battery storage will get closer, however. And battery power has the advantage of option value since you can build it much faster (about 10 times faster) than a big pumped hydro station.
      - Diederich 9y ago
        Yes! I've been following various storage technologies for a while and Pumped storage has always been fascinating. Indeed, we will likely end up using a wide variety of technologies for storage.
- adrianN 9y ago
  Do we even have enough Lithium to supply 100 gigafactories? Recycling Lithium batteries is still quite difficult.
  - Robotbeat 9y ago
    Yes we do, and no it's not, at least not the way Tesla is doing it. Because they're using a standardized cell and standardized packs, they can easily automate the careful recycling of a lithium cell.
    - hwillis 9y ago
      Tesla actually does a single/two step recycling process that incinerates/electrolytically separates the metals from the graphite/hydrocarbons/lithium. The lithium containing fraction is sold as clinker or aggregate. Rocks, basically. Only the steel, nickel and cobalt are really recycled.
      - Robotbeat 9y ago
        I'm talking about the newer process they're developing at the gigafactory. But you're right that lithium is so cheap at the moment (getting it from salty brines) that you don't really need to recycle it. The other metals, sure. But push comes to shove, you could pull it from ocean water. Won't ever be economically competitive with brines, but it's also not too expensive if that were the only option.
        hwillis 9y ago
        copying my other comment: >Lithium is one of the most prevalent elements on earth. Spodumene (rocky lithium ore) is likely to be a very important economic source in the future as it is much more common than the brine currently used to manufacture batteries. Brine requires a water pump to extract, spodumene requires mining like any normal mineral, but it's found in extremely high quality deposits in the US including single crystals up to 47 feet across. That means higher quality lithium in addition to greater availability. >Spodumene is ~6-7% lithium by mass and is mined in an open pit, so no worries about soil or water pollution. It's separated from other rocks by grinding, flotation, and then acid. Very few people like acid in their industrial processes but I will note that lithium production uses way less hydroflouric acid than oil refining. The final stage uses sulfuric acid and while again acid is never good, sulfuric acid is one of the most-used and most-produced chemicals. Most minerals require sulfuric acid for extraction. It comes in a bottle of drain cleaner. Mining lithium rock is as economically painless as buying blasting powder and excavators, and as environmentally painless as... well nothing. The pollution is basically negligible. I didn't know the gigafactory was gonna do component-level recycling, that's pretty cool. I think it should be relatively easy to separate the metals from the SEI and graphite/lithium in a recoverable way, but processing the SEI has to be pretty complex. Maybe acid would do it- at that point it would probably be worth it to recycle the lithium but you'd have to set up an entire process line just to be able to add it to raw feedstock ore. It'll take a LOT of battery recycling before that's more profitable than selling it as clinker.
petre 9y ago
To enable peak load, one can do pumped hydro (PHES) or molten salt storage when demand is low and the sun is shining or wind is blowing. Only short term storage is needed for peak load. Water can be stored indefinitely but you're probably getting back 70 to 80% of what you used to pump it.
- Declanomous 9y ago
  Yeah, but pumped hydro is really hard to implement in the Midwest since we don't even have hills. You can use quarries that are mined to two different depths, but you can't build a quarry large enough to really matter. Molten salt is interesting though, and I am not particularly familiar with that.

Robotbeat 9y ago

Storing energy for a few hours isn't that hard. I have no doubt we can store for 4 or even 8 hours of average load to replace all the peaker plants. It's the multiple-day cloudy spells during the winter when you really need that last 20% of power capability. It's not feasible to store energy like that for 200-1000+ hours (there are ways, but they're very, very difficult and generally inefficient... deep sea hydrogen storage, for instance). Since we have decent short-term storage tech, it's not the peaker plants I worry about but the constant baseload. Peakers will be replaced by utility-scale storage.

deleted 9y ago
[deleted]

Diederich 9y ago

Mr. Musk said that the world would need about 100 gigafactories in order to produce enough batteries to level out solar production off hours. One factory is producing batteries now, and Tesla is announcing three or four new gigafactory locations by the end of the year. It's a start.

ogrisel 9y ago
The first factory is not complete yet. According to Wikipedia: Tesla held a grand opening on July 29, 2016 of the operational facility, having only three of the final 21 "blocks" of the gigafactory built out, or approximately 14 percent of the final factory size expected by 2020. By September 2016 Tesla had spent $608 million on Gigafactory.
- Jweb_Guru 9y ago
  By those numbers it would take only about $425.6 billion to manufacture all 100 factories, which I think is probably an estimate that's off by orders of magnitude in the wrong direction. And of course time and materials are a large factor as well. I still feel like the reluctance to invest in pumped storage is ultimately going to be what does us in.
  - Robotbeat 9y ago
    Pumped storage at ~$150/kWh (for a large installation) is about half the Musk price of large scale battery storage ($250/kWh). I think there's room for both, as you can put batteries just about anywhere and at nearly any scale, while pumped hydro works best for large scale. Gigawatt-level for ~10 hours at a time potentially... Largest facility is 3GW for about 10-12 hours, about the same as the yearly battery production the completed Gigafactory will have: https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Station https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta... I do think the difference between pumped and battery storage will get closer, however. And battery power has the advantage of option value since you can build it much faster (about 10 times faster) than a big pumped hydro station.
    - Diederich 9y ago
      Yes! I've been following various storage technologies for a while and Pumped storage has always been fascinating. Indeed, we will likely end up using a wide variety of technologies for storage.
adrianN 9y ago
Do we even have enough Lithium to supply 100 gigafactories? Recycling Lithium batteries is still quite difficult.
- Robotbeat 9y ago
  Yes we do, and no it's not, at least not the way Tesla is doing it. Because they're using a standardized cell and standardized packs, they can easily automate the careful recycling of a lithium cell.
  - hwillis 9y ago
    Tesla actually does a single/two step recycling process that incinerates/electrolytically separates the metals from the graphite/hydrocarbons/lithium. The lithium containing fraction is sold as clinker or aggregate. Rocks, basically. Only the steel, nickel and cobalt are really recycled.
    - Robotbeat 9y ago
      I'm talking about the newer process they're developing at the gigafactory. But you're right that lithium is so cheap at the moment (getting it from salty brines) that you don't really need to recycle it. The other metals, sure. But push comes to shove, you could pull it from ocean water. Won't ever be economically competitive with brines, but it's also not too expensive if that were the only option.
      - hwillis 9y ago
        copying my other comment: >Lithium is one of the most prevalent elements on earth. Spodumene (rocky lithium ore) is likely to be a very important economic source in the future as it is much more common than the brine currently used to manufacture batteries. Brine requires a water pump to extract, spodumene requires mining like any normal mineral, but it's found in extremely high quality deposits in the US including single crystals up to 47 feet across. That means higher quality lithium in addition to greater availability. >Spodumene is ~6-7% lithium by mass and is mined in an open pit, so no worries about soil or water pollution. It's separated from other rocks by grinding, flotation, and then acid. Very few people like acid in their industrial processes but I will note that lithium production uses way less hydroflouric acid than oil refining. The final stage uses sulfuric acid and while again acid is never good, sulfuric acid is one of the most-used and most-produced chemicals. Most minerals require sulfuric acid for extraction. It comes in a bottle of drain cleaner. Mining lithium rock is as economically painless as buying blasting powder and excavators, and as environmentally painless as... well nothing. The pollution is basically negligible. I didn't know the gigafactory was gonna do component-level recycling, that's pretty cool. I think it should be relatively easy to separate the metals from the SEI and graphite/lithium in a recoverable way, but processing the SEI has to be pretty complex. Maybe acid would do it- at that point it would probably be worth it to recycle the lithium but you'd have to set up an entire process line just to be able to add it to raw feedstock ore. It'll take a LOT of battery recycling before that's more profitable than selling it as clinker.

petre 9y ago

To enable peak load, one can do pumped hydro (PHES) or molten salt storage when demand is low and the sun is shining or wind is blowing. Only short term storage is needed for peak load. Water can be stored indefinitely but you're probably getting back 70 to 80% of what you used to pump it.

Declanomous 9y ago
Yeah, but pumped hydro is really hard to implement in the Midwest since we don't even have hills. You can use quarries that are mined to two different depths, but you can't build a quarry large enough to really matter. Molten salt is interesting though, and I am not particularly familiar with that.