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Just use EVs. EVs are primarily energy storage devices, some people get to drive them about 20 - 30 mins/day. The remaining 23 hours, it is a energy storage dev

Just use EVs. EVs are primarily energy storage devices, some people get to drive them about 20 - 30 mins/day. The remaining 23 hours, it is a energy storage device. It can absorb excess power when price is negative, and can even supply power back to the grid when prices are high!

bee_rider 1y ago
This seems like building more batteries (just, with extra hardware). An EV could be good for this sort of thing, but I guess it would have to sit around at less than 100% charge, to have the capacity.
- bufferoverflow 1y ago
  We almost never charge our EV to 100%, to not degrade the battery faster.
  - bee_rider 1y ago
    But, if you are going to offer “absorbing energy from the grid as a service” the capacity you have to offer can only be <absolute max that you are willing to charge your battery to> - <minimum that you are willing have your battery sitting at> There definitely could be some gap there, but it does depend on the car sitting at less than “full” (however you define full).
two_handfuls 1y ago
Yes, exactly this has been proposed with "smart car chargers," along with other things you can do if the grid operator has some control over a bunch of grid-connected equipment. It hasn't taken off as far as I know, probably because that means the car battery wears out more. The "virtual power plants" are the closest thing to this idea that is actually done in practice. That's individuals who own batteries joining some collective that then sells to the grid the ability to reduce demand a bit. Tesla did a pilot program with its Powerwalls iirc.
rafaelmn 1y ago
Sounds like deprecating a >10k battery pack on a >30k vehicle and reducing your max range with power cycles to earn pennies.
- thelastgallon 1y ago
  Its more than pennies[1]. By several orders of magnitude. Car batteries now last longer the rest of the car lifespan, it will be millions of miles soon. Tesla Electric customers report making as much as $150 a day https://electrek.co/2023/07/05/tesla-electric-customers-report-making-150-day/ https://electrek.co/2023/07/05/tesla-electric-customers-repo...
  - rafaelmn 1y ago
    Lol at 5$ per kWh. In my country for home consumers the difference between day/night rates is 10-20c/kWh. With spot pricing I can see it working to cover the post commute power spike - but you're effectively doubling your commute discharge rate and pushing charge levels to suboptimal levels. Batteries might work but at 80% capacity they are worth significantly less than new - both in terms of utility and resale value. Maybe if battery range gets extended so far that even at 80% capacity it's an overkill - like 1000mile batteries - I could see myself doing something like this - but at current ranges and charging setups - I'll skip the few dozen euro a month.
    - gpm 1y ago
      On the other hand battery prices are dropping exponentially. There's a good argument to be made that your battery is a depreciating asset not (just) because it's degrading, but because the technology is getting cheaper, and thus you should extract as much value from it as possible as quickly as possible (and then replace it). The caveat to this market is who knows how much of a premium you'll end up paying to replace the battery given that it's attached to a certain model of car.
      - rafaelmn 1y ago
        > On the other hand battery prices are dropping exponentially. Are they ? I keep hearing this but in practice the price of an EV is still dominated by the battery pack and the movement in EV prices is anything but exponential. China started pushing out the affordable EVs but that's because they are using less efficient/cheaper chemistry and even with better packaging they are significantly less energy dense. I've seen Toyota announce 1000 miles solid state battery - if battery tech was dropping exponentially that should be cheaper than ICE in a few years - I would take the opposite side of that bet.
woda79 1y ago
That is a great thought and there is a lot of research in using batteries of vehicles for grid stabilization as well as arbitrage trading. The problem, however, is that a lot of plugged vehicles are required to guarantee a meaningful amount of firm power/energy capacity and owners typically do not want to sacrifice a lot of flexibility when they rent out their batteries to provide such services. Furthermore, as you can see from the replies, many are scared about battery degradation. Because of this and due to the fact that reverse charging is not possible for most vehicles, this schemes are often restricted to delayed charging which further limits revenue potential. However, using arrays of old car batteries as stationary batteries is a very viable idea that, in my estimation, will lead to a significant growth in installed BESS in a couple of years.

bee_rider 1y ago

This seems like building more batteries (just, with extra hardware). An EV could be good for this sort of thing, but I guess it would have to sit around at less than 100% charge, to have the capacity.

bufferoverflow 1y ago
We almost never charge our EV to 100%, to not degrade the battery faster.
- bee_rider 1y ago
  But, if you are going to offer “absorbing energy from the grid as a service” the capacity you have to offer can only be <absolute max that you are willing to charge your battery to> - <minimum that you are willing have your battery sitting at> There definitely could be some gap there, but it does depend on the car sitting at less than “full” (however you define full).

two_handfuls 1y ago

Yes, exactly this has been proposed with "smart car chargers," along with other things you can do if the grid operator has some control over a bunch of grid-connected equipment. It hasn't taken off as far as I know, probably because that means the car battery wears out more. The "virtual power plants" are the closest thing to this idea that is actually done in practice. That's individuals who own batteries joining some collective that then sells to the grid the ability to reduce demand a bit. Tesla did a pilot program with its Powerwalls iirc.

rafaelmn 1y ago

Sounds like deprecating a >10k battery pack on a >30k vehicle and reducing your max range with power cycles to earn pennies.

thelastgallon 1y ago
Its more than pennies[1]. By several orders of magnitude. Car batteries now last longer the rest of the car lifespan, it will be millions of miles soon. Tesla Electric customers report making as much as $150 a day https://electrek.co/2023/07/05/tesla-electric-customers-report-making-150-day/ https://electrek.co/2023/07/05/tesla-electric-customers-repo...
- rafaelmn 1y ago
  Lol at 5$ per kWh. In my country for home consumers the difference between day/night rates is 10-20c/kWh. With spot pricing I can see it working to cover the post commute power spike - but you're effectively doubling your commute discharge rate and pushing charge levels to suboptimal levels. Batteries might work but at 80% capacity they are worth significantly less than new - both in terms of utility and resale value. Maybe if battery range gets extended so far that even at 80% capacity it's an overkill - like 1000mile batteries - I could see myself doing something like this - but at current ranges and charging setups - I'll skip the few dozen euro a month.
  - gpm 1y ago
    On the other hand battery prices are dropping exponentially. There's a good argument to be made that your battery is a depreciating asset not (just) because it's degrading, but because the technology is getting cheaper, and thus you should extract as much value from it as possible as quickly as possible (and then replace it). The caveat to this market is who knows how much of a premium you'll end up paying to replace the battery given that it's attached to a certain model of car.
    - rafaelmn 1y ago
      > On the other hand battery prices are dropping exponentially. Are they ? I keep hearing this but in practice the price of an EV is still dominated by the battery pack and the movement in EV prices is anything but exponential. China started pushing out the affordable EVs but that's because they are using less efficient/cheaper chemistry and even with better packaging they are significantly less energy dense. I've seen Toyota announce 1000 miles solid state battery - if battery tech was dropping exponentially that should be cheaper than ICE in a few years - I would take the opposite side of that bet.

woda79 1y ago

That is a great thought and there is a lot of research in using batteries of vehicles for grid stabilization as well as arbitrage trading. The problem, however, is that a lot of plugged vehicles are required to guarantee a meaningful amount of firm power/energy capacity and owners typically do not want to sacrifice a lot of flexibility when they rent out their batteries to provide such services. Furthermore, as you can see from the replies, many are scared about battery degradation. Because of this and due to the fact that reverse charging is not possible for most vehicles, this schemes are often restricted to delayed charging which further limits revenue potential. However, using arrays of old car batteries as stationary batteries is a very viable idea that, in my estimation, will lead to a significant growth in installed BESS in a couple of years.