The blog recently showed an Alpaero Exelec electric motorglider to which Francis Marlier of the ultralight club of Alsace, France, had taped 66 square feet of solar cells. The Sunexelec that resulted has enhanced endurance, managing up to four-hour flights, although Francis does not indicate how much of that is soaring flight and how much powered. He reports, “Using SUNPOWER C65 solar cells which are encapsulated in modules of 20 or 15 cells. The total weight per wing of these modules is about 3 kilograms (6.6 pounds). “I have used special 3M adhesive tape to fix the modules [which are 0.8 millimeters (3/64-inch) thick] directly on the wing skin. Special covers are put on the wings that I remove just before the take-off. During the flight there is no risk to damage the epoxy resin.” His airplane has a 60 Volt, 30 Amp-hour battery pack measuring 30 x 30 x 20 centimeters (11-13/16 x 11-13/16 x 7-7/8 inches) to power …
Giving Power Walking a Whole New Meaning
Georgia Institute of Technology researchers have developed a self-charging power cell that uses a piezoelectric membrane to convert mechanical energy to chemical energy, then stores that energy until it can be released as en electrical current. Combining the power generator with the energy storage device, this hybrid is claimed to be more efficient than systems with separate generators and batteries. When the piezoelectric membrane is flexed, it moves lithium ions in the power cell from one side of the cell to the other. Membranes in shoe heels and soles could produce power when a person walked, powering small electronic devices such as calculators or cell phones. Zhong Lin Wang, a Regents professor in the School of Materials Science and Engineering Georgia Tech, explains the distinguishing feature of his team’s innovation. “People are accustomed to considering electrical generation and storage as two separate operations done in two separate units. We have put them together in a single hybrid unit to create a …
Hydrogen Scooters – A Possible Power Source?
Amateur aircraft builders, like Francis Marlier of the ULM Club in Alsace, France who recently converted his Exelec to a Sunexelec with the addition of solar cells, are always looking for reasonable options for powering their airplanes. Perhaps they could turn to fuel cells as a range extender. Several motor scooter makers are bringing out fuel-cell powered models that show some promise despite limited performance and high prices so far. Intelligent Energy, an English company, demonstrated a fuel cell scooter in 2005, and a number of aircraft developers, including Boeing, have crafted fuel-cell-powered vehicles. Intelligent Energy’s ENV was reportedly the world’s first purpose-built fuel cell motorbike, and Top Gear’s James May enjoyed the quiet ride, if only moderately endorsing the bike’s sedate performance. http://www.youtube.com/watch?v=igrKemNvxZQ Intelligent Energy’s entry for the Make It in Great Britain exhibit at the Science Museum gives a brief overview of proton exchange membrane fuel cell technology. “This award winning zero emission electric vehicle is powered by Intelligent …
Recharging in Flight – Two Approaches
Two videos made available in the last two days highlight different approaches to recharging an electric airplane in mid-air, one for a full-size, trans-Atlantic flight attempt, and the other for a miniature drone which could fly persistently in a battle zone. Both have been reported in this blog recently, but without the helpful animation. VIDEO WITHDRAWN BY REQUEST (PLEASE NOTE: Chip Yates sent the following message today, August 23: “The video of the mid air recharging was done without any involvement from us and by some unknown third party. We have no knowledge of how that video came to be or why the plane is flying backwards. Please make it clear to your readers that this is an unauthorized video done by some enthusiast and not our plan whatsoever!” Chip Yates’ Flight of the Century proposes staging a series of autonomous drones on mid-ocean platforms to recharge a larger airplane by climbing up to and docking with it as it passes overhead. The video shows …
Electrics Hit Their Stride at Pikes Peak Hill Climb
Since Chip Yates hit the fastest time ever for an electric motorcycle up Pikes Peak last year, then pulled the UQM motor from the bike and installed it in his Long-ESA (Electric Speed and Altitude) record-setting flying test vehicle this year, other Pikes Peak EVs have demonstrated the benefits of their high torque power units. Such performance shows the ready applicability of electric motors, with their uncompromised performance at altitude, as being great for hill climbers or aircraft. Toyota, Mitsubishi, and several private individuals entered the 2012 Pikes Peak International Hill Climb, three finishing in the top 15 of all competitors. Scheduled for July, the hill climb had to be set back to August because of massive wild fires in the area. David Herron reported in Torque News, “The top electric finisher, Fumio Nutahara, driving the Toyota Motorsports Group EV P002 electric race car. The EV P002 is built on a Radical race car chassis, and has pair of axial flux electric …
Silent Falcon – A Solar-Powered UAV
While Boeing and AeroVironment proceed with stratospheric, hydrogen-powered giants such as the Phantom Eye and the Global Observer for extremely long-range surveillance and monitoring duties, an Albuquerque, New Mexico company is exploring the potential of a small, lower-altitude, hand-launched craft that can search – and if necessary – destroy. A recent report from Volta Volare’s Paul Peterson attending the Association for Unmanned Vehicle Systems International conclave in Las Vegas, Nevada and an email from George Bye, Chairman and CEO of Bye Aerospace, alerted your editor to the new reconnaissance aircraft. George wrote, “While the electric Cessna program continues to advance under the leadership of Charlie Johnson and a new name, ‘Beyond Aviation’, we have continued our research into solar-electric hybrid propulsion in unmanned aircraft. At the early August 2012 AUVSI conference, my company, Bye Aerospace together with Silent Falcon UAS Technologies, unveiled a small solar-electric powered drone. The remarkable economics and technology is proven and the performance benefits have been demonstrated.” …
Green Speed Cup – Year Two Final Results
Stemme’s Green Speed Cup, a speed and economy run that was to have sped over six days, ended on the fifth, with all five Stemmes still competing, but with a big break between the top three and the bottom five. Stemme’s web site explains the deletion of the sixth event. “The final race of the 2012 GREEN SPEED CUP was a task of 246 km north of Berlin. Although the weather forecasts looked good this morning, the actual weather didn’t match the expectations. Thus the teams compared their powered flight capabilities as the weather didn’t offer too many possibilities for optimization.” Day five was a cat’s cradle of crossing triangles that added up to 248.2 kilometers (153.88 miles) and was won by Markus Scherdel in his S10VT at a speed of 143.2 kilometers per hour (88.78 mph) while burning 4.4 liters per 100 kilometers (53.46 mpg). This was not a best speed or most economical flight for the event, but …
Fixed Wings Find Their Way
Dynamic presentations by Sebastian Thrun and Nicholas Roy have alerted and informed CAFE Foundation’s Electric Aircraft Symposia attendees of highly sophisticated efforts to allow autonomous full-size automobiles and miniature helicopters to navigate through or over unfamiliar terrain. Using clues from lasers, infrared sensors, inertial guidance systems and sometimes GPS coordinates, the vehicles use control algorithms to guide themselves around obstacle-strewn courses. As noted in Science Daily and the The Massachusetts Institute of Technology’s press office this week, “Dozens of research teams have competed in a series of autonomous-helicopter challenges posed by the Association for Unmanned Vehicle Systems International (AUVSI); progress has been so rapid that the last two challenges have involved indoor navigation without the use of GPS.” Mini-copters have shown an amazing ability to not only navigate, but to perform complex tasks in swarms, such as building large architectural assemblies – all without human intervention (other than, one assumes, someone pushing a “go” button). MIT’s Robust Robotics Group has …
Green Speed Cup – Year Two, Days Three and Four
As the Stemme Green Speed Cup speeds into day five of a six-day series of challenges, the leaders are all – little surprise here – Stemme aircraft. Markus Scherdel took first place on day three’s task, a 346.1 kilometer (214.58 mile) triangle, with a new low in fuel consumption, 2.5 liters per 100 kilometers (94.08 mpg or 188.16 passenger miles per gallon) at an average speed of 142.2 kilometers per hour (88.16 mph). This is impressive because it comes close to requirements for Green Flight Challenge qualification. None of the five Stemmes competing managed less than 4.5 l./100 km. (52.26 mpg), right in Prius territory at much higher speeds. The Diamond DA40 TDI departed the contest because of other obligations for pilot Daniel Hirth: the Arcus electric motorglider did not compete because its limited range would have probably forced an outlanding. The video provides a warp-speed view of day four’s task. Day four found the S6RT, the retractable-gear version of …
Sunexelec – Recharging in Flight
The Club d’Ultra Léger d’Alsace is a group of French enthusiasts in Strasbourg, on the German border about halfway between Luxembourg and Switzerland. They have been building ultralight aircraft since 1983, tackling technological innovations such as carbon fiber leading edges, motorization, electrification, and now solar power. They were the first to motorize a Swift, and with one of their craft electrically powered, mounted strips of photovoltaic cells to the upper wing surface. Finding that worked to boost battery duration, the group went on to mount 6.1 square meters of solar cells on an Alpaero Exelec, an ultralight self-launching sailplane. After making 60 flights on battery power between May and April of this year, the group installed the solar cells on the wings, flying 18 times on solar assist between May 21 and July 20. These included eight launches in which the solar cells recharged the airplane’s LiFePO4 batteries during the flight, making the possibility of endless cross-country flight a realizable …