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1.21 GigaWatts - How Many Teslas?

Discussion in 'Charging Standards and Infrastructure' started by Cottonwood, Sep 7, 2014.

  1. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    #1 Cottonwood, Sep 7, 2014
    Last edited by a moderator: Mar 13, 2016
    One Point Twenty-One JigoWatts ??!!!

    Let's have some fun doing order of magnitude calculations on Tesla power use!


    DeLorean time machine - Wikipedia, the free encyclopedia




    Many of us know the reference from Back to the Future that it takes 1.21 GigaWatts to power the Flux Capacitor. How many Teslas does it take to use 1.21 GigaWatts, and other than the movie reference, why is that number interesting?

    If you look at List of countries by electricity consumption - Wikipedia and realize that there are 365.25*24 hours per year, then the average U.S. electrical consumption is 432 GigaWatts and the average world consumption is 2,146 gW. 1.21 gW is 0.28% and 0.056% respectively of those numbers.

    1.21 gW is also the level of power that the largest power plants can produce. List of power stations in Washington - Wikipedia and Power station - Wikipedia

    So, coincidentally, 1.21 gW, at a fraction of a percent, is a level of consumption that starts being noticeable in terms of a new load on the electrical grid.

    With that justification for this fun calculation, how many Teslas does it take to consume 1.21 gW? Here are some interesting results:









    Scenario Power (W) Number Notes
    Average 1,000 1,210,000 12,000mi*360Wh/mi/365.25days/yr/24hr/day*2.029167peakiness
    Single Charger 9,600 126,042 240V*40A
    Dual Chargers 19,200 63,021 240V*80A
    120kW Supercharger 133,333 9,075 120,000kW/90%
    135kW Supercharger 150,000 8,067 135,000kW/90%, really 16,133 stalls in use
    P85 320,000 3,781 maximum output power
    Average: It is a little contrived, :wink:, but if you assume 12,000 miles per year, 360 Wh/mi from the grid, and a "peakiness" factor of a little over 2, then each Tesla consumes an average power of 1,000 Watts or 1 kW. That means it takes 1.21 MegaTeslas at 1 kW each to consume 1.21 gW. It will take Tesla a few years to get to that count.

    Single and Dual Chargers: This is simply the number of Teslas that need to charge at the same time to reach 1.21 gW. Maybe, we can organize a great synchronous charge event to see what we do to our local grids. There may be some neighborhoods in California that don't want to tempt the fates with this test...

    120kW and 135kW Superchargers: This is the count of Supercharger Cabinets that need to operate at max power together to draw 1.21 gW. Note that I assumed a 90% efficiency for a Supercharger and did the calculations for power drawn from the grid. Because the most a single Stall (car) can draw is 120 kW, we need twice as many stalls (cars) as Supercharger Cabinets to hit the max with 135kW Superchargers. If we assume an average of 3 Supercharger Cabinets per Supercharger site, then this is about 3,000 Supercharger sites; even with 6 per site, that is about 1,500 sites. We have a ways to go to hit this number, and once again would need to plan a synchronous charge.

    P85: This is not power from the grid, but combined power from a group of P85's. If 3,781 P85's all punched the accelerator at the same time, the sum of the power consumed from their batteries would be 1.21 gW!


    The result of these calculations is that we have a while before all the Teslas in the world can consume 1.21 gW, and even then, that is only a fraction of a percent of world or even U.S. electrical power consumption.

    Have fun driving your time machine!!!
     
  2. tezco

    tezco Sig P85

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    I'm more concerned about my rural power feed. So far 5 of us on a single line, and two of us already have Teslas. That's 160 amps that wasn't on the drawing board when they put in the cable 40 years ago (and no one had AC back then either). Glad I upgraded my service to 400A while the bandwidth was still available.
     
  3. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Occasionally the distribution wiring can be a limit, but it's usually the transformers that limit power to users, and those can be upgraded. Remember that with a typical Distribution Voltage of 12,000 Volts, your 80 Amps at 240 Volts is only 1.6 Amps at 12,000 Volts on the Distribution wires coming to the transformer! Most utilities, even rural co-ops like mine in Pagosa are used to upgrading transformers to a larger size as electrical needs grow.
     
  4. FLDarren

    FLDarren Member

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    #4 FLDarren, Sep 22, 2014
    Last edited: Sep 22, 2014
    I got curious and wondered how long could the Model S batteries supply 1.21 Gigawatts of power. If any of my calculations are wrong, please correct me.

    This is assuming a couple things.
    1. Ignore the heat generated.
    2. No limit on the power output of the batteries.


    60 kWh battery. T=time

    60kWh=T x 1.21GW

    60kWh=T x 1,210,000 kW

    60kWh/1,210,000kW= T

    T= .00004958677686 hours

    T/3600= seconds

    T= .000000013774105 seconds

    T= 13.774105 Nanoseconds


    85kWh battery

    85kWh=T x 1.21GW

    85kWh=T x 1,210,000 kW

    85kWh/1,210,000kW=T

    T= .00007024793 hours

    T/3600= seconds

    T=.000000019513315 seconds

    T= 19.513315 Nanoseconds

    Just to put things into perspective. It takes 1.017 nanosecond for light to travel 1 foot.


    According to Wikipedia:One nanosecond is to one second as one second is to 31.710 years.
     
  5. Cottonwood

    Cottonwood Roadster#433, Model S#S37

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    Your calculation of T in hours is correct, but your conversion to seconds needs to be corrected.

    To convert T in hours to T in seconds, you need to multiply by 60 seconds/minute times 60 minutes per hour or by 3,600 sec/hr.

    With that correction, and assuming no limit on current or power delivery from the battery, 60 kWh would last 0.179 seconds and 85 kWh would last 0.253 seconds.

    BTW at an average Voltage of 370 Volts on an 85 kWh pack, the current would have to be 3.27 million Amps. The wires and contacts might have to be a little thicker to carry this current. That is why I proposed 3,781 P85's working in parallel to generate the 1.21 gW.

     
  6. etheric_jerry

    etheric_jerry Member

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    Or MAYBE some inventor can figure out a way to charge your batts with a LIGHTNING BOLT, BAMMMMMMMM!!!!!!! Riding around with a LIGHTNING Rod sticking outa the trunk would sure be a unique way of ending RANGE ANXIETY ...........................

    lightning-delorean.jpg
     
  7. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    Proof positive a higher capacity battery is needed.
     
  8. brianman

    brianman Burrito Founder

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    ... if you want to use the vehicle as a time travel device, sure.
     

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