So what regenerative systems are out there? Only two:
1). Photovoltaic Panels (on the wings and stabilizer). This technology has the advantage of being lightweight, easily integrated into an airframe, and provides consistent power. (When solar energy can be accessed). Without doubt the stunning proof-of-concept came from the team at Solar Impulse, a Swiss-origin company that produced a mega-motor glider that circumnavigated the globe heading east from Abu Dahbi on March 9, 2015 and back there on July 26, 2016. Pilots Bertrand Piccard and Andre’Borschberg alternated legs of the flight, setting numerous sustainable flight records, including Flight 8, from Negoya Japan to Hawaii in 5 days and nights. (Average speed of the big bird was 31 mph (50 km/h).
The company is without peer in promoting clean, renewable aerospace technologies. The website is also a technological achievement: http://www.solarimpulse.com/adventure
A good overview is found on Wikipedia: https://en.wikipedia.org/wiki/Solar_Impulse
The other ‘currently’ popular in-flight charging system?
2). Regenerative propeller. AKA Regenerative braking. The electric aircraft, while gliding or descending, uses the changed angle of attack to create torque on the prop shaft to invert the current from the motor, sending it back into the battery pack. Most electric motors, when spun backward or when the direction of the current is inverted, act as generators. This does create some drag, which I’m told can be beneficial during descent — acting as an airbrake. Regenerative braking is used as a selling point by European electric aircraft builders — trying to alleviate range anxiety among buyers. It does very little good–what percentage of a typical GA flight is spent gliding or descending? ElectronAir’s system can be activated during the majority of a cross country flight.
We learned personally that regenerative braking while descending is not going to fly with some pilots. Recently we wrote a letter to the Lindbergh Foundation/Powering Imagination (Eric Lindbergh, grandson of Charles ‘Spirit of St. Louis’ Lindbergh) to introduce ElectronAir LLC and our regen patent/system. We described our system (using the prop blast to spin a small turbine). Eric Bartsch, COO, of Powering Imagination was kind enough to respond, and his information is useful. We must not have been clear about our prop blast, not prop braking, regen system:
“Thank you for contacting us and for sharing the information about your aircraft work. I will not be at Sun N’ Fun (airshow) this year due to conflicting meetings with some of our electric aircraft development partners. There are several electric flight programs, including one I was previously involved with, that have flown systems that were capable of regenerating power during descent at the end of the flight. My personal experience was that the amount of energy we were recovering was not particularly large. Hybrid or electric car systems benefit from the amount of stopping and starting done in normal driving, but there is relatively little acceleration and deceleration during a typical flight.
I don’t want to dissuade you from pursuing this concept, but I did want to share personal experience with a similar system. As a pilot I found that I did not necessarily want the prop turning into an airbrake when throttling back at the end of the flight. Regenerating any significant amount of power requires recapturing a lot of the planes energy and slowing it down substantially. The added descent rate and/or reduced airspeed weren’t always desirable characteristics during the transition from cruising flight to final approach. Best of luck with your aviation program and I would love to hear more about them as you make progress.”
–Eric Bartsch, COO Powering Imagination
Mr. Bartsch is high on our list to receive the power-point video we are now producing, and a demonstration of our prototype.