Tesla S3X power consumption versus high power electric bike (estimates)... WTF

[dustNbone]

Yeah we need to quit hoping/waiting for the technical marvel that's going to allow us to continue travelling and consuming energy the same way we have been for the last number of decades.

I know it's not popular, especially in North America, but the painful reality is that if we're actually serious about about conservation, we need to slow the $@%# down. Same as speeding up a little increases consumption a whole lot, slowing down a little decreases consumption by a whole lot. Airliners and cargo ships go slower now than they did 40 years ago, not because we're forgotten how to make them go fast.

2 ton luxury boats going 90mph down the highway is NOT the future, even if they're electric. Electricity still has a cost, and will continue to be finite for the foreseeable future.

 

[MikeSSS]

Surface to volume ratio is one of the most important factors in nature. Large things have lower surface to volume ratios than small things. This is surface area divided by volume. Square meters / cubic meters, that sort of thing.

Large vehicles will always have an advantage over small vehicles. The Concorde airliner cruised at Mach 2.04, an F-15 has a faster top speed, about Mach 2.5, but cruises at Mach 0.9 or less.

When I was teenage I flicked a line of ants off a railroad overpass, these ants were about 1/360 the length of a 6 foot man. The overpass was about 30 feet high. The scale distance of the ants fall was about 11,000 feet. A man falling 11,000 feet and landing on concrete will be very dead and not a pretty sight. The ants were walking around on the concrete they landed on and were not squashed in the least. Even a fall from an actual 11,000 feet would not kill an ant, its terminal velocity is much less than that of a human. It has less terminal velocity because its air drag per unit weight is proportionally much higher than that of a man. Reason for this is much lower surface to volume ratio. There is more too, an ant has an external skeleton and a human has an internal skeleton because these designs are dictated by surface to volume ratio.

A bike has much dirtier aerodynamics than a modern car but it is also much smaller. The bike has a double dose of the laws of nature working against it, compared to a car.

Surface to volume ratio is also the reason that very small piston engines have higher fuel consumption per horsepower per hour than larger piston engines of the same type. The very small engines simply have proportionally higher heat rejection to the surroundings because they have proportionally higher surface area. Same type is important in this, comparing a modified Atkinson cycle to a two cycle would be completely invalid.

Moving 30 people by bus rather than by 30 motorcycles will always use less fuel. Same for moving 350 people by A340, it will always use less fuel than moving them in many business jets.

Then there are things like combustion, a match held to a steel wrench will not ignite it but the same match held to steel wool will light it.

Hope this helps.

 

[bakaneko]

Not to belabor this point as interesting as I think it is. But, maybe we go the aero road bike route. Check this out. I actually want to get into cycling too. Near professional rider hits 42mph on 1300W burst. Its impressive the speeds these guys get too and maintain though they do rotate lead bikers and draft behind him and are in aero tuck/clothes and have like $5k bikes.

https://www.youtube.com/watch?v=zQquWLlPc6Y