Interesting!<p>> The above figures were all produced by assuming average or typical cases. To be fair, it is entirely possible for a bicycle rider to deliberately eat only locally grown and unprocessed foods. In that case, the ratio of primary energy to food calories is closer to 1:1 (Günther 3). Combined with a metabolic efficiency of 25%, this increases the human energy efficiency to 1:4, slightly better than the lithium-ion electric bike.<p>> ...<p>> 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.
Recognizing it was first-order approximation, two significant problems with the comparison:
1. E-bike riders likely to travel much faster. Since drag is quadratic, change in consumption significant.
2. The important energy comparison might not be manual bikes, but other modes of transit. A current driver/transit-rider might choose to bike 15 miles each way only if on an e-bike.
"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."<p>And obviously, caveat lector: there are huge assumptions going on here, because the "real" cost of stuff like food and batteries aren't trivial to calculate at all. It's not like you can feed em both the same resources anyhow, so at best this is an analysis that the efficiency is sort of comparable. In 2004.
I've been an e-bike advocate since the first time I rode one. It's an amazing feeling being able to effortlessly overcome hills and riding as fast as 28mph on flat terrain without struggling too much.<p>The major downsides are: weather extremes (that are going to be more common). The bike is generally heavier (much more effort to get it into the building or onto a bus).<p>And of course, the biggest one of them all - you are now vilified by both car drivers and pedestrians, while taking on more risk than either one. And of course suburban sprawl being the center-point of US culture, anywhere takes too damn long to get to even on an e-bike.<p>It's unfortunate that the US isn't more dense, which would make an ebike an ideal mode of transport in ~80% of cases.
Bottom line is that bikes are efficient because they’re slow and light, not necessarily because they’re human powered.<p>In both cases the energy use is lower than lots of things that we don’t think of in terms of energy.<p>By way of comparison, a hot shower used about 300 Wh (a full charge on a smallish ebike battery) every <i>minute</i>.
> To travel one kilometre by bike requires approximately 5-15 watt-hours (w-h) of energy, while the same distance requires 15-20 w-h by foot, 30-40 w-h by train, and over 400 w-h in a singly occupied car.<p>Since the rise in popularity of electric cars 400wh/km is actually quite high.<p>Most electric vehicles are rated city/highway 15/20kwh/100km
(150 w-h/km / 200 w-h/km)<p>On this page:<p><a href="https://forum.abetterrouteplanner.com/blogs/entry/13-model-3-consumption-and-charging/" rel="nofollow">https://forum.abetterrouteplanner.com/blogs/entry/13-model-3...</a><p>it shows the model 3 gets 143 Wh/km at 110 km/h
> <i>The metabolic efficiency of a human on a bicycle is remarkably good. Calorimetric studies have shown that a properly trained athlete will have
efficiencies of 22 to 26% depending on pedal cadence and power output.</i><p>Anectdote about this, is that my watt meter on my bicycle gives out the total amount of work done in kJ at the end. To convert that to kcal in food, one can convert 1-to-1, as the metabolic efficiency matches roughly the ratio between kcal and kJ.
I think they should count energy savings associated with health benefits of riding normal bike. Hospitalisations use ton of single use items that bound to have some energy cost.
The author lost me at the assumption that humans on electric bikes eat less than humans on pedal bikes.<p>Personally I eat about the same whether I drive or bike, just ride to avoid getting fatter.
They want to sell electric bikes, so they found an obscure point of view from which they may be preferable to the ordinary one. Ignoring the obvious points of view from which they are not - health disservice to the rider, battery tech non-monetary costs, increased electricity consumption of the owner.<p>Electric bike has its legitimate target group - elderly or ill or handicapped people. If you're fine, get that ordinary bike and build some form.
I think this is one of the few edge cases where gifs could improve the comments on HN<p><a href="https://tenor.com/view/walle-humans-lazy-eve-disney-gif-5471514" rel="nofollow">https://tenor.com/view/walle-humans-lazy-eve-disney-gif-5471...</a>