Flying 40,000 km around the world with no fuel is no easy task. Pilot Bertrand Piccard at Solar Impulse did it, but to enable the rest of us to do so will require some engineering.

Imagine all the passenger and private fixed wing and rotary wing aircraft that fly each day in our world and the pollution it brings to our air. How can we improve this situation? Clean energy is coming.

I recently came across a really neat concept from a paper, SUAV:Q – A Hybrid Approach To Solar-Powered Flight,1 given at the 2016 IEEE International Conference on Robotics and Automation (ICRA) in Stockholm, Sweden, on May 16-21, 2016 by Ruben D’Sa, Devon Jenson, and Nikolaos Papanikolopoulos from the University of Minnesota. This paper looks at the concept of a small-scale hybrid unmanned aerial vehicle that can enhance the maneuverability of a quad-rotor with the energy collection and power supply of a solar-powered fixed-wing aircraft. They investigate the aircraft design, transforming mechanism, and energy management of the multi-state system using a quad-rotor demonstration.

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=7487501&url=http%3A%2F%2Fieeexplore.ieee.org%2Fiel7%2F7478842%2F7487087%2F07487501.pdf%3Farnumber%3D7487501

It’s frustrating when someone with little or no understanding of the reality of engineering tradeoffs in a design makes casual, offhand comments, such as, “Why didn’t they just add this function?” That sort of remark tells me that they have no experience or insight into the realities of the situation. Design is all about making decisions within a square defined by parameters of power, performance, practicality, and cost at its corners. Some designs will do almost anything to be at one of those corners and are only lightly constrained by the other ones, but most designs strive to find an acceptable “sweet spot” somewhere within that box.

So it is with the all-electric airplane. Regardless of your views on the wisdom, desirability, and near-term practicality of such a craft, it’s a fascinating design exercise. This was made clear in the recent article “How I Designed a Practical Electric Plane for NASA”

How I Designed a Practical Electric Plane for NASA
http://spectrum.ieee.org/aerospace/aviation/how-i-designed-a-practical-electric-plane-for-nasa

To win a competition, a Georgia Tech student devised a fuel-cell plane to rival today’s best-selling small aircraft

Submitted to a NASA competition for students, the design for this electric aircraft had to meet certain requirements, the most important of which was that it could be manufactured within five years.