M3 home charging is wow

[superbenbenben]

just got my 14-50 plug installed on 50 amps breaker. the car was pulling at 32 amps. then i checked my energy monitor, holy cow, it was using 1/3 more watts than my central AC (recently installed). then i found this

Fact #995, September 18, 2017: Electric Vehicle Charging at Home Typically Draws Less Than Half the Power of an Electric Furnace

Electric vehicles can be charged at power draws comparable to various household appliances.

www.energy.gov

it is like running another AC at home. i can't wait to see next month bill

 

[PDX-Y]

Yes, the peak draw is going to be higher than probably anything else in your breaker box. I have an induction range on a 50A circuit, and nothing else above 30, for example.

Unless you do a lot of driving, though, the car charger isn't going to be operating much. The average american vehicle drives 30 miles per day (and EV owners probably somewhat less). At 300 wH/mi, that's a little under an hour a day on a 11 kW wall charger. On balance your other appliances are going to consume more in total.

 

[jjrandorin]

just got my 14-50 plug installed on 50 amps breaker. the car was pulling at 32 amps. then i checked my energy monitor, holy cow, it was using 1/3 more watts than my central AC (recently installed). then i found this

Fact #995, September 18, 2017: Electric Vehicle Charging at Home Typically Draws Less Than Half the Power of an Electric Furnace

Electric vehicles can be charged at power draws comparable to various household appliances.

www.energy.gov

it is like running another AC at home. i can't wait to see next month bill

If you were charging at home previously, you were likely using the same amount of power, just spread out. If you wernt, then yeah. Back pre "work from home all the time" covid, I commuted to work and back daily 80 real miles round trip. This took me between 90-120 "tesla miles" depending on the time of year, whether it was raining, etc.

About 25-30kW of power, daily, which is almost the exact same amount my 3300 square foot 4 bed 3.5 bath home uses in a 24 hour period. Now, my wife and I are empty nesters now, so there are only 2 of us in this home, and I have taken time to swap everything in here to efficient appliances (except my TV... I have a big ole 85 high end back lit LED TV that is definitely not efficient).

Anyway, my car uses almost the exact same amount of electricity as my home, when I commute to work, for a 24 hour period. The thing some people ignore, for some reason, is that for many, even though they spend more on electricity, they are not spending anything on gas. I used to spend $45 every 3 days, driving my BMW to work and back. I dont spend even 1/2 that in electricity, driving my model 3 the same commute, and CA has some of the highest electricity costs (and gas costs) in the nation.

Right now, Premium unleaded is like $4.50 a gallon, around me (Jun 25th 2021).

 

[AlanSubie4Life]

i can't wait to see next month bill

Because you now have less charging overhead, your bills will be lower, all else being equal.

You've taken your charging efficiency (assuming you previously were using 120V/15A) from the mid/upper 70s to near 90%. This is 1) because the car will be sleeping for a longer period, and 2) while charging, other electronics in the charging circuit in the car consuming power not proportional to the rate of charge are on for a shorter period.

 

[Resist]

That's why having solar makes a difference in offsetting the cost to charge, or being on a Time of Use schedule EV plan so it's less expensive during non peak times.

 

[Rottenapplr]

That's why having solar makes a difference in offsetting the cost to charge, or being on a Time of Use schedule EV plan so it's less expensive during non peak times.

Yes unlike gas where you either don't drive or you pay the gas station, at least with EV you can offset the cost with solar at least my house has had solar for 20 years now. Plus in California, we are paying close to $5 for gas and some are paying more. EV just makes sense here if you have the means and the set up (house) already.

 

[jjrandorin]

Yeah, in my post above, I left off that I have solar, it complicates things a bit because solar isnt "free" but once you have it installed, it sure is nice to go from paying every 3 days for gas to NOT paying, and having my commute come out of the solar I am already generating.

 

[cwerdna]

just got my 14-50 plug installed on 50 amps breaker. the car was pulling at 32 amps. then i checked my energy monitor, holy cow, it was using 1/3 more watts than my central AC (recently installed). then i found this

Fact #995, September 18, 2017: Electric Vehicle Charging at Home Typically Draws Less Than Half the Power of an Electric Furnace

Electric vehicles can be charged at power draws comparable to various household appliances.

www.energy.gov

it is like running another AC at home. i can't wait to see next month bill

240 volts * 32 amps = 7,680 watts = 7.68 kW

Not sure how that's surprising...

 

[cwerdna]

About 25-30kW of power, daily, which is almost the exact same amount my 3300 square foot 4 bed 3.5 bath home uses in a 24 hour period

Are you talking about 25 to 30 kWh of energy daily?

Even an older Model S w/dual on-board chargers only can pull 80 amps from the wall max: 240 volts * 80 amps = 19,200 watts = 19.2 kW. Tesla doesn't even sell/lease vehicles in the US with above 48 amps of OBC any longer.

(We have some Model S at work w/dual OBCs and we have some older X and I think S with 72 amps of OBC. We have some gen 2 Tesla WCs on 100 amp circuits.)

 

[AlanSubie4Life]

7.68 kW

That's nearly 1.21 GIGAWATTS!

 

[jjrandorin]

Are you talking about 25 to 30 kWh of energy daily?

Even an older Model S w/dual on-board chargers only can pull 80 amps from the wall max: 240 volts * 80 amps = 19,200 watts = 19.2 kW. Tesla doesn't even sell/lease vehicles in the US with above 48 amps of OBC any longer.

(We have some Model S at work w/dual OBCs and we have some older X and I think S with 72 amps of OBC. We have some gen 2 Tesla WCs on 100 amp circuits.)

Yeah sorry kWh not kW. You would think I wouldnt mix those up as much as I do, especially being a moderator for tesla energy section here (lol). I know the difference, I always type it wrong though.

 

[Gauss Guzzler]

I thought that energy.gov report was just fabricated nonsense from some idiot who didn't know the first thing about anything.

But it turns out that the idiot was me. I had no idea there was such a ridiculous contraption as a "20kW electric furnace".
Wow. No wonder Elon has been talking about entering the residential heat pump market.

 

[tstolze]

I thought that energy.gov report was just fabricated nonsense from some idiot who didn't know the first thing about anything.

But it turns out that the idiot was me. I had no idea there was such a ridiculous contraption as a "20kW electric furnace".
Wow. No wonder Elon has been talking about entering the residential heat pump market.

View attachment 678501

We went from a 15 kW furnace to a 2 ton two stage Ground Source Heat pump... The Heat pump runs longer but it uses 1.4 kW in first stage which maintains our temperature even when the outdoor temperature is in the single digits. Electric resistive heat is power hungry but simple to produce.

 

[Resist]

Yeah, in my post above, I left off that I have solar, it complicates things a bit because solar isnt "free" but once you have it installed, it sure is nice to go from paying every 3 days for gas to NOT paying, and having my commute come out of the solar I am already generating.

Actually, after around 10 years (the payoff period), depending on the size of solar then the power is free. And at the very least it's clean power that was made at home.