| Potential energy is only one component of the power required by aircraft. If you want to actually go somewhere, you need speed, which means drag. Drag increases the square of the velocity. That means going at 500knots (as an airliner does) uses a lot more power than going at the 150knots this seaplane might fly at. You can calculate an approximate power requirement for the aircraft based on its glide ratio [1] or look at the power based on engine thrust [2]. In all cases you get figures in the 14-80MW range (engines don't tend to be full throttle during cruise) That means your 260Wh/kg battery would need to weigh somewhere between 54 and 308 tonnes to sustain an hour of flight. That doesn't include takeoff, which is only a few minutes but might reach towards 200MW. For reference, the 737 (low end power calculation) max takeoff weight is 62 tons and the 747-400 max takeoff weight is 397 tons. So in both cases you're looking at basically 30 minutes of useful cruise with current battery tech. The range loss is additionally confounded by the fact that current aircraft lose fuel, so lose weight, during the flight. This accounts for a not-insignificant portion of the range. [1]: http://large.stanford.edu/courses/2013/ph240/eller1/
[2]: https://aviation.stackexchange.com/questions/19569/how-many-... So basically for electric passenger aircraft with even remotely comparable performance, we need a battery revolution. It definitely won't be by 2030. |