Tesla Car Charger???

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Besoeker

Senior Member
Location
UK
You have a point here. The pole pigs would be overwhelmed if a whole street started charging at the same time in high current fashion.
Assume you mean pole mounted transformers?
Have very few of those here.
We, along with our street neighbours, get our juice from an 11kV to 400V transformer. It's about 1500kVA as I recall. Domestic supplies are phase to neutral at 230V. Nominally.
Other than electric cookers, outlets are rated at 13A. That equates to about 3kW and unity power factor. So the Nissan battery would need ten hours plus the system losses.

From what I have seen it appears to be a problem that has not been addressed.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
From what I have seen it appears to be a problem that has not been addressed.

I mentioned the utility issue way back in this thread. There have been a few articles stated that it can be a real issue if everyone went out and bought an electric car. Imagine the demand in the summer with a/c's going full blast and then car's being charged. The a/c's allow can actually tax the system that is around here.
 

peter d

Senior Member
Location
New England
I mentioned the utility issue way back in this thread. There have been a few articles stated that it can be a real issue if everyone went out and bought an electric car. Imagine the demand in the summer with a/c's going full blast and then car's being charged. The a/c's allow can actually tax the system that is around here.


I'd much rather have a/c than an electric car.
 

JFletcher

Senior Member
Location
Williamsburg, VA
I mentioned the utility issue way back in this thread. There have been a few articles stated that it can be a real issue if everyone went out and bought an electric car. Imagine the demand in the summer with a/c's going full blast and then car's being charged. The a/c's allow can actually tax the system that is around here.

When I worked at waste water plants, on hot summer days the plants would go off grid and run on internal power, typically from 2-9pm. Happened in winter too but not as often. I believe this was to keep Dominion Power from having to either bring more equipment on-line or do rolling brownouts on its customers. This past summer they curtailed our AC from 2-4pm at least a dozen times via the 'power box' on the side. They give you a discount for having it.

You are correct tho; we do not have anywhere near the electrical infrastructure to allow for John Q Public to run a 50A draw all night, every night for his EV vehicle.
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
IMHO I say it depends on when usage will occur. If EV charging occurs at night during off peak hours the extra load will not stress the system.

off peak hrs = night time ??

where do you get all that power at night? you think with the current generation system that the decrease in off-hrs load can accommodate the load demand of proliferated EV's that charge at night? i dont think it can, and, if proliferation of EV's mostly charge at night then night time is no longer "off-hrs", thus we consumers no longer get the benefits of reduced pricing for off-hrs use.

many more aspects to EV's than one sees just by looking at a Leaf on showroom floor.


Come to the mountains and you don't need a/c.
and in deserts like AZ and Vegas, EV bat packs dont par so well during the intense summer months. the heat kills most std car bats in about 2-3yr time. full EV's simply cannot replace fossil fueled vehicles.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
off peak hrs = night time ??

where do you get all that power at night? you think with the current generation system that the decrease in off-hrs load can accommodate the load demand of proliferated EV's that charge at night? i dont think it can, and, if proliferation of EV's mostly charge at night then night time is no longer "off-hrs", thus we consumers no longer get the benefits of reduced pricing for off-hrs use.

I agree with you for once. I'd predict that, as solar proliferates, time of use rates will eventually flip-flop.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I said POWER, not energy. Anyway 24.1% is a 'player in grid power'.

If it's wind or solar, it's "power"; what the heck, you think they're back to grinding wheat with windmills???

"Player" is not "nearly 100%" which is what you claimed. C'mon, you can say it, you were wr..., wr..., wrong!
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
If it's wind or solar, it's "power"; what the heck, you think they're back to grinding wheat with windmills???

"Player" is not "nearly 100%" which is what you claimed. C'mon, you can say it, you were wr..., wr..., wrong!

If you don't understand the difference between power and energy I'm not going to spend a lot of words explaining it to you. That's basic stuff, like understanding the difference between speed and distance.

Every summer when solar is at its best Germany breaks its own record for how much POWER it gets from renewables at the peak of daily solar production.

78% is near enough to 100%, in the context of responding to someone who was claiming it was close to zero. I'm not going to take back what I said. :happyno:
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
If you don't understand the difference between power and energy I'm not going to spend a lot of words explaining it to you. That's basic stuff, like understanding the difference between speed and distance.

Every summer when solar is at its best Germany breaks its own record for how much POWER it gets from renewables at the peak of daily solar production.

78% is near enough to 100%, in the context of responding to someone who was claiming it was close to zero. I'm not going to take back what I said. :happyno:

In this context, "power" and "energy" are interchangeable and you are picking nits. There is no solar and no wind that isn't going into making electricity, whether you are talking about peak output in megawatts or delivered power in megawatt-hours. And as of the most recent data I could find, the Germans are paying handsomely for the honor; $0.35/kWh vs the US at $0.12/kWh (average price, 2011)

More telling is the fact that despite the high installed base, they still have to maintain all their fossil fuel plants 'cause the wind doesn't always blow and the sun don't always shine; see here from the same week they set that record. That means that you now have to maintain capital investment in the old infrastructure while deploying the new one; forever. Pointless duplication of costs, much?
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
I'm not picking nits. I made a statement that is backed up by fact. You chose to misinterpret it as saying something completely different from what I said. That's called a strawman argument.

None of your points, correct as they may be, amount to argument that solar and wind are not 'a grid player' in Germany. :happyno:

I'm done repeating myself. :bye:
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
power = energy/time
its that simple.

W is power
kWh is power
Joule is energy

so, in essence, you could have lots of coulombs (stored eV, aka "battery") of energy sitting there, but unless you use it over a period of time, no power.
 

Iron_Ben

Senior Member
Location
Lancaster, PA
power = energy/time
its that simple.

W is power
kWh is power
Joule is energy

so, in essence, you could have lots of coulombs (stored eV, aka "battery") of energy sitting there, but unless you use it over a period of time, no power.

Except that kWh, kilowatt-hours, is a unit of energy, not power.
 

Fulthrotl

~Autocorrect is My Worst Enema.~
There are none so blind as those who will not see.

i love threads here....

we start off with a simple inquiry about a car charger,
and eight pages later, we are attempting to divide coulombs per foot second......
let's not forget to consider the phase shift of the defibrillator, as it core soaks.
that is frequently overlooked in charging cars.

but how are we going to get germany's 24.1% energy over to this car that needs
charging? if we can get it fully charged, can we just drive it to feen-x and leave it
out in the sun until the batteries explode from the heat, and be done with it?
 

FionaZuppa

Senior Member
Location
AZ
Occupation
Part Time Electrician (semi retired, old) - EE retired.
reply to post just before this one. we must understand the fundamentals for discussions like this, otherwise its all overt the place.

Except that kWh, kilowatt-hours, is a unit of energy, not power.


??

Power is defined as the rate of producing or consuming energy

joule or eV are units of energy. Watt (energy/time) is a rate typically in the context of producing or consuming. i can in fact have Watts and not fall into producing or consuming realm, such as the flux of light energy passing through an aperture (area), so for any given time t the aperture (area) would have seen X amount of energy passing through, yet no energy is produced or consumed there (hence no power).

so, unless you want to be on the not-so-common side of the lingo, power is a rate of energy produced or consumed, and once you throw in Watts you are in "power" land.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
So I put a 50 amp conductor with a 50 am overcurrent protective device which means the unit probably draws 40 amps or so. Now charge the car for 7 hours-- home owner states that what it takes for a full charge - and that is a lot of energy and money to charge that vehicle.
(40A)(240V)(7hr) = 67.2kWh = 6 to 7 bucks at normal utility rates.
 
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