4 ms·

I was talking with an electrician about electric cars and he said the neighborhood/city electric grids aren't prepared for everyone to come home at 5 and plug i

I was talking with an electrician about electric cars and he said the neighborhood/city electric grids aren't prepared for everyone to come home at 5 and plug in their cars. Thinking in terms of bandwidth, each neighborhood's circuit is woefully oversubscribed and the thought of a house pulling a ton of current to charge a vehicle was not planned for.

onlyrealcuzzo 4y ago
The US is at least 20 years away from ~70% of cars being electric. In that time, ~50% of people could be either not commuting or commuting in some other way than by car. That gives the power grid plenty of time to adapt.
- willcipriano 4y ago
  I agree. The problem is people are pushing electric cars as a solution to today's gas prices, not gas prices in future decades. Even if they could be manufactured, even if people could afford them, the grid would need some work to accommodate them. That isn't "big oil propaganda"
shiftpgdn 4y ago
That’s nonsense and mostly a big oil talking point. In the south every single home has at least one large A/C unit, most of which draw the amount or more as an electric car being charged and yet the grid doesn’t fall over when it’s noon and everyone’s air conditioning is running full blast during the summer. This is like that old fable about the English power companies having to fire up peaker plants during the commercial breaks of soccer games because of so many people putting the kettle on. Further, most electric car owners I know charge at night when the grid usually has excess capacity. I personally am on a time of use plan where I get free charging from midnight to 3AM, and that’s the window in which I charge my electric cars every day.
- urthor 4y ago
  Yeah, it's basically a software update to the cars, and suddenly the cars are only pulling from the grid at 4am based on the average spot price of electricity. I think the biggest issue is that if nobody charges during the day, and all the energy is coming from solar, demand for energy during the night will skyrocket. But that's solvable by literally putting some power plugs into parking spaces. Not a huge ask.
- danpalmer 4y ago
  > In the south every single home has at least one large A/C unit, most of which draw the amount or more as an electric car being charged and yet the grid doesn’t fall over when it’s noon and everyone’s air conditioning is running full blast during the summer. Texas has had grid problems because of this. It was especially bad in the winter. > This is like that old fable about the English power companies having to fire up peaker plants during the commercial breaks of soccer games because of so many people putting the kettle on. This isn't a fable, I've seen interviews with National Grid staff where they talk about tracking the TV schedule. This is one of the reasons why we have pumped-hydro capacity, to handle quick spikes. I think this issue may end up being less of an issue than the doomsayers go on about. When I looked into this in ~2012 the solution was going to be "smart grids" where components would collaborate. Now, we've pretty much got there with electric cars being relatively smart, energy pricing being quite dynamic on some tariffs, and smart meters understanding that relationship.
  - tr_user 4y ago
    That sounds like a Texas underinvesting in the grid problem
    - dopidopHN 4y ago
      Yes. A few hours driving East, and the only power outage I had in Louisiana were related to weather even. I think the comparison the other poster make is useful. If Louisiana small town can handle AC usage, they should be able to handle charging EV.
  - 4y ago
smileysteve 4y ago
> aren't prepared for everyone to come home at 5 and plug in their cars. 200 mile range cars and 20 mile average commutes make this not a necessity. The need to use fast charging even less, as slow charging from 5pm-5am provides more than enough miles for the average commute. I wonder what your electrician thinks about HVAC systems? They all do turn on at roughly the same time (a top cause of brownouts in under prepared grids), don't have a slow charging equivalent (they even depend on large capacitors to start the compressors). The even worse case is a house with multiple heat pumps and auxiliary heating. Or what does your electrician think about hot water heaters? Fast charging requires similar supply as every house coming home and taking a shower at 5pm. Or, perhaps the most likely, every house starting the oven at 5pm, the stove, The microwave, With some hot water. What about all of these combined? Information; on circuit breaker size required Low speed charger 120x15amp Highest speed residential charger: 240x40amp Water heater 240x30amp Instant whole house hot water heater 240x40 HVAC 240x30 Aux heat 240x30 Stove 240x30 Oven 240x30 Microwave 120x15
- philg_jr 4y ago
  All teslas besides the SR Model 3 charge at 48A. At home with the Tesla wall connector, it’s a 240V charger, so roughly 11k watts, and they recommend a 60A breaker.
  - vel0city 4y ago
    All Teslas will charge at whatever rate the EVSE says it's rated for. If you have a 36A EVSE it'll pull 36A. You don't have to have it set to 48A, you don't need a 60A circuit to charge a Tesla.
    - philg_jr 4y ago
      Yes you are correct. I guess I was just stating that it can pull up to 48A, which can be a lot higher than most other appliances in a home.
- spockz 4y ago
  I think the parents post is claiming that the grid isn’t able to handle the additional load of charging everyone’s car at the same time on top of the stoves etc that you mention. It will be in addition to not instead.
crikeyjoe 4y ago
theplumber 4y ago
I guess everyone has a pump station at home right? This is a false argument given that electric chargers are so much easier to install and convenient to use. I don't think anyone takes it seriously
- smileysteve 4y ago
  This! The top 10% of use cases (high mileage a day) have incentive to use substation (or at least commercial) charging stations. Many utilities are installing chargers at major brand gas stations.
ageitgey 4y ago
No offense to the electrician you talked with, but they are ill-informed. Electric grids have been planning for the shift to EVs for years. This isn't a surprise to them. This is what they do all day. In the UK for example, the Nation Grid reports that grid-source electricity use peaked in 2002 and has fallen 16% since then (due to increased solar panel installations, etc). If all cars switched to electric overnight with no time for additional planning, grid-source electricity use would increase 10%, still under 2002 numbers and still well within manageable limits. [1] But obviously in a real-world scenario, they have plans to better handle the pace of adoption more intelligently than that. It is true that everyone charging at full speed simultaneously at 5pm would be an issue. So that's why every car sold is smart enough to charge when rates are cheap and skip charging during peak hours. This is further incentivized by fluctuating power prices. People vote with their wallet and if they can get the same result (a fully charged car) for half price or less, they are certainly going to skip charing during peak hours unless they are on empty. I think people who haven't owned an electric car are imaging how home charging works in the wrong way. Most people don't need to supercharge their car every night at 5pm to fill up the battery from empty to full by 5:30pm. Most of the time, your car has lots of power left after a normal commute and you just plug it in when you park so it is full again tomorrow. It doesn't matter what time during the night it charges and the car will figure it out. It's just not a big deal. [1] https://www.nationalgrid.com/stories/journey-to-net-zero/5-myths-about-electric-vehicles-busted https://www.nationalgrid.com/stories/journey-to-net-zero/5-m...
mechagodzilla 4y ago
Electric cars support 'charging schedules' - my utility gives me discounted electricity to charge between midnight and 8AM, and it took about 5 minutes to setup. I plug in my car when I get home from work, and it happily sits there until midnight when it starts charging (and when the grid is otherwise unstressed).
spywaregorilla 4y ago
Don't downvote this one! There's a bunch of issues on this that are hard to judge. The obvious one is power availability. Likely solveable, but not trivial. The non obvious one is the grid itself. A lot of grid systems are overloaded already. And this is fine. They run hot during the day, they cool off at night, and by morning they're good to go. Electric vehicles demand a lot of power. Even if you're doing it at night, it's going to add a lot of heat to the system. It's going to be an expensive and difficult thing to solve if transformers start dropping like flies during a heatwave.

onlyrealcuzzo 4y ago

The US is at least 20 years away from ~70% of cars being electric. In that time, ~50% of people could be either not commuting or commuting in some other way than by car. That gives the power grid plenty of time to adapt.

willcipriano 4y ago
I agree. The problem is people are pushing electric cars as a solution to today's gas prices, not gas prices in future decades. Even if they could be manufactured, even if people could afford them, the grid would need some work to accommodate them. That isn't "big oil propaganda"

shiftpgdn 4y ago

That’s nonsense and mostly a big oil talking point. In the south every single home has at least one large A/C unit, most of which draw the amount or more as an electric car being charged and yet the grid doesn’t fall over when it’s noon and everyone’s air conditioning is running full blast during the summer. This is like that old fable about the English power companies having to fire up peaker plants during the commercial breaks of soccer games because of so many people putting the kettle on. Further, most electric car owners I know charge at night when the grid usually has excess capacity. I personally am on a time of use plan where I get free charging from midnight to 3AM, and that’s the window in which I charge my electric cars every day.

urthor 4y ago
Yeah, it's basically a software update to the cars, and suddenly the cars are only pulling from the grid at 4am based on the average spot price of electricity. I think the biggest issue is that if nobody charges during the day, and all the energy is coming from solar, demand for energy during the night will skyrocket. But that's solvable by literally putting some power plugs into parking spaces. Not a huge ask.
danpalmer 4y ago
> In the south every single home has at least one large A/C unit, most of which draw the amount or more as an electric car being charged and yet the grid doesn’t fall over when it’s noon and everyone’s air conditioning is running full blast during the summer. Texas has had grid problems because of this. It was especially bad in the winter. > This is like that old fable about the English power companies having to fire up peaker plants during the commercial breaks of soccer games because of so many people putting the kettle on. This isn't a fable, I've seen interviews with National Grid staff where they talk about tracking the TV schedule. This is one of the reasons why we have pumped-hydro capacity, to handle quick spikes. I think this issue may end up being less of an issue than the doomsayers go on about. When I looked into this in ~2012 the solution was going to be "smart grids" where components would collaborate. Now, we've pretty much got there with electric cars being relatively smart, energy pricing being quite dynamic on some tariffs, and smart meters understanding that relationship.
- tr_user 4y ago
  That sounds like a Texas underinvesting in the grid problem
  - dopidopHN 4y ago
    Yes. A few hours driving East, and the only power outage I had in Louisiana were related to weather even. I think the comparison the other poster make is useful. If Louisiana small town can handle AC usage, they should be able to handle charging EV.
- 4y ago

smileysteve 4y ago

> aren't prepared for everyone to come home at 5 and plug in their cars. 200 mile range cars and 20 mile average commutes make this not a necessity. The need to use fast charging even less, as slow charging from 5pm-5am provides more than enough miles for the average commute. I wonder what your electrician thinks about HVAC systems? They all do turn on at roughly the same time (a top cause of brownouts in under prepared grids), don't have a slow charging equivalent (they even depend on large capacitors to start the compressors). The even worse case is a house with multiple heat pumps and auxiliary heating. Or what does your electrician think about hot water heaters? Fast charging requires similar supply as every house coming home and taking a shower at 5pm. Or, perhaps the most likely, every house starting the oven at 5pm, the stove, The microwave, With some hot water. What about all of these combined? Information; on circuit breaker size required Low speed charger 120x15amp Highest speed residential charger: 240x40amp Water heater 240x30amp Instant whole house hot water heater 240x40 HVAC 240x30 Aux heat 240x30 Stove 240x30 Oven 240x30 Microwave 120x15

philg_jr 4y ago
All teslas besides the SR Model 3 charge at 48A. At home with the Tesla wall connector, it’s a 240V charger, so roughly 11k watts, and they recommend a 60A breaker.
- vel0city 4y ago
  All Teslas will charge at whatever rate the EVSE says it's rated for. If you have a 36A EVSE it'll pull 36A. You don't have to have it set to 48A, you don't need a 60A circuit to charge a Tesla.
  - philg_jr 4y ago
    Yes you are correct. I guess I was just stating that it can pull up to 48A, which can be a lot higher than most other appliances in a home.
spockz 4y ago
I think the parents post is claiming that the grid isn’t able to handle the additional load of charging everyone’s car at the same time on top of the stoves etc that you mention. It will be in addition to not instead.

crikeyjoe 4y ago

theplumber 4y ago

I guess everyone has a pump station at home right? This is a false argument given that electric chargers are so much easier to install and convenient to use. I don't think anyone takes it seriously

smileysteve 4y ago
This! The top 10% of use cases (high mileage a day) have incentive to use substation (or at least commercial) charging stations. Many utilities are installing chargers at major brand gas stations.

ageitgey 4y ago

No offense to the electrician you talked with, but they are ill-informed. Electric grids have been planning for the shift to EVs for years. This isn't a surprise to them. This is what they do all day. In the UK for example, the Nation Grid reports that grid-source electricity use peaked in 2002 and has fallen 16% since then (due to increased solar panel installations, etc). If all cars switched to electric overnight with no time for additional planning, grid-source electricity use would increase 10%, still under 2002 numbers and still well within manageable limits. [1] But obviously in a real-world scenario, they have plans to better handle the pace of adoption more intelligently than that. It is true that everyone charging at full speed simultaneously at 5pm would be an issue. So that's why every car sold is smart enough to charge when rates are cheap and skip charging during peak hours. This is further incentivized by fluctuating power prices. People vote with their wallet and if they can get the same result (a fully charged car) for half price or less, they are certainly going to skip charing during peak hours unless they are on empty. I think people who haven't owned an electric car are imaging how home charging works in the wrong way. Most people don't need to supercharge their car every night at 5pm to fill up the battery from empty to full by 5:30pm. Most of the time, your car has lots of power left after a normal commute and you just plug it in when you park so it is full again tomorrow. It doesn't matter what time during the night it charges and the car will figure it out. It's just not a big deal. [1] https://www.nationalgrid.com/stories/journey-to-net-zero/5-myths-about-electric-vehicles-busted https://www.nationalgrid.com/stories/journey-to-net-zero/5-m...

mechagodzilla 4y ago

Electric cars support 'charging schedules' - my utility gives me discounted electricity to charge between midnight and 8AM, and it took about 5 minutes to setup. I plug in my car when I get home from work, and it happily sits there until midnight when it starts charging (and when the grid is otherwise unstressed).

spywaregorilla 4y ago

Don't downvote this one! There's a bunch of issues on this that are hard to judge. The obvious one is power availability. Likely solveable, but not trivial. The non obvious one is the grid itself. A lot of grid systems are overloaded already. And this is fine. They run hot during the day, they cool off at night, and by morning they're good to go. Electric vehicles demand a lot of power. Even if you're doing it at night, it's going to add a lot of heat to the system. It's going to be an expensive and difficult thing to solve if transformers start dropping like flies during a heatwave.