Electric cars charging at night could make America’s power grids unstable, study warns

STANFORD, Calif. — Leaving your luxury electric car charging overnight to have it ready in the morning seems like a good idea in theory. But in reality, research suggests doing so does more harm in the long run. Stanford scientists say that it’s more costly to charge your electric car at night and it could stress out your local electric grid.

Instead, researchers suggest drivers should switch to charging their vehicle at work or in public charging stations. Another added benefit to charging in the daytime at a public station is that it reduces greenhouse gas emissions.

With the effects of climate change more apparent than ever—frequent forest fires, widespread flooding, and stronger hurricanes—car companies are expecting people to start investing in electric-powered cars in the future. For example, California residents are expected to buy more electric cars as the state is planning to ban sales of gasoline-powered cars and light trucks in 2035.

“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,” says study’s co-senior author, Ram Rajagopal, an associate professor of civil and environmental engineering at Stanford University, in a statement.

So far, electric cars make up one million or 6% of automobile sales in California. The state’s goal is to increase that number to five million electric vehicles by 2030. However, the study authors say that the change from gas to electric will cause a strain in the electric grid when there’s 30% to 40% of cars on the road.

READ: Best Electric SUVs of 2022 — Top 5 Models Most Recommended By Expert Websites

“We were able to show that with less home charging and more daytime charging, the Western U.S. would need less generating capacity and storage, and it would not waste as much solar and wind power,” explains Siobhan Powell, a doctor of mechanical engineering and lead study author. “And it’s not just California and Western states. All states may need to rethink electricity pricing structures as their EV charging needs increase and their grid changes.”

If half of vehicles in the western United States are electric, the team estimates it would take over 5.4 gigawatts of energy storage—equivalent to five large nuclear power reactors—to charge the cars. However, if people charged their electric cars at work instead of home, the electric demand is expected to go down to 4.2 gigawatts.

California currently uses time-of-use rates to encourage people to use electricity at night such as running the dishwasher and charging cars. However, the authors argue that with growing demand of electric cars, this strategy is outdated and will soon incur high demand with low supply. More specifically, the teams says if a third of homes were to charge their electric cars at 11 PM or whenever electricity rates go down, the local grid would become unstable.

“The findings from this paper have two profound implications: the first is that the price signals are not aligned with what would be best for the grid – and for ratepayers. The second is that it calls for considering investments in a charging infrastructure for where people work,” says Ines Azevedo, associate professor of energy science and engineering and co-senior author.

“We need to move quickly toward decarbonizing the transportation sector, which accounts for the bulk of emissions in California,” Azevedo adds. “This work provides insight on how to get there. Let’s ensure that we pursue policies and investment strategies that allow us to do so in a way that is sustainable.”

The study is published in Nature Energy.

About the Author

Jocelyn Solis-Moreira

Jocelyn is a New York-based science journalist whose work has appeared in Discover Magazine, Health, and Live Science, among other publications. She holds a Master’s of Science in Psychology with a concentration in behavioral neuroscience and a Bachelor’s of Science in integrative neuroscience from Binghamton University. Jocelyn has reported on several medical and science topics ranging from coronavirus news to the latest findings in women’s health.

The contents of this website do not constitute advice and are provided for informational purposes only. See our full disclaimer


  1. First came the problem with usage of gasoline and now even the battery charge is becoming a problem. There is the Hybrid / Plug In which uses gasoline and electricity but most important is that the battery is charged by the gasoline engine when the battery goes low. It is a matter of the onboard computer switching from one to the other. Yes the car uses gasoline but not all the time. On a long road trip once the battery is low the gasoline engine kicks in and charges the battery.
    Toyota has this system.

    1. Yes. Toyota is wisely not going full EV direction only for many good reasons. They have the foresight to see it won’t fully work at this time for sure. And there is no infrastructure and people would not be able tovtravel distances among other things.

  2. As a long time employee of a Transmission Company where my responsibility was the stability of the power grid I have two comments:
    1. I am 62 years old and in my short time on this earth I have seen alternating “studies” that claim to be hard science, tell me that Coffee will kill me or make me healthier. Not sure what the current “study” says but I drink coffee. “Studies” are not science.
    2. I can say with certainty that today, charging electrical vehicles at night makes the power grid MORE stable. It is ironic that wind blows more at night and at night the grid actually has way too much generation capacity and way to little load. Charging vehicles at night will increase the load and stabilise the generation load balance. I cannot predict what will happen 20 years from now but it is my observation and non scientific opinion that the build out of a stable transmission system will happen along side of the increase use of electric cars.

    1. Salt was bad for you and a decade later slat was a necessity.

      Science is fact, scientific studies only deal with a limited amount of data to come up with a position usually influence by the agenda of the researchers. Thus, the research is NOT necessarily fact.

  3. “…to silence,disarm, and immobilize the people.”

    Preciselomundo !

    You must go back to knowing what you are. A slave to satanhood. The gloves are coming off and the globalists (satanslave masters) are letting you know; you will own nothing and you will be happy.

  4. So the dateline on this article is the Stanford suburb of Cali, Colombia? Or is this some newfangled code in search of breaking standards of journalism?

  5. This article is ridiculous. Our provider even discounts the electricity if we restrict our charging to off-peak times of 10pm to 6am. The concept is called “flattening” not “exasperating” the consumption curve.

  6. EVs have a greenhouse emissions issue? who would have guessed, any intelligent individual not consumed by an agenda not full thought out.

    And they blow up. And recycle issues with batteries. And, and, and,

    Unintended consequences as usual.

  7. We need to rethink how humans work. Driving to an office and then driving back driving to the grocery store and then driving back. All these activities Drive the need for transportation. We need Central hub walking communities with no driving. I have not driven since the pandemic started and I’m a car guy. But my pollution contribution dropped drastically. Conversion from gas to electric isn’t fixing the problem of needing energy. We need to use less of it.

  8. The UN climate report is that there is not worse or more intense weather. What there is is people live in places they never lived in the past like on barrier islands and reclaimed seashore which people avoided in the past. The developed world uses massive amounts of water that depletes reservoirs. 10 million people now live in the US desert. Global warming is 12, 000 years old and is real . The climate scam is where governments and insiders use the weather to gain power just like old Aztec kings . The Holocene heat period we are in is the basis for the scam. So, developers build where no one should live using permits from government then government uses the destruction of those buildings to justify more government power. What a scam. And, electric cars that use masses of rare minerals and need huge electricity to run are the latest part of the scam where government pushes citizens to go buy more new cars where there is no electricity to charge .

  9. Why are all you talking about EV’s?
    Californians have a more pressing issue at hand & I’ll bet they won’t make it to 2035…why?
    They water their grass once a week and fill pools while draining and drying up every water source tapped into over the past 100 years & there simply isn’t enough water to get them to 2035.
    Richy Rich’s spend their money to make it to space but should use their resources to help humanity today on earth by developing a more cost effective desalination process on a grand scale to support citizens in that region.
    Blah blah, back to the EV grid problem and how stupid this article is….

    1. This article is horseshit. I worked in the electric utility industry for 30 years. Night time charging is safe, more economic and more pro environment. I’ll tell you. People just write anything today. A true fact free society.

  10. Just wait until there’s 5 million electric commercial trucks charging on the grid EVERY NIGHT to transport and deliver EVERYTHING EVERYBODY uses in their daily lives. Keep in mind those trucks average 500 miles a day. 🤔

  11. It takes 10 kWh in a battery to give the same amount of driving as 1 gallon of gasoline. If all cars are electric and charged at night there is no longer any off peak time. In places with a lot of solar electricity storage is needed and electric car batteries need energy. The obvious solution is to plug cars in daytime parking lots in. It would be easy and not very expensive to put level 2 charging cords at parking places that are usually occupied in daytime.

    1. Exactly! Charging at night is a red herring in the article- the problem is that Cali and the rest of the country have been paying for poorly maintained and managed centralized utilities that can’t adapt to new lifestyles. We need to phase them out

  12. The link the author provided as evidence that hurricanes are stronger due to climate change presents no such evidence, while multiple studies in the past 2 decades have found otherwise

  13. Today, a typical EV battery weighs one thousand pounds. It contains twenty-five pounds of lithium, sixty pounds of nickel, 44 pounds of manganese, 30 pounds of cobalt, 200 pounds of copper, and 400 pounds of aluminum, steel, and plastic. Inside are over 6,000 individual lithium-ion cells.

    It should concern you that all those toxic components come from mining. For instance, to manufacture each EV auto battery, you must process 25,000 pounds of brine for the lithium, 30,000 pounds of ore for the cobalt, 5,000 pounds of ore for the nickel, and 25,000 pounds of ore for copper. All told, you dig up 500,000 pounds of the earth’s crust for just ONE battery.

    So, the next time you are thinking about purchasing an electric vehicle or driving your EV, before congratulating yourself on saving the environment, remember that it came at a cost of entire mountains in poor developing countries, with documented human rights abuses, thousands of square miles of land, and billions of gallons of oil and fuel.

  14. Today, a typical EV battery weighs one thousand pounds. It contains twenty-five pounds of lithium, sixty pounds of nickel, 44 pounds of manganese, 30 pounds of cobalt, 200 pounds of copper, and 400 pounds of aluminum, steel, and plastic. Inside are over 6,000 individual lithium-ion cells.

    It should concern you that all those toxic components come from mining. For instance, to manufacture each EV auto battery, you must process 25,000 pounds of brine for the lithium, 30,000 pounds of ore for the cobalt, 5,000 pounds of ore for the nickel, and 25,000 pounds of ore for copper. All told, you dig up 500,000 pounds of the earth’s crust for just ONE battery.

    So, the next time you are thinking about purchasing an electric vehicle or driving your EV, before congratulating yourself on saving the environment, remember that it came at a cost of entire mountains in poor developing countries, with documented human rights abuses, thousands of square miles of land, and billions of gallons of oil and fuel.

  15. The solution to all this problem is, follow the advice of our Australian Prime Minister ..
    Have Solar Panels installed on the roof of your house to produce electric power for recharging your Tesla car overnight ..

  16. A simple back of the envelope calculation indicates that even if the entire personal automobile market consisted 100% of EVs and all of those EVs charged at night, night-time electricity demand would only increase by 16%. This is far below today’s daytime peak. This article is complete nonsense and the authors lack even rudimentary math skills.

    The only way you can come remotely close to the bogus conclusions of this “study” is if you assume that every car is an electric vehicle and every electric vehicle starts every night at 0% battery and needs to charge to 100%.

  17. These ‘if this goes on’ fear mongering articles have one flaw. This doesn’t go on. The Y2k did not destroy the computer networks. The depletion of oil did not extinguish the lamps of USA. etc.

    Two factors to consider. One is grid scale storage which allows energy flows to be ‘evened out’ to compensate for time of use, not matter how that goes.

    The other is the rise in solar (with maximum power in the daytime). This will drive the ‘storage’ concept as much as anything. This is where the driving force to ‘grid stabilization’ will come from as the lower costs of power generation and the rising falling profile of the power output will necessitate power storage anyway (and it saves enough to cover the cost). Best practices is to oversize the solar array so that more of the day meets demand (which also has a daytime peak, so nice bonus) while storing the excess for the ‘tail’s where generation is lower than demand. This makes for ‘dispactable power’ with guaranteed levels.

  18. One way to start find a way to turn our oldschool cars to an eco friendly way for gas. Electric cars though are deffiantly not for everyone right now. Ev’s are the thing of the future not a right now thing just my opinion. If you care about the planet and your work force something should be done in that manner to help us reach to getting an EV. But I do not see anything wrong with making an eco friendly gas for people that want to drive that and let others have electric cars. A middle ground right now would be nice because a lot of us dont wanna go in debt being forced to go to EVs right now and also most work places dont have that. It’s a lot more expensive to pay at a public charger and most people dont even know how to work on EVs where I live. So good luck to ya forcing all America to do it because we all know how to make homecooked meals, grow gardens down in the country and make things work in our favor tell the time comes.

  19. Something for all the greenies to think about. Stars eventually become super novas. Then they collapse on themselves becoming black holes from which no light can escape. Before becoming a supernova there is a period of enhanced solar activity. Our sun is a star. Everything has a life span. How old is our sun? How much time does it have left? There could be a solar eruption tomorrow and we would cease to exist. In the context of a universe that has no boundaries (no beginning or end) we are soooooo insignificant. Put your faith in God and enjoy the time He has allowed us.

  20. With all this heat in the summer you need all the power for A/C during the day. Maybe during the cooler months this could work most charging during the day. However, A/C has always been the big user of electricity that is where peak power usage came from

  21. When the article starts off with the unproven statement that hurricanes are worse, and flooding and wildfires are more numerous because of climate change/global warming, I really can’t read anymore. Stick to the facts, these statements can’t be backed up by.

  22. I worked at a utility optimizing and leveling costs some time ago – and I find this rather difficult to swallow. Electricity prices at night are lower than the day for a reason.

    Baseload power is cheaper and the distribution system is infrastructure that doesn’t care.

    Now California, in their stupidity of getting rid of baseload power might be straining their gas turbines to keep up, but blame the morons that got rid of baseload capacity.

    And I also once had a commercial size windmill on my farm and I can assure you they turn at night.

    Academics, politicians, and journalists are not problem solvers.

  23. I have completely different take away from that study- you can go to Stanford’s site and read the original- The solution isn’t to continue to accommodate an old unreliable centralized utility. If we are saying that we want to get off fossil fuels then we have to skip these half measures. Certainly public charging stations are built to handle more use- but homes can handle personal use if they get off the grid and make use of house battery tech. In fact, in sunny Cali, a house battery neighborhood can send an immense amount of energy back to the grid cutting everyone’s costs (of course, we know the folks at the energy company aren’t about to give anyone a cost break). I love how these articles slant everything to keep us thinking we need fossil fuels…

  24. The study makes no sense whatever. There can’t be a decline in the energy required to charge EV’s regardless of the time of day or night.

  25. So the difference is 5 to 4 nuclear plants. That CA for one won’t build.
    But you can’t charge when there are conditions for forest fires.
    You can’t charge when it’s hot because grid is overloaded with 5 % of sales per year electric cars. What % of total cars are electric in CA ? 1%
    Good luck you will need it when it’s closer to 20% never mind 50 or 100 %

  26. Charging ev vehicles during the night when the majority of people are in bed sleeping so the only real electrical power draw is the ev vehicles charging and that’s causing problems with the power grid yet in CA which gets the majority of it’s electricity from Arizona has had the governor Gavin Newsom issue an executive order for the production of new vehicles to be 💯% electric by 2035 and within the last week he has pushed through something that bans natural gas water heaters and ocen/range stove’s. And that’s not even including the fact that he made an executive order/law that bans the production and sales of small gas engine equipment

  27. It is unthinkable how we are in a society of a majority of experts who offer no constructive solutions, just criticism and occasionally insults.
    Much of the cited content is based on science that has a foundation on data.
    When tribal factions emerge to support whatever the narrative is that they support much gets lost.

    To support the solution keep a mind open to the possibilities.
    I am an electrical contractor and I have an EV for commuting, as well as ICE equipment for work, I am building out an RE system with storage with expansion capability on my property. I must concede the possibility that all the pollution has been contributing to the damage to the Ozone, as well as the CO2
    Levels, but there are also many cyclical changes that have occurred on our planet through the millennium as core samples in ice dating back through at least 2 ice ages confirm this as well.

    There is no need to get hysterical, or abuse others who don’t read all the studies, as it is not possible.
    Some people approach this as a religion, when we have enough data to understand or indicate scientific theories that are supported by evidence.

    To discredit both of those obvious points is being irrational and irresponsible.

    Ignorance is far more dangerous that anything what is being ranted about.

    Take the time to read all points of the science, don’t read one person’s opinion and climb on a soap box and then presume to be such an expert as to insult another American who shares a possibly uniform or partially informed opinion on such things.

    I admittedly am not an expert on Rewable Energy though I am licensed to install it. I have experience and there are many segments of the industry that I am familiar with, but I think it is is Hubris to read or watch something for a few minutes, and adopt it as my “expert” opinion. Having experience may qualify me to install it safely, but I am certainly not going to develop my identity around such things, Nor am I a better person for having read about things or done things on a certain subject. That is simply acting out on insecurity.

  28. It’s actually generated by the earth, ongoing. So is oil. Oil is not dead dinosaurs, and natural gas isn’t dead dinosaur farts. These are facts that the greenies don’t want to get out. Hell, even big oil wants us to believe there is only so much out there, like the diamond industry.

    There has been a natural gas fire burning constantly in a desert for over 50 years. Yes, I do think it should be put out, yes, I do think we should cap and pipe that gas to be used elsewhere. But the earth just keeps on supplying that gas…

  29. Anybody that has an electronic car in my area be warned! I will blow that piece of shit up! Fuck you stupid green global warming believers! It’s a fucking hoax n your my target! As well as anyone that pushes this fake news on global warming from the Globalist Federal government! That includes obiden n his cronies! Gasoline cars will never be replaced n climate change happens naturally! Fuck all Woke stupid idiots!

  30. Wejo and Palantir have a partnership and have developed a EV Operating System that is designed to be used nationwide to regulate charging station usage to the most optimal times of the day based on power grid demand. Google search “Wejo” and you can read about it. It is very interesting and they have daily data on over 18 million vehicles and are already working with cities on projects such as this.

  31. This is the biggest BS I ever heard, charging car during daytime reduces greenhouse gas. How is charging at day any different than charging at night. Its using the same means to produce energy. Especially during night time there is less stress on the grid when most of the industries are shut down at night. Except if you charge during daytime u ll be hiking your bill 3 folds. And office and public places do not have enough port to cover the the charging need for how many cars are out there, also most places its not free. You will be paying a lot more if you are not charging at home. Especially if you have solar, your bills will be significantly less. The only way to reduce this grid stress is make the renewable energy requirement to 70% instead of 30, and place solar on the top of every roof possible where sunlight is available year round, like FL and CA. That is the only solution. Not some stupid theory when and where to charge, focus on not the consumption of energy but the production of energy by increasing twice than it is now, if you want to reduce dependencies on fossil fuel and make most cars EV by 2050.

  32. Everybody, read “One Second After” by Willam Forstchen. Its only fiction for now. Won’t matter EV or ICG, we are all gonna be screwed! LOL

  33. You have to be seriously low information and completely uninterested in truth and facts to believe an alternative energy / ev vehicle solution is viable and is required to “save the planet”. Cone on people, wake the fuck up!

  34. My uncle invited a car to run off of water. The oil companies hired someone to shoot at him. So he didn’t go on and get it going. So now they have electric cars and they still have problems. Mankind will kill mankind lucky for me I’ll be dead soon and I have no children

  35. stating the results of climate change are more hurricanes, flooding and fires or that they are more extreme is false. Temps have risen about 1 degree in 100 years and deaths from climate or weather related events has dropped by over 90% in that same time. There is no data to show we have more events than we had 100 years ago, so please stop stating incorrect facts.
    The US has reduced its [email protected] emissions by over a billion tons since 2005, while China, India, Africa and the Middle East have all increased dramatically over that same time; BUT we are supposed to pay higher utility rates and endure brown outs so we can feel good about our impact on the climate.

  36. In south Ontario where I live 92% of the electricity comes from hydro and nuclear during night time. I charge my Leaf at night. Intermittent few seconds outages all happen during daytime. (I know that because then I have internet outage.) The problem with mass charging can be easily alleviated by dividing urban areas into zones that have lower price at different times of the day to flatten the demand curve. All EVs can be programmed when to charge, no issue there. Plus Leaf has chargers available to upload electricity back to grid when the demand is high.
    Mining minerals for batteries is polluting, but unlike fossil fuels that once burnt are gone forever, batteries can be recycled. It is surely easier to melt and separate metals than to mine.
    CO2 levels can disrupt life if change too rapidly because the evolution takes time to adapt organisms to new conditions. Nowadays organisms would not thrive in dinosaurs’ times and vice versa. Plants cannot use too much more CO2 as food, because they are adapted to current concentration. If the concertation was higher for long enough then most likely the plants would be able to use it and grow faster. And so our lungs and blood would be different.

  37. This article is dead wrong if you don’t live in California. California has a surplus of power during the day and imports 35% of its power from neighboring states at night. The author did not state that his comments only pertain to California. The opposite is true in all the other states.

  38. It seems that the match up of production of renewable energy to the charging of electric cars. Different geographic locations of the country will have different power production times. With excess solar, daytime would work very well. If wind production overproduces at night then night time would be a good working time. I don’t see transmission issues at night, it would be time of transmission. Should we still want to charge cars at night, battery storage could be increased to be used for car charging.

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