I've read that a typical human-powered bicycle power generator generates around 100W. For the same amount of effort, the bike travels probably around 20k/h on a road. Does that mean it requires 100Wh for a ~70kg load to travel 20km? If so, does it mean that a 70kg-machine with wheels (e.g., a RC car) requires 125Wh (100Wh / 0.8 assuming 80% motor efficiency) to travel 20km? But how well can one translate the energy human expends when cycling into energy a machine with wheels expends?

  • $\begingroup$ The human body has an efficiency of about 0.25, so you'll burn energy at a rate of 400 Watt to deliver that 100 Watt to your bike. $\endgroup$ – Count Iblis Mar 6 at 5:29
  • $\begingroup$ @CountIblis Yes, but if a human rider burns 400W to travel at 20kph, will a machine only need 125W to travel at 20kph given that motors have an efficiency of around 80%? $\endgroup$ – John M. Mar 6 at 11:06
  • $\begingroup$ Yes, that's right $\endgroup$ – Count Iblis Mar 7 at 3:54

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