CAFE Symposium Celebrates the 'Dawn of Electric Flight'
Part 2
By Patrick Panzera, Editor — Experimenter, EAA 555743
Part 1
May 3, 2011 —Picking up where we left off in Part I of this series, David Calley, Co-Founder and Chief Technology Officer of Motor Excellence gave his presentation “Ideal Electric Aircraft Motors.†The primary point Calley made was that a key barrier to widespread adoption of electric vehicles is the additional cost above comparable internal combustion engine vehicles due to large, expensive batteries.
The focus of Motor Excellence has been to develop lighter, highly efficient, and thermally stable motors that provide the same power and torque at a lower power demand than the current state-of-the-art motor technology allows. This enables a significant reduction in battery size and cost, netting a result similar to increased battery energy density.
Coming from the wind generator side of the clean-energy movement, with generators and electric motors having much in common, Calley, the founder of Southwest Windpower, brings his decades of experience from creating highly efficient generators to the electric motor industry. Using what he refers to as "3-D construction" (where there is only a single winding made from heavier gauge wire resulting in less resistance), Calley has designed high-torque, low-RPM, thermally stable electric motors that are suitable for direct-drive use in bicycles and automobiles. In some aviation applications however, they might need to be geared up.
Motor Excellence feels confident that even with a shortage of rare earth magnets, they can still outperform conventional highly efficient electric motors.
Two additional points of interest Calley brought up were 1) the current rate of the world demand for eBikes is in the 30 million per year range, and 2) China controls nearly all the rare earths necessary for neodymium magnet (rare-earth magnet) production, essential in creating small, light and powerful electric motors.
While the focus of the Electric Aircraft Symposium would seemingly be electric aircraft, a lot of what was discussed was either in support of efficient flight or a seemingly practical application of electric flight where it could be potentially more efficient than an internal combustion engine.
