Environmental and ecological discussion, particularly of things like weather and other natural phenomena (especially if they're not breaking news).
See also our Nature and Gardening community for discussion centered around things like hiking, animals in their natural habitat, and gardening (urban or rural).
This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.
Simple physics demands that this use less energy.
E = mv^2/2.
Say cars are 10x the weight and drive 2x the speed of an electric bike. That's 40x energy.
Additionally, bikes are more likely to have less erratic go/stop behavior, so even more efficient. For example, I'm much more careful to coast on a bike than a car because it's my energy.