Charging cars at home at night is not the way to go: study • Hacker News Board

Re: Charging cars at home at night is not the way to go: study

#141

Post by Animats » Fri, Sep 23, 2022, 5:12 PM UTC

"more than 5.4 gigawatts of energy storage would be needed if charging habits follow their current course."

Gigawatts are a unit of power, not energy. Storage is measured in gigawatt-hours. Stanford's PR department should know this. The question is, how much storage is needed to make it through the night?

The biggest pumped storage station in the US [1] generates 2.7GW of power and stores 24GWH. So, two of those, somewhere in the Sierras, should cover a night of charging.

[1] https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...

Re: Charging cars at home at night is not the way to go: study

#142

Post by Overtonwindow » Fri, Sep 23, 2022, 5:14 PM UTC

alexb_ wrote: post #17

>We're doing it wrong, according to a new Stanford study Wrong according to what metric? Cost? Raw efficiency? A lot of people are more than willing to give up efficiency so that they don't have to actually worry about finding a station during the day. To say that something is just outright "wrong" based on their personal preference of priorities comes off as unhelpful to me. The solution is simple. Make electricity…

If only there were a clean energy source that we could harness.. Hey what about nuclear!?

Re: Charging cars at home at night is not the way to go: study

#143

Post by drak0n1c » Fri, Sep 23, 2022, 5:15 PM UTC

denimnerd42 wrote: post #18

I would be curious about a study done for the Texas market. From what I understand, you'd definitely want to charge at night due to the vast amounts of wind power available and the otherwise low demand. Even better would be to plug the car in at all times when parked either at work or home and it just charges when the rate is cheapest. You don't need to charge every day to refill that 20 or 30 miles.

Many electricity co-ops and providers in Texas offer a choice of plans, one of which is higher rates during daytime but free electricity during nights and weekends. But that allowance doesn't kick in until later in the night, so a programmable clock on the charger would be a killer feature for electric car sellers.

Re: Charging cars at home at night is not the way to go: study

#144

Post by aidenn0 » Fri, Sep 23, 2022, 5:15 PM UTC

Considering that less than half of all cars in California are parked in a garage overnight, charging at home has a ceiling on it anyways.

Re: Charging cars at home at night is not the way to go: study

#145

Post by marcosdumay » Fri, Sep 23, 2022, 5:18 PM UTC

landemva wrote: post #86

GoOnThenDoTell wrote: post #55

Earlier quoted context omitted.

time-of-use is also cognitive load that can cause anxiety

For the small amount I consume, tiny potential savings are not worth the mental hassles. I switched a residence to flat rate to avoid these mental games.

It's probably worse for poor people, that already deal with the extra cognitive load on every other pricing...

But it's also probably best for poor people, that will optimize their usage and get better deals out of it.

Re: Charging cars at home at night is not the way to go: study

#146

Post by marcosdumay » Fri, Sep 23, 2022, 5:20 PM UTC

Retric wrote: post #131

lostmsu wrote: post #127

Earlier quoted context omitted.

Just having my 4x3090 constantly running deep learning experiments consumes 1MWh/month. And that's GPUs only.

Except constantly running can’t benefit from time of day pricing. Essentially it needs to be some 15kWh load that only needs to run for 6 hours per day.

If the price changes are large enough, you can just buy an extra board and have them at the best half of the time.

Re: Charging cars at home at night is not the way to go: study

#147

Post by aidenn0 » Fri, Sep 23, 2022, 5:22 PM UTC

more_corn wrote: post #108

What? Peak electrical consumption is during the day. The big challenge for electric companies is the swing between the night trough in demand and the day peak. Night charging is excellent because it flattens that curve. Bringing demand into a straighter line and allowing electric companies to generate at a steady rate without having to cycle production up and down. I glanced though the article and found no mention of…

I have TOU based electric plan in CA, and the summer times are about to shift to peak starting at 4pm (from 10am). This huge shift is because of excess capacity from installed solar. 4pm is early enough that there's lots of use, but late enough that solar is tapering off.

Re: Charging cars at home at night is not the way to go: study

#148

Post by kieranmaine » Fri, Sep 23, 2022, 5:23 PM UTC

ParksNet wrote: post #129

upsidesinclude wrote: post #66

This article does a poor job of explaining why there is going to be a problem and relaying the point of the study. To model the grid and power infrastructure into the future, assumptions must be made about where the power is derived. The article fails to provide the basic factors contributing to the problem, even though the study itself does a fine job. So California wants to legislate electric cars. That means highe…

Each car is typically driven 35 miles daily in the USA. Against a capacity of ~250 miles, this represents many days of non-charging, and thus a lot of flexibility in when charging occurs. EVs can potentially strengthen the grid: if they are charged smartly, to balance demand. We need manufacturers, regulators, grid operators to align on how to figure this out. At the least, grid conditions/pricing should be sent to t…

This is spot on. Kaluza (https://www.kaluza.com/demand-response/) are working on this problem, by giving EV drivers reduced prices for EV charging as long as the Kaluza platform controls when you car is charged, with the Kaluza platform using price signals to decide when to stop/start charging.

The larger impact will come from V2G (Vehicle-to-grid) charging. This will require manufacturers to add this capability to vehicle but the savings for customers are significantly greater than just smart charging (see see https://www.kaluza.com/case-studies/case-study-kaluza-enable...).

Re: Charging cars at home at night is not the way to go: study

#149

Post by marcosdumay » Fri, Sep 23, 2022, 5:23 PM UTC

AceyMan wrote: post #107

notatoad wrote: post #99

Earlier quoted context omitted.

it is, but that's the part that technology can actually help us with. all the internet-connected smart home stuff that companies have been trying to sell us is a bit silly when electricity is sold at a flat rate, but if my car charger, my clothes dryer, or my or my dishwasher could sit idle until electricity prices drop into the cheap zone and then turn themselves on, that internet connection becomes useful. an attit…

this just makes me think of the situation that resulted in Global TCP Synchronization flapping problem; when everyone is operating on the same premise without some random delay or other way to 'shard' the load it seems like a Slashdot effect is bound to happen.

You are comparing a complex, out of band, auction-based organization system with a simple, no added overhead, parameter-guessing system. Those don't fail on the same ways.

Re: Charging cars at home at night is not the way to go: study

#150

Post by aidenn0 » Fri, Sep 23, 2022, 5:24 PM UTC

cortesoft wrote: post #36

dominotw wrote: post #19

I personally think Govt should ban home charging if they are going to ban non-EV vehicles. How is that rich people with homes charge at home while everyone else has to queue up and waste their time at charging stations. Doesn't seem fair at all. Its a extra time tax on the poor.

So your solution to some people having an easier time charging is to make it worse for everyone?

There are people who suggest banning private schools so that the wealthy and powerful will be incentivized to improve public schooling. GP seems to apply the same logic to EV charging.