A Milestone on the Road to Dr. Cui’s 10X Battery

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Seeing the Amprius web site, one would never know that some “dramatic improvements” promised in the terse announcement might mean so much in terms of true breakthroughs. Neatly centered, Amprius’ total web site is a few  lines of discrete text. Amprius is a leading Lithium-Ion battery developer Amprius’s silicon technology was originally developed at Stanford University and enables dramatic improvements in the energy density and specific energy of Lithium-Ion batteries. Amprius is backed by some of the world’s leading investors, including Trident Capital, VantagePoint Venture Partners, IPV Capital, Kleiner Perkins Caufield & Byers, and Dr. Eric Schmidt. Amprius, Inc., 225 Humboldt Ct. Sunnyvale, CA 94089 But the battery manufacturer has two first-generation product offerings with volumetric energy densities of 580 Watt-hours and 600 Watt-hours per liter.    Most lithium batteries fall into a range from 250-500 Wh/l., putting the new cells at the upper limit of such batteries.  Both Amprius batteries are now in production and available to original equipment manufacturers, …

Navette Brettone Carries On

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The April, 2013 issue of Info.Pilote magazine, a French publication, features the air-show pairing of the electric Cri-Cri E-Cristaline, powered by two Electravia GMPE 104 motors and riding atop a Broussard – what the DeHavilland Beaver might look like if it had been built in France. The great photos by Jean-Marie Urlacher are supplemented by a dynamic video showing a typical airshow lofting and separation – something that happens quickly even in slow motion. Info.Pilote has an informative table comparing the Navette Brettone (Brittany Shuttle), named for the sponsoring ferry boat operation, with the Navette Spatial, our space shuttle/Boeing 747-100 combo. While the big Boeing spans 196 feet, the Broussard is a relatively petite 45 feet.  The Space Shuttle riding on the 747 is a substantial 78 feet, while the tiny Cri-Cri is a mere 16 feet across. The different airplanes’ relative weights are even more revealing.  The 708,400 pound Boeing carries a 286,000 load: the 5,940 pound Broussard lofts …

Eurosport Crossover Sports Many Tricks

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

We’re used to seeing motorgliders which pop an engine or motor up on a tall stalk behind the cockpit, then retract it into the slim tailboom for minimum drag.  Why not do the same with two electric motors on each side of the airplane, tucking them in a slender fuselage for soaring? Emails with Eurosport’s Tom Leite and perusal of the Portuguese firm’s web site and on-line brochure verified that almost everything on the Crossover motorglider is electric and retractable. Tom notes, for instance, “Our motor/props fold into the fuselage: [they are] 3-phase PMSM motors up to 40Kw at takeoff each.”  In the video, see the long, spar web-like structure with lightening holes that separates the two motors as they slide into and out of the fuselage. “Our wing span is set from 9.6 to 15 meters and is electrically operated.”  Tom refers to the special version that will have extendable and retractable wings, with tip segments sliding out from …

Ion Tiger Exceeds 48 Hours in Flight

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Researchers at the U.S. Naval Research Laboratory flew their fuel cell powered Ion Tiger UAV for 48 hours and 1 minute on April 16-18 by using liquid hydrogen fuel in a new, NRL-developed, cryogenic fuel storage tank and delivery system. This flight shatters their previous record of 26 hours and 2 minutes set in 2012 using the same vehicle, but with gaseous hydrogen stored at 5000 psi.  The airplane had flown 23 hours, 17 minutes in 2009. The 550 Watt (0.75 horsepower) fuel cell onboard the Ion Tiger has about four times the efficiency of a comparable internal combustion engine and the system provides seven times the energy in the equivalent weight of batteries.  The Ion Tiger weighs approximately 37 pounds and carries a 4- to 5-pound payload.”   Gerard Thevenot, who flew the English Channel on a hydrogen-powered “trike” in 2009, used about 550 grams per flight hour, with the craft’s 5-liter tank allowing about one hour flying time. …

Brien Seeley to Speak at AirVenture’s Innovations Pavilion

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Dr. Brien Seeley, founder and head of the CAFE Foundation, presented his vision for the future of small, electric commuter aircraft at the seventh annual Electric Aircraft Symposium held in late April at Santa Rosa, California.  He gave a forceful, detailed picture of why we need to lift some of the traffic from the highways and examined the benefits that society and the environment would accrue from such sweeping changes. Imagine, for instance, not having to build another highway or on-ramp because existing roads were capable of handling the decreased surface traffic without further expansion.  Think of being able to hop over traffic on a 50-to-400 mile excursion – something not handled well at all by current surface or aerial alternatives.  Think of a “pocket” airport that took up only a few acres of land, and that could be sited safely within walking distance of your home.   Finally, imagine this costing no more than current, ground-bound options.  That is …

Wollongong Cites Battery Breakthrough

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Professor Zaiping Guo at the University of Wollongong’s Institute for Superconducting & Electronic Materials is working on improving lithium-ion batteries for use in electric vehicles, as well as portable devices like mobile phones, and her school proclaims a breakthrough. Her team has developed a novel nanostructured Germanium (Ge)-based anode material for high-powered rechargeable lithium batteries. Professor Guo, an Australian Research Council (ARC) QEII Fellow, said the development of this inexpensive manufacturing technique is a breakthrough that will provide a significant improvement in battery technology, which can be used to power the next generation of clean-tech electric cars. “The novel anode materials are very simple to synthesize and cost-effective,” she said. “They can be fabricated in large-scale by industry, therefore have great commercial potential.” In tests, Ge-based cells have five times more energy storage and the potential to go at least twice as far on a charge as batteries used in current electric vehicles, according to the University. “This equates to …

Avoiding Propeller Strikes on Electric Aircraft

Dean Sigler Electric Powerplants, GFC, Sustainable Aviation Leave a Comment

At last year’s Electric Aircraft Symposium, Ron Gremban, developer of the Prius plug-in hybrid, shared several questions about promoting safety in electric aircraft.  One aspect that provoked deep thought was that of safety for those working around an electric airplane, whose propeller could start quietly and possibly strike an unaware bystander.  During the Green Flight Challenge, it was noteworthy that unlike their gasoline-powered counterparts which idled while awaiting takeoff, the Pipistrel G4 and e-Genius awaited their turn to launch with propellers at rest, only spinning when commanded – and very quietly at that. The question of avoiding prop strikes found at least one answer at EAS VII.  Karl Kaser demonstrated, in model form, his ePropeller Safety Device (eSD), noting “the risk to people, animals or objects in the propeller disk area and that they can be injured or damaged accidentally during the run-up of the propeller.”  He first noted that issue in the case of e-Genius, on which he was …

A Smart Battery Management System and Multiple Sensors

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Fraunhofer and the Hochschule Esslingen University of Applied Sciences have created an electronic race car that they will show at the Sensor + Test Measurement Fair in Nuremberg, Germany from May 14 through 16.  Not only electrically driven, the innovative vehicle holds a number of sensor and control systems that might be of interest to electric aircraft designers. EVE, the product of the school and Fraunhofer’s labors, can sprint from 0 to 100 kilometers an hour (62 mph) in 3.6 seconds with its twin 60 kilowatt, 4,500 rpm motors, and reach a top speed of 140 km/hr (86.8 mph).  Its 8 kilowatt-hour lithium polymer batteries allow only a short run of 22 kilometers (13.64 miles) though, not surprising in terms of high power outputs pulling the cells down quickly. Electrical engineering students from the e-racing team at the Hochschule designed the 300 kilogram (660 pound) car as an elective project to augment their studies, and ran it at the International Formula …

Sunseeker Duo Shows Completed Form at Friedrichshafen, Moves to Italy

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Erik Raymond is moving his shop and Sunseeker Duo project to Voghera, Italy, nestled in Northern Italy between Milan and Genoa.  He showed the completed airframe at this year’s Aero Expo at Friedrichshafen, Germany and discussed, no doubt, the future of electric aviation with Axel Lange, the CEO of Lange Aviation.  Lange has developed the Antares and Arcus electric motorgliders, both outstanding designs. Following the Expo’s finale, Erik and his wife Irena drove south to Italy, where their enterprise will complete work on the Duo and plan for their proposed trips in unexplored realms– all on solar power. With Solar Impulse crossing the United States (which Erik did in 1990 in Sunseeker I) and more flights planned by other participants, we might see the next few years create an intensified interest in green aviation. Erik notes that, “The solar cells used by the Duo are better than 50% more efficient than those used by Sunseeker II. While Sunseeker II is …

Solar Impulse Lifts Off on First Leg of Cross America 2013 Tour

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With Bertrand Piccard at the controls, Solar Impulse completed its motor runups a few minutes before its scheduled 6:00 a. m. PDT takeoff.  The project commentator in Switzerland noted that Piccard looked “a little pensive” in the minutes leading up to the historic departure from Moffett Field in Mountain View, California. The first leg of the trip involves a stepped climb – first to 5,000 feet for about two hours, then to a little over 20,000 feet until about 7:00 p. m. , when the craft will begin a stepped descent for the next several hours and arrive over Phoenix near midnight. As cars whizzed by on the nearby Highway 101 linking San Jose and San Francisco, Solar Impulse’s crew in Payerne, Switzerland called the tower at Moffet to coordinate final departure instructions.  After receiving the go-ahead from Payerne, Piccard guided the airplane from the runway at about 6:12 and made an effortless climb into the dawn’s glow over the …