Electric bikes get over 1,100 mpg...

Bicyclista

Active Member
Or so says bike engineer Zach Krapl in this TED talk:

This astounding figure is reached only if you charge your ebike battery via a solar panel. Otherwise, the equivalent mileage goes down to around 500 mpg. Not shabby! I assume those numbers are reached via a math formula that takes into account all the energy expenditure in getting to the point of riding your electric bike: manufacture, electrical generation and distribution, calories spent, etc.

The question is, What is the formula? What are the assumptions and what are the calculations? I've googled this question to no avail. It's not that I doubt the figures, it's just that I want to understand them well.

Thanks in advance!
 

Dunbar

Well-Known Member
I read here that there are 32,000wH of energy in a gallon of gasoline. E-bikes use around 10wH/mile to go 20mph and 30-35wH/mile to go 30mph. I'm guessing his speed assumptions are in the 20mph range (not unreasonable to assume in urban rush hour traffic.) His MPG figures for automobiles look pretty standard so I doubt he's including the total energy used to mine/refine and get the energy to the pump/outlet.

I'm sort of skeptical of his claim about local food being lower energy though. The economies of scale that come with mass agriculture are hard to ignore. I've read transportation accounts for less than 10% of the energy used in food production. Most of the energy is used in the farm equipment and to create the fertilizer.