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"In a renewable energy grid, batteries can handle about 80 percent of storage needs." Why couldn't you just add 25% more batteries?

by bagels 3y ago

marcosdumay 3y ago
It's not 25% more batteries. It's some 500% to 1000% more. But those would be used very few times.
- chrisco255 3y ago
  So in other words batteries don't get us anywhere close to 80% of the way.
  - elcritch 3y ago
    Depends on how you're slicing it. By the total flux of energy batteries may be able to handle 80% of the "energy traffic" over the course of a day by smoothing out day/night cycles. However that last 25% needs to be stored over long periods where the cost is prohibitive to store in current battery systems.
  - audunw 3y ago
    There's many ways to judge what "80%" is. The batteries will cycle many times every week. They will have much more energy flowing through them in a year than the storage we need for dunkelflaute would. Yes, in terms of amount of energy stored at full capacity, batteries would not get us to 80%. But those last 20% have reduced requirements for charge/discharge rates, effiency, cost/kWh, which makes many other solutions viable.
- _hypx 3y ago
  A system that can store 1000% more energy than what is possible with batteries could very well power the entire system. Thus eliminating the need for batteries for this purpose. It's always something that stuck out to me as an obvious point that few have noticed.
  - Retric 3y ago
    Batteries have reasonably high round trip efficiency ~80%, where many proposed long term storage options are much much lower. If your storing nearly free power for 9 months then having 40% round trip efficiency may not actually be a problem. But it’s terrible for daily storage as you would need roughly twice as many solar panels etc.
    - _hypx 3y ago
      You can build twice as many solar panels. It is making batteries that is problematic. Not to mention the argument supposes that the storage system must only output electricity, which is not necessarily the case.
      - Retric 3y ago
        Batteries really aren’t problematic. EV’s need more batteries than the grid and there’s plenty of raw materials to cover global EV’s needs on top of this grid batteries have more options because they didn’t need portability or a 25 year lifespan etc. If your alternative now needs massive amounts of solar panels just to charge it then suddenly it’s vastly more expensive. Also, both batteries and solar panels are bottlenecked by production capacity, so no you can’t just snap your fingers and have twice as many panels. Also, deploying any other system at scale means ramping up production of that.
        _hypx 3y ago
        Those sound like excuses. FYI, a lot of the alternatives are things like pumped hydro which isn't that inefficient. Many situations just need heat at the end, and therefore don't need pure electricity. I am merely pointing out that the battery part seems like an unnecessary component.
        Retric 3y ago
        There are zero viable alternatives when you start talking TWh. That’s simply the reality and why there isn’t any long term grid storage, nothing is even close to viable when compared to batteries and extra generation. Pumped hydro simply doesn’t scale. You can look at topographic maps and do some basic math but the vast quantities of water you would need simply don’t have enough locations to be viable. Worse, the fewer times you use that infrastructure the larger the payback you need when it’s actually in use. Hydrogen is expensive, has terrible round trip efficiencies, dangerous to store, etc etc.
ZeroGravitas 3y ago
Most storage is short term, so the same battery can be re-used again and again by charging and discharging it, e.g. 365 solar peaks a year in sunny countries. Longer term storage would lock up the battery for longer, which given the cost of batteries, wouldn't make financial sense.

"In a renewable energy grid, batteries can handle about 80 percent of storage needs." Why couldn't you just add 25% more batteries?

by bagels 3y ago

"In a renewable energy grid, batteries can handle about 80 percent of storage needs." Why couldn't you just add 25% more batteries?

marcosdumay 3y ago

It's not 25% more batteries. It's some 500% to 1000% more. But those would be used very few times.

chrisco255 3y ago
So in other words batteries don't get us anywhere close to 80% of the way.
- elcritch 3y ago
  Depends on how you're slicing it. By the total flux of energy batteries may be able to handle 80% of the "energy traffic" over the course of a day by smoothing out day/night cycles. However that last 25% needs to be stored over long periods where the cost is prohibitive to store in current battery systems.
- audunw 3y ago
  There's many ways to judge what "80%" is. The batteries will cycle many times every week. They will have much more energy flowing through them in a year than the storage we need for dunkelflaute would. Yes, in terms of amount of energy stored at full capacity, batteries would not get us to 80%. But those last 20% have reduced requirements for charge/discharge rates, effiency, cost/kWh, which makes many other solutions viable.
_hypx 3y ago
A system that can store 1000% more energy than what is possible with batteries could very well power the entire system. Thus eliminating the need for batteries for this purpose. It's always something that stuck out to me as an obvious point that few have noticed.
- Retric 3y ago
  Batteries have reasonably high round trip efficiency ~80%, where many proposed long term storage options are much much lower. If your storing nearly free power for 9 months then having 40% round trip efficiency may not actually be a problem. But it’s terrible for daily storage as you would need roughly twice as many solar panels etc.
  - _hypx 3y ago
    You can build twice as many solar panels. It is making batteries that is problematic. Not to mention the argument supposes that the storage system must only output electricity, which is not necessarily the case.
    - Retric 3y ago
      Batteries really aren’t problematic. EV’s need more batteries than the grid and there’s plenty of raw materials to cover global EV’s needs on top of this grid batteries have more options because they didn’t need portability or a 25 year lifespan etc. If your alternative now needs massive amounts of solar panels just to charge it then suddenly it’s vastly more expensive. Also, both batteries and solar panels are bottlenecked by production capacity, so no you can’t just snap your fingers and have twice as many panels. Also, deploying any other system at scale means ramping up production of that.
      - _hypx 3y ago
        Those sound like excuses. FYI, a lot of the alternatives are things like pumped hydro which isn't that inefficient. Many situations just need heat at the end, and therefore don't need pure electricity. I am merely pointing out that the battery part seems like an unnecessary component.
        Retric 3y ago
        There are zero viable alternatives when you start talking TWh. That’s simply the reality and why there isn’t any long term grid storage, nothing is even close to viable when compared to batteries and extra generation. Pumped hydro simply doesn’t scale. You can look at topographic maps and do some basic math but the vast quantities of water you would need simply don’t have enough locations to be viable. Worse, the fewer times you use that infrastructure the larger the payback you need when it’s actually in use. Hydrogen is expensive, has terrible round trip efficiencies, dangerous to store, etc etc.

ZeroGravitas 3y ago

Most storage is short term, so the same battery can be re-used again and again by charging and discharging it, e.g. 365 solar peaks a year in sunny countries. Longer term storage would lock up the battery for longer, which given the cost of batteries, wouldn't make financial sense.