Jump to content

mptjelgin

Validated Members
  • Posts

    1,412
  • Joined

  • Last visited

About mptjelgin

  • Birthday 05/18/1960

Optional Fields

  • SKP#
    094494
  • Lifetime Member
    Yes

Profile Information

  • Gender
    Male
  • Location
    Medina, Texas and on the road.
  • Interests
    Birding, Photography, Hiking, Disc Golf

Recent Profile Visitors

12,155 profile views

mptjelgin's Achievements

  1. Rivian may be a decent comparison/replacement to the popular 1/2 ton trucks in terms of load carrying and towing capability, but they are a very long way from the one-tons. But as I said earlier, it really doesn't matter what you or I think right now, hopefully we'll be around to see the reality in 5 (or ten) years.
  2. I think that "obsolete" is a pretty specific term, and I doubt that it is correct. I find that articles like this tend to concentrate on the typical urban/suburban commuter whose driving patterns are quite predictable (and modest) and very well suited to EV's. And for that very significant portion of the market, gasoline vehicles becoming obsolete in 10 (I doubt 5) years may well be. But I live in a very rural area, where driving a couple of hundred miles a day, perhaps pulling a trailer or carrying a large load is very common. The most common vehicle in my part of the world is the 3/4 or one ton diesel pickup. Current diesel pickups are putting out 1000+ kip-ft of torque and 450 - 500 hp, and doing it for hundreds on miles on a single tank of fuel. And then filling up in 5 - 10 minutes and doing it all again. I haven't seen any EV proposed yet that is a viable replacement for those vehicles, nor do I see one on the horizon. But you know what? It doesn't matter what I think or what Kirk thinks or what you think about this. In 5 - 10 years we'll know the answer. You enjoy discussing this type of thing ad-nauseum, while I am primarily interested in RV's and RV'ing. That is why I am on this board!! When I am looking for solid information regarding EV's or investing I look elsewhere...
  3. There are two different measurement types to consider. When the 80% term is being used, it is based on volume. That is, only 80% of the volume of the tank is filled with liquid propane to allow 20% gas volume above the liquid. The paper that you refer to is based on weight. Since liquid propane weighs much less than water (4.1 - 4.2 pounds per gallon, depending on temperature vs. water at 8.3 pounds per gallon) the fill percentage numbers based on weight are much different. The 42% of WC referred to in the referenced paper corrects for the weight difference between the two liquids as well as the 80% fill volume. So the maximum weight of liquid propane is 42% of the full liquid weight of water. Volume-wise, that is about 80% full of propane.
  4. Correct. I assumed that he would be using a battery charger or inverter/charger with the Honda. I don't know why anyone would use that anemic 12V output.
  5. No! The Honda is putting out 8 amps at 120 volts. A 100 watt solar panel is putting out 8 amps at (approximately) 12 volts. So the Honda is putting out 10 times as much power (1000 watts) as the solar panel (100 watts). To compare apples-to-apples with regard to amps, you've also got to make certain that the voltage is the same.
  6. So it was. My apologies for muddying the water...
  7. The manufacturer that you linked to manufactures composite cylinders, which very well may not be DOT approved. But the steel cylinders utilized by 99.99% of RVs are steel and DOT approved, and the 12 year limit applies.
  8. Most portable tanks on RV's are DOT tanks and therefore are required to be recertified 12 years after the date of manufacture. This is why it is seldom an issue for RV'ers, as most don't keep a trailer for that long.
  9. This is typical behavior for a spammer on this forum. The behavior is: First time poster bumps an old thread, and then edits it a few days later to add a commercial link. Interesting that I was dressed down by one of the "Weekend Moderators" for pointing this out on a previous post.
  10. Getting a vehicle with a tune, but without the original tuner is a real problem. Is there any way possible to contact the previous owner about getting the tuner with the stock program? If not you may be able to go to a Ford dealer and have them reflash the ECM with a stock tune, and then take it from there. Many dealers may not want to mess with it, but if you have a friendly dealer you might try them. I had two different pickups with the V-10, and pulled heavy fifth wheels with both. While the mileage of the V-10 isn't anything to brag about, 4.3 mpg is unusually poor. Speed makes a big difference in mileage with this motor. How fast are you generally running?
  11. Nothing invented, no issue with reading comprehension on this end. One more time, from the article that you yourself provided: It will get most of its electricity from a 4500 square foot solar array that will feed a 3 MWh Megapack battery storage system. That’s large enough to supply the needs of all 40 chargers."
  12. And recognize that my answer is based on the top-producing solar panels currently available. When (if) these new cells become commercially available and if they can be affordably mass-produced is anyone's guess.
  13. The math is very simple and is presented in my first post on this thread. To summarize: At best, a 9000 sf array of solar panels will produce 200 Kw. This is based on the most efficient solar panels today producing 22 watts/square foot in full sun. So 9000 x 22 = 198,000 watts, which I rounded up top 200 Kw for discussion purposes. Most experts state that a full summer days production is the equivalent of 5 - 6 hours of full output. So let's give the benefit of the doubt here and use six hours. Total output of this 9000 sf array in summer, in full sun, would be around 1200 Kw-hours. So this array, in summer, can supply the power used by one of the 250 Kw charging stations for 4.8 hours. So even the first station being discussed (9000 sf panels, 40 - 250Kw V3 Charge Stations) can get only a tiny fraction of the necessary power from the solar array. Not to mention the second article, quoted by you, with half of the solar array and chargers with 40% higher output. The 4500 sf solar array will provide approximately 600 Kw-hours production in a day, enough to run a single 350 Kw V4 Charge Station for less than two hours. Directly from the second article that you linked: "...It will get most of its electricity from a 4500 square foot solar array that will feed a 3 MWh Megapack battery storage system. That’s large enough to supply the needs of all 40 chargers." More than one word, but it clearly states (my emphasis added) "That's large enough to supply the needs of all of the 40 chargers".
  14. Confirmation bias is often brought up in these discussions. The referenced article (assuming that is is accurate) provides enough usable information to actually run some calculations and look at some numbers. This is what I do day in and day out as a practicing Engineer, where I don't have the luxury of ignoring the math. In this case the numbers regarding solar providing most or all of the power for these Supercharger stations just don't work out. In fact, they are off by more than an order of magnitude. But presented with this analysis, some folk's response is to ignore the numbers and fall back on the idea that ol' Elon always comes through. This is pretty much the definition of Confirmation Bias. From Wikipedia, my emphasis added: People display this bias when they select information that supports their views, ignoring contrary information, or when they interpret ambiguous evidence as supporting their existing attitudes. Note that my analysis was of a 9000 sf solar array feeding 40 250 kW Superchargers and the numbers don't come close to working. RV later posts this article: Tesla is planning to build a 40 stall Supercharger facility near the Dateland Travel Center on Interstate 8, the main highway between San Diego and Tucson. According to Twitter user Marco-Supercharger, the new location will be one of the first to feature Tesla’s V4 350 kW chargers. It will get most of its electricity from a 4500 square foot solar array that will feed a 3 MWh Megapack battery storage system. That’s large enough to supply the needs of all 40 chargers." So now we have a solar array with only 4500 sf, feeding 40 350 kW chargers? How is this supposed to work? Musk Magic?
×
×
  • Create New...