Electrical cost higher than gas to run Prime (I think)!

Discussion in 'Prime Main Forum (2017-Current)' started by IABoy987, May 21, 2020.

  1. IABoy987

    IABoy987 Member

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    Dug out my electric bills and did some back of envelope calculations.
    Our electric company on average charges 14 cents per kilowatt hour for on peak day time electricity, while night time off peak is $0.04986 per kilowatt hour.

    If I assume 5 hours charging that would be about 25 cents a night to recharge car which works out to a penny a mile (25 miles EV only mode) if battery run down to zero before going into HV mode every day.

    Our old Prius averaged 45 miles per gasoline mile. Gas prices here are now $1.95, and using 45,this works out to $0.0433 per mile.

    So by my thinking, until gas exceeds $2.24 per gallon ($0.4986 x 45 miles), it seems more economical to run in HV mode on gas and let engine recharge battery (assuming Prime does recharge battery like gen3 and before did)..

    Have I done wrong way thinking here, and "driven into the swamp"?
     
  2. fuzzy1

    fuzzy1 Senior Member

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    In the math of my world, $0.01/mile for electric is much cheaper than $0.0433/mile for gasoline.
    Where does this come from? o_O

    ===========
    This part needs some review. I thought others were getting recharges of about 6 kWh, or closer to 30 cents per charge at your night price. That means about 1.2 cents per mile on EV.

    From that, assuming 45 mpg on gas, the breakeven gas price should be 1.2 cents/mile X 45 mpg = 54 cents/gallon. I.e. $0.54/gallon.
     
    #2 fuzzy1, May 21, 2020
    Last edited: May 21, 2020
  3. Randi

    Randi Junior Member

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    That’s what I was thinking .
     
  4. mr88cet

    mr88cet Senior Member

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    For our particular electric-bill circumstances (typically around 13¢/KWh after adding all fees), and $2.20/ gallon, it works out to about 40% cheaper per mile than gas.

    However, with the lockdowns, gas prices dropped to around $1.40/gallon, which put it very-approximately at parity for us.

    Then again:
    * Gas prices are starting to rise again,
    * EV is quieter, drives more precisely and cleanly in several senses of the word, and
    * Gas, gas pumps, and gas stations are all disgusting!
     
  5. pghyndman

    pghyndman Active Member

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    The "Charge Station Gods" have smiled down in our neck of the woods: several of our favorite haunts with freebie joy-juice stations ensure a extra electrons whenever we scoot into town (our other vehicles aren't quite as thrifty, having enough oomph to pass anything but a gas pump). But yeah, gas has gone down to $1.52/gal at the local Costco soooo it probably is cheaper to go ICE but we do like the smooth, quiet, EV mode

    Hey, have I said it often enough? We LOVE our Prime!

    Old and New Primes.jpg SL500CLK350.jpg
     
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  6. Tideland Prius

    Tideland Prius Moderator of the North
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    120V/12A charging takes more than 1kW every hour (it's 1.6kW actually). Accounting for losses while charging, you should see around 6.1-6.1kW at the meter putting it at 31 cents. (That's 88.5% efficient)

    but I guess 1¢/mile is a nice round number haha.


    But either way, 1¢ is less than 4.33¢, no? So for the first 25 miles, it's cheaper to run on electricity. (and in the summer, it's more than 25 miles)
     
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  7. schja01

    schja01 One of very few in Chicagoland

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    OP: I like electric. I don’t have to get off my lazy butt and drive to a gas station. I just need to open a little door on the car and plug in a fancy plug that only I touch. And that gets even more convenient in rain, winter snow. You get the picture?
    Convenience has value in my equations. Plus I don't mind in the least not giving $$ to big oil. Being in Illinois I suspect the preponderance of my electric $$ goes to clean, safe, ecologically sound nuclear. But I digress. :)
     
    #7 schja01, May 22, 2020
    Last edited: May 22, 2020
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  8. Salamander_King

    Salamander_King Senior Member

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    Your calculation is off. I am not sure how you got this conclusion.
    Simple way to compare the cost of EV vs. HV is this:

    (rate of your electricity in $/kWh)*6 *2 = cost to run ~50-70 miles on pure EV
    (rate of your gasoline in $/gal) = cost to run ~50-70 miles on pure HV

    It assumes it takes approximately 6kWh to charge the traction battery full from the wall and your EV range is approximately a half of your HV only mpg. This turns out to work for both cold and warm seasons. In winter I get ~25 miles EV range, but HV efficiency also diminishes to ~50mpg, and in summer time EV range increase to ~35 miles, but HV efficiency also increase to ~70mpg.

    So, for your $0.04986/kWh (for simplicity round to 0.05)
    0.05*6*2=$0.60 to drive pure EV equivalent of distance you can drive by 1 gal of gas on pure HV mode. Unless you can find gasoline stand where you can buy gas less than 60 cents/gal, EV is cheaper.

    Even with your higher rate of 14 cents/kWh
    0.14*6*2=$1.68
    Recent crush in gas price may have reached this price range $1.68/gal, but I don't think it will last long.

    For your information, I live in area where electricity rate is very high 24/7/365 at $0.21/kWh (no TOU pricing), and our regional gas price has been relatively low. Now it is at $1.70/gal.

    0.21*6*2=$2.52 HV vs $1.70 HV. So yes in our local, it is much more expensive to drive EV than HV.
     
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  9. john1701a

    john1701a Prius Guru

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  10. IABoy987

    IABoy987 Member

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    Hi everybody. :)
    These calculations were just back of envelope what ifs game.
    SO before anyone thinks wife and I are in any way dis-satisfied with our Prime, let me state this unequivocally, and paraphrasing Charlton Heston (I think):
    "You will get our Prime when you pry it out of our cold dead fingers!" :ROFLMAO:
     
  11. fuzzy1

    fuzzy1 Senior Member

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    When trying to shift that from the back of the envelope to a formal calculation, I'm still baffled where this came from:
    It seems to me that the $0.4986 factor has a slipped decimal point, and the output units (($*miles)/(kWh*gallons)) have no obvious useful meaning. So absent further explanation, I must ignore the resulting 2.24.
     
  12. bisco

    bisco cookie crumbler

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    i have been paying more for electricity than gas for 8 years. it's worth every penny imo.
     
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  13. Mendel Leisk

    Mendel Leisk Senior Member

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    What's your rate again @bisco? Something like 24 cents US?
     
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  14. jerrymildred

    jerrymildred Senior Member

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    I'd almost call that a NFS price, but we were paying about half a dollar per kWh in Honduras. I think we're permanently in the hyper frugal mode with electricity.
     
  15. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    With all taxes and fees in California totaling about $0.80/gal, plus the requirement to use a special low-pollution blend refined only in California, that pretty much eliminates prices ever being less than $2.00/gal in our state. I think it is currently around $2.80/gal. The back-of-the envelop calculations that many here on PriusChat use is that a full charge is around 6.2kwh on 120V, more like 6.0kwh at 240V, which takes you about as far as a half gallon of gas, so the break-even price for gasoline is (price per kwh)*6*2. For me, electricity is a flat $0.093/kwh (no time-of-use), so the my breakeven price is $1.12, which it will never be here. We have low electricity rates since we have a city-owned electric utility.
     
  16. bisco

    bisco cookie crumbler

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    yep, 24 cents last time i looked
     
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  17. Mendel Leisk

    Mendel Leisk Senior Member

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    I recall listening to one blog story, someone recalling their childhood: they had one light bulb at a time in the house, would take it around the house, screw it in for use as and where needed, lol.
     
  18. fuzzy1

    fuzzy1 Senior Member

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    Any chance of that story coming from East Germany? Or North Korea?

    It wasn't a shortage of bulbs. It was a shortage of electric energy to operate them, so governments imposed a one-bulb-at-at-time limit. For the masses, of course, not for the elites.
     
    #18 fuzzy1, May 22, 2020
    Last edited: May 22, 2020
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  19. bisco

    bisco cookie crumbler

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    my dad used to complain that when he was a kid, circa 1930, the electric companies gave away free light bulbs
     
  20. fuzzy1

    fuzzy1 Senior Member

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    That was a way to encourage consumption. The traditional incandescent bulbs themselves were very cheap compared to the cost of the energy needed to light them up.
     
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