Chet Fuller of GE Aviation showed that electrification of aircraft can go beyond the powering of relatively small general aviation aircraft: many of the systems aboard large commercial jets can be electrified as well, removing their loads from the powerplants and thus increasing overall efficiency.

Additionally, replacement of complex and sometimes maintenance-intensive systems such as pneumatics and hydraulics can improve overall safety and reliability.

Fuller noted that Boeing's new 787, "the first all-electric airliner," will have dual generators providing a total power of 1.4 mW-enough to power a subdivision of over 100 homes.

Cell structures: Batteries still key
JB Straubel of electric-car maker Tesla Motors noted that while automotive applications differ from aviation ones, a great deal of commonality and crossover exists between them.

This is particularly true in areas such as battery technology, with the huge size of the automotive market helping inevitably to drive down the price of advanced battery cells.

Since the Tesla roadster is exposed to the risks and bumps of road travel, the design of its battery packs embodies many safety features that could easily be applied to aviation systems.

Other speakers came from NASA and Ford and a number of themes recurred throughout the afternoon sessions.

On the technical side, everyone agrees that at present, battery capability is the main bottleneck. When better batteries are developed-as they inevitably will be-the motor and controller technology already available will be waiting for them.

And on the economic side, everyone agrees that electric propulsion, both on the ground and in the air, will gradually supplant more and more fossil fuel technologies.

As Straubel put it, "as batteries get cheaper, oil will only get more expensive."