5 ms·

Why lithium ion batteries — are they much cheaper to make than new gravitational potential (i.e. hydroelectric) storage systems?

bobthepanda 7y ago
Hydro can be extremely disruptive to ecosystems, and you also need a suitable site for it. It's very situational, from what I understand.
- Animats 7y ago
  very situational Yes. You need a mountain lake and a low level lake close to each other, and the lakes aren't useful for much else because the water level goes way up and down every day. The US has 10 pumped storage plants bigger than a gigawatt, and few attractive sites for more.
  - cmoscoe 7y ago
    I've hear the Hoover Dam proposed, and theoretically any existing dam could be converted? Just need to pump some water back upstream when there's excess load in the system. Here in Canada a lot of our energy is hydroelectric and I know there's a lot of talk about this sort of solution in Quebec.
    - cesarb 7y ago
      > theoretically any existing dam could be converted? Just need to pump some water back upstream when there's excess load in the system. For that, you need water that can be pumped back upstream, that is, you need also a lower reservoir. If your dam discharges directly into a river, you won't have enough water downstream of the dam to pump back upstream. Not all dams have suitable geology to form another reservoir below them. An alternative would be to create a new reservoir higher than the dam, using the existing dam as the lower reservoir, with a set of tunnels with the reversible generator/pumps linking both reservoirs (this new upper reservoir does not need to be in the path of the river).
    - Obi_Juan_Kenobi 7y ago
      > Just need to pump some water back upstream In this situation, you'd simply never let the water flow through in the first place. This amounts to releasing water while generating energy, only to pump it back. The net result is just a lot of wasted energy. Pumped hydro requires two reservoirs. There's no way around it.
  - organsnyder 7y ago
    Or build a reservoir next to a body of water. The Ludington Pumped Storage Plant next to Lake Michigan has 2172 MW of generating capacity and 19,548 MWh of storage capacity.
    - Animats 7y ago
      That site has a hill. 111 meter difference between the reservors. More would be better, but that part of the country doesn't have mountains.
- dreamcompiler 7y ago
  It's not (very) disruptive if you build an artificial closed-cycle lake on an existing elevation difference. But such sites are not very commonly available where storage is needed. You have to refresh the water to compensate for evaporation, and that's about the extent of the impact. Dammed streams of course are a completely different story.
- jjoonathan 7y ago
  Like that time Banqiao dam burst and killed 100,000 people...
- nanomonkey 7y ago
  I wonder if it would be better to go distributed, pump water into a water tower from a well, or from a municipal source, and then generate electricity and release it back into municipal lines when solar power is not present.
jpollock 7y ago
No moving parts, and finding free water for pumped storage is going to be hard in California.
deleted 7y ago
[deleted]
codesushi42 7y ago
Of course. You would have to build a generator. You would need to lay the lines from your hydroelectric source, which could extend many, many miles. And you'd need step down transformers for the last mile. Lipo would supply DC power directly from within your neighborhood.
philipkglass 7y ago
For systems that only run for a few hours per day (4-6), battery systems are cheaper to build, faster to build, and far easier to site. There are only a few critical hours of peak demand in California, in the late afternoon/early evening. For example, look at the demand graph here for yesterday (11 July 2019): http://www.caiso.com/TodaysOutlook/Pages/default.aspx http://www.caiso.com/TodaysOutlook/Pages/default.aspx Demand goes above 35 gigawatts at 3:30 in the afternoon and is back below that level by 7:00 PM, 3.5 hours later. Battery systems are useful for shaving off that daily peak. They reduce the need to activate more expensive and more polluting open cycle gas turbines that have typically been used as peakers. It will be a few years more yet before solar plus storage systems can make a significant dent in the use of more efficient combined cycle gas turbine generation.
dreamcompiler 7y ago
You need the existing terrain to provide a significant elevation change, and building that artificially is probably not worthwhile in most cases.
StreamBright 7y ago
Well depends on the timeframe you are looking at. Hydro can do a lot more cycles than li-ion batteries.

bobthepanda 7y ago

Hydro can be extremely disruptive to ecosystems, and you also need a suitable site for it. It's very situational, from what I understand.

Animats 7y ago
very situational Yes. You need a mountain lake and a low level lake close to each other, and the lakes aren't useful for much else because the water level goes way up and down every day. The US has 10 pumped storage plants bigger than a gigawatt, and few attractive sites for more.
- cmoscoe 7y ago
  I've hear the Hoover Dam proposed, and theoretically any existing dam could be converted? Just need to pump some water back upstream when there's excess load in the system. Here in Canada a lot of our energy is hydroelectric and I know there's a lot of talk about this sort of solution in Quebec.
  - cesarb 7y ago
    > theoretically any existing dam could be converted? Just need to pump some water back upstream when there's excess load in the system. For that, you need water that can be pumped back upstream, that is, you need also a lower reservoir. If your dam discharges directly into a river, you won't have enough water downstream of the dam to pump back upstream. Not all dams have suitable geology to form another reservoir below them. An alternative would be to create a new reservoir higher than the dam, using the existing dam as the lower reservoir, with a set of tunnels with the reversible generator/pumps linking both reservoirs (this new upper reservoir does not need to be in the path of the river).
  - Obi_Juan_Kenobi 7y ago
    > Just need to pump some water back upstream In this situation, you'd simply never let the water flow through in the first place. This amounts to releasing water while generating energy, only to pump it back. The net result is just a lot of wasted energy. Pumped hydro requires two reservoirs. There's no way around it.
- organsnyder 7y ago
  Or build a reservoir next to a body of water. The Ludington Pumped Storage Plant next to Lake Michigan has 2172 MW of generating capacity and 19,548 MWh of storage capacity.
  - Animats 7y ago
    That site has a hill. 111 meter difference between the reservors. More would be better, but that part of the country doesn't have mountains.
dreamcompiler 7y ago
It's not (very) disruptive if you build an artificial closed-cycle lake on an existing elevation difference. But such sites are not very commonly available where storage is needed. You have to refresh the water to compensate for evaporation, and that's about the extent of the impact. Dammed streams of course are a completely different story.
jjoonathan 7y ago
Like that time Banqiao dam burst and killed 100,000 people...
nanomonkey 7y ago
I wonder if it would be better to go distributed, pump water into a water tower from a well, or from a municipal source, and then generate electricity and release it back into municipal lines when solar power is not present.

jpollock 7y ago

No moving parts, and finding free water for pumped storage is going to be hard in California.

deleted 7y ago

[deleted]

codesushi42 7y ago

Of course. You would have to build a generator. You would need to lay the lines from your hydroelectric source, which could extend many, many miles. And you'd need step down transformers for the last mile. Lipo would supply DC power directly from within your neighborhood.

philipkglass 7y ago

For systems that only run for a few hours per day (4-6), battery systems are cheaper to build, faster to build, and far easier to site. There are only a few critical hours of peak demand in California, in the late afternoon/early evening. For example, look at the demand graph here for yesterday (11 July 2019): http://www.caiso.com/TodaysOutlook/Pages/default.aspx http://www.caiso.com/TodaysOutlook/Pages/default.aspx Demand goes above 35 gigawatts at 3:30 in the afternoon and is back below that level by 7:00 PM, 3.5 hours later. Battery systems are useful for shaving off that daily peak. They reduce the need to activate more expensive and more polluting open cycle gas turbines that have typically been used as peakers. It will be a few years more yet before solar plus storage systems can make a significant dent in the use of more efficient combined cycle gas turbine generation.

dreamcompiler 7y ago

You need the existing terrain to provide a significant elevation change, and building that artificially is probably not worthwhile in most cases.

StreamBright 7y ago

Well depends on the timeframe you are looking at. Hydro can do a lot more cycles than li-ion batteries.