How I Designed a Practical Electric Plane for NASA
While the range of electric aircraft has been growing, limited flight time remains their main weakness. The reason is that batteries are heavy relative to the propulsive energy they provide—by a factor of 10 or more compared with that of gasoline-powered internal combustion. For ground vehicles, designers can compensate somewhat for this shortcoming by adding more or bigger batteries. But aircraft are extremely sensitive to extra weight: Just about every component of a plane’s structure must grow in size for each added kilogram. The requirement for beefier components in turn leads to a heavier aircraft, one that requires still more energy and therefore larger batteries to fly. This vicious circle means that for electric-plane design, adding batteries to boost range isn’t a viable strategy.