The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…
> trains about the same amount
The nice thing about trains is that they can run on electricity.
The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…
> trains about the same amount The nice thing about trains is that they can run on electricity. It does require investing in overhead wires.
They aren’t great at shipping things from Europe and Asia to the United States, though.
>> The “dirty electricity” angle is less obvious to me. A power plant typically gets about 60% of energy from a fossil source. A car does about 30%. So even if the electricity comes from say coal, it's still more efficient than buying gas in a car engine. Of course, these days, it's likely that a substantial portion (up to 100% in some cases) is not "fossil electricity" but rather comes from solar, wind, hydro etc. I…
60% efficiency? How do these power plants manage to circumvent the limit set by Carnot efficiency?
Natural gas burns at ~2200 K. Ambient temperature is ~300 K. 1 - 300/2200 = 86% as the Carnot limit?
I've only had an EV 3 months now, but it'll never see a charging station. I pay around $.12/kw and get 4 miles per kw. So my "energy" costs are $.03/mile. I have a Mazda cx50 as well, it gets about 20-22mpg, with the gas prices here in Seattle that's around $.30/mile. Even where gas is cheaper that's still $.20/mile. Literally 10x the cost to run a gas car vs an EV. I'm honestly shocked at how many people have EVs an…
The pacific northwest’s vast hydro capacity makes it maximally attractive to own an EV. The rest of the country isn’t nearly so lucky.
I’m at $0.11 in Maryland which gets 40% of its power from nuclear.
The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…
Why is the EV better? Because electricity transmission is more efficient than gas? What about the losses in the electricity transmission and the batteries and the conversion to motive force in the motor? Is it way less than that 40%? And wouldn’t there be more than 0% losses because refinery -> power plant shipping? I’m pro EV by the way, I just want to understand your point better. Being able to go all the way to tr…
Briefly, the most important reason an EV is better because it unlocks energy portability. You gain the flexibility to source your energy in many more ways than with a gas car. Oil energy is about as optimized as it's ever going to get. With electricity, we're just getting started.
What the hell is this headline and the article trying to say..? "40% of horse-drawn carriage cargo is hay, but 50% of what we feed horses is hay". So what?
If you stop using horses other places, you don't need to move around hay, so you need even fewer horses.
(If the world generally uses less fossil fuels, the demand for shipping goes down as well, since much of shipping is just shuffling around fossil fuels.)
The top graph makes it seem much more dramatic than it is. Maritime shipping is very efficient, and consists of a very small fraction of overall petroleum usage. Road transportation uses about 20x as much fuel as ocean shipping, planes use about 2x as much, and trains about the same amount. The typical rule of thumb is that about 40% of the energy in a barrel of petroleum is lost before it goes into your gas tank. An…
> buy electricity at a random charging station Well there's your problem. Try doing the same calculation with the average residential electricity cost. Most car use is for commutes after all, so most people can just charge their EV in their driveway every night. Destination charging and rapid charging are notoriously expensive. It's a luxury product intended for a once-a-year road trip. It is not even remotely repres…
> so most people can just charge their EV in their driveway every night. That does presume that those "most people" have a driveway where they can do charging. I.e., all apartment dwellers with cars in parking lots/garages (excluding those few that may have installed electrical plugs at each parking spot) are cut off, as are city dwellers without driveways who park on the street (or in another garage, again without e…
It's probably too much to say everybody can do this, but a lot more can than seem to be included in typical estimates. Tomorrow I will walk to work and probably (if the owner hasn't left by then) I'll pass an EV that's plugged in to presumably an ordinary mains supply... via a hole cut in their fence because their car is sat on the street. I'm sure that sometimes they find somebody else took their prime parking spot, but not often. And of course "run the cable through the hole in my fence and lay down the conduit to protect it" isn't exactly an ideal setup, but it works and the car doesn't care how the electricity got there.
> buy electricity at a random charging station Well there's your problem. Try doing the same calculation with the average residential electricity cost. Most car use is for commutes after all, so most people can just charge their EV in their driveway every night. Destination charging and rapid charging are notoriously expensive. It's a luxury product intended for a once-a-year road trip. It is not even remotely repres…
> so most people can just charge their EV in their driveway every night. That does presume that those "most people" have a driveway where they can do charging. I.e., all apartment dwellers with cars in parking lots/garages (excluding those few that may have installed electrical plugs at each parking spot) are cut off, as are city dwellers without driveways who park on the street (or in another garage, again without e…
In the city you just take the bus or metro. Did that for 22 years, no issues.