ebike vs pedal power: which is more energy demanding

[mnplus1556]

hey guys, I remember a few years back i came across like an essay pdf file, i think it was on this forum, that compared the ebike to regular pedal. Like which was more efficient and consumed more resources and stuff like that. it talked about the whole line of both; from the beginning which was more energy/resource intense. i never had a chance to read it or save it. Anybody know what im talking about or know where i could find this? thanks, all appreciated!

 

[mrzed]

http://www.ebikes.ca/sustainability/Ebike_Energy.pdf

Written and hosted by the same man who shelled out the money and time to keep the forum free for all.

 

[melodious]

Conclusion
Despite the intuitive sense that electric bikes would require more resources than
regular bikes, life-cycle analysis shows that they actually consume 2-4 times less
primary energy than human riders eating a conventional diet. This conclusion is
largely due to the considerable amount of transportation and processing energy
that is associated with our western food system.
From a sustainability perspective, the best battery chemistry for electric bicycles
is the lithium-ion cell. In the optimum scenario it can deliver nearly 1/3rd of all the
energy put into manufacturing and charging to the wheels of a bike. Since lithium
batteries have a high energy density, they are also desirable from a rider’s
perspective because only a lightweight pack is required. Unfortunately, the
current high-cost of lithium batteries generally makes them less favorable then
other chemistries from an economic perspective.

 

[John in CR]

If the work output is the same, then you have to look at the fuel input and efficiency. The human body is only about as efficient as ICE motors, maybe slightly above 30% efficiency. That's why we shed so much heat and cool off mostly by evaporative cooling. Electric motors are commonly over twice as efficient and some quite a bit more than that. Next look at the cost of fuel, and food as an energy source is several times more expensive than electricity.

Pedalists will typically introduce arguments that some of that energy to pedal would have been eaten and used anyway. While that does have some validity, it's impossible to measure and could only be true for very short commutes. Look at the many thousands of calories needed as fuel for competitive cyclists, and they're perfectly tuned maximally efficient human machines.

Then pedalist would want to talk about resources used to make batteries and the CO2 output from making most electricity. Batteries last a long time now, though they are a major component in cost that should be considered. Agriculture is quite carbon intensive too, and if the pedalist wants to grow his own food, then the ebiker counters with solar panels.

Cycling is great exercise and sport, but as economical and practical transportation for more than very short distances, an ebike comes out several times ahead by all measures. Plus an ebike can be set up to pedal just fine too.

John

 

[USAEBIKECO]

Electric bikes are more effecient than pedal power.

Think about commuting to work 8 miles. Riding an ebike on electric it costs abour .03 cents to charge the battery. If you had to do that same 8 mile commute pedaling on a regular bike you would need to drink water, so obviously there is a cost there. Bottled water is what 1$ a bottle usually? Then think about the calories burned while pedaling, you will need to replenish those calories with food. There is another expense.

That 8 mile commute can be done in HALF the time on electric vs regular pedal bike.

Electric bike wins! Unfortunately more hard core cyclists dont agree. They dont see things the way we do.

 

[mrzed]

Justin's argument is purely energy efficency, and so ebikes win out. Lester, you are talking cost efficiency, and then you include the time parameter, which is so variable if you are trying to convert it to $.

Taking into account the health benefits of pedaling, I think I'd have to side with the pedalists. Health care is enormously expensive. The time I spent pedaling has been a big part of the reason I am still fairly fit in my middle years. A bike is way cheaper than a gym membersip or even treadmill, and it also gets you to work.

 

[neptronix]

Energy efficiency depends on where the food comes from.
Most people eat the stuff that comes out of industrial agriculture, which requires petrochemical fertilizers and lots of energy input as well. Now if you eat all organic locally grown, or like from your backyard, then i truly don't know how to work that equation. You could have a net zero energy impact.

I did an economics comparison of cars vs motorcycles vs pedaled bikes vs electric bikes in this thread a while back:
http://endless-sphere.com/forums/viewtopic.php?f=7&t=25832

 

[hjns]

Having four children, I can certainly certify that ebikes are much more efficient to get from A to B than raising children until they are old enough to pedal me from A to B. Apart from all the money that it takes to get them, feed them, nurse them, clothe them, and house them, the psychological strains are immense, not to mention the worries, dealing with teachers, other parents, other kids who are always raised in the most abominal ways (definitely worse than your own), and finally the (grand) parents in law....

No, if you talk about energy investments for the whole line from the first concept to the final delivery of getting me from A to B, or cost efficiency, E-bikes rule the world for me! Kids are more like a life ensurance, which I can not say of my ebike.