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If it took me an hour to fill the tank - absolutely. It takes me less than 5 minutes and I often still have to wait in line if I'm forced to fill up on the way

by tw04 11y ago

If it took me an hour to fill the tank - absolutely. It takes me less than 5 minutes and I often still have to wait in line if I'm forced to fill up on the way to, or way home from work.

aerovistae 11y ago
But they know this, and will keep ahead of that demand. Thanksgiving 2018 is a long time away, and building more superchargers is the least of their engineering problems. Very easy to do. And I think you're not grasping how small a number 142 is for a full-fledged gas station. There are over 200 million people in the US with driver's licenses, and over 114,000 gas stations. If only half of those people are driving, that's almost 900 drivers per gas station. 142 is nothing! Particularly since this isn't accounting for the fact that many/most Tesla owners fill up at home. The competition for charging space you're anticipating is simply an imagined worry.
- mattzito 11y ago
  Sure, but you get that the whole distribution model is different, right? Gas stations accept everyone who has a gas-powered vehicle, and take 5-10 minutes to fill up. Supercharger stations accept people who are on long trips and take 40-something minutes to fill up at best case. So it's reasonable to say that the usage patterns are totally different.
mikeash 11y ago
But you never hit the Supercharger on your way to and from work, because you charge at home. You only need Superchargers on long trips. Most people will visit them only a few times a year, so the demand is much lower.
- mattzito 11y ago
  Right, BUT - everyone tends to make those long trips at the same time. Thanksgiving, Mother's Day, Spring Break, Easter, Passover.
  - mikeash 11y ago
    Most of those trips aren't that long. The average Thanksgiving trip is a bit over 200 miles, for example: http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/america_on_the_go/us_holiday_travel/html/entire.html http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/pub... Maybe 40% of gas cars will need to stop for fuel during a trip of that length, assuming a range of 500 miles and refueling when near empty. EVs should be able to make it directly, since they'll start at 100%. You're absolutely right that the network needs to be sized for peak demand much higher than average demand, but even then I think it's less than what you'd need for the same number of gas cars.
    - ams6110 11y ago
      Why do you assume you're starting at 100%? That doesn't seem like a given to me. You go to work on Wednesday, maybe run a couple of errands, and then leave on your Thanksgiving drive. It's nightime in November so you need the heat and the headlights. There are no superchargers within 50 miles of your planned route. Now what?
      - mikeash 11y ago
        Yes, in that scenario you'd have to stop. But then gas station usage goes up too. There's some crossover point where the EVs need more, but I don't think this gets you there. By the way, don't mention headlights. Their power consumption is absolutely negligible. Heat, for sure, but not lights.
        Grishnakh 11y ago
        Headlight consumption is "absolutely negligible"? I've measured D2S headlight consumption at about 3A, or 6A for a pair; roughly 50W total, and it's constant. While I'm sure that's a lot less than you're using for propulsion or heat, that still doesn't seem quite "negligible". Of course, the on-board computer in the Tesla, plus its giant LCD screen and backlight, probably use at least that much continuously.

by tw04 11y ago

If it took me an hour to fill the tank - absolutely. It takes me less than 5 minutes and I often still have to wait in line if I'm forced to fill up on the way to, or way home from work.

aerovistae 11y ago

But they know this, and will keep ahead of that demand. Thanksgiving 2018 is a long time away, and building more superchargers is the least of their engineering problems. Very easy to do. And I think you're not grasping how small a number 142 is for a full-fledged gas station. There are over 200 million people in the US with driver's licenses, and over 114,000 gas stations. If only half of those people are driving, that's almost 900 drivers per gas station. 142 is nothing! Particularly since this isn't accounting for the fact that many/most Tesla owners fill up at home. The competition for charging space you're anticipating is simply an imagined worry.

mattzito 11y ago
Sure, but you get that the whole distribution model is different, right? Gas stations accept everyone who has a gas-powered vehicle, and take 5-10 minutes to fill up. Supercharger stations accept people who are on long trips and take 40-something minutes to fill up at best case. So it's reasonable to say that the usage patterns are totally different.

mikeash 11y ago

But you never hit the Supercharger on your way to and from work, because you charge at home. You only need Superchargers on long trips. Most people will visit them only a few times a year, so the demand is much lower.

mattzito 11y ago
Right, BUT - everyone tends to make those long trips at the same time. Thanksgiving, Mother's Day, Spring Break, Easter, Passover.
- mikeash 11y ago
  Most of those trips aren't that long. The average Thanksgiving trip is a bit over 200 miles, for example: http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/america_on_the_go/us_holiday_travel/html/entire.html http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/pub... Maybe 40% of gas cars will need to stop for fuel during a trip of that length, assuming a range of 500 miles and refueling when near empty. EVs should be able to make it directly, since they'll start at 100%. You're absolutely right that the network needs to be sized for peak demand much higher than average demand, but even then I think it's less than what you'd need for the same number of gas cars.
  - ams6110 11y ago
    Why do you assume you're starting at 100%? That doesn't seem like a given to me. You go to work on Wednesday, maybe run a couple of errands, and then leave on your Thanksgiving drive. It's nightime in November so you need the heat and the headlights. There are no superchargers within 50 miles of your planned route. Now what?
    - mikeash 11y ago
      Yes, in that scenario you'd have to stop. But then gas station usage goes up too. There's some crossover point where the EVs need more, but I don't think this gets you there. By the way, don't mention headlights. Their power consumption is absolutely negligible. Heat, for sure, but not lights.
      - Grishnakh 11y ago
        Headlight consumption is "absolutely negligible"? I've measured D2S headlight consumption at about 3A, or 6A for a pair; roughly 50W total, and it's constant. While I'm sure that's a lot less than you're using for propulsion or heat, that still doesn't seem quite "negligible". Of course, the on-board computer in the Tesla, plus its giant LCD screen and backlight, probably use at least that much continuously.