Charging Math, Miles Per Dollar - Is this right?

Riotous

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Am i computing this correctly?

Charging log says 58% charged. I charge to 90%, so, 88kWh battery * .9 *.58 = 45.92 kWh added
That part is about right, eh.

Now, since I added ~46 kWh, does that mean I drew ~46 KWh from my house power, is is 1 to 1?
If so, then @ 11.6 cents per hour, this cost me $5.33.

If so, then after 1,000 miles on the GTPE, driving around greater Houston, I am getting right around 30 miles per $. Not bad. 5 times better than my F150.
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RedStormREHS

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I just charged-up from 25% to 90% this week. My EVSE sub-electrical meter (City property) says I used exactly 65 kWh for this 65% charge! I pay only $0.1056/kWh rate for EV charging & $5/mo for sub-meter ($0.63/charge estimating 8 charges/month). This charge cost me exactly $7.49! Fordpass estimated I gained about 185 miles... So, grand estimated total cost per mile for me is 4 cents! Holly cow!
 

Nklem

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I just charged-up from 25% to 90% this week. My EVSE sub-electrical meter (City property) says I used exactly 65 kWh for this 65% charge! I pay only $0.1056/kWh rate for EV charging & $5/mo for sub-meter ($0.63/charge estimating 8 charges/month). This charge cost me exactly $7.49! Fordpass estimated I gained about 185 miles... So, grand estimated total cost per mile for me is 4 cents! Holly cow!
Yes. It blows a 40 MPG ice vehicle driving cost out of the water. Gas is $3.60 in Maine and that’s $0.09/mile. 30 MPG is $0.12/miles. And the Mach E is much more fun than nearly every ICE.
 

RickMachE

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I just charged-up from 25% to 90% this week. My EVSE sub-electrical meter (City property) says I used exactly 65 kWh for this 65% charge! I pay only $0.1056/kWh rate for EV charging & $5/mo for sub-meter ($0.63/charge estimating 8 charges/month). This charge cost me exactly $7.49! Fordpass estimated I gained about 185 miles... So, grand estimated total cost per mile for me is 4 cents! Holly cow!
If in fact you took 65kWh from the wall and put 57.2 into the vehicle, that's a 12% loss.
 

jetermeyer

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If in fact you took 65kWh from the wall and put 57.2 into the vehicle, that's a 12% loss.
I think you need to include delivery charges as part of the calculations. Delivery charges are mostly based on the amount of KW delivered. There is a flat fee but it is a small portion of the delivery charge. The real cost to you is the combination of KW cost and Delivery charges.
 

RickMachE

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I think you need to include delivery charges as part of the calculations. Delivery charges are mostly based on the amount of KW delivered. There is a flat fee but it is a small portion of the delivery charge. The real cost to you is the combination of KW cost and Delivery charges.
We're talking about two different things. @RedStormREHS was saying how many kWh he sent from the wall to the car. I was pointing out that his car received 12% less kWh than was sent to it (not unusual to have a 7 - 15% loss. Same is true when you DC fast charge. You paid for 50kW, and your car gets 46.5.

As to the cost of that electricity at home, yes, people need to look at every variable cost they get charged on the bill. Many have just one fixed cost - a monthly customer charge or meter charge. Then there can be 1/2 dozen variable costs, including generation, delivery, paying for investments like a nuclear plant, etc. Some have a higher unit cost when they exceed a certain amount of usage, and that marginal cost should be used. And then there is sales tax.

Here's my bill for a given month. All my vehicle charging is done off-peak.

So my low $0.0116 per kWh cost has to have added to it $0.0426 plus $0.00322 plus $0.066110, plus a portion of LIEAF Factor and Other Delivery Charges, plus sales tax. That takes my 1.16 cents to over 12 cents.

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Neilthepilot

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We're talking about two different things. @RedStormREHS was saying how many kWh he sent from the wall to the car. I was pointing out that his car received 12% less kWh than was sent to it (not unusual to have a 7 - 15% loss. Same is true when you DC fast charge. You paid for 50kW, and your car gets 46.5.

As to the cost of that electricity at home, yes, people need to look at every variable cost they get charged on the bill. Many have just one fixed cost - a monthly customer charge or meter charge. Then there can be 1/2 dozen variable costs, including generation, delivery, paying for investments like a nuclear plant, etc. Some have a higher unit cost when they exceed a certain amount of usage, and that marginal cost should be used. And then there is sales tax.

Here's my bill for a given month. All my vehicle charging is done off-peak.

So my low $0.0116 per kWh cost has to have added to it $0.0426 plus $0.00322 plus $0.066110, plus a portion of LIEAF Factor and Other Delivery Charges, plus sales tax. That takes my 1.16 cents to over 12 cents.

dte.PNG
I agree, I see lots of really low electricity costs and wonder if they are including delivery cost. I think my current cost is closer to $.23 KWH. My mistake, I took my recent bill divided by KW used and I am paying $.17/KWH out the door.
 
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Nklem

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We're talking about two different things. @RedStormREHS was saying how many kWh he sent from the wall to the car. I was pointing out that his car received 12% less kWh than was sent to it (not unusual to have a 7 - 15% loss. Same is true when you DC fast charge. You paid for 50kW, and your car gets 46.5.

As to the cost of that electricity at home, yes, people need to look at every variable cost they get charged on the bill. Many have just one fixed cost - a monthly customer charge or meter charge. Then there can be 1/2 dozen variable costs, including generation, delivery, paying for investments like a nuclear plant, etc. Some have a higher unit cost when they exceed a certain amount of usage, and that marginal cost should be used. And then there is sales tax.

Here's my bill for a given month. All my vehicle charging is done off-peak.

So my low $0.0116 per kWh cost has to have added to it $0.0426 plus $0.00322 plus $0.066110, plus a portion of LIEAF Factor and Other Delivery Charges, plus sales tax. That takes my 1.16 cents to over 12 cents.

dte.PNG
Must be nice to have cheap power. Mines going up to $0.225/kWh January 1. I love the deregulated markets in New England, Not! Thank goodness for free charging at work.
 
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Riotous

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Well, I live outside of Houston, so electricity is pretty cheap - well, it was until the deep freeze last February completely blew the grid and power markets in Texas... It's still below the national average here, but getting more expensive, the consumers will have to pay for that debacle. Gasoline is cheap too, $2.75 a gallon.
 

Vulnox

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With delivery costs ours is 16 cents/kWh.

An aspect I always keep in mind too is the cost of time. As my tag shows I have an F-150 PowerBoost, and it has done very well for us, in city getting 24-30 MPG isn't unusual. But I still have to visit the gas station.

Assuming I stop at a gas station while already out for something, it is still 5 minutes or so of my time. If I have to make a special trip for gas, like I forgot to get gas and I am low and don't want to stop before work, then it's 10-15 minutes of my time. That's multiplied by maybe 20-30 times per year depending on your vehicle and how much you drive.

If I take my salary and turn it to an hourly rate and "pay myself" for all that time spent getting gas, or doing oil changes and so on, then I can pay for several full charges of the MME.

I know it starts to get a bit out there, but aside from the cost of gas was the often inconvenience of gas. And yeah that flips a bit on a long road trip, no doubt, but unless you are road tripping monthly your benefit for daily home charging will still come out ahead.
 
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Riotous

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Re the power draw from the house (source), does the car know this? I guess not. The EVSE should know it, or seems like it could at least know it. I guess this kind of data is the value-add of some of the higher end EVSEs.
 
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Riotous

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I know it starts to get a bit out there, but aside from the cost of gas was the often inconvenience of gas. And yeah that flips a bit on a long road trip, no doubt, but unless you are road tripping monthly your benefit for daily home charging will still come out ahead.
Great point - and I don't waste money (or my wife rather) on damn lottery tickets and candy for the kids, and other convenience store items. It all adds up... :)
 

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Am i computing this correctly?

Charging log says 58% charged. I charge to 90%, so, 88kWh battery * .9 *.58 = 45.92 kWh added
That part is about right, eh.

Now, since I added ~46 kWh, does that mean I drew ~46 KWh from my house power, is is 1 to 1?
If so, then @ 11.6 cents per hour, this cost me $5.33.

If so, then after 1,000 miles on the GTPE, driving around greater Houston, I am getting right around 30 miles per $. Not bad. 5 times better than my F150.
As others mentioned there is a 10% or so overhead loss due to heating and component inefficiencies so assume you actually drew 50kwh instead. The range estimator isn't overly accurate so I would go by the mi/kwh that you actually get as you drive to come up with a more accurate measurement. And yes, definitely make sure you include all the delivery charges and other fees in your $/kwh rate. There is also a little bit less math if you simply compute $/mi:

Assuming gas is $3.50/gal and your truck gets 25 mpg:
$3.50/25 = $.14/mi

For your mach-e if your correct per-kwh rate is $.116 and your car reports an average of 3 mi/kwh:
$.116/3 = $.038/mi

BUT you need to increase the Mach E $/mi by 10% because of the loss during charging:
$.038 x 1.1 = $.043/mi including charging losses

So, in the example above your F-150 would cost more than 3 times as much per mile. That's why the oil companies are so desperately doing whatever they can to discourage BEV adoption with disinformation and massive campaign contributions.
 
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