[lizardmancan]

imagine the thing has no wheels. the wind provides an energy source.

now imagine a sail cart. you can put a dynamo on the wheel and extract power

now imagine a sail boat sailing close to the wind. it can go much much faster than the wind speed

now imagine a batter powerd propeller pushing a cart forwards.

now imagine the battery powered prop is pushing against the wind. a+b

now remove the battery and extract the power (a) from the wheels.