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

news.stanford.edu

311–320 of 394 posts

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

#311

Earlier quoted context omitted.

If someone is doing something because they think it makes a real difference, then it's not virtue signaling by definition.

Those are orthogonal. You can either think something helps or it doesn’t and virtue signal in either case. It’s right in the name. When you “virtue signal”, you are signaling morals to a wider audience. It’s “virtue signaling” regardless of conviction.

I think you didn't read @JohnFen carefully enough.

If the reason I am doing something is that I believe it will create results independent of being seen to have done it, I am not virtue signalling. Which is what @JohnFen said.

Conversely, if the reason I am doing something is because of the signalling value I believe will be attached to the way others see my actions, I am virtue signalling. Which is what you said.

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

#312

"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, som…

So we're just going to destroy huge parts of the Sierras so we can charge electric cars?

Wait until you hear about the mining operations needed to build them.

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

#313

This all depends on the local energy mix at night. If the local mix has a lot of nuclear or hydro then charging at night is a good idea. If instead it has a lot of gas or coal then it is a bad idea. It depends on whether there is cleanish energy available at night. There is no single answer.

> … they applied their model to the whole of the Western United States and examined the stress the region’s electric grid will come under by 2035 from growing EV ownership.

You're right, there is no single answer. This paper doesn't try to provide a single answer.

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

#314

Earlier quoted context omitted.

Way more complex than that. Different packs have very different voltage and current delivery characteristics. A bunch of motor management depends on the battery pack characteristics, including things like regen braking. Charge times are already under 20 minutes for the best cars and will likely continue to come down. Swappable batteries would be a massively expensive undertaking that would hugely limit innovation in…

To some extent, the forced downtime is a benefit. Instantly refeullable vehicles enable fatigued driving. It's not even healthy to be sitting for that long as a passenger.

I believe the EU trucking downtime rules actually line up pretty nicely. Building trucks with enough range to maximize the driver time and then charge during the refresh period works out just about right.

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

#315
post #238

Earlier quoted context omitted.

This is precisely what the linked article says. From the section "Charging Incentives": “And it’s not just California and Western states. All states may need to rethink electricity pricing structures as their EV charging needs increase and their grid changes,” added Powell, who recently took a postdoctoral research position at ETH Zurich. The article also includes other interesting and more nuanced policy details tha…

> This can disincentivize employers from installing chargers, especially once half or more of their employees have EVs. > So yes, there are weird red herrings in this thread from people who want a technology first and a solution second (or never) and/or who don't understand design of incentive structures. Speaking of incentive structures, one of my former employers installed EV chargers in all of the bottom floors of…

The harm is polen on your car? It's harm, sure, but seems pretty minor at this point.

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

#316
post #309

Earlier quoted context omitted.

Losing 30-70% of the power and adding a bunch of cost doesn't seem like the way forward. Cables exist for a reason. They are the best way to move charge.

They claim it's 10% total loss, not 30%. And yes, it's got a cost, but depending on how things shake out, it might not be much more if any. Cables are the best way to move charge, assuming you don't have to worry about the cables. But once you factor in damage from vandalism or theft or just accidents, how hefty the cables actually are, etc, compared to having the cable buried nice and safe. As for the difference in…

I'll believe 10% when I see it. you can definitely get that in a lab, but once you bury it under asphalt, and the driver parks 6 inches off center, does the efficiency still hold up? also, most cars are largely metal. how much energy do you lose from inducing current through the rest of the car?

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

#317
post #228

I need ELI5: electric cars have very large and heavy batteries right? Why is it prohibitively difficult to replace them on demand? What if there were 2-3 batteries charging at home or hundreds at a "battery station", where you would park at a spot/drive-thru garage and have a hydraulic machine drop your old battery and lift in a new battery and the whole swap can take no longer than the time it takes to fill up a has…

> I just don't get it. Governments around the world and spending trillions on this stuff so why is there no clear answer on this? Why would there need to be a "clear answer" on something that quite obviously wouldn't work? Everyone here has done a great job of explaining to you the complexity of your "simple" solution, but you don't seem to want to accept any of the explanations. You seem to think that your back-of-t…

Give me a break, what I have seen is someone showed me this is already being done in China. So anything you say is an excuse that is dangerously preventing climate change prevention efforts. I literally saw a video of NIO doing this and arguments like yours "cars aren't television remotes" "it's too hard" are bullshit. The interstate freeway project was hard yet it was done with trillions of dollars spent because it had to. Since china is doing it the only thing hard is that it costs more but our tax dollars are set aside to subsidize this shit but home owning rich people can make electric cars work for them with chargers so everyone better find extra time and houses fast else you're shit out of luck.

Governments can force car companies to use stanrdized connections, every car has plenty of government regulated things like this.

I said ELI5 so you can explain to me why my back of napkin calculation does not work when seemingly endless subsidies and cost that is passed down to consumers are in the works. NIO is already doing this without a $300B subsidy...oh and get this: selling batteries is more profitable for companies! One car is one battery but when battery stations also buy batteries that is more profit. Tesla literally sells batteries to power grids because of profit.

"Who will spend tens of billions to do this" is the question and we have an answer now, but you don't seem to gey that it will be largely wasted because people will not buy electric cars if they have to wait in line every day to get a charge or filling up the charge can cause them to be late to places. An inconvenient solution is a dead solution, in a free market consumer satisfaction comes first.

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

#318

Earlier quoted context omitted.

More expensive than alternatives, sorry.

Maybe not, if the alternative is installing enough battery to charge most people's electric cars at night. My state's grid is over half nuclear, and our electric rates are not high.

Good news! The very article we're discussing explains why you don't have to install enough batteries to charge most people's electric cars at night.

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

#319

Earlier quoted context omitted.

They are making politically expedient decisions that move the state towards its clean energy commitments. Yes, there may be some hiccups down the road, but that is the price to pay for putting off the transition for so long. And as one of the faster movers in this space CA will almost undoubtedly move the market in a way that will make it cheaper and easier for everyone else. Look at the "California Solar Initiative"…

Have you seen BART? The freeways in every major metro of CA? You are defending politics and not engaging the reality of failed infrastructure in the state. Now they are going to lead the country in developing a new paradigm in power infrastructure? The same that has PG&E blowing up neighborhoods because the company got so much tax incentive to continue building they failed to record where they placed capital assets a…

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

#320

Earlier quoted context omitted.

> Charge your car at work in the sun and use it to power your home at night. Completely infeasible in cold climates if your house is heated by electrically-powered air source heat pumps, as it probably should be.

I live in a cold climate and it would take only take more than 50% of charge to keep the house warm overnight with an air source heat pump. Since I rarely use more then 10% of range per day driving this would easily work for me. With an LFP battery car the cycle usage wouldn’t even be a big deal. It’s not impossible.

I live near Santa Fe at 6000'. I have a 6.6kW array out front. It generates 3x what we need in the summer, and 1/3rd of what we need in the winter, when we heat with an air source heat pump. Yes, it's an old adobe and not well insulated, but even with those things fixed, the amount of power we'd need to stay warm would require a battery system of immense size, much larger than a car (for now, anyway).
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