Electric Bikes - Which is greener? electric bike or human powered bike?

The only way I see an e bike being greener is if riding means you take extra hot showers because of it.

I ride (sometimes) 12.5 miles to work under my own power. I do ride pretty hard and am pretty well soaked with sweat when I get to work. Unfortunately, we do not have showers, so, I keep a hand towel at work which I soak with cold water to sponge off when I change.

I find that as long as you do this as soon as you get to work, you will be as fresh as a daisy all day long. The only time I end up smelly is after I get home at night and sit down and have dinner/watch tv/surf the interwebs. Sweat only stinks if you let it dry up.

So, my experience is that you can do a reasonably lengthy commute and not take extra showers which blows the only rationale that e is greener, right out of the water.

The extra food rationale is laughable. Most everyone eats more than he needs. Riding will get you in better shape which will cause you to lose weight and, imo, end up actually eating less. Also, when I ride to work, I will usually have a few sips of juice and maybe a few slices of toast with PB on them. If I am driving, I usually will have a bowl of cereal, toast and maybe a cup of coffee before I leave.

There is one legitimate way that makes ebiking greener. That would be if having an ebike means you will ride more often than driving the car. But, the question was not put that way. It did not say ebike vs too lazy to pedal cager.

The only way I see an e bike being greener is if riding means you take extra hot showers because of it.
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There is one legitimate way that makes ebiking greener. That would be if having an ebike means you will ride more often than driving the car. But, the question was not put that way. It did not say ebike vs too lazy to pedal cager.

Guilty as charged. :D Actually, it's more like, too lazy to pedal real hard in the morning cager for me. Plus, there is the shower factor. I don't have to shower at work if I rely heavily on the electricity to support my pedaling. Afternoon is the harder pedaling, sweaty time.

OK, now back on topic: the food vs. electricity debate.

OK... I suffer from the curse of being an engineer... I have a Master's Degree in Systems Engineering, and my coursework included studies in research methodology and statistical analysis. I have to tell you... I have read so many wildly unsubstantiated theories and claims that it amazes me. But the dangerous thing is the claims that SEEM to make sense on the surface because of the way that they're presented.

The paper that you guys linked to earlier in the thread is a great example. My training allows me to see that the holes in that paper are gigantic. That paper would earn a failing grade at most reputable engineering schools. It seems like a research result paper on the surface, but to us researchers... it isn't even a good hypothesis summary. It mixes so many concepts and formulas that it renders it's own points invalid... and it dismisses or oversimplifies points that are so complex that it would take many months to accurately analyze and quantify. Basically, I'm calling BS on the paper's conclusions.



But the point is that a hybrid human electric bike is better for the environment at any speed than human power alone at the same speeds.

I would love to see some real research to back this up. All I've seen so far is calculations based on anecdotal numbers and formulas. Besides emotion, what leads you to say this?


It would be up to you to decide how fast to go taking into account that the faster you go, the more CO2 you output.

You've got to be kidding me. Do you know how minuscule that this difference would be? So should I always walk instead of jog so as to minimize my CO2 output??


And IMHO, you need more electricity to produce 276 kCal of food than 100 Wh of electricity.

Opinion isn't proof... Your decisions are all well and good. But please just admit it when emotion or devotion to a cause are behind your choice. Don't try to sell it as scientifically accurate research.

You've got to be kidding me. Do you know how minuscule that this difference would be? So should I always walk instead of jog so as to minimize my CO2 output??

I don't know if you got my point based on that response. An earlier post by someone else pointed out one disadvantage (in terms of energy efficiency) of an electric bike is that it causes you to go faster and therefore use more energy for fighting wind resistance. I'm trying to argue that at any given practical speed on a bicycle and an ebike, the electric bike is more efficient and "greener" because the energy source is greener.



Opinion isn't proof... Your decisions are all well and good. But please just admit it when emotion or devotion to a cause are behind your choice. Don't try to sell it as scientifically accurate research.

Read my earlier post in this thread at how I got this number. It appears you missed it.

Even with my earlier post, I think it's obvious to all that no one, including myself, is trying to scientifically prove anything. Why get bent out of shape that we all can't talk like graduate students with a masters? Step down and join in on the debate.

Here's my argument in a nut shell.

A. Humans are about 20-25 % efficient. Battery + motor is about 80% efficient.
B. To power humans, you need to produce western food... a very energy intensive process. To power a battery, you just burn some coal and send it down the power system.

Both A and B seem to be heavily in favor of the electric bike being greener position.

All these anecdotal stories about how I seem to eat less after I started biking aren't gonna put a dent in the argument above. I'd like to hear it from an energy conservation point of view. Anyone who's taken a physics course before knows that energy has to come from somewhere. What factor am I missing in the argument above?

adam,

I have one question for you.

Are you on a subsistence diet?

If you are, then what you say MAY possibly be true. I'll leave it to hydrated and his post grad degrees to blow holes in it.

Most of us are not on subsistence diets. Infact, I'd guess that the average person is atleast at twice his subsistence caloric intake. My chunky ass is probably at three times. What can I say, I like eating!!!! I think it's an italian thing.

So, if you too are consuming excess calories, your BS arguement deserves every bit of derision it gets.

I am not saying that extreme levels of excercise don't require higher caloric intake. I read an article about Michael Phelps' diet. Dude eats enough in a day to feed a dozen people. He then jumps in the pool and breaks off miles and miles at an absolutely ridiculous pace. I would guess that he swims further than some of us commute in a day. And each one of those laps is swam faster than most of us could swim a single lap.

So, if you too are consuming excess calories, your BS arguement deserves every bit of derision it gets.


I thought we were debating, not trying to attack each other.

We are debating. Part of debating is pointing out stupid arguements.

That and this is the interweb, where our anonimity tends to turn us into arseholes! :)

Take no offense adam.

So, back to the debate. Do you live on a subsistence diet? Do you get by with such a low caloric intake that a rise in activity will require a rise in food consumption? If you do, you are in a very small minority. Atleast in the developed world, you are.