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Filling up a Model S using Natural Gas

Discussion in 'Energy, Environment, and Policy' started by deonb, Apr 9, 2013.

  1. deonb

    deonb Active Member

    Mar 4, 2013
    Redmond, WA
    #1 deonb, Apr 9, 2013
    Last edited: Apr 9, 2013
    For some reason our county insists on running electricity lines through the air, and we also have heavy windstorms. Put the 2 together and we get power outages every year. In 2006 I actually had a power outage for 10 straight days (in the middle of a city :eek:). I lived in Africa for 25 years, and I've never seen anything like that. Anyway, getting off topic...

    If something like that happens again it can leave me quite stranded in the Model S. So I'm considering getting a natural gas backup generator, and wanted to run the numbers to see how much it would be to charge a Model S.

    Turns out to be very interesting:

    Costco has a cheap Honeywell (Model 006032-0) for $2700. Gives about 40 Amps continuous @ 240V. Familiar numbers to all of us :smile:.

    That should give you a nice 240 mile standard charge in about 8 hours. Ok, so how much would it cost to charge a Model S using that?

    Spec for the Honeywell says 156 cu.ft/gas per hour at full load (i.e. 40 AMP)
    156 cu.ft/hour x 8 hours totals = 1248 cu.ft. of natural gas for a standard charge.

    1248 cu.ft of natural gas = 1.317 MMBTUs. (x 1.056 for relative heat content and / 1000. Why they sell it like this is beyond me.)

    Now here comes the fun part:

    2012 national average for natural gas is $10.98 per MMBTU.

    1.317 MMBTUs @ $10.98 each = $14.47 to standard charge a 85kWh.

    To put that in perspective, at a gas price of $3.62 per gallon, $14.47 buys about 4 gallons of gas. To travel 240 miles on 4 gallons, gives you 60 mpg. Heck, using Chad's worst case 2/3 planning equation, you'd still be getting close to 40 mpg.

    There are obviously other cars that get 40, and even a few that break 50. But then you're not talking about something the size & performance of a Model S.

    And all this from a rinky dink home generator.

    These cars are crazy efficient.:love:

    PS: Of course this is just for an emergency backup, I realize that natural gas used this way would still release a lot of CO2. Usually I'm either 100% on hydro or baseline.
  2. SwedishAdvocate

    SwedishAdvocate Active Member

    Jul 26, 2012
    Sweden, Earth
    I don’t know enough about these things, but this thread might be worth checking out:

    Hack-charging on a generator

    Some excerpts:

    From post #4:
    From post #6:
    From post #7:
    From post #10:
  3. mknox

    mknox Well-Known Member

    Aug 7, 2012
    Toronto, ON
    ... and there's this.
  4. wycolo

    wycolo Active Member

    May 16, 2012
    An Inverter type of generator employs an inverter to boost the voltage(s) to the everyday 120/240 volts alternating current. Just as your typical inverter does from 12/24 volts dc in a vehicle to provide you with "household" electricity while camping or traveling. Using an inverter frees the designer to choose whatever voltage range alternator is cheapest, easiest, etc. The designer is not stuck with using only 120/240 volt alternators since it is a trivial task to create an inverter with almost any input voltage desired. So maybe Honda has decided that the alternator of choice is in the 48 volt dc range. So they attach these alternators to gasoline or diesel engines and market them to the public as "household generators". Inside this package is an inverter that brings the 48 volts dc up to the 120/240 volts ac that the public uses. They can use alternators that produce messy waveforms; not to worry, the inverter will clean that up so the output will approximate a pure sinewave. Thus the Roadster or Model_S will readily accept this for charging purposes.

    Trying to clarify the issue here.
  5. Martini

    Martini Member

    Nov 16, 2012
    Paris, France, France
    I think that those aluminium air batteries that Phinergy is messing with would make an excellent stationary backup power solution (much better than for cars). You could recharge it by stealing your neighbour's aluminium siding.
  6. Robert.Boston

    Robert.Boston Model S VIN P01536

    Oct 7, 2011
    Portland, Maine, USA
    I know that you're joking, but someone did steal all the copper downspouts from my church. Fortunately, aluminum is cheap enough that most people probably won't resort to crime.

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