Electric-assist bicycles are becoming very popular in Europe and industry insiders at this year’s Interbike show were speculating that they may be the next big thing here in the U.S.
With high gas prices and dire economic conditions on everyone’s mind, more people than ever are looking at the bicycle as a serious mode of transport. The problem is that many people are not capable of just hopping on a bike and making a 10-20 mile (or longer) daily commute after being sedentary for years. The e-assist bike may be a solution for these people, as well as for those with physical handicaps or injuries that prevent them from riding a traditional bicycle long distances.
One of the arguments against e-assist bikes is that they’re not as environmentally-friendly as standard bicycles. At first glance, this seems true enough, but upon closer inspection it appears the answer may not be so simple. From e-bikes.ca:
Surprisingly, electric bikes can have a smaller environmental footprint than pedal-only bicycles. Not convinced? Look at it this way, a human powered vehicle is using the human metabolism to convert food energy into work, with a conversion efficiency of about 25%. That’s the first part of the picture, then we have to step back and look where the food energy comes from. In north america and europe, the food is grown with the aid of chemical fertilizers and machinery, it is then transported, processed, packaged, transported, sold, transported again, and finally cooked before consumption. In the end about 10 times more primary energy went in to producing the food than is actually stored in the food itself. The net effect is that for every unit of human energy used on a bike, about 40 times that much was consumed.
By comparison, with an electric vehicle you are taking primary energy from the grid and storing it in a battery at between 60-80% efficiency, and then converting it to work through an electric motor with roughly 75% efficiency. That’s a lot more direct than the human route. Once you take into account the energy to manufacture and recycle the batteries, e-bikes end up consuming from 2 to 10 times less fossil fuel energy than their human-powered equivalents. To see more details and references, have a look at the Ebike Energy article.
I can’t vouch for the above analysis, but however you spin the numbers, e-bikes are highly efficient and a heck-of-a-lot better than automobiles. And more importantly, they provide an alternative to the traditional bicycle for those who would otherwise be excluded from using bicycles for transportation.
There are currently over 1,400 e-bike manufacturers in China, producing over 5.5 million units a year (mostly low-end models in the $500-$1500 price range). High-end models manufactured in Canada and Europe can run as high as $3000-$4000.