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If you're regularly committing a certain percentage of your car's battery capacity to powering your house, wouldn't it make more sense to just have a stationary

by NickM 4y ago

If you're regularly committing a certain percentage of your car's battery capacity to powering your house, wouldn't it make more sense to just have a stationary battery at home? Otherwise you can't rely on that extra range in your car if you need it to power your home anyway, and you're just spending extra energy carrying around extra battery weight in your car every day.

Schroedingersat 4y ago
I wonder if there's any correlation between times someone travels 400 miles and times when they are not home... we probably need a study or something to figure it out.
- NickM 4y ago
  The problem is, you need a full charge in the morning if you're leaving on a road trip, so then your car will not be powering your house the night before. This would likely lead to big spikes in demand the night before the start of holiday a weekend, for example.
  - kevinpet 4y ago
    I don't have an electric car, but I can't imagine this is a challenging problem at all. All you need is a target charge level. If you're going on a trip tomorrow, set it to 100%. If your normal commute is 20 minutes, no reason to charge past 75% or even 50%.
    - tsimionescu 4y ago
      They were saying this creates huge problems for the grid. Let's assume people will want to destroy their car battery by draining it to power their house every night, and that this indeed supplements the need for grid storage overnight. However, when holiday seasons comes around, all of a sudden a significant percentage of homes will start demanding much higher power usage from the grid, as people co-ordinate in setting their cars not to drain power into their homes on the night before.
      - nikau 4y ago
        Sounds like the UK where everyone used to turn their kettles on during the ad breaks of popular TV shows
upsidesinclude 4y ago
If we're seriously going there , then legislate mandatory carpool or motorcycles for single occupants. The thing is, California isn't making great policy decisions or even efficient power decisions. They are making virtue decisions. Moving 1.5 tons of battery or 1.25 tons of battery isn't where the hairsplitting should take place
- Schroedingersat 4y ago
  If only there were a way to encourage upwards of 50% of trips to be done via methods that take a tiny fraction of the energy with no or negligible battery without invasive freedom limiting legislation just by spending roughly as much as EV manufacturers have received in subsidy on infrastructure. Oh well. Guess we'll have to give another billion to elon.
- NickM 4y ago
  My point isn't that we should actually shrink EV batteries and use the excess for stationary storage, my point is that car batteries as a demand-leveling mechanism is not likely to be an optimal solution. That said, it's not something that's really happening right now anyway, so the "power your home with your car at night" idea seems unlikely to take off unless there is a (possibly misguided) legislative push for it.
  - qqqwerty 4y ago
    Batteries are a bit too expensive to make sense as stationary storage outside of some specialty cases right now. But EVs have been economical for a while. So while we wait for battery prices to drop, two way EV charging absolutely make sense as a transition technology. Most of those EV batteries are sitting unused for large chunks of the day, and the entire capacity of the battery is often only needed by the driver a few times per year. Adding two way charging is not a prohibitive cost, and that installation can be reused if/when an onsite battery is added in the future. The rest of the program can be managed with software.
    - tsimionescu 4y ago
kieranmaine 4y ago
This requires extra cost for the consumers and will drive up battery demand. It will be cheaper for the consumer to use their car to help balance the grid, as long as they have the required range for when it's needed (with current smart charging solutions already providing this).

by NickM 4y ago

Schroedingersat 4y ago

I wonder if there's any correlation between times someone travels 400 miles and times when they are not home... we probably need a study or something to figure it out.

NickM 4y ago
The problem is, you need a full charge in the morning if you're leaving on a road trip, so then your car will not be powering your house the night before. This would likely lead to big spikes in demand the night before the start of holiday a weekend, for example.
- kevinpet 4y ago
  I don't have an electric car, but I can't imagine this is a challenging problem at all. All you need is a target charge level. If you're going on a trip tomorrow, set it to 100%. If your normal commute is 20 minutes, no reason to charge past 75% or even 50%.
  - tsimionescu 4y ago
    They were saying this creates huge problems for the grid. Let's assume people will want to destroy their car battery by draining it to power their house every night, and that this indeed supplements the need for grid storage overnight. However, when holiday seasons comes around, all of a sudden a significant percentage of homes will start demanding much higher power usage from the grid, as people co-ordinate in setting their cars not to drain power into their homes on the night before.
    - nikau 4y ago
      Sounds like the UK where everyone used to turn their kettles on during the ad breaks of popular TV shows

upsidesinclude 4y ago

If we're seriously going there , then legislate mandatory carpool or motorcycles for single occupants. The thing is, California isn't making great policy decisions or even efficient power decisions. They are making virtue decisions. Moving 1.5 tons of battery or 1.25 tons of battery isn't where the hairsplitting should take place

Schroedingersat 4y ago
If only there were a way to encourage upwards of 50% of trips to be done via methods that take a tiny fraction of the energy with no or negligible battery without invasive freedom limiting legislation just by spending roughly as much as EV manufacturers have received in subsidy on infrastructure. Oh well. Guess we'll have to give another billion to elon.
NickM 4y ago
My point isn't that we should actually shrink EV batteries and use the excess for stationary storage, my point is that car batteries as a demand-leveling mechanism is not likely to be an optimal solution. That said, it's not something that's really happening right now anyway, so the "power your home with your car at night" idea seems unlikely to take off unless there is a (possibly misguided) legislative push for it.
- qqqwerty 4y ago
  Batteries are a bit too expensive to make sense as stationary storage outside of some specialty cases right now. But EVs have been economical for a while. So while we wait for battery prices to drop, two way EV charging absolutely make sense as a transition technology. Most of those EV batteries are sitting unused for large chunks of the day, and the entire capacity of the battery is often only needed by the driver a few times per year. Adding two way charging is not a prohibitive cost, and that installation can be reused if/when an onsite battery is added in the future. The rest of the program can be managed with software.
  - tsimionescu 4y ago

kieranmaine 4y ago

This requires extra cost for the consumers and will drive up battery demand. It will be cheaper for the consumer to use their car to help balance the grid, as long as they have the required range for when it's needed (with current smart charging solutions already providing this).