There are many types of electric aircraft, from helicopters to blimps, and different ways of propelling them include considerable numbers of electric motors driving many airscrews - because electric motors are not as scalable as jet engines - down to single screw manned aircraft such as those of PC-Aero.
Most of the focus has been use of pure electric drive systems from NASA envisaging electric motors driving the wheels to takeoff and regenerating electricity on landing to PC-Aero manned pure electric aircraft that are similar to conventional ones.
Then there are hand launched unmanned pure electric aircraft from ETH Zurich and the belief that aircraft that dive and float are now feasible, in the view of Hawkes Ocean Technologies. It does not stop there because larger aircraft will need to be hybrid at least initially, as will those manned aircraft that need a more realistic range for general use. For example, the large airframe manufacturers envisage passenger craft taking of and landing silently i.e. electrically.
The University of Colorado has struck a deal intended to bring improved hybrid engine technology to aircraft, the University of Colorado Technology Transfer Office announced this month. Tigon EnerTec Inc. is a startup that designs eco-friendly propulsion systems and it is working on a system that allows aircraft to use both traditional internal combustion engines and electric motors during flight.
Aircraft operators would have the ability to switch between systems during flight, allowing them to optimize fuel use, Tigon President Jean Koster said. His vision is that gas-powered engines could be used during takeoffs, when aircraft use the most energy, while battery-powered motors could power the aircraft while it is cruising or landing.
He designs modular, energy efficient, and eco-friendly propulsion systems to increase safety, performance, and reliability of operation. Tigon has focused on the product's "variable optimization", or the ability of the platform to adapt to a variety of applications of Concepts of Operations. For example, Tigon has designed and developed a proprietary gearing system for a hybrid propulsion system. Input may come from a combination of select combustion and/or electric motors, with the mechanical output to a single shaft.
The system, confusingly nicknamed HELIOS (there is already a Helios electric aircraft), was developed by a team affiliated with the CU Aerospace Engineering Department. It evolved from a student project, Koster reported.
Tigon is working with aerospace and defense contractors to investigate possible applications for unmanned air vehicles. It also is pursuing technology with applications for general aviation and marine and ground transportation.
The company will receive $40,250 from the University's Renewable and Sustainable Energy Institute Market Assessment Program to finance a proof-of-concept project, a statement from the Technology Transfer Office said. Tigon is based in Louisville but is planning on moving to Boulder in the next few months, Koster said.
That area of the USA is famed for its development of the most advanced solar cells - another part of the equation as they power pure electric aircraft of ETH Zurich and others.An elegant alternative hybrid aircraft technology for light duty will involve the tiny Bladon Jets turbine as a range extender in light aircraft.
For more attend: Future of Electric Vehicles which uniquely covers the whole electric vehicle market - land, sea, air whether hybrid or pure EV - with emphasis on future breakthroughs.