19 ms·

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

127 points by hhs 4y ago

olivermarks 4y ago
Fire risks are also much greater at night if you are charging a BEV in your house while asleep. Far safer to charge in an open area preferably away from other vehicles and stuctures. https://www.ntsb.gov/news/press-releases/Pages/NR20210113.aspx https://www.ntsb.gov/news/press-releases/Pages/NR20210113.as...
- wing-_-nuts 4y ago
  Frankly, if a user cannot trust their EV to charge without going up in flames it is not ready for prime time and should be recalled. Period.
  - ctrlmeta 4y ago
    Yes! It surprises me that the reliability issues in charging an EV are not discussed more. This bears more discussion and subject to regulations. It is not ok for companies to push EVs to general consumers without creating a good safety record.
    - adrianN 4y ago
      How many EVs spontaneously combust while charging?
      - rcMgD2BwE72F 4y ago
        Less than ICE anyway. Who wants to talk about gas cars burning? It's so frequent journalists won't report them. But Teslas? Oh, my.
    - wing-_-nuts 4y ago
      I think we already have enough regulations to hold companies liable for creating a dangerous product, we simply need to use them to hold corporations accountable. None of this 'oh, our owners manual says you should only charge in these special conditions or we can't be held responsible'. Nope. You make a product and it hurts people or destroys property? You better make your peace with punitive damages that'll make you wish you properly tested before shipping to customers.
- dymk 4y ago
  The press release you linked to is about cars catching fire after they crash. Can you give a source for how many cars catch fire spontaneously when they're stationary and charging?
  - olivermarks 4y ago
    I don't have a source of data but this article might be useful if you've watched the NTSB video and other material https://www.washingtonpost.com/technology/2021/08/04/tesla-fire/ https://www.washingtonpost.com/technology/2021/08/04/tesla-f... 'Battery-powered vehicles have not been shown to catch fire at rates higher than gasoline cars, but when fires do erupt, they burn longer and hotter, propelled by lithium-ion batteries that supercharge the blazes, experts say.'
- vel0city 4y ago
  I've had several recalls for spontaneous combustion of my ICE cars suggesting I don't park in the garage. At least one car had multiple fire risk recalls for starting fire while parked. I guess ICE cars should never be parked in a garage.
notjustanymike 4y ago
Turns out the sun is out during the day.
- sambeau 4y ago
  And in cold climates there is a greater need for heating at night.
3pt14159 4y ago
This is simple. Musk just needs to throw 1% of his AI talent at optimizing charging times via realtime grid negotiating and nobody will need to even think about this. Cars will turn into one of our most valuable assets as they help stabalize the grid by being both sinks when energy is plentiful and sources when it's not. There are certain problems we all need to think about, but this is not one of them. It will effectively solve itself because all the incentives are aligned.
- nightski 4y ago
  So electric car owners need to just cover all the battery wear out of their own pockets? Wouldn't that make electric cars even more expensive since battery replacement will be needed more often?
  - toomuchtodo 4y ago
    Batteries are lasting far longer than anticipated. Anecdotally, I have fast DC charged my 2018 Model S (100kw pack) for the majority of the 100k miles I’ve put on the car, and only have 7% battery degradation. Others are seeing similar longevity well into hundreds of thousands of miles. https://news.ycombinator.com/item?id=32758881 https://news.ycombinator.com/item?id=32758881 https://www.forbes.com/sites/carltonreid/2022/08/01/electric-car-batteries-lasting-longer-than-predicted-delays-recycling-programs/ https://www.forbes.com/sites/carltonreid/2022/08/01/electric... https://cleantechnica.com/2022/03/29/tesla-founder-ex-cto-says-ev-batteries-will-last-15-years/ https://cleantechnica.com/2022/03/29/tesla-founder-ex-cto-sa...
    - nightski 4y ago
      That doesn't really matter. If you own a resource, and I utilize it, are you going to let me do so without compensating you in some fashion? If so I'll take you up on that offer. I have no problems with encouraging people to charge at certain times. Using personal batteries for energy storage and draw without any compensation however seems to cross a line. Your argument seems to me like justifying petty theft because in the end it doesn't really affect the store owner.
guywithahat 4y ago
This is a very California problem caused by very California policies
- kadoban 4y ago
  It's not a problem, it's an opportunity to optimize energy use to match how it's now generated.
  - guywithahat 4y ago
    Shouldn't it be an opportunity to match energy generation to how it's consumed? No industry survives long by offering a worse product to consumers than what they had before
    - upsidesinclude 4y ago
      Unfortunately for them it isn't a product they can control with the legislation they are choosing. There will be significant problems with CA power infrastructure in the near future.
    - kadoban 4y ago
      If consumption has a good reason to be as it is maybe. The whole reason we have lower night rates and such was due to how it was generated in the past though. Why would we continue that if it no longer makes sense? It's something that should be looked at on the whole and tradeoffs considered.
    - kadoban 4y ago
      > No industry survives long by offering a worse product to consumers than what they had before That's ... optimistic, but not really true. It also doesn't seem to match what's happening here either. How is power generation when demand is highest a worse product?
      - myko 4y ago
        I assumed the comment meant EVs were worse than ICE vehicles (not an opinion I hold)
lelag 4y ago
It's not just about the rate. Charging at night happens because the car is conveniently parked at home doing nothing and EV owners want a car ready to go in the morning. Charging at EV station during the day is time consuming and is often expensive. I'm sure that the lucky few that can charge at work already do so...
- floatrock 4y ago
  It's almost as if the logical conclusion is to invest in convenient workplace charging infrastructure so charging is simple when the car is conveniently parked at work doing nothing and the owner wants a car ready to go home in the evening... > “We encourage policymakers to consider utility rates that encourage day charging and incentivize investment in charging infrastructure to shift drivers from home to work for charging,” said the study’s co-senior author, Ram Rajagopal
  - greedo 4y ago
    The logical conclusion is to try to get away from needing to drive to work at all.
    - neon_electro 4y ago
      Right? Then it becomes trivial to charge at home, during the day (if that really does make an impact).
      - r00fus 4y ago
        Or simply not have a car (or reduce cars in the household). That'd make an even bigger difference in energy usage an GHG emissions.
    - davidro80 4y ago
- m463 4y ago
  Most EVs charging at home are plugged in from say 6pm to 7am. It would be most convenient to charge immediately but the electric rates (in california at least) are highest at 6pm and lowest at 7am. There is choice in that equation.
syntaxing 4y ago
What’s the alternative? Not like you can charge your EV at home when you’re working when…you’re at work
- kadoban 4y ago
  Charge at work.
  - ctrlmeta 4y ago
    But how many work areas have a charging station available easily?
    - kadoban 4y ago
      Not as many as should. The state can probably incentivize creating some more, and job seekers can prioritize it as well. Not to mention workers just asking their employers to do it.
    - floatrock 4y ago
      Literally the point of the study > “We encourage policymakers to consider utility rates that encourage day charging and incentivize investment in charging infrastructure to shift drivers from home to work for charging,” said the study’s co-senior author, Ram Rajagopal
    - _ph_ 4y ago
      The term "charging station" is hinting at a too big infrastructure. All you need is a power outlet per car. If the car parks for 8 to 9 hours, you don't need a huge amount of power to recharge it.
      - toast0 4y ago
        You need more than just a power outlet per car, with regular 120vac, you pretty much need a breaker and circuit per car, because you shouldn't put two of those on a single circuit, since they'll usually pull up to the 15A rating of the plug, and code restricts you from using more than 20A breaker on a circuit with 15A plugs, so you'll pop the breaker if you've got two 15A loads and they don't communicate to share. It probably makes more sense to get a two or maybe four car charging station per breaker and circuit, and set it for the appropriate amps on the circuit, it can share that appropriately amongst the cars plugged in.
alexb_ 4y ago
>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 cheaper when it's more available, and people will use it. You don't need any complex "AI" like people in this thread are saying, you just use natural market forces and the problem fixes itself. Too much energy being used at night - price increases. It's not complicated, and it's what we're doing already. People don't need a Stanford study to convince them to get their energy for cheaper.
- Grimburger 4y ago
  > The solution is simple. Make electricity cheaper when it's more available From the parts of the world I come from the majority of people are vehemently opposed to time of use pricing. Because that's when they use it most. They and their political representatives would much prefer to keep taking from those who consume in off-peak rather than fix the underlying mechanism.
  - GoOnThenDoTell 4y ago
    time-of-use is also cognitive load that can cause anxiety
    - zbrozek 4y ago
      Yeah it is. I hate having to have a process in my brain thinking about optimizing everything. So I bought solar panels and batteries. Now I no longer care. The grid can keep getting more expensive and less reliable without causing me grief.
      - alexb_ 4y ago
        >So I bought solar panels and batteries ...Mission accomplished?
denimnerd42 4y ago
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.
- lbriner 4y ago
  I guess the issue with this report is that it is specific to the unique mix of energy that the (west of the) USA has compared to other areas/countries. Countries with a lot of nuclear see that energy wasted at night because you can't just dial down the level very quickly, in that sense, in most of Nothern Europe this would be desirable. In countries that have extreme levels of solar, clearly this only works during the day and perhaps leaves the night being covered by fossil fuel plants instead where they are happy to use less/dial it down. The massive missing piece, at least in the UK, is a genuine Smart Grid that can drive usage to meet supply. I have precisely zero appliances in my house that can make any use of cheap electricity and even worse, if I want a dual-tariff to get cheaper overnight electric, I get punished for it costwise.
  - jayd16 4y ago
    Smart metering would make it easily enforceable but couldn't tie into the smart thermostat system to at least delay charging to off peak hours?
  - maccard 4y ago
    > I have precisely zero appliances in my house that can make any use of cheap electricity and even worse, if I want a dual-tariff to get cheaper overnight electric, I get punished for it costwise No dishwasher or washing machine? I have a hog water tank with an immersion switch on it, I would love to heat that with cheap electricity overnight. I agree on the stupidity of punishing people for taking on the cheaper night tariffs - we should be goint for as much carrot as we can over stick! The other aspect of this is price and consumption. I work from home with a workstation PC and an electric over that we use maybe every other day. Meanwhile my annual electricity bill is 1/4 of what my annual heating (gas) is, and of that, hot water is only 1/4 of that. Well over half of my annual bill and energy consumption is just heating my house during winter. The real goal is to get storage heat sources heated by renewable sources for those of us in the UK.
dominotw 4y ago
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.
- alexb_ 4y ago
  This is nonsensical. You are taking away extremely useful technologies from people who can afford a parking space next to a power outlet, all because it's not fair to people who don't have that.
  - dominotw 4y ago
    >This is nonsensical. Whats nonsensical is thinking people will vote to increase taxes on themselves to improve public infrastructure if it doesn't benefit them. we shouldn't create public policy expecting ppl to vote for it purely out of goodness of their hearts.
- cortesoft 4y ago
  So your solution to some people having an easier time charging is to make it worse for everyone?
  - aidenn0 4y ago
    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.
    - dominotw 4y ago
      Exactly!!!. Thats one of the example I had in mind.
    - xboxnolifes 4y ago
      Which is a bad idea, considering public school admissions are generally district based, so only only rich districts, the ones with already generally better schools, would (maybe) improve. This fixes nothing.
m0RRSIYB0Zq8MgL 4y ago
> Current time-of-use rates encourage consumers to switch electricity use to nighttime whenever possible, like running the dishwasher and charging EVs. This rate structure reflects the time before significant solar and wind power supplies when demand threatened to exceed supply during the day, especially late afternoons in the summer. So, if you have a grid that doesn't heavily rely on solar then charging at night makes sense. > Today, California has excess electricity during late mornings and early afternoons, thanks mainly to its solar capacity. If most EVs were to charge during these times, then the cheap power would be used instead of wasted. How are people going to charge their cars during commutes?
- tantalor 4y ago
  From the article: > drivers should move to daytime charging at work
- floatrock 4y ago
  > > Today, California has excess electricity during late mornings and early afternoons, thanks mainly to its solar capacity. If most EVs were to charge during these times, then the cheap power would be used instead of wasted. > How are people going to charge their cars during commutes? Come on, you're saying most commutes are "late morning and early afternoon"? I too would like a job where my commute in is at 11 and my commute home is at 2. Rather than spreading EV FUD, can we instead discuss what the article is actually talking about, like installing charging infrastructure in daytime parking lots so we can take better advantage of the cheap, plentiful, and often curtailed solar energy?
  - jonahhorowitz 4y ago
    We should install solar panels over those lots at the same time. It covers some of the capacity need, cools the lot and the cars, and is an efficient use of space.
    - yjftsjthsd-h 4y ago
      It would also conveniently reduce transmission loss, and if you did it right you could probably skip the inverter overhead by going all DC.
ctrlmeta 4y ago
> We’re doing it wrong, according to a new Stanford study. This requires further clarification. What is it that we want to optimize? How do we know we want to optimize that?
digdugdirk 4y ago
"Electric vehicles will contribute to emissions reductions in the United States, but their charging may challenge electricity grid operations. We present a data-driven, realistic model of charging demand that captures the diverse charging behaviours of future adopters in the US Western Interconnection. We study charging control and infrastructure build-out as critical factors shaping charging load and evaluate grid impact under rapid electric vehicle adoption with a detailed economic dispatch model of 2035 generation." The opening lines of the actual study paper. Wanted to put that out into the mix before this turns into another Soleus Pushup debacle. That said, I think University of Houston actually did a better job with their press release than Stanford did, both in clarity of explanation and in the quality of presentation. I'd like to hear some thoughts for/against though.
calrain 4y ago
My understanding was that it helps countries with nuclear powered base electrical load to use that power at night, when there isn't a lot of demand. With further development, a key side benefit is that the grid can then tap into about 5% of your cars battery storage during the day when demand is higher (if you allow it).
- elzbardico 4y ago
  The same issue applies to almost every country's baseload generation infrastructure, with a small exception of hydro (that has some small degree of dispatchability), it is not exclusive to nuclear power generation. Traditional thermo-electric plants also can't ramp up and down their power levels instantaneously.
DropPanda 4y ago
This is very interesting and perfectly logical. I wrote a fairly recent report looking at a very similar question, and reached the opposite conclusion: night time charging is far better for the grid. That study however focuses on Sweden, where solar power only marginally impacts day-time supply. Link to the study: http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-57521 http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-5752... If the western US has a surplus in mornings and afternoons, you guys really should invest in dynamic charging using electrified roads (commonly referred to as wireless inductive charging in California, but there are conductive solutions as well).
- Gasp0de 4y ago
  Inductive charging seems like a horrible solution as it must surely be extremely inefficient? Also, if dynamic charging refers to charging while in motion, why would that be a good solution? It seems way more complicated and inefficient than charging while stationary, and personally owned cars are stationary more than 90% of the time.
  - DropPanda 4y ago
    Surprisingly, transmission efficiency (grid to motor) does not appear to be lower with inductive methods than conductive. Numbers above 90% should be expected. A bit lower for the dynamic (in-motion) solutions, but not so much that it’s a deal breaker. There seem to be much larger savings/costs elsewhere in the system that make transmission efficiency of less importance. Cars that are stationary most of the time are a pretty good reason to put charging infrastructure on the only land they actually share - the roads.
    - Gasp0de 4y ago
      This source (https://batteryuniversity.com/article/bu-412-charging-without-wires#:~:text=Adding%20the%20losses%20of%20the,plugged%20into%20AC%20outlets%20worldwide https://batteryuniversity.com/article/bu-412-charging-withou....) says efficiency is only 75-80% when charging inductively. Do you have any better sources for those 90%?
adrianN 4y ago
So plugging in the car whenever it's parked and letting the grid decide when to charge it is the way to go?
- toomuchtodo 4y ago
  Works for thermostats shedding AC loads on hot days for consumers who have opted in.
- thehappypm 4y ago
  I would love to have a charger that just has a knob on it. Charge fast on one side, charge cheap on the other.
  - adrianN 4y ago
    I would be okay with a "give me at least x range by tomorrow" button, so that the car can also feed back to the grid if I happen to have more in the tank than I need.
rr888 4y ago
We really need a way for power hungry smart devices to charge by spot pricing. By default your car charges when rate is low eg windy nights and sunny lunch times and not a heatwave. Having Night and Day rates is too simplistic.
cortesoft 4y ago
It sounds like the real issue is that the time-of-use rates are wrong. Just adjust them to match the actual energy production/demand, and the behavior change will follow. My solar, battery, and car setup automatically adjusts to the rate for power. It sends all my energy to the grid when costs are high and I get the most back, and uses the battery at that time... and then charges the battery when rates are low. Set the rates to be accurate and the system will work itself out. I am not going to use more expensive electricity just because the rates are set wrong.
- Gibbon1 4y ago
  It seemed obvious to me that time of use rates will have to change when you switch from thermal generation to solar because when you have over/under-provisioning is different. Thermal plants have excess capacity late at night, early morning. And under during the late afternoon early evening. Solar will have excess during the late mid morning. And nothing in the early evening. I don't think you need smarties at Standford to figure that out.
sudden_dystopia 4y ago
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.
- trgn 4y ago
  They are more quiet and don't pollute the local environment. They are a small but meaningful improvement to the quality of city life.
- _ph_ 4y ago
  It is very easy to keep up expanding renewable energy with the ramp up of electric cars. In Germany (which is pretty far north), about 10 solar panels are enough to cover one cars electric needs. And it is not true, that batteries are non-recyclable. Currently, they can be recycled to about 95% and of course this is cheaper than to mine the minerals for a new battery and also saves a lot of energy. It is just that it will quite a few more years before we need much recycling capacity, as the bulk of the batteries will live at least 10 to 15 years.
- dymk 4y ago
  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.
  - erichocean 4y ago
    > 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-solar-market-insight-what-you-need-to-know https://www.ny-engineers.com/blog/seia-publishes-the-2021-so...
wongarsu 4y ago
Skimming the article it seems the crux of the matter is that with home charging people charge either a) when they come home b) with a timer, at 9pm, or c) with a timer, at 12am (with b and c driven by fixed changes in electricity prices). Electricity demand for everything else is highest at about 7pm, so both a and b charge at times where there isn't a lot of unused grid capacity. And to make things worse, at all three times you don't get a lot of solar power. I wonder why the recommendation is to go to daytime charging, instead of timers staggered around 4am (when grid utilization is lowest). Sure, no solar, but potentially lots of unused wind, and lots of spare capacity on the power lines that already exist.
upsidesinclude 4y ago
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 higher demand in a shorter period of time. Meanwhile Calofornia wants to legislate 'clean' or 'green' energy production. If that's a design limitation then the outcome is a shift away from what is the normal situation we face with energy use today. Energy use at night with a highly solar derived power system requires significant storage and efficiency loss. Charging all of California's electric cars in 2035 will be a demand that far surpasses anything seen today. These things that we see causing rolling black outs and brown outs, like AC use spikes in summer will be a blip compared to the consistent vehicle charging demand. Interesting, though, the electric vehicle adoption basically negates the storage problem if a parallel infrastructure of charge back from homes at night is implemented. Charge your car at work in the sun and use it to power your home at night.
- 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.
elzbardico 4y ago
Of course, it is far more efficient system-wide to charge electric cars around noon, where photovoltaic energy produces a surplus of energy with zero marginal economic value. It is an elegant way of solving at least part of the storage problem and the mismatch between peak power and demand times.
sempron64 4y ago
The article predicts that even with the proposed changes, 4.2 GW of storage or other generation capacity will be necessary, as opposed to 5.2 GW without the changes. I'd advocate getting on the power supply or storage solution immediately rather than trying to change consumer habits by e.g. funding or legislating power station installations in workplaces (a nice convenience, but not one that will solve this problem). Tesla has already built a very large power storage station in Australia https://www.pv-magazine.com/2022/07/27/tesla-big-battery-begins-providing-inertia-grid-services-at-scale-in-world-first-in-australia/ https://www.pv-magazine.com/2022/07/27/tesla-big-battery-beg... Obviously the notion of building >5GW of generation capacity on fossil fuels or nuclear in under 10 years seems wild. So it's probably going to have to be solar + storage.
more_corn 4y ago
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 that. You can’t write a piece like this and begin anywhere else. This article gets an F- for effective communication and persuasion.
- e63f67dd-065b 4y ago
  The article (and paper) is saying that in solar-dominated generation regions, peak electrical production is during the day when the sun is out, and the trend seems like it's not stopping. I haven't actually read the full paper, but to quote the abstract: > We study charging control and infrastructure build-out as critical factors shaping charging load and evaluate grid impact under rapid electric vehicle adoption with a detailed economic dispatch model of 2035 generation. We find that peak net electricity demand increases by up to 25% with forecast adoption and by 50% in a stress test with full electrification. The paper is at https://www.nature.com/articles/s41560-022-01105-7 https://www.nature.com/articles/s41560-022-01105-7, I only briefly skimmed through it but it seems plausible. The assumption that a flat electrical load is desirable is less and less true as renewables go on the grid; of course, if we just took the (imo sensible) step to go all-nuclear, hydro, and geothermal for baseline load, then diurnal electrical consumption would not be desirable, but with the solar that might not be the case.
- aidenn0 4y ago
  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.
ttGpN5Nde3pK 4y ago
Crazy concept: instead of banning cars, forcing electric cars, mandating specific efficiency, etc... we _could_ work towards a world less dependent on personally owned vehicles. And yet, huge companies will continue to just get a pass for forcing people to commute to jobs to sit on a computer all day.
- kitkat_new 4y ago
  how about all of it?
- chickenpotpie 4y ago
  False dichotomy
kwhitefoot 4y ago
Sounds like the problem is simply that the US doesn't seem to have real time pricing of electricity. In Norway we pay what the market determines is the current price. Most people don't have flat rate charges. I can see the spot price in real time in an app. Why isn't that good enough?
- faxmeyourcode 4y ago
  >Residents with variable-rate power plans are being hit the hardest. Such plans charge different prices for electricity depending on how much demand there is. The more demand, the higher the price. This is a thing for some power companies in Texas, but during peak times or in a crisis like TX experienced in winter of 2021, the prices skyrocketed because demand was out of control trying to keep warm. People ended up with a $5k electric bill trying to keep a modest single family home "warm" (in the article they mentioned they kept lights off and thermostat set at 60F/15C, not very warm). https://www.npr.org/sections/live-updates-winter-storms-2021/2021/02/21/969912613/after-days-of-mass-outages-some-texas-residents-now-face-huge-electric-bills https://www.npr.org/sections/live-updates-winter-storms-2021...
  - FullyFunctional 4y ago
    This is all true, but I think the Texas issue is an outlier. Many things went wrong and all of them were preventable issues caused by mind-boggling terrible governance. Somehow these people are still in power.
- FullyFunctional 4y ago
  "The US" doesn't have a single system, not even within each state. Anecdotally, I have Time-of-Use billing with my PG&E electricity, but AFAICT, I was only allowed get that because I have BEVs. I think the "problem" is that someone needed to publish. This is a complete non-issue and utilities will shift the load as needed by adjusting the billing. Also, the notion that everyone going "in to work" is some antiquated pre-covid thinking.
- jjav 4y ago
  > the US doesn't seem to have real time pricing of electricity "The US" is a big place. Depends which city/county you're in and who is providing the electric service. > I can see the spot price in real time in an app. That sounds like a nightmare. Does it really change hourly? How can you program your systems to use the most efficient rate if you have no idea in advance what it is? Here in PG&E California we have time of use tiers, but they are known. So I can for example let the EV start charging only at midnight when the cheapest tier kicks in. But I know it is cheap midnight to 3pm, brutally expensive 3pm to 9pm and fairly expensive 9pm to midnight.
Animats 4y ago
"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_Station https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...
- sidewndr46 4y ago
  So we're just going to destroy huge parts of the Sierras so we can charge electric cars?
  - elihu 4y ago
    The reservoirs we're using as an example are in the hundreds of acres of surface area. That's not "huge parts of the Sierras". If you look at Bath County Pumped Storage Station on Google maps, the bigger reservoir is a skinny lake about a mile long. Perhaps it makes sense to use much larger reservoirs, but even then I have trouble equating the creation of a few artificial lakes with severe environmental destruction. Really, it all depends on where they put it and whether they do reasonable due diligence to not impact existing habitat too severely. The environmental destruction that results from burning petroleum for ground transportation is far worse.
  - CameronNemo 4y ago
    Wait until you hear about the mining operations needed to build them.
aidenn0 4y ago
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.
insane_dreamer 4y ago
If utilities change their time-of-use time slots (when electricity is cheaper to consumers) and EV owners will quickly change their charging habits (and companies will be incentivized to provide them with on-premise charging stations available at those hours and with cheaper rates).
JMiao 4y ago
op, how did you get that vanilla formatted view of new.stanford.edu?
mise_en_place 4y ago
I would love to charge in public while doing errands but every supercharger station is always occupied. I am forced to charge at home for this reason.
exabrial 4y ago
I know this is against the grain, but I do think clean hydrogen is the future fuel. I know hydrogen is less efficient than Battery-Electric, but it's not about efficiency, it's about convenience. One can transfer millions of joules at the petro pump in a few minutes without having to actually "handle" said joules.... but to transfer hundreds of joules with a battery-electric vehicle, one currently must actually "conduct" or directly "handle" all of the power that will eventually be used to propel the vehicle. Gasoline in a sense, "compresses" the energy for transfer... That being said, Battery-Electric is a "here and now" technology. Perfection is the enemy of progress, so I'll gladly take a 1000HP Battery Electric GMC Hummer thank you.
- Schroedingersat 4y ago
  Hydrogen has a number of hard to solve problems. But there are other fuels that are both burnable or usable in fuel cells. But all these improvements will mean nothing if we increase consumption enough to offset any efficiency increases.
CameronNemo 4y ago
This will happen when/if TOU rates change, which will happen when/if solar gets built way out... There is a lot of inertia in the grid. No need to rush things and mess with incentives without good reason. Being receptive to and prepared for employers who want to offer EV charging is a good idea, but it is definitely early days. No need to panic and implement a bad solution.
_8j50 4y ago
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 car and you have less queues. Why is this not possible? If it takes an hour to charge a battery and a battery station has 200 charging at any given time, and it takes 2 minutes to swap a battery then 6 charging bays can replace batteries for 180 cars leaving 20 extra batteries for defects and other issues. Couldn't such a charging station be implemented on a similar lot and budget of constructing a medium size gas station (at least a dozen pumps and around 1 acre lot). A charging station that is twice as efficient with a 30min charge time can do 2 cars at most in one hour. You need 90 charging station to reach that efficiency even without considering the queues. 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?
- tacostakohashi 4y ago
  We're talking about an industry that has failed to standardize on a single, interchangeable charging plug here. What do you think the chances of a single, interchangeable battery for such a "battery station" to remove, recharge, replace are? Or are you proposing such stations for each individual manufacturer, model, model year, etc?
  - CryptoBanker 4y ago
    They haven’t standardized because they haven’t been given an incentive to standardize. I would argue that perhaps the incentives mentioned in the article could be given to companies instead to encourage them to standardize in plugs and batteries, but many people prefer to see financial incentives given to people instead of corporations
  - meatmanek 4y ago
    The industry _has_ standardized, except for one hold-out (Tesla): https://youtu.be/sZOuz_laH9I?t=990 https://youtu.be/sZOuz_laH9I?t=990 > CCS is the established industry standard DC fast-charging connector, and every automaker selling cars for the US market is already using it, or, in the case of Nissan, has pledged to use it going forward. Except, oh right, except for... them [Tesla]. The charger situation is quite analogous to Lightning vs. USB-C for smartphones. USB-C is the industry standard, and there's one manufacturer still using a proprietary connector. And in both cases, the hold-out manufacturer provides an adapter cable so you can use the standard connector. (To your point about standardized batteries having approximately 0% chance of happening any time soon, I 100% agree.)
Traubenfuchs 4y ago
Did anyone do the math for when gasoline car sales will be banned? How many more power plants to we need? How much more Lithium do we need? I don‘t want to be a luddite, but the ev revolution seems to be unfeasible.
- sidewndr46 4y ago
  As long as the internal combustion engine is banned the EV revolution is entirely feasible. No one said everyone would be able to afford to drive an EV. Just that people would stop driving internal combustion engine vehicles.
  - Test0129 4y ago
    No one has answered how people intend to do things that require transportable fuel. I can't buy a Tesla (or whatever) and hot-swap batteries. If I travel 200 miles to go camping and the nearest charging station is 150 miles away I am hosed. No electric vehicle to date (nor planned for release) has the towing capacity needed to haul a week or two of gear, solar panels, deep cycle batteries, alternators, etc needed to set up a system. Even if you could, the risk of starting a forest fire due to reflections and/or sudden spontaneous battery deconstruction is non-negligible. The torque of an electric truck makes it attractive as an off road vehicle, however it's entirely infeasible in practice. So the government rules by fiat that ICE vehicles are to be banned. I guess someone better tell people that they won't be able to travel as far, or for as long, until the 22nd century when battery technology catches up and you can charge it with a single lightweight panel where ever you are. The energy density of a can of gasoline is so much higher than a towable array of solar panels the EV solution may as well be horse and buggy. It will be decades before remote gas stations in the middle of no where have a charging station available. The government can "ban" things all they want. If the alternative isn't acceptable to people who don't want to live a life of being a metropolitan worker drone who owns nothing they will find a way.
saisundar 4y ago
Also worth noting That ev platforms are now essentially closely engineering the power train and the battery systems to work and extract maximum juice ( similar to Apples battery/cpu control on the iPhone). When the above is executed well, you get performance and range that are moats to car manufacturers, which reduces the incentive to partake in such efforts as well. ( Tesla, and of course the recent EGMP platform is an example of this. The latter powers 3 best selling cars in the US this year).
timwaagh 4y ago
The market would come to the same conclusion in time but only if they are right. The conclusion about the need for incentives is therefore wrong. It will just encourage rent seeking and destroy efficiency. It's important for the government to support optimal price finding instead by removing possible oddities in how energy prices are created.
nmstoker 4y ago
Did anyone get the sense the article was dancing around the main point with vague language? They left it ambiguous about whether they meant effectively all charging should switch to the day or a portion should switch (to give some kind of optimal balance). I haven't looked at the model but it seems really odd to think that there shouldn't still be some night charging, to soak up the fixed capacity that's there to cover variations in solar/wind.
musicale 4y ago
Didn't we just get a Flex Alert in California telling us to not use power between 4 and 6pm?
pfdietz 4y ago
Obviously people need to work at night.
colechristensen 4y ago
> may need to rethink electricity pricing structures as their EV charging needs increase Duh. With the ramp up of solar production and the increase of EV demand, there will certainly need to be pricing changes, or simply more people will need to pay more dynamic rates. This will easily shift behaviors, really simple economics at work here. “At night” is a bad title. People need to not charge their EV right when they get home in the evening which is near peak energy usage, there needs to either be a delay circuit to actually charge at night during the usage minimum (which will actually lower costs and make things more efficient) or during the ever increasing daily solar maximum which is somewhat earlier than the daily usage maximum. We don’t need rules or morality here, just pricing that motivates people to match their behavior to demand. Really though charging at home should be fine as long as there’s a “wait until 10pm to save $2” button, or whatever. It really would be better because raising grid utilization during idle times really helps efficiency. Some California live power production and usage data: https://www.caiso.com/todaysoutlook/Pages/supply.html https://www.caiso.com/todaysoutlook/Pages/supply.html TL;DR plug in your car when you go to bed, not when you get home from work.
CalChris 4y ago
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.
- CaliforniaKarl 4y ago
  > … 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.
slowmovintarget 4y ago
The study presupposes everyone is going to drive in to the office every day. I haven't worked in an office since Mar of 2020. If I can help it, I'm going to stay remote. I'll need to charge my car at home, should I get an EV.
jondwillis 4y ago
algorithmic charging / evolving peak demand… eh.
kkfx 4y ago
The original Green New Deal design have chosen BEVs not at "electric cars" but as connected batteries reasoning of usage like "you arrive at home and plug the car", "you depart from home, go to work and plug the car" etc so most of the time the battery is connected with an AC inverter to the grid, so something who can suck or push power looking at current grid frequency. That ideas is (was?) the solution to keep a large grid powered with massive renewables who make grid loads vary much in very little time, something NO fossil/nuclear power plant can cope, so something that provoke continuous blackouts because when the Sun rise suddenly the "classic" power plant load fall and they can't reduce power quickly enough so the frequency skyrocket and they disconnect. Similarly when clouds pass or Sun goes down the inverse (a sudden peak) provoke a quick drop in frequency with equal effects, instead of power plants entire part of distribution network disconnect suddenly to reduce the load and the the frequency. Batteries are quick enough to cope. So the idea was: when the Sun goes up the sudden drop in load will be absorbed by cars who start charging full power than slowly reduce to give times to classic PP lower their production, when the Sun goes down they discharge to the grid for a little while with the similar target. Since batteries do not last longer and cost a fortune EVs are a way to shift the costs to the users. If you have p.v. at home you have to face big capex BUT you can lower opex lowering high electricity price using your p.v. and car, or so to speak if you help the transition you get paid back. If you can't you simply suffer higher tariff getting equally more poor from another way. The wealthy became poor due to high investments, the less wealthy due to the sky high cost of living. And you know the classic WEF/2030 https://youtu.be/Hx3DhoLFO4s https://youtu.be/Hx3DhoLFO4s vision. Casually people are a bit dumb en-masse, as Gustave Le Bon and Eduard Bernays wrote in their masterpieces, but not that dumb so while p.v. is actually a bit spread because anyway lower enough the electricity cost to pay back EVs/domestic batteries are not because simply they do not pay back despite the claim. And that's why we have blackouts and sky-high energy costs plus menace of scarcity of diesel and gasoline to makes EVs convenient "enough". Charging at night is the logical choice FOR MOST, since normally we are active in the day and sleeping at night, but doing so means charging from the grid wanting a certain SOC in the morning. Green New Deal theorist have imagined remote workers who do not use their cars all days and workers how drive to the work and there charge the car in large parks with p.v. roofs. That's of course happen, but for a small cohort of people, while MOST EV owners so far are from dense cities where such model simply do not work because they have common garages, without p.v. or without enough p.v. both "at home" and "at work". So far those theorist have found no solution: they can try push blackouts a bit more than natural to push people buying EVs as home batteries BUT due to EVs prices most people will not buy them anyway so the shift to renewables will not happen. They can't lower EV prices, most of the supply chain is in foreign hands and anyway there are way to expensive to manufacture to lower the price much. Not only, since they do not state clearly such cars-as-a-grid-balancers perhaps to avoid being accused of shifting costs to the people most EVs are NOT made to be used as home batteries. Something start happening BUT at very limited and slow rate. Some inverter-chargers charge on DC and so can offer "standard power" to the home, but most do not offer micro-grid islandic setups so they can't work in case of an outage, some V2L do exists with in-car inverters, but for very limited power (like 2kW while potentially the car can deliver 50+kW) etc. That's the issue when managers are in charge: they dream something and run with the idea of fixing and detailing anything on the go, that the reality hit.

127 points by hhs 4y ago

Fire risks are also much greater at night if you are charging a BEV in your house while asleep. Far safer to charge in an open area preferably away from other vehicles and stuctures. https://www.ntsb.gov/news/press-releases/Pages/NR20210113.aspx https://www.ntsb.gov/news/press-releases/Pages/NR20210113.as...

wing-_-nuts 4y ago
Frankly, if a user cannot trust their EV to charge without going up in flames it is not ready for prime time and should be recalled. Period.
- ctrlmeta 4y ago
  Yes! It surprises me that the reliability issues in charging an EV are not discussed more. This bears more discussion and subject to regulations. It is not ok for companies to push EVs to general consumers without creating a good safety record.
  - adrianN 4y ago
    How many EVs spontaneously combust while charging?
    - rcMgD2BwE72F 4y ago
      Less than ICE anyway. Who wants to talk about gas cars burning? It's so frequent journalists won't report them. But Teslas? Oh, my.
  - wing-_-nuts 4y ago
    I think we already have enough regulations to hold companies liable for creating a dangerous product, we simply need to use them to hold corporations accountable. None of this 'oh, our owners manual says you should only charge in these special conditions or we can't be held responsible'. Nope. You make a product and it hurts people or destroys property? You better make your peace with punitive damages that'll make you wish you properly tested before shipping to customers.
dymk 4y ago
The press release you linked to is about cars catching fire after they crash. Can you give a source for how many cars catch fire spontaneously when they're stationary and charging?
- olivermarks 4y ago
  I don't have a source of data but this article might be useful if you've watched the NTSB video and other material https://www.washingtonpost.com/technology/2021/08/04/tesla-fire/ https://www.washingtonpost.com/technology/2021/08/04/tesla-f... 'Battery-powered vehicles have not been shown to catch fire at rates higher than gasoline cars, but when fires do erupt, they burn longer and hotter, propelled by lithium-ion batteries that supercharge the blazes, experts say.'
vel0city 4y ago
I've had several recalls for spontaneous combustion of my ICE cars suggesting I don't park in the garage. At least one car had multiple fire risk recalls for starting fire while parked. I guess ICE cars should never be parked in a garage.

notjustanymike 4y ago

Turns out the sun is out during the day.

sambeau 4y ago
And in cold climates there is a greater need for heating at night.

3pt14159 4y ago

This is simple. Musk just needs to throw 1% of his AI talent at optimizing charging times via realtime grid negotiating and nobody will need to even think about this. Cars will turn into one of our most valuable assets as they help stabalize the grid by being both sinks when energy is plentiful and sources when it's not. There are certain problems we all need to think about, but this is not one of them. It will effectively solve itself because all the incentives are aligned.

nightski 4y ago
So electric car owners need to just cover all the battery wear out of their own pockets? Wouldn't that make electric cars even more expensive since battery replacement will be needed more often?
- toomuchtodo 4y ago
  Batteries are lasting far longer than anticipated. Anecdotally, I have fast DC charged my 2018 Model S (100kw pack) for the majority of the 100k miles I’ve put on the car, and only have 7% battery degradation. Others are seeing similar longevity well into hundreds of thousands of miles. https://news.ycombinator.com/item?id=32758881 https://news.ycombinator.com/item?id=32758881 https://www.forbes.com/sites/carltonreid/2022/08/01/electric-car-batteries-lasting-longer-than-predicted-delays-recycling-programs/ https://www.forbes.com/sites/carltonreid/2022/08/01/electric... https://cleantechnica.com/2022/03/29/tesla-founder-ex-cto-says-ev-batteries-will-last-15-years/ https://cleantechnica.com/2022/03/29/tesla-founder-ex-cto-sa...
  - nightski 4y ago
    That doesn't really matter. If you own a resource, and I utilize it, are you going to let me do so without compensating you in some fashion? If so I'll take you up on that offer. I have no problems with encouraging people to charge at certain times. Using personal batteries for energy storage and draw without any compensation however seems to cross a line. Your argument seems to me like justifying petty theft because in the end it doesn't really affect the store owner.

guywithahat 4y ago

This is a very California problem caused by very California policies

kadoban 4y ago
It's not a problem, it's an opportunity to optimize energy use to match how it's now generated.
- guywithahat 4y ago
  Shouldn't it be an opportunity to match energy generation to how it's consumed? No industry survives long by offering a worse product to consumers than what they had before
  - upsidesinclude 4y ago
    Unfortunately for them it isn't a product they can control with the legislation they are choosing. There will be significant problems with CA power infrastructure in the near future.
  - kadoban 4y ago
    If consumption has a good reason to be as it is maybe. The whole reason we have lower night rates and such was due to how it was generated in the past though. Why would we continue that if it no longer makes sense? It's something that should be looked at on the whole and tradeoffs considered.
  - kadoban 4y ago
    > No industry survives long by offering a worse product to consumers than what they had before That's ... optimistic, but not really true. It also doesn't seem to match what's happening here either. How is power generation when demand is highest a worse product?
    - myko 4y ago
      I assumed the comment meant EVs were worse than ICE vehicles (not an opinion I hold)

lelag 4y ago

It's not just about the rate. Charging at night happens because the car is conveniently parked at home doing nothing and EV owners want a car ready to go in the morning. Charging at EV station during the day is time consuming and is often expensive. I'm sure that the lucky few that can charge at work already do so...

floatrock 4y ago
It's almost as if the logical conclusion is to invest in convenient workplace charging infrastructure so charging is simple when the car is conveniently parked at work doing nothing and the owner wants a car ready to go home in the evening... > “We encourage policymakers to consider utility rates that encourage day charging and incentivize investment in charging infrastructure to shift drivers from home to work for charging,” said the study’s co-senior author, Ram Rajagopal
- greedo 4y ago
  The logical conclusion is to try to get away from needing to drive to work at all.
  - neon_electro 4y ago
    Right? Then it becomes trivial to charge at home, during the day (if that really does make an impact).
    - r00fus 4y ago
      Or simply not have a car (or reduce cars in the household). That'd make an even bigger difference in energy usage an GHG emissions.
  - davidro80 4y ago
m463 4y ago
Most EVs charging at home are plugged in from say 6pm to 7am. It would be most convenient to charge immediately but the electric rates (in california at least) are highest at 6pm and lowest at 7am. There is choice in that equation.

syntaxing 4y ago

What’s the alternative? Not like you can charge your EV at home when you’re working when…you’re at work

kadoban 4y ago
Charge at work.
- ctrlmeta 4y ago
  But how many work areas have a charging station available easily?
  - kadoban 4y ago
    Not as many as should. The state can probably incentivize creating some more, and job seekers can prioritize it as well. Not to mention workers just asking their employers to do it.
  - floatrock 4y ago
    Literally the point of the study > “We encourage policymakers to consider utility rates that encourage day charging and incentivize investment in charging infrastructure to shift drivers from home to work for charging,” said the study’s co-senior author, Ram Rajagopal
  - _ph_ 4y ago
    The term "charging station" is hinting at a too big infrastructure. All you need is a power outlet per car. If the car parks for 8 to 9 hours, you don't need a huge amount of power to recharge it.
    - toast0 4y ago
      You need more than just a power outlet per car, with regular 120vac, you pretty much need a breaker and circuit per car, because you shouldn't put two of those on a single circuit, since they'll usually pull up to the 15A rating of the plug, and code restricts you from using more than 20A breaker on a circuit with 15A plugs, so you'll pop the breaker if you've got two 15A loads and they don't communicate to share. It probably makes more sense to get a two or maybe four car charging station per breaker and circuit, and set it for the appropriate amps on the circuit, it can share that appropriately amongst the cars plugged in.

alexb_ 4y ago

>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 cheaper when it's more available, and people will use it. You don't need any complex "AI" like people in this thread are saying, you just use natural market forces and the problem fixes itself. Too much energy being used at night - price increases. It's not complicated, and it's what we're doing already. People don't need a Stanford study to convince them to get their energy for cheaper.

Grimburger 4y ago
> The solution is simple. Make electricity cheaper when it's more available From the parts of the world I come from the majority of people are vehemently opposed to time of use pricing. Because that's when they use it most. They and their political representatives would much prefer to keep taking from those who consume in off-peak rather than fix the underlying mechanism.
- GoOnThenDoTell 4y ago
  time-of-use is also cognitive load that can cause anxiety
  - zbrozek 4y ago
    Yeah it is. I hate having to have a process in my brain thinking about optimizing everything. So I bought solar panels and batteries. Now I no longer care. The grid can keep getting more expensive and less reliable without causing me grief.
    - alexb_ 4y ago
      >So I bought solar panels and batteries ...Mission accomplished?

denimnerd42 4y ago

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.

lbriner 4y ago
I guess the issue with this report is that it is specific to the unique mix of energy that the (west of the) USA has compared to other areas/countries. Countries with a lot of nuclear see that energy wasted at night because you can't just dial down the level very quickly, in that sense, in most of Nothern Europe this would be desirable. In countries that have extreme levels of solar, clearly this only works during the day and perhaps leaves the night being covered by fossil fuel plants instead where they are happy to use less/dial it down. The massive missing piece, at least in the UK, is a genuine Smart Grid that can drive usage to meet supply. I have precisely zero appliances in my house that can make any use of cheap electricity and even worse, if I want a dual-tariff to get cheaper overnight electric, I get punished for it costwise.
- jayd16 4y ago
  Smart metering would make it easily enforceable but couldn't tie into the smart thermostat system to at least delay charging to off peak hours?
- maccard 4y ago
  > I have precisely zero appliances in my house that can make any use of cheap electricity and even worse, if I want a dual-tariff to get cheaper overnight electric, I get punished for it costwise No dishwasher or washing machine? I have a hog water tank with an immersion switch on it, I would love to heat that with cheap electricity overnight. I agree on the stupidity of punishing people for taking on the cheaper night tariffs - we should be goint for as much carrot as we can over stick! The other aspect of this is price and consumption. I work from home with a workstation PC and an electric over that we use maybe every other day. Meanwhile my annual electricity bill is 1/4 of what my annual heating (gas) is, and of that, hot water is only 1/4 of that. Well over half of my annual bill and energy consumption is just heating my house during winter. The real goal is to get storage heat sources heated by renewable sources for those of us in the UK.

dominotw 4y ago

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.

alexb_ 4y ago
This is nonsensical. You are taking away extremely useful technologies from people who can afford a parking space next to a power outlet, all because it's not fair to people who don't have that.
- dominotw 4y ago
  >This is nonsensical. Whats nonsensical is thinking people will vote to increase taxes on themselves to improve public infrastructure if it doesn't benefit them. we shouldn't create public policy expecting ppl to vote for it purely out of goodness of their hearts.
cortesoft 4y ago
So your solution to some people having an easier time charging is to make it worse for everyone?
- aidenn0 4y ago
  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.
  - dominotw 4y ago
    Exactly!!!. Thats one of the example I had in mind.
  - xboxnolifes 4y ago
    Which is a bad idea, considering public school admissions are generally district based, so only only rich districts, the ones with already generally better schools, would (maybe) improve. This fixes nothing.

m0RRSIYB0Zq8MgL 4y ago

> Current time-of-use rates encourage consumers to switch electricity use to nighttime whenever possible, like running the dishwasher and charging EVs. This rate structure reflects the time before significant solar and wind power supplies when demand threatened to exceed supply during the day, especially late afternoons in the summer. So, if you have a grid that doesn't heavily rely on solar then charging at night makes sense. > Today, California has excess electricity during late mornings and early afternoons, thanks mainly to its solar capacity. If most EVs were to charge during these times, then the cheap power would be used instead of wasted. How are people going to charge their cars during commutes?

tantalor 4y ago
From the article: > drivers should move to daytime charging at work
floatrock 4y ago
> > Today, California has excess electricity during late mornings and early afternoons, thanks mainly to its solar capacity. If most EVs were to charge during these times, then the cheap power would be used instead of wasted. > How are people going to charge their cars during commutes? Come on, you're saying most commutes are "late morning and early afternoon"? I too would like a job where my commute in is at 11 and my commute home is at 2. Rather than spreading EV FUD, can we instead discuss what the article is actually talking about, like installing charging infrastructure in daytime parking lots so we can take better advantage of the cheap, plentiful, and often curtailed solar energy?
- jonahhorowitz 4y ago
  We should install solar panels over those lots at the same time. It covers some of the capacity need, cools the lot and the cars, and is an efficient use of space.
  - yjftsjthsd-h 4y ago
    It would also conveniently reduce transmission loss, and if you did it right you could probably skip the inverter overhead by going all DC.

ctrlmeta 4y ago

> We’re doing it wrong, according to a new Stanford study. This requires further clarification. What is it that we want to optimize? How do we know we want to optimize that?

digdugdirk 4y ago

"Electric vehicles will contribute to emissions reductions in the United States, but their charging may challenge electricity grid operations. We present a data-driven, realistic model of charging demand that captures the diverse charging behaviours of future adopters in the US Western Interconnection. We study charging control and infrastructure build-out as critical factors shaping charging load and evaluate grid impact under rapid electric vehicle adoption with a detailed economic dispatch model of 2035 generation." The opening lines of the actual study paper. Wanted to put that out into the mix before this turns into another Soleus Pushup debacle. That said, I think University of Houston actually did a better job with their press release than Stanford did, both in clarity of explanation and in the quality of presentation. I'd like to hear some thoughts for/against though.

calrain 4y ago

My understanding was that it helps countries with nuclear powered base electrical load to use that power at night, when there isn't a lot of demand. With further development, a key side benefit is that the grid can then tap into about 5% of your cars battery storage during the day when demand is higher (if you allow it).

elzbardico 4y ago
The same issue applies to almost every country's baseload generation infrastructure, with a small exception of hydro (that has some small degree of dispatchability), it is not exclusive to nuclear power generation. Traditional thermo-electric plants also can't ramp up and down their power levels instantaneously.

DropPanda 4y ago

This is very interesting and perfectly logical. I wrote a fairly recent report looking at a very similar question, and reached the opposite conclusion: night time charging is far better for the grid. That study however focuses on Sweden, where solar power only marginally impacts day-time supply. Link to the study: http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-57521 http://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-5752... If the western US has a surplus in mornings and afternoons, you guys really should invest in dynamic charging using electrified roads (commonly referred to as wireless inductive charging in California, but there are conductive solutions as well).

Gasp0de 4y ago
Inductive charging seems like a horrible solution as it must surely be extremely inefficient? Also, if dynamic charging refers to charging while in motion, why would that be a good solution? It seems way more complicated and inefficient than charging while stationary, and personally owned cars are stationary more than 90% of the time.
- DropPanda 4y ago
  Surprisingly, transmission efficiency (grid to motor) does not appear to be lower with inductive methods than conductive. Numbers above 90% should be expected. A bit lower for the dynamic (in-motion) solutions, but not so much that it’s a deal breaker. There seem to be much larger savings/costs elsewhere in the system that make transmission efficiency of less importance. Cars that are stationary most of the time are a pretty good reason to put charging infrastructure on the only land they actually share - the roads.
  - Gasp0de 4y ago
    This source (https://batteryuniversity.com/article/bu-412-charging-without-wires#:~:text=Adding%20the%20losses%20of%20the,plugged%20into%20AC%20outlets%20worldwide https://batteryuniversity.com/article/bu-412-charging-withou....) says efficiency is only 75-80% when charging inductively. Do you have any better sources for those 90%?

adrianN 4y ago

So plugging in the car whenever it's parked and letting the grid decide when to charge it is the way to go?

toomuchtodo 4y ago
Works for thermostats shedding AC loads on hot days for consumers who have opted in.
thehappypm 4y ago
I would love to have a charger that just has a knob on it. Charge fast on one side, charge cheap on the other.
- adrianN 4y ago
  I would be okay with a "give me at least x range by tomorrow" button, so that the car can also feed back to the grid if I happen to have more in the tank than I need.

rr888 4y ago

We really need a way for power hungry smart devices to charge by spot pricing. By default your car charges when rate is low eg windy nights and sunny lunch times and not a heatwave. Having Night and Day rates is too simplistic.

cortesoft 4y ago

It sounds like the real issue is that the time-of-use rates are wrong. Just adjust them to match the actual energy production/demand, and the behavior change will follow. My solar, battery, and car setup automatically adjusts to the rate for power. It sends all my energy to the grid when costs are high and I get the most back, and uses the battery at that time... and then charges the battery when rates are low. Set the rates to be accurate and the system will work itself out. I am not going to use more expensive electricity just because the rates are set wrong.

Gibbon1 4y ago
It seemed obvious to me that time of use rates will have to change when you switch from thermal generation to solar because when you have over/under-provisioning is different. Thermal plants have excess capacity late at night, early morning. And under during the late afternoon early evening. Solar will have excess during the late mid morning. And nothing in the early evening. I don't think you need smarties at Standford to figure that out.

sudden_dystopia 4y ago

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.

trgn 4y ago
They are more quiet and don't pollute the local environment. They are a small but meaningful improvement to the quality of city life.
_ph_ 4y ago
It is very easy to keep up expanding renewable energy with the ramp up of electric cars. In Germany (which is pretty far north), about 10 solar panels are enough to cover one cars electric needs. And it is not true, that batteries are non-recyclable. Currently, they can be recycled to about 95% and of course this is cheaper than to mine the minerals for a new battery and also saves a lot of energy. It is just that it will quite a few more years before we need much recycling capacity, as the bulk of the batteries will live at least 10 to 15 years.
dymk 4y ago
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.
- erichocean 4y ago
  > 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-solar-market-insight-what-you-need-to-know https://www.ny-engineers.com/blog/seia-publishes-the-2021-so...

wongarsu 4y ago

Skimming the article it seems the crux of the matter is that with home charging people charge either a) when they come home b) with a timer, at 9pm, or c) with a timer, at 12am (with b and c driven by fixed changes in electricity prices). Electricity demand for everything else is highest at about 7pm, so both a and b charge at times where there isn't a lot of unused grid capacity. And to make things worse, at all three times you don't get a lot of solar power. I wonder why the recommendation is to go to daytime charging, instead of timers staggered around 4am (when grid utilization is lowest). Sure, no solar, but potentially lots of unused wind, and lots of spare capacity on the power lines that already exist.

upsidesinclude 4y ago

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 higher demand in a shorter period of time. Meanwhile Calofornia wants to legislate 'clean' or 'green' energy production. If that's a design limitation then the outcome is a shift away from what is the normal situation we face with energy use today. Energy use at night with a highly solar derived power system requires significant storage and efficiency loss. Charging all of California's electric cars in 2035 will be a demand that far surpasses anything seen today. These things that we see causing rolling black outs and brown outs, like AC use spikes in summer will be a blip compared to the consistent vehicle charging demand. Interesting, though, the electric vehicle adoption basically negates the storage problem if a parallel infrastructure of charge back from homes at night is implemented. Charge your car at work in the sun and use it to power your home at night.

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.

elzbardico 4y ago

Of course, it is far more efficient system-wide to charge electric cars around noon, where photovoltaic energy produces a surplus of energy with zero marginal economic value. It is an elegant way of solving at least part of the storage problem and the mismatch between peak power and demand times.

sempron64 4y ago

The article predicts that even with the proposed changes, 4.2 GW of storage or other generation capacity will be necessary, as opposed to 5.2 GW without the changes. I'd advocate getting on the power supply or storage solution immediately rather than trying to change consumer habits by e.g. funding or legislating power station installations in workplaces (a nice convenience, but not one that will solve this problem). Tesla has already built a very large power storage station in Australia https://www.pv-magazine.com/2022/07/27/tesla-big-battery-begins-providing-inertia-grid-services-at-scale-in-world-first-in-australia/ https://www.pv-magazine.com/2022/07/27/tesla-big-battery-beg... Obviously the notion of building >5GW of generation capacity on fossil fuels or nuclear in under 10 years seems wild. So it's probably going to have to be solar + storage.

more_corn 4y ago

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 that. You can’t write a piece like this and begin anywhere else. This article gets an F- for effective communication and persuasion.

e63f67dd-065b 4y ago
The article (and paper) is saying that in solar-dominated generation regions, peak electrical production is during the day when the sun is out, and the trend seems like it's not stopping. I haven't actually read the full paper, but to quote the abstract: > We study charging control and infrastructure build-out as critical factors shaping charging load and evaluate grid impact under rapid electric vehicle adoption with a detailed economic dispatch model of 2035 generation. We find that peak net electricity demand increases by up to 25% with forecast adoption and by 50% in a stress test with full electrification. The paper is at https://www.nature.com/articles/s41560-022-01105-7 https://www.nature.com/articles/s41560-022-01105-7, I only briefly skimmed through it but it seems plausible. The assumption that a flat electrical load is desirable is less and less true as renewables go on the grid; of course, if we just took the (imo sensible) step to go all-nuclear, hydro, and geothermal for baseline load, then diurnal electrical consumption would not be desirable, but with the solar that might not be the case.
aidenn0 4y ago
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.

ttGpN5Nde3pK 4y ago

Crazy concept: instead of banning cars, forcing electric cars, mandating specific efficiency, etc... we _could_ work towards a world less dependent on personally owned vehicles. And yet, huge companies will continue to just get a pass for forcing people to commute to jobs to sit on a computer all day.

kitkat_new 4y ago
how about all of it?
chickenpotpie 4y ago
False dichotomy

kwhitefoot 4y ago

Sounds like the problem is simply that the US doesn't seem to have real time pricing of electricity. In Norway we pay what the market determines is the current price. Most people don't have flat rate charges. I can see the spot price in real time in an app. Why isn't that good enough?

faxmeyourcode 4y ago
>Residents with variable-rate power plans are being hit the hardest. Such plans charge different prices for electricity depending on how much demand there is. The more demand, the higher the price. This is a thing for some power companies in Texas, but during peak times or in a crisis like TX experienced in winter of 2021, the prices skyrocketed because demand was out of control trying to keep warm. People ended up with a $5k electric bill trying to keep a modest single family home "warm" (in the article they mentioned they kept lights off and thermostat set at 60F/15C, not very warm). https://www.npr.org/sections/live-updates-winter-storms-2021/2021/02/21/969912613/after-days-of-mass-outages-some-texas-residents-now-face-huge-electric-bills https://www.npr.org/sections/live-updates-winter-storms-2021...
- FullyFunctional 4y ago
  This is all true, but I think the Texas issue is an outlier. Many things went wrong and all of them were preventable issues caused by mind-boggling terrible governance. Somehow these people are still in power.
FullyFunctional 4y ago
"The US" doesn't have a single system, not even within each state. Anecdotally, I have Time-of-Use billing with my PG&E electricity, but AFAICT, I was only allowed get that because I have BEVs. I think the "problem" is that someone needed to publish. This is a complete non-issue and utilities will shift the load as needed by adjusting the billing. Also, the notion that everyone going "in to work" is some antiquated pre-covid thinking.
jjav 4y ago
> the US doesn't seem to have real time pricing of electricity "The US" is a big place. Depends which city/county you're in and who is providing the electric service. > I can see the spot price in real time in an app. That sounds like a nightmare. Does it really change hourly? How can you program your systems to use the most efficient rate if you have no idea in advance what it is? Here in PG&E California we have time of use tiers, but they are known. So I can for example let the EV start charging only at midnight when the cheapest tier kicks in. But I know it is cheap midnight to 3pm, brutally expensive 3pm to 9pm and fairly expensive 9pm to midnight.

Animats 4y ago

"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_Station https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta...

sidewndr46 4y ago
So we're just going to destroy huge parts of the Sierras so we can charge electric cars?
- elihu 4y ago
  The reservoirs we're using as an example are in the hundreds of acres of surface area. That's not "huge parts of the Sierras". If you look at Bath County Pumped Storage Station on Google maps, the bigger reservoir is a skinny lake about a mile long. Perhaps it makes sense to use much larger reservoirs, but even then I have trouble equating the creation of a few artificial lakes with severe environmental destruction. Really, it all depends on where they put it and whether they do reasonable due diligence to not impact existing habitat too severely. The environmental destruction that results from burning petroleum for ground transportation is far worse.
- CameronNemo 4y ago
  Wait until you hear about the mining operations needed to build them.

aidenn0 4y ago

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.

insane_dreamer 4y ago

If utilities change their time-of-use time slots (when electricity is cheaper to consumers) and EV owners will quickly change their charging habits (and companies will be incentivized to provide them with on-premise charging stations available at those hours and with cheaper rates).

JMiao 4y ago

op, how did you get that vanilla formatted view of new.stanford.edu?

mise_en_place 4y ago

I would love to charge in public while doing errands but every supercharger station is always occupied. I am forced to charge at home for this reason.

exabrial 4y ago

I know this is against the grain, but I do think clean hydrogen is the future fuel. I know hydrogen is less efficient than Battery-Electric, but it's not about efficiency, it's about convenience. One can transfer millions of joules at the petro pump in a few minutes without having to actually "handle" said joules.... but to transfer hundreds of joules with a battery-electric vehicle, one currently must actually "conduct" or directly "handle" all of the power that will eventually be used to propel the vehicle. Gasoline in a sense, "compresses" the energy for transfer... That being said, Battery-Electric is a "here and now" technology. Perfection is the enemy of progress, so I'll gladly take a 1000HP Battery Electric GMC Hummer thank you.

Schroedingersat 4y ago
Hydrogen has a number of hard to solve problems. But there are other fuels that are both burnable or usable in fuel cells. But all these improvements will mean nothing if we increase consumption enough to offset any efficiency increases.

CameronNemo 4y ago

This will happen when/if TOU rates change, which will happen when/if solar gets built way out... There is a lot of inertia in the grid. No need to rush things and mess with incentives without good reason. Being receptive to and prepared for employers who want to offer EV charging is a good idea, but it is definitely early days. No need to panic and implement a bad solution.

_8j50 4y ago

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 car and you have less queues. Why is this not possible? If it takes an hour to charge a battery and a battery station has 200 charging at any given time, and it takes 2 minutes to swap a battery then 6 charging bays can replace batteries for 180 cars leaving 20 extra batteries for defects and other issues. Couldn't such a charging station be implemented on a similar lot and budget of constructing a medium size gas station (at least a dozen pumps and around 1 acre lot). A charging station that is twice as efficient with a 30min charge time can do 2 cars at most in one hour. You need 90 charging station to reach that efficiency even without considering the queues. 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?

tacostakohashi 4y ago
We're talking about an industry that has failed to standardize on a single, interchangeable charging plug here. What do you think the chances of a single, interchangeable battery for such a "battery station" to remove, recharge, replace are? Or are you proposing such stations for each individual manufacturer, model, model year, etc?
- CryptoBanker 4y ago
  They haven’t standardized because they haven’t been given an incentive to standardize. I would argue that perhaps the incentives mentioned in the article could be given to companies instead to encourage them to standardize in plugs and batteries, but many people prefer to see financial incentives given to people instead of corporations
- meatmanek 4y ago
  The industry _has_ standardized, except for one hold-out (Tesla): https://youtu.be/sZOuz_laH9I?t=990 https://youtu.be/sZOuz_laH9I?t=990 > CCS is the established industry standard DC fast-charging connector, and every automaker selling cars for the US market is already using it, or, in the case of Nissan, has pledged to use it going forward. Except, oh right, except for... them [Tesla]. The charger situation is quite analogous to Lightning vs. USB-C for smartphones. USB-C is the industry standard, and there's one manufacturer still using a proprietary connector. And in both cases, the hold-out manufacturer provides an adapter cable so you can use the standard connector. (To your point about standardized batteries having approximately 0% chance of happening any time soon, I 100% agree.)

Traubenfuchs 4y ago

Did anyone do the math for when gasoline car sales will be banned? How many more power plants to we need? How much more Lithium do we need? I don‘t want to be a luddite, but the ev revolution seems to be unfeasible.

sidewndr46 4y ago
As long as the internal combustion engine is banned the EV revolution is entirely feasible. No one said everyone would be able to afford to drive an EV. Just that people would stop driving internal combustion engine vehicles.
- Test0129 4y ago
  No one has answered how people intend to do things that require transportable fuel. I can't buy a Tesla (or whatever) and hot-swap batteries. If I travel 200 miles to go camping and the nearest charging station is 150 miles away I am hosed. No electric vehicle to date (nor planned for release) has the towing capacity needed to haul a week or two of gear, solar panels, deep cycle batteries, alternators, etc needed to set up a system. Even if you could, the risk of starting a forest fire due to reflections and/or sudden spontaneous battery deconstruction is non-negligible. The torque of an electric truck makes it attractive as an off road vehicle, however it's entirely infeasible in practice. So the government rules by fiat that ICE vehicles are to be banned. I guess someone better tell people that they won't be able to travel as far, or for as long, until the 22nd century when battery technology catches up and you can charge it with a single lightweight panel where ever you are. The energy density of a can of gasoline is so much higher than a towable array of solar panels the EV solution may as well be horse and buggy. It will be decades before remote gas stations in the middle of no where have a charging station available. The government can "ban" things all they want. If the alternative isn't acceptable to people who don't want to live a life of being a metropolitan worker drone who owns nothing they will find a way.

saisundar 4y ago

Also worth noting That ev platforms are now essentially closely engineering the power train and the battery systems to work and extract maximum juice ( similar to Apples battery/cpu control on the iPhone). When the above is executed well, you get performance and range that are moats to car manufacturers, which reduces the incentive to partake in such efforts as well. ( Tesla, and of course the recent EGMP platform is an example of this. The latter powers 3 best selling cars in the US this year).

timwaagh 4y ago

The market would come to the same conclusion in time but only if they are right. The conclusion about the need for incentives is therefore wrong. It will just encourage rent seeking and destroy efficiency. It's important for the government to support optimal price finding instead by removing possible oddities in how energy prices are created.

nmstoker 4y ago

Did anyone get the sense the article was dancing around the main point with vague language? They left it ambiguous about whether they meant effectively all charging should switch to the day or a portion should switch (to give some kind of optimal balance). I haven't looked at the model but it seems really odd to think that there shouldn't still be some night charging, to soak up the fixed capacity that's there to cover variations in solar/wind.

musicale 4y ago

Didn't we just get a Flex Alert in California telling us to not use power between 4 and 6pm?

pfdietz 4y ago

Obviously people need to work at night.

colechristensen 4y ago

> may need to rethink electricity pricing structures as their EV charging needs increase Duh. With the ramp up of solar production and the increase of EV demand, there will certainly need to be pricing changes, or simply more people will need to pay more dynamic rates. This will easily shift behaviors, really simple economics at work here. “At night” is a bad title. People need to not charge their EV right when they get home in the evening which is near peak energy usage, there needs to either be a delay circuit to actually charge at night during the usage minimum (which will actually lower costs and make things more efficient) or during the ever increasing daily solar maximum which is somewhat earlier than the daily usage maximum. We don’t need rules or morality here, just pricing that motivates people to match their behavior to demand. Really though charging at home should be fine as long as there’s a “wait until 10pm to save $2” button, or whatever. It really would be better because raising grid utilization during idle times really helps efficiency. Some California live power production and usage data: https://www.caiso.com/todaysoutlook/Pages/supply.html https://www.caiso.com/todaysoutlook/Pages/supply.html TL;DR plug in your car when you go to bed, not when you get home from work.

CalChris 4y ago

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.

CaliforniaKarl 4y ago
> … 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.

slowmovintarget 4y ago

The study presupposes everyone is going to drive in to the office every day. I haven't worked in an office since Mar of 2020. If I can help it, I'm going to stay remote. I'll need to charge my car at home, should I get an EV.

jondwillis 4y ago

algorithmic charging / evolving peak demand… eh.

kkfx 4y ago

The original Green New Deal design have chosen BEVs not at "electric cars" but as connected batteries reasoning of usage like "you arrive at home and plug the car", "you depart from home, go to work and plug the car" etc so most of the time the battery is connected with an AC inverter to the grid, so something who can suck or push power looking at current grid frequency. That ideas is (was?) the solution to keep a large grid powered with massive renewables who make grid loads vary much in very little time, something NO fossil/nuclear power plant can cope, so something that provoke continuous blackouts because when the Sun rise suddenly the "classic" power plant load fall and they can't reduce power quickly enough so the frequency skyrocket and they disconnect. Similarly when clouds pass or Sun goes down the inverse (a sudden peak) provoke a quick drop in frequency with equal effects, instead of power plants entire part of distribution network disconnect suddenly to reduce the load and the the frequency. Batteries are quick enough to cope. So the idea was: when the Sun goes up the sudden drop in load will be absorbed by cars who start charging full power than slowly reduce to give times to classic PP lower their production, when the Sun goes down they discharge to the grid for a little while with the similar target. Since batteries do not last longer and cost a fortune EVs are a way to shift the costs to the users. If you have p.v. at home you have to face big capex BUT you can lower opex lowering high electricity price using your p.v. and car, or so to speak if you help the transition you get paid back. If you can't you simply suffer higher tariff getting equally more poor from another way. The wealthy became poor due to high investments, the less wealthy due to the sky high cost of living. And you know the classic WEF/2030 https://youtu.be/Hx3DhoLFO4s https://youtu.be/Hx3DhoLFO4s vision. Casually people are a bit dumb en-masse, as Gustave Le Bon and Eduard Bernays wrote in their masterpieces, but not that dumb so while p.v. is actually a bit spread because anyway lower enough the electricity cost to pay back EVs/domestic batteries are not because simply they do not pay back despite the claim. And that's why we have blackouts and sky-high energy costs plus menace of scarcity of diesel and gasoline to makes EVs convenient "enough". Charging at night is the logical choice FOR MOST, since normally we are active in the day and sleeping at night, but doing so means charging from the grid wanting a certain SOC in the morning. Green New Deal theorist have imagined remote workers who do not use their cars all days and workers how drive to the work and there charge the car in large parks with p.v. roofs. That's of course happen, but for a small cohort of people, while MOST EV owners so far are from dense cities where such model simply do not work because they have common garages, without p.v. or without enough p.v. both "at home" and "at work". So far those theorist have found no solution: they can try push blackouts a bit more than natural to push people buying EVs as home batteries BUT due to EVs prices most people will not buy them anyway so the shift to renewables will not happen. They can't lower EV prices, most of the supply chain is in foreign hands and anyway there are way to expensive to manufacture to lower the price much. Not only, since they do not state clearly such cars-as-a-grid-balancers perhaps to avoid being accused of shifting costs to the people most EVs are NOT made to be used as home batteries. Something start happening BUT at very limited and slow rate. Some inverter-chargers charge on DC and so can offer "standard power" to the home, but most do not offer micro-grid islandic setups so they can't work in case of an outage, some V2L do exists with in-car inverters, but for very limited power (like 2kW while potentially the car can deliver 50+kW) etc. That's the issue when managers are in charge: they dream something and run with the idea of fixing and detailing anything on the go, that the reality hit.