When will we see 3000 Watts?

[Chriull]

27 minutes ago, Mono said:

OK, cool, so the efficiency graph is always increasing up to the point where load and power become the same. As if one could not have predicted that . But that means just choosing the optimal throttle should always give 80%+ efficiency. Why should we even talk about efficiency then?

??? Try changing the "grade %" (= higher load) and max efficiency possible will drop. Especially if one wants to ride slower...

Or did i miss(understand) something?

[Mono]

True, if speed approaches zero then also efficiency approaches zero and that happens more quickly on steeper inclines (above 20% incline and below 10km/h speed the efficiency seems to drop below 50%). I am not sure though that this should be attributed to a suboptimal electric motor. It seems rather due to the nature of the physical setup: if we need to push against a force (here gravity) we need to invest energy but do not create kinetic/mechanical/potential energy in return, hence zero efficiency. That is the nature of the setup. Computing efficiency how it's done is certainly useful, say, for excess heat considerations and energy balancing in general. But for evaluating the motor, the result seems rather a defect in how we define or conceive efficiency in this setup, because it seems not to be the "lack of efficiency of an electric motor". If this is so, any new motor design won't do anything to address this efficiency deficiency.

Is it even possible to build a free-floating device that can push itself up against gravity with 80% efficiency at any speed?

Edited December 19, 2019 by Mono