Humans are a pathetically inefficient motor; Gasoline engines are around 30% efficient and battery-electric drivetrains are more than 90% efficient. A bicycle looks efficient because that inefficient motor is also pathetically low in power - a typical recreational cyclist can only sustain about 120 watts of output.

The leading vehicles in the Shell Eco-marathon routinely exceed 10,000 MPGe. PAC-Car II is the current world record holder, achieving 12,600 MPGe on hydrogen fuel.

Photovoltaic cells are also astonishingly more efficient than photosynthesis. The theoretical maximum efficiency of photosynthesis is ~11%, but most plants only achieve 3-6% efficiency. The leading commercially-available PV panels achieve ~22% efficiency and prototype concentrator PV cells have achieved over 46% efficiency.