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Discussion Starter · #1 ·
I'm really hoping some of you knowledgable people here can help me understand how to calculate the cost of charging. It seems like I need to multiple my electric rate, with the kWh/mile for the car (which we don't officially know) and then multiple my mileage per year. Is that correct? How do I estimate the kWh/mile for the Solterra. I've been trying different numbers, and I'm not really seeing that much savings versus gas so I hope I'm doing something wrong.

Example, I drive about 12,000 miles per year and my base electric rate in Los Angeles is $0.195/kWh. If I put in a separate meter, then my rate would go down to $0.17. How much would I spend to charge this car per year? I've spent $1500 a year for my 2017 Impreza.

I really appreciate anyones help. Thanks.

Peter
 

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[Q
I'm really hoping some of you knowledgable people here can help me understand how to calculate the cost of charging. It seems like I need to multiple my electric rate, with the kWh/mile for the car (which we don't officially know) and then multiple my mileage per year. Is that correct? How do I estimate the kWh/mile for the Solterra. I've been trying different numbers, and I'm not really seeing that much savings versus gas so I hope I'm doing something wrong.

Example, I drive about 12,000 miles per year and my base electric rate in Los Angeles is $0.195/kWh. If I put in a separate meter, then my rate would go down to $0.17. How much would I spend to charge this car per year? I've spent $1500 a year for my 2017 Impreza.

I really appreciate anyones help. Thanks.

Peter
Peter, you are paying about twelve and a half cents per mile for gas. If Solterra gets 3.3 miles per kWh, it would be five or six cents per mile. We can expect both gas and electricity to keep rising and exact numbers will depend on the actual efficiency of the Solterra. Electricity from my provider is cheaper than yours ($0.1210) and gasoline probably is too (Eastern U.S.)
It means that whatever savings accrue to a switch to electricity will partly depend on where we live.
(Warning: Do not place bets in VEGAS on my numbers).
 

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Yes, a good estimate is about 3 miles per kWh. So that would be about 4,000 kWh per year, or 4,000 x 0.195 or $780
Pilot
Agree. I hope the range estimate of 220 miles for the 71kWh Soterra battery is conservative. I would expect quite a spread between colder and warmer states as well as differences among drivers. I once was a heavy foot on the throttle but I found that a lighter foot means components last a LOT longer.
 

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2019 Ascent Touring (me) 2020 Forester Limited (Spouse)
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If any utility charges beyond raw usage vary with said usage, that has to be taken into account in addition to the base rate. IE, anything charged for kwh used, not just the actual power. For example, my utility has a variable distribution charge per kwh used over a fixed $10 and change distribution charge in addition to the actual electric used.
 

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Discussion Starter · #6 ·
Very true. My utility only has a fixed distro charge, but we have a tiered system where is reality for me, I am always close to the 2nd tier so my car would really be using the higher tier rate of $.25/kWh. I don't think TOU would be good for my house because my wife works from home and we use power all day. That's why I believe a separate meter would be best for me so I can use the EV TOU discount ($.17). I'm going to call them tomorrow to get some info and they will run an analysis on my account and also come by to check my power line. Hopefully I won't need any upgrades.
 

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Our Utility did away with separate meters for things like "off peak", etc., years ago...'just had one removed from the house when our whole house generator went in and found out they had been charging us $2.50 a month for that extra meter that didn't really provide any benefit. If there is a program for separately metering for EV charging, it's worth checking out. Do remember that there will be a cost to install the infrastructure to support that and it's not DIY for most folks, either.
 

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Unfortunately, PSEG here in NJ doesn't seem to offer any beneficial. My supply and delivery charges are separate, combining for about 0.17 cents per kWh. Like people have mentioned above, they seem to have tiers of billing based off your usage.

Here's a snapshot of my last bill for example-

Total usage 471 kWh
Delivery Charges fixed 471 kWh x $0.044140 = 20.79
Delivery Charges Flat Fee Monthly Service Charge = $4.95

Total Delivery Charges = $25.74

Supply Charges -
First 161 kWh x $0.111056 = $17.88
Next 310 kWh x $0.130935 = $40.59
Total Supply Charges = $58.47

Total Electric Charges = $84.21

So, if I am driving 1,200 miles in a month, and I know that I roughly "average" about 3 miles per kWh, that means I'd need 400 kWh of power to travel those 400 miles.

Using the referenced tier above (because that's all the information I have to go on), that would mean I'd also be billed an extra 400 kWh of power usage at $0.130935 plus the delivery of $0.044140.

So, that's 400 kWh x ($0.130935 + $0.044140)
400 kWh x ($0.175075) = $70.03 for that power (again, assuming you aren't using free sites which would reduce your cost or using DCFC networks which typically would cost more than the $0.175 per kWh and raise your cost)

$70.03 in "fuel" divided by 1200 miles driven would give you your operating cost of $0.0583583 cents per mile (let's say $0.06 per mile.)

Contrarily, with my local Costco selling 93 at $4.40 and with that 1 gallon I can go about 20.2 miles according to my universal average on my Fuelly app; that's $4.40 divided by 20.2, or an operating cost of $0.21782 per mile. That is a considerable difference - it is nearly 27% of the cost of gasoline.

What's this? Don't use 93 you say (even though it is suggested for high-load driving such as mountainous driving or towing)? Let's recalculate with good ol' 87 octane at Costco, $3.84 per gallon. $3.84 divided by that same 20.2 yields an operating cost per mile of $0.19 - a savings of about 2 1/2 cents. Compared to electricity, that's still 30% of the cost - putting 70% of your fueling costs back into your pocket!
 
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