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

news.stanford.edu

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

#321

Post by ehnto »

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…

I had a related epiphany regarding car traffic today. When thinking about how autonomous cars could increase efficiency of taking off from stop lights by doing it syncronously, I realised that to put it bluntly, nobody would actually give a shit. We drive cars for personal autonomy and a level of freedom and protection from the car centric cities we build. Making that efficient is nice, but no one is willing to sacrifice the core point of driving for the various minor efficiencies.

It was an epiphany I had in relation to my staunch pro-bike/public transport internal discourse. It occurred to me that we need to focus on the main motivations for driving and public transport in order to make them both better. Road networks should focus on freedom and personal autonomy, and public transport should focus on throughput efficiency. Making PT better at throughput by expanding the networks would give people more freedom on the road network too by reducing traffic.

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

#323

Post by Stupulous »

parker_mountain wrote: post #269
ars wrote: post #199

Earlier quoted context omitted.

> If all iPhones do this it will matter. No it won't. An phone has around 5 watt hours. So: 5 watt hours / day * 150 million people * 365 days = 273GWh / year / 4,116 billion kilowatthours / year = 0.006651% of electrical usage. Yah, it's virtue signaling, not anything real. And keep in mind 0.006651% is total electrical usage - this time shifting might save 10%, so actual savings are even less than that.

"150 million people" There are over a billion iPhones in use worldwide. This technology is also being brought to MacBooks (100 million+), Watches (100 million+), and iPads (150 million+). Your fundamental numbers are staggeringly inaccurate. And, most crucially, representing it as a whole of the electric usage instead of peak hours intentionally misses the point of reducing peak hour usage. It's called "peak hour" fo…

They're using US numbers both for iPhone count (which they overestimate by ~40 million) and total electricity. That should bias their estimate against their point, as the US is particularly consumerist. Correct me if I'm wrong, but I would think that measuring as a fraction of total usage would also bias their result upwards- x/avg(y) > x/max(y).

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

#324

Post by sfifs »

ehnto wrote: post #321
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…

I had a related epiphany regarding car traffic today. When thinking about how autonomous cars could increase efficiency of taking off from stop lights by doing it syncronously, I realised that to put it bluntly, nobody would actually give a shit. We drive cars for personal autonomy and a level of freedom and protection from the car centric cities we build. Making that efficient is nice, but no one is willing to sacri…

Glad you were able to make the connection. Too many folks passionate on reforming transport focus primarily on the moral/technical problem/solution Vs the actual "job to be done" for people of owning a personal car.

Where I live, I don't own a car largely because the "jobs" for which having access to a car is critical is handled by a reliable, efficient and safe cab/taxi on demand system (you need to get somewhere quickly, carry a lot of stuff, take your family/friends to A&E at night etc). So then I can rely on the very good Public Transit system for the bulk of my regular commute needs confident that I can get a cab when I need to.

If the reliable cab/taxi on demand didn't exist (which was indeed the situation before Uber and it's ilk), I would buy a car irrespective of how good the public transport system was (it was good even then) and irrespective of taxation dis-incentives. Once you own a car, for many use cases it becomes a lot more convenient and has low incremental cost to just drive.

As you may note, these "jobs to be done" vary by geography, lifestage and income - so while general principles can be drawn up, they need to be locally customized.

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

#325

Post by erichocean »

dymk wrote: post #71
sudden_dystopia wrote: post #47

EV’s are only a solution as far as renewable energy can keep up with electricity demands. And that doesn’t appear to be the case right now. Coupled with the mining of minerals, violent venting of batteries, and non-recyclable/non disposable nature of the batteries it’s not obvious that EV’s are more environmentally friendly.

EVs become carbon neutral after around 6 months of existing, taking into account emissions to manufacture them. Solar panels are between 6 months and 3 years. And batteries are highly recyclable, and only getting better. The US doubled its solar capacity in 2021, and adoption is only speeding up.

> The US doubled its solar capacity in 2021

No it didn't.

> The US solar industry broke records in 2021 with 23.6 GW installed, bringing the cumulative capacity to 121.4 GW.

So it increased by less than 25%, not 100%. You were only off by 4x.

Source: https://www.ny-engineers.com/blog/seia-publishes-the-2021-so...

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

#326

Post by wodenokoto »

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…

> Make electricity cheaper when it's more available, and people will use it.

It’s _not_ like that in the states? In Denmark people are sharing spreadsheet that can tell you when to run the washing machine to save on electricity since the energy crisis following Russias invasion of Ukraine has pushed prices enough that these optimizations become valuable to regular consumers.

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

#327

Post by ThatPlayer »

parkingrift wrote: post #209
ThatPlayer wrote: post #168

Earlier quoted context omitted.

California's electricity has been mandated to switch to TOU since 2015: https://www.cpuc.ca.gov/industries-and-topics/electrical-ene...

I couldn't find data more recent than 2017, but as of 2017 fewer than 4% of utility customers were using time of use billing.

Actual migration is more recent than that in California. Looks like PG&E started migrating customers to TOU (unless they chose to stay on the old plan) this year: https://www.yahoo.com/now/eligible-pg-e-customers-moving-061...

Similarly for SoCal Edison, last year: https://ktla.com/news/local-news/socal-edison-moving-custome...

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

#328

Post by upsidesinclude »

PaulDavisThe1st wrote: post #320
theluketaylor wrote: post #300

Earlier quoted context omitted.

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).

From two googlings,

avg home consumption daily : 30kwh

Avg EV consumption per 100mi : 30kwh

That is about a third of a typical modern vehicle range.

Sounds like an adequate amount for your needs, but what you really should do is install passive solar heating like a thermal mass. If you're in Santa Fe then you already know the what and how. There's about 325 days of sunshine over there

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

#329

Post by morsch »

kodah wrote: post #238
saidajigumi wrote: post #51

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…

Buy a small EV for everyday trips and rent another car for road trips. Nobody in our car culture, where people drive F150s just in case they need them; nobody is going to do that, but environmentally it'd be much preferable to everybody getting a big Tesla weighing several tons.

Financially it works out for a couple of road trips a year, not so much if you're doing it a couple of times a month.

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

#330

Post by codelord »

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…

-Charge your car at work in the sun and use it to power your home at night.

This doesn't make any sense. If you don't need the capacity, why do you wanna carry a ton of battery everywhere with you wasting energy? Buy a smaller battery for the car. Keep another battery installed at home. The battery at home is also more flexible to draw power at the optimal time for the grid.

Not to mention that this constant charging and recharging would decrease the lifetime of the battery, causing more environmentally unfriendly waste and inefficiency.

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