Three companies with divergent backgrounds launched three new electric aircraft in the last few months.

1973, and Its Descendants are Still Electric

As noted in the blurb for its historic YouTube video for its first electric flight 46 years ago, “HB Flugtechnik is the pioneer in electric flight. The world’s first electric powered flight took place on October 21st, 1973 in Austria. 50 years later this company is still in business and doing better than ever. Given, that we talk about the aviation business, this is an outstanding and remarkable achievement. Today, HB Flugtechnik located at the now newly refurbished airfield Hofkirchen LOLH is not only the major MRO (Maintenance, Repair Organization or Maintenance, Repair, and Overhaul) for aircraft in Austria, it is still working on the new frontier of electric flight.”

In a 2012 presentation at the AVT-209 Workshop in Lisbon, Portugal in 2012, Dr. Martin Hepperle of the DLR Institute of Aerodynamics and Flow Technology in Braunschweig, Germany discussed the seminal work by Fred Militky, who as chief engineer at Graupner, a model aircraft firm, went from designing small electric models (1960’s Silentius, 1972’s Hi-Fly, a twin-motor radio-controlled craft) and the MB-E1, the world’s first person-carrying electric aircraft.

He wrote, “There is nothing new under the sun… One of the Pioneers of Electric Flight, Fred Militky began with 1940 first trials,[and] after 1945 [became] chief engineer at Graupner.”  His electric motor glider MB-E1 (a Brditschka HB-3 with a span of 12 meters (39.4 feet) and a weight of 440 kilograms (968 pounds) flew on October 21, 1973.  The flight lasted about 11 minutes and reached an altitude of 360 meters (1,181 feet) under the direction of Heino Brditschka.  Its Bosch 13-horsepower motor was driven by Varta nickel-Cadmium batteries.  The two-seater became a one-seater with a large energy storage compartment behind the pilot.

 

Today HB Technik markets a very similar airplane, but with better batteries (that shows what 46 years of battery betterment can do), and a reasonable payload and performance.  According to its video, there’s plenty of room to grow, with even hydrogen power on the horizon.

Switzerland’s H-55 Bristell Energic

Andre’ Borschberg didn’t give up electric flight after Solar Impulse’s around-the-world conquest.  He did downsize to a more practical level, though.  We’ve reported on the H-55 Bristell Energic previously, and it has achieved its test flights last month, seeming to fly every bit as nice as it looks.  Enjoy the long interview above and the short promotional video below.

Energic’s test flight displays the stability and maneuverability of its fossil-fuel cousins.  One good outcome of all this will be fairly even comparisons of the two types of power.

And Meanwhile in China

Starting five years ago, Shenyang’s Liaoning Ruixiang General Aviation Company  started test flights on its two-seat RX1E.

The electric trainer was reputed to be the world’s first certified electric trainer (in China).  It has a longer span and slower cruise speed than Pipistrel’s Alpha Electro.

The RX4E four-seat variant flew for the first time in October, has a sailplane-like 13.5 meter (44.3 feet) wingspan and a gross weight of 1,200 kilograms (2,540 pounds).

With new craft flying in three different countries, battery-powered flight seems to be on its way to being an international thing.

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Tony Bishop reports on The Royal Aeronautical Society’s International Light Aircraft Design Competition, which provided stimulating simulations for on-screen air racing.

The 2019 RAeS competition was to design an electric air-racer, inspired by Air Race E’s new competition starting up in 2020. With a single pilot and short duration, this is an excellent proving ground for new electric power train technologies.

According to the RAES, “The design rules were based on Air Race E, but widened to encourage a broader range of configurations. Air Race E rules include a minimum empty weight of 227 kg, a maximum motor power of 150 kW, fixed pitch propellers, a minimum wing area of 6.132 square meters and a fixed main undercarriage. Air Race E also demands that all motors have the same thrust line. This limitation was removed from the RAeS competition to encourage wider innovation.”

Rendering of Madison Square Gardens in 2016 shows crowd potential for cyber games similar to computer-based air races

According to Flyer magazine, racers had to fly around a five-kilometer (3.1 miles) course, staying within high and low limits and not cutting any horizontal boundaries.  “The results were announced at the Royal Aeronautical Society’s annual Light Aircraft Design Conference on Electrifying General Aviation on 18 November.  Awards were presented to the top three by Steve Slater, CEO of the Light Aircraft Association.”

An international lineup of 15 contestants pushed those rules, already more flexible than those for Air Race E, to their absolute limits. They came up with configurations featuring single to four motors, propelling monoplanes, biplanes and triplanes (or three-wing configurations).

Iontrepid

Winner Iontrepid showed a maximum speed of 330 knots (380 mph).  It is able to take high-G turns without losing speed, despite its high-aspect ratio flying wing configuration – more something one would seen on a sailplane. Its pusher motor and retractable nosewheel, designed by Cameron Garner from x-aerodynamics of Timaru in New Zealand, minimizes drag “with the short fuselage, and the rear propeller ingests the fuselage boundary layer. Wing sections were tailored to increase laminar flow.  X-aerodynamics develop flight-realistic aircraft models for the x-plane simulator.”

Iontrepid won first place in England’s Light Aircraft Design competition emulating Air Race E rules

Showing the firm’s ability to provide realistic flight simulation, they gift users with two freeware samples, one for the Aerobask-Robin-DR401 shown below, and one for the Aerobask Lancair Legacy FG XP11.

Garner won the contest’s first prize of an aerodynamic analysis (CFD) of their configuration, provided by Airshaper in Belgium.  The winners think this will give a rigorous comparison of the design and a high-resolution analysis of the anticipate real-world performance.

Software such as that from Airshaper can predict performance from designs that otherwise might be too risky for flight tests without in-depth analysis of their characteristics – such as the Peugeot designer’s unique approach shown above.

This use of CFD and on-screen performance testing will enable designers to “wring out” designs in a safe setting and one can foresee large scale “air racing” on screen in venues like those in Madison Square Garden that attract huge crowds of cyber-gaming fans.

Sparrowhawk R-1

Second- place Sparrowhawk R-1 features a triple wing configuration with twin, wing mounted motors and a V-tail.  It’s mainly of metal construction designed for easy home-building.

Sparrowhawk, powered by two motors and controlled by three wing surfaces, is intended for home-building

AFormX

Third place AFormX fielded the eponymous AFormX, featuring three motors much like a single seat Eviation Alice.   AFormX contracts flight testing for Pipistrel, and builds virtual reality flight simulators.

AFormX has three motors in a configuration much like that of Eviation’s Alice.  Wing-tip motors are intended to reduce tip vortices

We hope some of these designs will be developed into the Air Race E aircraft of the future.

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First Lindbergh E-flight Rally

The Lindbergh E-flight Rally coinciding with Friedrichshafen’s annual Aero Expo will explore the growing capabilities of these amazing machines.  The Lindbergh Foundation invites owners of electric aircraft to gather two days before the opening of Aero Expo 2020 to fly over the scenic marvels of Germany, alighting on Expo opening day “around 11 a.m., just on time for the AERO press conference.”

The hoped-for en masse arrival would highlight the number of electric aircraft now flying and their reliability.  Organizers explain, “Like the first ultralight aircraft did then, the first electric aircraft today need to prove that they already function perfectly.”

The two-day aerial cortege would fly “along Lake Constance, and past castles, palaces, and churches, to a first stopover at Regio Airport Mengen, which was recently awarded a contract by the state of Baden-Württemberg for the construction of a test platform for electric flight/autonomous flying.”  There, entrants will charge their batteries and head for their second and last stop of the day, the Bad Waldsee-Reute glider airfield.

The second day, all competitors fly from Bad Waldsee to Friedrichshafer Airport, where the planes will go on display in one of the large halls.

Pilots (or their passengers) would photograph turnpoints on the two days, and their graphic documentation reviewed by judges after the craft land.  Craft will be recharged, measuring directly how much energy they used in the last part of their journey, and points added to their overall score.

 

Flyeurope.tv reports, “A prize is awarded in each of three classes: trikes, three-axle, and hybrid aircraft. Every day during the exhibition, a television escort team will capture impressions of the first Lindbergh e-flight rally, which will be shown on a large screen. Manufacturers of electric aircraft have received requests from visitors, underscoring the importance of this first worldwide rally for electric aircraft. The plan is to increase the scope every year.

Find further information, the registration form, and the conditions for the competition on the AERO website.  Entrants can exhibit series-build aircraft or prototypes.   Closing date for entries is January 31, 2020.

The AERO will take place from Wednesday, April 1 to Saturday, April 4, 2020, in Friedrichshafen on Lake Constance and is open from Wednesday to Friday from 9 a.m. to 6 p.m. and on Saturday from 9 a.m. to 5 p.m.

An outgrowth of the Green Flight Challenge

As signaled by the preceding videos, several of the aircraft projected to be on display will be outgrowths of the machines that took place in the 2011 Green Flight Challenge in Santa Rosa, California.  The first-place winner, Pipistrel’s G4, managed the electric equivalent of 403.5 passenger miles per gallon. A close second-place finish by Stuttgart University’s e-Genius used 375.7 ePMPG (equivalent Passenger Miles per Gallon of gasoline)

 As we reported at the time, “… a little over 11 US gallons of gasoline (energy equivalent) were used to fly seven people [in four aircraft) (Embry Riddle’s Eco-Eagle flew with only one pilot) over a total of 725.5 miles.” (Embry Riddle flew a shorter total distance on both “runs”).

e-Genius and Pipistrel’s G4 (now the hydrogen-powered H4) will probably be on hand, and the now electric Phoenix, which ran on a Rotax internal combustion engine in 2011, might be there in its latest configuration as the Φnix (Φ being the Greek letter phi used for electrical potential and a neat pun on the original name.

Those and other electric craft including those presented at Grenchen, Switzerland’s SmartFlyer Challenge could make a sweeping change in the public’s perception of electric flight.  Think what’s happened in electric aviation since the last Expo, and what will happen in the six months before the next event.  We wish the Lindbergh Foundation, Aero Expo and all the competitors the best of fortunes.

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Breakthrough Batteries Two Years Away?

Breakthrough Batteries: Powering the Era of Clean Electrification

A paper by Charlie Bloch, James Newcomb, Samhita Shiledar, and Madeline Tyson of the Rocky Mountain Institute describing the near future of battery development predicts and accelerated pace of “the global energy transition” and the growing role of energy storage in “addressing the climate crisis.”  Will these “breakthough batteries” power us into the near future?

Their report* notes the economic investment and potential impacts of ongoing research, which to this editor seems minor when compared to the gravity of the ongoing climate crisis.  Researchers estimate “more than $1.4 billion invested in battery technologies in the first half of 2019 alone,” less than 10 percent of the $16 billion spent in 2016 on plastic surgery.  Apparently, saving the planet is not nearly as crucial as getting butt lifts and Botox wrinkle removals.

Regardless of how quickly new battery technologies come to fruition, it will take time to replace existing technology infrastructures – in which trillions are already involved

Despite this, the Institute insists, “… {M}assive investments in battery manufacturing and steady advances in technology have set in motion a seismic shift in how we will organize energy systems as early as 2030.”

More hopeful, “Increased demand for electric vehicles, grid-tied storage, and other emerging applications further fuels the cycle of investment and cost declines and sets the stage for mass adoption.”  Manufacturing investment totals around $150 billion, with capital costs for new planned capacity possibly dropping by more than half from 2018 to 2023.  Dropping costs have in turn incentivized purchases and further driven demand – and will push both lithium-ion (Li-ion) and new battery technologies across competitive thresholds faster than anticipated.”

The report provides an overview of the leading technologies and chemistries, including solid-state cells and flow batteries.  It explains that rapidly-increasing demand for different energy-storage is having an effect on investments in coal, natural gas and other fossil fuels, which leaves investors at the risk of seeing their money in those enterprises stranded in an economic wasteland.

Referring to Nobel Prize winner John Goodenough’s recent claimed battery breakthough, EVobsession reported,Several manufacturing companies are interested in the new battery technology, and are currently working in getting it ready for mass production; however, a working product will be ready in a few more years from now.”  Since this was said two years ago, we might grow impatient waiting for mass production to take place.

“More specifically in March 2017, Professor Goodenough had this to say, ‘…we have done many tests with laboratory cells. Manufacturing a marketable battery cell will take about 2 years of development by a competent battery company, but we have over 50 companies showing interest to be able to perform tests of our results. I am optimistic that our tests will be verified and that product development will begin soon.’ These ‘…battery companies have shown interest in validating our findings and marketing products.’”

“Non-confirmed comments suggest that Tesla is aware of this technology.”

* Breakthrough Batteries Report includes the link in the RMI article.

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Air Race E Leaps Forward with Eight Teams

The public got a glimpse of Air Race E at this year’s Dubai Air Show.  Jeff Zaltman, CEO of Air Race E and Sandra Bour-Schaeffer, head of XO Airbus Demonstrators, pulled the wraps on Team Condor’s converted Cassutt racer – one of eight teams entering the fray.

Jeff Zaltman and Sandra Bour-Schaeffer display Team Condor’s highly modified Cassutt racer 

 

Race E is an update of the classic small aircraft races held following World War II, and many of the airplanes in the upcoming events will be re-motored and redesigned versions of these craft.  Formula 1 racing has not changed much since its 1947 inception.

Most air small air racers relied on the Continental C-85 engine, mildly uprated and turning faster than it did in Aeronca Champions or Piper Cubs.  Formula E is the first major change and new technology in the field in over 70 years.

With the advent of Air Race E, designers are encouraged to create new machines and rethink the means of propulsion.  At least eight organizations are working on new or re-imagined aircraft, and at least two have new power systems.

Eight Contenders

Team Condor

Since 1979, Andrew Chadwick raced White Lightning, a highly-modified Cassutt aircraft.  He donated the well-traveled airplane to Team Condor, whose leader, Martyn Wiseman and his crew converted it to a “fully-electric racing machine.  Its Contra-Electric twin motors and contra-rotating propellers should be able to pull White Lightning to 300 mph.

Team Condor craft is modified Cassutt racer, popular in Formula 1 competition

University of Nottingham

According to the school, “Richard Glassock is a Research Fellow in Hybrid Electric Propulsion Systems for Aircraft at the University of Nottingham Faculty of Engineering. He is working with Air Race E and leading the project to build the world’s first electric race plane through the University of Nottingham’s Beacons of Future Propulsion program.”  Richard leads Nottingham’s Aerospace Technology Center in the UK as part of its £13M (about 16,640,000 USD) Propulsion Futures Beacons of Excellence research program.  Richard assisted with the development of White Lightning in addition to his academic duties.

Richard Glassock working on Cassutt racer at Nottingham University’s Aerospace Technology Center

Allways Air Racing

Casey Erickson, a Reno Air Race biplane class pilot, is starting with a SnoShoo SR1.1, a conventional Reno racer, modifying the wing to make it faster around the tight turns on the Formula E course, and converting to electric power.  She add the team has “done more computational analysis than probably anyone else has to ensure good air flow and minimal drag for our entire aircraft.”

Team Allways Racing’s Shoshoo SR-1

Blue -BETA Racing

Already flying an electric vertical takeoff and landing machine, Kyle Clark, CEO and chief test pilot of BETA Technologies says, “We see the Air Race E series as a design accelerant that will push the development of advanced concepts while showcasing the amazing engineers and thought leaders working in this space.”  Relying on experts in electric power and composites, his “ground up” design will look almost sailplane-like from the front, taking advantage of the slenderness enabled by electric power plants.

Team Blue-Beta has yet to reveal its e-racer, but it come from the company that produced this eVTOL machine

Team Hangar-1

Asked what might surprise people about his team’s design, the company’s CEO, Adrian Schmer, explains, “The aircraft will get technical features from completely different designs. A glider canopy mixed with a “Pitts” throttle quadrant and tailwheel from inline skates.”

Hangar-1 engine repair in foreground frames Airbus Beluga spacecraft carrier taxiing by

Based at facilities in Oldenburg-Hatten and Leer-Papenburg in northern Germany, Team Hanger-1, named in conjunction with their main sponsor Flugwerft Hangar-1 GmbH, is led by the company’s CEO Adrian Schmer, an SEP and aerobatics instructor.  A team of “self-confessed aviation junkies, ” Eline Tjaden, Chris Höland, Jakob Møller and Ingo Seidl, work on the craft’s development.

Team Möbius

Team Möbius, based in Fort Worth, Texas, is led by Carl Copeland, a serial entrepreneur and CEO of MμZ Motion, a robotics firm.  Their airplane, under development and awaiting a name, will be powered by a new type of smaller, lighter motor.

the Muz Field Modulation Motor promises somewhat unbelievable size and perfromance

Copeland claims their Field Modulation Motor “is constructed of 100% recycled or recyclable materials. Even the magnets will be from reclaimed and recycled materials. The mining, processing and manufacturing of the minerals used in permanent magnets are very energy intensive and toxic to the environment. Our use of recycled material will have a significant impact on the carbon and chemical footprint of the plane. Similar precautions will be taken in the development and use of the batteries and electronics.”

Team NL

“Team NL” from the Netherlands and led by Rick Boerma are a design team made up of university students. They will work from “scratch.”  Rick said, “To design, build, test and fly a new aircraft for the Air Race E next year is going to be a seriously difficult challenge, but one we are ready to take head on. Time is ticking, but we are excited to get started.”

Team NL’s entry is orange, the Netherland’s national color

 Team Outlaw

With pilot and Team Leader Scott Holmes in the cockpit, the Canadians are adapting their 1993 Cassutt to be able to fly with electric power, asking, “Do you think we’ll be able to fit enough batteries under the cowl for 8 laps? Here’s a few of Grepow’s best getting stress tested by the world’s most intelligent (and probably youngest) electric airplane research group in silicon valley.”  The pouch-type cells are otherwise unidentified as to chemistry or output.

Canadian team’s batteries being stress tested

Team Scramasaxe

Based at Aérodrome de Cuers-Pierrefeu in the south east of France, Team Scramasaxe is led by Eric de Barberin-Barberini, a former fighter pilot who has set five aviation world speed records in his aircraft, Shark.

French team’s SCRAMASAXE has tricycle gear with retractable nose wheel

The craft features innovations including a tricycle landing gear incorporating a retractable front wheel, while the air foil will be modified to sustain speeds as high as 500 kilometers per hour.

More to Follow

With eight teams developing new technology to gain the “racer’s edge,” we can expect some exciting outcomes in short order.  We anxiously await what comes next.

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Project 804 Turns Turboprop into Hybrid

Uniting Technologies

United Technologies, an aerospace leader, expands its role as United Technologies Advanced Projects (UTAP), uniting Pratt & Whitney, Collins Aerospace, United Technologies Research Center “and certain as-yet-unannounced external institutions.”  The organization’s Project 804. A hybrid-electric “X-plane” intended to reduce aircraft noise, improve fuel consumption, reduce carbon dioxide emissions and cut airline operating and maintenance costs.

As exciting as the prospect sounds, the new aircraft probably won’t draw a lot of attention on the ramp.  It will look pretty much like a DeHavilland Dash 8-400, a short-to-mid range passenger hauler at just about every commercial airport in the world.  It is, indeed, a Dash 8, converted to a new and innovative hybrid-turbine power system.

Project 804 displayed at this year’s Paris Air Show

Entering service in 1984 as the Dash 8-100 carrying 37 passengers, the airplane went through different owners and models, reaching today’s 400 series that can haul up to 92 passengers.  DeHavilland delivered 1,258 of all models as of March 31, 2019.  Its ubiquity and solid reputation in service would lead to extending its service with even more reliable powerplants than the turbines pulling it along for the last 35 years.

“Disrupts From Within”

“904” is the straight-line mileage between Montreal and the Collins Aerospace facility in Rockford, Illinois.  There, UTAP will invest $50 million in a high-voltage laboratory called “The Grid,” a test bed for future electric power plants of up to one megawatt.  Their first project will re-engine and fly a Dash 8-100 with a “two-megawatt class hybrid-electric propulsion system.”

With a tight timeline, things take on a hectic pace typical of a “startup-like organization” that, “disrupts from within.”  The projects will reflect what can be quickly accomplished through the use of existing materials and components driven by experienced workers.  The hybrid power system is probably typical of what we can expect.

United Technologies reports in a white paper, “Its configuration will consist of an engine optimized for cruise efficiency augmented by a battery-powered electric motor to assist during the missions’ 20-minute take off and climb.”

“The engine and electric motor will each generate about 1 megawatt of power in a parallel hybrid configuration. While the battery cells are off-the-shelf, the packaging and battery management system (BMS) are custom-designed for efficiency and to meet necessary safety requirements. This approach could be suitable for a clean-sheet regional design as well as a retrofitted option for existing airframes.”

Pushing an aggressive schedule, UTAP already has a Dash 8 and is working through the preliminary design process, according to UTAP executive director Jason Chua.  He foresees a first flight in late 2021 – ambitious but doable.

Although it will look familiar, the 804 Dash 8 will sound and perform differently.  Collins Aerospace Kelly Ortberg reports, “Our internal UTC studies indicate that commercial electric and hybrid electric propulsion could reduce aircraft noise by up to 85 percent, can improve fuel consumption by up to 40 percent, can reduce carbon dioxide emissions by more than 20 percent and reduce airline operating and maintenance costs by up to 20 percent.”

Future Disruptions

The UTAP lab will have four independent modular electric power systems labs to be fully operational by 2021.  The 25,000 square foot facility will design and test hybrid-electric propulsion technologies for next-generation business, commercial, military, and urban air mobility aircraft.  Evoking the spirit of a startup, things should happen quickly and with the assurance that great experience provides.

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Hydrogen-powered Drone Makes Ocean Flight

A one-hour, 43-minute flight between a hospital on the Caribbean island of St. Croix and a testing facility on the neighboring island of St. Thomas probably set a record for hydrogen-powered multi-rotor, over-water drone flight.  The flight delivered live bacteria samples from a hospital on the Caribbean island of St. Croix to a testing facility on the neighboring island of St. Thomas.  The demonstration was carried out by Guinn Partners and associated organizations.

Most such medical deliveries are usually over land and within urban areas. Fixed-wing drones flying with Zipline in Rwanda deliver clinical samples and blood 80 kilometers (49.6 miles) each way out and return.

DMI DS-30 drone at recent Guinn Partners meeting

The Doosan Mobility Innovations (DMI) DS-30 drone is a large machine able to carry a 10.8 liter, 4.3 kilogram (9.46 pound) compressed hydrogen container – good enough for two hours endurance.   There was 30 minutes’ supply left in the tank when the drone landed on St. Croix.   The machine can carry up to a five-kilogram (11-pound) payload.

Members of Guinn Partners worked with Doosan Mobility Innovations, in collaboration with Skyfire Consulting, and the US Department of Health, to execute the delivery.

The DS-30’s capabilities can be a literal life-saver for patients.  NewAtlas reports, “According to Guinn Partners, it can ordinarily take up to a week before patients’ biological fluid samples are transported between the two islands by manned aircraft – in the case of illnesses such as Dengue fever, the infection can progress to dangerous levels within that amount of time. Because using a drone is much cheaper and simpler, though, samples could conceivably be sent to St. Croix immediately.”

Although the recent flight relied on control from a boat trailing the drone, future outings will be autonomous.

A Strong Tank

The H2 tank on the DS-30 is capable of withstanding shots from a large military rifle round, based on illustrations provided by Doosan.  That, and the simple approach to transporting tanks and connecting them to the drones indicates a well-though-out approach to logistics.  The one thing that might prevent broader adoption of the system is the need for DMI to supply the already-filled tanks, with “empties” returned like deposit beverage containers.

Future Outings?

With increasingly large multi-rotor machines taking an increasingly large chunk of the drone market, Doosan seems to be positioning itself in fixed-wing arena, perhaps in anticipation of longer-range missions.

 

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SAS 2019: Larry Cooke and NovaSolix

Laurence H. (Larry) Cooke, Chief Technology Officer for NovaSolix, a California-based solar panel manufacturer, discussed a way to make what are essentially radio waves into efficient, inexpensive solar power.  His biography includes this indicator of a productive life. “Larry “Cooke has written one book, multiple papers and have over 100 granted US patents. Cooke is currently CTO and Chairman of NovaSolix, a revolutionary Carbon Nanotube Rectenna array based solar cell start-up.”

NovaSolix separates its approach to capturing solar energy from the “traditional” solar cell, solar panel method.

“The Old Way”

Thoughtco.com says, “Any device that directly converts the energy in light into electrical energy through the process of photovoltaics is a solar cell.”  Such devices have a longer history than your editor anticipated.  Antoine-Cesar Becquerel noted a voltage drop when light fell on a solid electrode in an electrolyte solution.  It took until 1839 for Charles Fritt to develop the first genuine solar cell, by coating semiconducting selenium with an extremely thin layer of gold.

In 1941, Russel Ohl created the silicon solar cell, the predecessor of today’s rooftop panels.  His cell achieved less than one percent efficiency, though.  According to Thoughtco.com, “In 1954, three American researchers, Gerald Pearson, Calvin Fuller, and Daryl Chapin, designed a silicon solar cell capable of a six percent energy conversion efficiency with direct sunlight.”  Bell Laboratories followed with early mass production of such cells, installing a Bell Solar Battery in a telephone carrier system on October 4, 1955.

current solar cell efficiency. National Renewable Energy Laboratory

Most panels on rooftops today are still only about 15 to 20-percent efficient and even those on Solar Impulse were rated at around 22.7-percent.

Novasolix explains this lack of efficiency.  “Today’s common solar technology is based upon the photovoltaic effect that was first shown in 1839. Photovoltaic solar cells operate at the quantum level. A photon approaches an electron. If the photon has the required minimum energy, it can be absorbed by the electron that excites the electron (moving it to a higher energy state). Capturing the resulting diffused electrons creates an electric current.

“The key with PV technology is that not just any photon can excite an electron. The photon needs a minimum amount of energy . That means that lower energy infrared light (about 40% of all solar energy to hit the surface of the Earth) will not generate electricity. Furthermore, only certain frequencies of light (specific colors) correspond to the energy states required to knock an electron free. And, of course, a weak light cannot excite an electron to the next higher energy state, so dim lights produce zero power in PV cells.”

The NovaSolix Way

Larry’s description of NovaSolix’s technology shows a very different approach.  “We are developing rectifying antenna based solar devices used to capture solar energy with an initial target of twice the efficiency at 20% of the cost and 20% of the weight per watt of current single junction solar cells. We are using multi-wall carbon nanotubes (CNTs) grown in arrays of tiny antennas that are suspended between Aluminum ground/contact lines.”

All solar energy up to this point requires that photons push electrons to a higher energy state.  Novalsolix uses microscopic antennas to capture the light energy “as very high frequency alternating current and then use a diode to convert the alternating current into usable direct current.  Each carbon nanotube antenna is about one micron (1/10,000,000th of a meter) long with a diode on one end that operates at frequencies approaching 1 PHz or one quadrillion cycles per second.  Compare that to  AM radio, which operates at around one million cycles per second.  AM antennas are about a meter long.

Using LCD (liquid crystal display) flat-panel TV processing equipment, NovaSolix can mass produce rectenna solar cells at low cost

Because NovaSolix collectors place “roughly one million tiny radio receivers per square inch, they are able to retrieve frequencies “from low infrared through visible light and up into the ultraviolet.”  Gathering the full spectrum enables conversion of weak light to small amounts of power.  A currently real 40-percent efficiency with a theoretical limit of 90 percent enables smaller, lighter panels to generate 400 Watts per square meter to 900 Watts per square meter.

The blue represents modern solar modules conversion ranges, the light green represents a working prototype by NovaSolix, and the dark green (plus areas under) is the goal. Yellow and grey represent potential at sea level and in space. Source: PV magazine

Revised manufacturing techniques using existing tooling will produce cells at very low cost and which weigh less while bringing flexibility that will allow their use on curved aircraft surfaces.

The NovaSolix approach places roughly one trillion tiny radio receivers (rectennas) per square inch.  Unlike PV cells, the NS cells are compatible with a wide range of frequencies from low infrared through visible light and up into the ultraviolet. Furthermore, the NS cells are able to convert weak light to small amounts of power. The theoretical limit on efficiency of NS cells is roughly 90% or three times the energy of a PV cell. Initial NS cells will be roughly 40% efficient, producing roughly 400 watts/square meter. Finally, due to the different underlying manufacturing process, NS cells are cheaper and lighter weight than PV cells while also being flexible.

Solar Transportation

Cooke suggested a Tesla with NovaSolix cells covering its surfaces could recharge the equivalent of an additional 16 miles of range per hour.  The firm’s web site claims that would be sufficient to recharge the batteris of 68-percent of all commuters in the U. S., with one hour’s car-top recharging enough for a one-way commute.  88 percent of all commuters would not need to recharge their cars with four hours of sunlight.

Four hours driving at 60 mph would take the car 240 miles and add 64 miles of solar charging.  One tricky calculation adds 16 miles for the hour saved by not having to stop to recharge.  Even the half-hour spent at a Tesla Supercharger would add eight miles of capacity.

Sono Motors is a separate company that makes an electric car with built-in solar power supplemental charging. A sunny day can provide 18 miles of driving range on a 24% efficient solar cell. If NovaSolix increased solar cell efficiency to 90% then one day of sunlight driving would be 67 miles.

NovaSolix suggest, “A similar analysis shows that by covering a railroad boxcar with NS cells, the sun would be capable of powering the refrigeration system and still have power left over for propulsion.”  Even better, perhaps, a Tesla or Freighliner eCascadia with a semi-trailer covered with NS cells might be literally unstoppable in range.

Aerospace

NovaSolix’s initial application seems to be aimed at satellites and drone aircraft.  The company notes, “Modern communications satellites are power constrained. Even with huge banks of PV cells, few modern satellites have more than 4000 or 5000 watt power envelopes. Using NS cells, the same weight of cells could result in a tenfold increase in power budget. Furthermore, since NS cells can convert infrared radiation (normally seen as heat) into power, the satellites will have less difficulty staying cool in direct sunlight.”

The technology would be applicable to high-altitude, long-endurance craft such as those used for surveillance missions.  Again, the light weight and high power output would enable essentially endless missions.

We can wish Larry Cooke and NovaSolix the best of fortunes.  Their success be a game changer in electric aircraft.

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Volocopter and John Deere Partner on VoloDrone

We usually think of farming as a back-to-the-earth, humble enterprise, eschewing urban sophistication for rural simplicity.  Volocopter, the height of such urbanity, and John Deere, its green and yellow tractors shearing suburban lawns and its giant combines harvesting wheat fields worldwide, are blurring those lines with the VoloDrone, an agricultural implement like no other.

The largest John Deere combines weigh over 30,000 pounds (13,608 kilograms), while the most a Volocopter can carry is around 440 pounds (200 kilograms).   This disparity can seem heavily on the side of brutish strength, but agility and finesse also play a part in farming.

Unveiled at the aptly named Future Technology Zone in Hall 13 at Agritechnica in Hanover, Germany, a demonstrator model of the VoloDrone equipped with a crop protection sprayer hung over the John Deere exhibit.  Those 200 kilos of potent spray can cover a large area.  With autonomous possibilities, the machine is not a threat to anything but the bugs or weeds it attacks.  The joint press release notes, “The VoloDrone is able to cover an enormous area, especially under difficult operating conditions.”

Click here to take a virtual reality tour of Agritechnica, and then watch the following video for the profound changes coming to a formerly low-technology occupation.

John Deere, bringing its agricultural expertise and Volocopter its large drone skills, have crafted a multi-functional vehicle with a variety of farm applications, with related options for construction and other heavy-lift uses.

As with its passenger-carrying cousin, Volodrone’s 18 rotors and lithium batteries allows 30-minutes trips, with remote and automatic operation on a pre-programmed route an option.

Multiple applications are adaptable to non-agricultural uses

Its frame, equipped with a “flexible payload attachment system, can mount different devices.  It can carry two-large-capacity tanks, a pump, and a spray bar, for instance, for crop protection.

Because of its low flight altitude, the makers claim the VoloDrone has the ability to cover up to six hectares (14.83 acres) per hour.  It should be significantly less expensive to operate than a conventional crop duster/sprayer aircraft, which need large engines to lift large amounts of material.  Additionally, “This makes the VoloDrone a sustainable, precise, and cost-effective alternative to helicopters. Due to the system’s high flexibility and GPS control, more selective area-specific treatments are also possible.”

Appropriate flight and application tests will be carried out with the demonstrator VoloDrone sprayer over the next growing season.

Further information on John Deere and Volocopter can be found at www.deere.de and www.volocopter.com.  Following, view a John Deere farming aid using a much smaller drone.

Proactive throughput controller – Beyond Drones

Volodrone is a relatively simple solution to many farming problems.  Going into more complex realms, even satellites help the modern farmer.  A combine, for instance, is a huge, complex machine.  In the past, all these harvesters were manually controlled, but the modern farmer has bushels of technology to gain better crop yields while protecting the land.

Predictive Feedrate Control is the first feedrate control system which combines two proactive input sources from GPS satellites and cab mounted sensors. This self-learning technology uses forward-looking perception information as well as crop data.

“Throughput controllers on combine harvesters cannot react to changes in the harvested crop conditions until the material is already in the harvesting header, in the intake duct or in the threshing unit. With extreme changes in harvesting conditions, such as lying crops, partial gaps and weed areas, result in correspondingly high over- or under-loading, and combine driving speeds that change too drastically. The throughput controller is then often deactivated.

“John Deere solves this problem with the proactive throughput controller. 3D stereo cameras detect the crop situation in front of the combine just like a proactive driver. Crop heights, lying crop with lying direction, gaps, driving lanes and harvested areas are detected and classified by so-called “machine learning”. In addition, the system also uses the data of vegetation models, which consist of biomass maps generated via satellite or other technologies. Camera and biomass signals can also be used alone in each case. As soon as the combine harvester begins harvesting, the system calculates regression models from the real-time and the geo-referenced vegetation data. The harvesting conditions in front of the machine are therefore known, as are the strategies still specified by the driver. The combine harvester merges all sensor values and then adjusts its driving speed and its settings to the harvest situation.

“The proactive combine harvester operates automatically for the first time, just like a combine harvester operated by a proactive, experienced driver. With this technology, John Deere has taken a major step in the further development of the automation of threshing crop harvesting.”

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Go With the CoFlow Jet

Ge-Cheng Zha, Professor in the Mechanical and Aerospace Engineering Department of the University of Miami (Florida) explores new realms of augmenting lift on wing surfaces.  He recently presented one aspect of this study, which he calls the CoFlow Jet.

Most conventional airfoils generate increasing amounts of lift with an increasing angle of attack, but that increase stops at around 12 to 15 degrees AOA.  The wing “stalls”, sometimes suddenly.  The ability to avoid this stall would increase flight safety immeasurably.

Zha’s presentation at SAS 2019 at UC Berkeley, “A High Efficiency Low Noise VTOL/ESTOL Concept Using CoFlow Jet,” showed off some startling high angle of attack capabilities that went well beyond the normal limits for conventional airfoils.

CFJ airfoil can achieve startling angles of attack without stalling

Phil Hendrie, a comedian with a radio and now podcast career, defined the worst possible circumstance as something that sucks and blows at the same time.  The antithesis to that is the CoFlow Jet (CFJ), offering an “active flow control airfoil.”  Described as, “An integrated system with propellers mounted above the CFJ wing suction surface,” CFJ offers better performance with lower power than conventional configurations by sucking and blowing at the same time.

Zha’s research, shown in short form in this video, highlights the high angle of attack achievable with this technology, although paying passengers may want a return on their funds after experiencing such attitudes.

David Ullman’s IDEAL: Integrated Distributed Electric-Augmented Lift project “makes use of multiple Electric Ducted Fans (EDFs) mounted, so they not only propel the aircraft but shape high-velocity air over the top surface of the wing. Ullman’s electric ducted fans are mounted above the forward portion of the wing, while Zha’s work integrates the distributed powerplants into the wing itself.

Performing high fidelity CFD (computational fluid dynamics) simulation at low speed, Zha’s  team has obtained a maximum lift coefficient of 9.6 at an angle of attack of 700 with no stall.

The lift coefficient is substantially greater than the theoretical limit of the maximum lift coefficient of 7.6. It is thus named super-lift coefficient. At the same time, the team’s CFD simulation shows that the CFJ airfoil is able to increase productivity efficiency by 36 percent for a supercritical transonic airfoil at cruise.  Thus, small electric motors could potentially power the theoretical craft at much lower power settings than for conventional aircraft.

Simplified diagram of embedded power system in wing driving CFJ

According to a report from the University of Miami, “Zha actually developed CFJ technology in 2003 while working at the Dayton, Ohio-based Wright-Patterson Air Force Base on a summer research project to improve the efficiency of jet engines.”   He has spent 15 years at the U of M designing, developing and building a prototype airfoil and wind tunnel testing it at Texas A&M and at a U of M-operated wind tunnel.

The University adds, “Test results have been astonishing, with data showing the new wing and its airfoil achieving a maximum lift coefficient that exceeds the theoretical limit of classical aerodynamics. ‘The co-flow airfoil can also have cruise efficiency significantly greater than the conventional one when the flow is benign,’ said Zha.”

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