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Charging your EV home at night is bad!


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8 hours ago, mackinaw said:

From a Stanford University study.  I think it's a bunch of malarky, but draw your own conclusions.

 

https://biz.crast.net/stanford-study-warns-against-charging-electric-cars-at-home-overnight/

 

That article was terribly edited...or not edited at all!

What I took away from it is that the issue doesn't became an issue till 50% of the market is BEVs and there isn't any improvements in infrastructure between now and then. I'm also curious as to what they used as metric for charging at night-are they using a battery that discharged to say 10-20% every day and charged back up to 80-100% every night? I'm going to assume the average use case is maybe using 20-30% of your range every day.

 

I know in my case I can can commute to work (two days a week) plus whatever other driving I'm doing and maybe have to charge up every other week (what I'm currently doing with an ICE)...so I wouldn't be charging every night either. 

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2 hours ago, silvrsvt said:

That article was terribly edited...or not edited at all!


You may prefer original from months ago. 
 

https://news.stanford.edu/press-releases/2022/09/22/charging-cars-honight-not-way-go/
 

To me it sounds like charging at night versus day only reduces a huge problem.  When 50% vehicles are BEVs, required storage will be reduced from equivalent of 5 large nuclear plants down to 4.  Daytime charging will help, but they better get serious about grid before they reach 50%.

 

“Once 50% of cars on the road are powered by electricity in the Western U.S. – of which about half the population lives in California – more than 5.4 gigawatts of energy storage would be needed if charging habits follow their current course. That’s the capacity equivalent of 5 large nuclear power reactors. A big shift to charging at work instead of home would reduce the storage needed for EVs to 4.2 gigawatts.”

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2 hours ago, silvrsvt said:

I'm also curious as to what they used as metric for charging at night-are they using a battery that discharged to say 10-20% every day and charged back up to 80-100% every night? I'm going to assume the average use case is maybe using 20-30% of your range every day.

 

I know in my case I can can commute to work (two days a week) plus whatever other driving I'm doing and maybe have to charge up every other week (what I'm currently doing with an ICE)...so I wouldn't be charging every night either. 


This part shouldn’t matter much at all in my opinion.  When looking at millions of vehicles it all averages out.  They probably considered weekend or seasonal traffic being different, for example, but usage at  individual owner level should not be an issue.  That is, charging 10% every night versus 20% every other night averages out when millions of cars are charged repeatedly. 
 

What’s most important is total energy usage, so miles driven and BEV efficiency are very important.  And that’s why a Tesla 3 is easier on the grid than a Lightning or Hummer, yet not much is said to promote efficiency.

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1 hour ago, fordmantpw said:

When switching so much power generation over to solar, of course charging at night is going to be bad!  The panels aren't producing at night!  I said this several months ago on this same forum...BEV vehicles are less green if you charge them at night.

I will show my ignorance here, where I live in the SE USA I was under the ASSumption? that nighttime electricity would be cheaper/more available at night because most homes and businesses would use less.  Is that not true?

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34 minutes ago, tarheels23 said:

I will show my ignorance here, where I live in the SE USA I was under the ASSumption? that nighttime electricity would be cheaper/more available at night because most homes and businesses would use less.  Is that not true?


How do you get solar energy at night?

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2 hours ago, Rick73 said:


This part shouldn’t matter much at all in my opinion.  When looking at millions of vehicles it all averages out.  They probably considered weekend or seasonal traffic being different, for example, but usage at  individual owner level should not be an issue.  That is, charging 10% every night versus 20% every other night averages out when millions of cars are charged repeatedly. 
 

What’s most important is total energy usage, so miles driven and BEV efficiency are very important.  And that’s why a Tesla 3 is easier on the grid than a Lightning or Hummer, yet not much is said to promote efficiency.

 

I'm waiting for the "your EV isn't efficient enough/uses too much electricity" arguments that will inevitably come.

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My local power utility (live in a rural area, so I have a co-op, not an electric company) is actively encouraging us to use more electricity during the night, especially in the summer with all of the household AC units on.  Ditto for those few who own BEV's, they're encouraged to plug-in at night.  

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30 minutes ago, akirby said:


But that wasn’t the question.


"How do you get solar energy at night?"

By putting it in batteries during the day

Maybe I'm missing your point, wasn't being argumentative - just offering an answer to what I thought you were asking.

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1 hour ago, mackinaw said:

My local power utility (live in a rural area, so I have a co-op, not an electric company) is actively encouraging us to use more electricity during the night, especially in the summer with all of the household AC units on.  Ditto for those few who own BEV's, they're encouraged to plug-in at night.  

 

It makes sense if the demand is significantly lower (which it is for the most part) but apparently this study has concluded that once the Western US hits 50% BEV penetration, that the grid won't be able to support overnight charging because that slack demand will be eaten up by BEVs charging. I think they are expecting worst case with charging only at night and are forgetting the fact that if you work a 10 hour work day (8 hours plus 2 hours travel time) you still have 14 other hours to charge...but it might not be as cheap to to do if its done between 11PM and 6AM

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3 hours ago, tarheels23 said:

I will show my ignorance here, where I live in the SE USA I was under the ASSumption? that nighttime electricity would be cheaper/more available at night because most homes and businesses would use less.  Is that not true?

 

Yes, that is true, currently.  Most electricity generation is done by base load plants that need to run at a constant rate 24 hours/day.  You can't just crank a 1200MW generator up and down based on load, it needs to generate the same power around the clock.  We had to turn our nuke plant down ~10% for a few days in some extremely cold weather in December in order to keep grid voltage in check, and that was a HUGE deal.  That's why, today, nighttime power is less expensive.  The same (relatively) amount is being generated, but less is being consumed. 


However, with the transition to renewables, that isn't the case any more.  Solar is a huge part of renewables, and it doesn't generate any electricity at night, so there goes a huge chunk of your generation when the sun goes down.  You don't have all that base load running 24/7 anymore.  As more coal plants get shut down in favor of green energy, I expect to see a parity of prices between night and day power usage.  Nighttime power will be more sparse, and base loads will need to be supplemented by energy stored in batteries.  Those batteries take on all shapes and forms, including water stored in big reservoirs on top of a hill.

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1 hour ago, fordmantpw said:

 

Yes, that is true, currently.  Most electricity generation is done by base load plants that need to run at a constant rate 24 hours/day.  You can't just crank a 1200MW generator up and down based on load, it needs to generate the same power around the clock.  We had to turn our nuke plant down ~10% for a few days in some extremely cold weather in December in order to keep grid voltage in check, and that was a HUGE deal.  That's why, today, nighttime power is less expensive.  The same (relatively) amount is being generated, but less is being consumed. 


However, with the transition to renewables, that isn't the case any more.  Solar is a huge part of renewables, and it doesn't generate any electricity at night, so there goes a huge chunk of your generation when the sun goes down.  You don't have all that base load running 24/7 anymore.  As more coal plants get shut down in favor of green energy, I expect to see a parity of prices between night and day power usage.  Nighttime power will be more sparse, and base loads will need to be supplemented by energy stored in batteries.  Those batteries take on all shapes and forms, including water stored in big reservoirs on top of a hill.

OK, I am aware of that so I was basing this on the current situation, like all the folk who say BEVs won't work for them based on the current situation.?

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3 hours ago, silvrsvt said:

I think they are expecting worst case with charging only at night and are forgetting the fact that if you work a 10 hour work day (8 hours plus 2 hours travel time) you still have 14 other hours to charge...but it might not be as cheap to to do if its done between 11PM and 6AM


The study assumes “charging habits follow their current course”. 

 


Additionally, the study predicts the grid will be significantly stressed much before 50% (they mention 30~40%) without major investments “and” changes in charging habits.   Quote below covers this well.  Basically, changing charging habits alone will not be nearly enough regardless.

 

 

“In February, cumulative sales of EVs in California reached one million, accounting for about 6% of cars and light trucks. The state has targeted five million EVs on the road by 2030. When the penetration hits 30% to 40% of cars on the road, the grid will experience significant stress without major investments and changes in charging habits, said Rajagopal. Building that infrastructure requires significant lead time and cannot be done overnight.“

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3 hours ago, Captainp4 said:


"How do you get solar energy at night?"

By putting it in batteries during the day

Maybe I'm missing your point, wasn't being argumentative - just offering an answer to what I thought you were asking.


The question was around overnight charging being cheaper but that’s not applicable if you’re using solar energy.

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47 minutes ago, tarheels23 said:

OK, I am aware of that so I was basing this on the current situation, like all the folk who say BEVs won't work for them based on the current situation.?


Using solar it’s best to charge during the day otherwise you’d have to use battery reserves at night.  It’s completely different than using the grid which is the point I was trying to make.

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Loss of solar power at night is very predictable, but let’s not forget variations in weather can affect daytime solar production also, and that’s not as predictable.  Fortunately, in southern areas of US, solar is a great match for air conditioning in summer since highest loads and production often track well.  However, in winter this balance isn’t as clear since highest demand for heat is often at night.  Just mentioning that energy storage at grid level could get even more expensive if required for more than one day’s worth of power.

 

In my opinion, it’s likely natural gas or other source for electricity will need to serve as backup.

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4 hours ago, fordmantpw said:

 

Yes, that is true, currently.  Most electricity generation is done by base load plants that need to run at a constant rate 24 hours/day.  You can't just crank a 1200MW generator up and down based on load, it needs to generate the same power around the clock.  We had to turn our nuke plant down ~10% for a few days in some extremely cold weather in December in order to keep grid voltage in check, and that was a HUGE deal.  That's why, today, nighttime power is less expensive.  The same (relatively) amount is being generated, but less is being consumed. 


However, with the transition to renewables, that isn't the case any more.  Solar is a huge part of renewables, and it doesn't generate any electricity at night, so there goes a huge chunk of your generation when the sun goes down.  You don't have all that base load running 24/7 anymore.  As more coal plants get shut down in favor of green energy, I expect to see a parity of prices between night and day power usage.  Nighttime power will be more sparse, and base loads will need to be supplemented by energy stored in batteries.  Those batteries take on all shapes and forms, including water stored in big reservoirs on top of a hill.

 

I came to post this pretty much verbatim. 

 

Night time charging now is generally considered green because we are just wasting that output to keep the base load on conventional power plants.

 

Night time charging in the future will be less green because it will be disproportionally fossil fuel generated. While day time electricity will more likely be renewable.

 

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38 minutes ago, AGR said:

Uh, there's this thing called wind power. The wind generally blow stronger at night:

Wind power is so cheap at night in Texas, some companies give it away | Grist


See I already have a plan in my head for when I move to run my house off of a combination solar/wind with battery backup (particularly in the outbuilding(s) where energy demand won’t be nearly what the house is) and basically cut DTE and their BS unreliable service completely out of the equation. Michigan law says I can’t be completely off grid since I have children but I can come damn close. Added bonus in becoming an electrician is I can study the applicable codes and do the installation myself when the time comes. 

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56 minutes ago, fuzzymoomoo said:

Michigan law says I can’t be completely off grid since I have children...

 

Seriously?  There is a law in Michigan that says that?  What BS!

 

Bad thing is, you still have to pay the connection fee every month, even if you are only burning an LED light bulb.

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16 hours ago, silvrsvt said:

 

That article was terribly edited...or not edited at all!

What I took away from it is that the issue doesn't became an issue till 50% of the market is BEVs and there isn't any improvements in infrastructure between now and then. I'm also curious as to what they used as metric for charging at night-are they using a battery that discharged to say 10-20% every day and charged back up to 80-100% every night? I'm going to assume the average use case is maybe using 20-30% of your range every day.

 

I know in my case I can can commute to work (two days a week) plus whatever other driving I'm doing and maybe have to charge up every other week (what I'm currently doing with an ICE)...so I wouldn't be charging every night either. 

You would if you’re stuck with low power 240 volt charging, topping up most nights is prudent.

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8 hours ago, fordmantpw said:

 

Seriously?  There is a law in Michigan that says that?  What BS!

 

Bad thing is, you still have to pay the connection fee every month, even if you are only burning an LED light bulb.


Yep, it’s absolutely stupid. There’s many, many things about the way this state is run that is very very stupid and I have no hope it will ever change either. 

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