As Common As It Gets – But Hard to Get

Since Michael Faraday first split water into hydrogen and oxygen in 1820, scientists have puzzled over how to do this economically in large quantities.   The Blog continues to run stories about “artificial leaves,” low-energy approaches to dividing the hydrogen in water from the oxygen, and doing so economically.  The current most widely-used approach to capturing hydrogen is pulling it from natural gas via several processes.  The Office of Energy Efficiency and Renewable Energy explains the process on its web site.

Steam-methane Reforming

In steam-methane reforming, “high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas. In steam-methane reforming, methane reacts with steam under 3–25 bar pressure (1 bar = 14.5 psi) in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. Steam reforming is endothermic—that is, heat must be supplied to the process for the reaction to proceed.”

Breaking down natural gas to form hydrogen

Several steps are required in steam methane reforming to break down natural gas to form hydrogen

In a “’water-gas shift reaction,’ the carbon monoxide and steam are reacted using a catalyst to produce carbon dioxide and more hydrogen. In a final process step called ‘pressure-swing adsorption,’ carbon dioxide and other impurities are removed from the gas stream, leaving essentially pure hydrogen. Steam reforming can also be used to produce hydrogen from other fuels, such as ethanol, propane, or even gasoline.”

Environmentalists would decry this approach, pointing out that it relies on extracting natural gas, itself running into more opposition because of the hydraulic fracturing (fracking) of rock in which the gas is trapped.   Another objection might come from the heat and high pressure required to produce the gas, both energy-intense processes that reduce the overall benefits of the hydrogen produced.

Partial Oxidation

Another process, partial oxidation, use a low-oxygen reaction in a vessel to pull out the hydrogen from natural gas, but quantities are lower than those produced in the more energy intense steam reforming.   All the objections involved with extracting natural gas in the first place remain.

Extraction of H2 from Coal

DOE includes extraction of H2 from coal, using a water-gas shift reaction, with CO2 removed and sequestered (another can of worms) and other impurities removed and stored.  The description is light on details as to what those impurities are or how they will be stored.

Converting coal to hydrogen gas leaves several components to be cleaned and sequestered

Converting coal to hydrogen gas leaves several components to be cleaned and sequestered

Biomass Gasification

Biomass, including non-food plant material, animal and human waste, and other organic sources, can be “converted into a gaseous mixture of hydrogen, carbon monoxide, carbon dioxide, and other compounds by applying heat under pressure in the presence of steam and a controlled amount of oxygen (in a unit called a gasifier).”  This takes materials which would otherwise devolve into methane – said to be 20 times the greenhouse gas that CO2 is – into synthetic gas, or “syngas,” a mixture of hydrogen, carbon monoxide, and carbon dioxide.  The DOE explains that. “The carbon monoxide then reacts with water to form carbon dioxide and more hydrogen (water-gas shift reaction). Adsorbers or special membranes can separate the hydrogen from this gas stream.”

Biomass conversion leads to several possible products, one of which is hydrogen

Biomass conversion leads to several possible products, one of which is hydrogen

In an alternative approach called pyrolysis, the biomass can be gasified in the absence of oxygen, but according to the DOE, biomass does not gasify as easily as coal, probably requiring more energy to create the desired hydrogen end product.   An additional step reforms the hydrocarbons produced to get the “clean” mix of hydrogen, carbon monoxide and carbon dioxide, which is then catalyzed and separated to extract the H2.

Unfortunately, the DOE says these processes are not practical at large scales, partly because of the need to handle and transport large quantities of biomass.  An alternative plan may be to use local biomass in small conversion facilities to produce local fuels and hydrogen.

That seems to cover the largest potential sources for producing hydrogen from fossil fuels or biomass (The Blog is always open to comments and reliable information).  All require at least some energy input, and the amount of H2 produced does not always seem to justify the energy required.

We’ll next look at the variety of “clean energy” sources, including solar power and more “artificial leaves” that could produce the hydrogen we will need if fuel-cell-powered cars are to become a reality on our roads – and thus provide the components we can use in our fuel cell-powered airplanes.  The allure of clean motoring and flying is inescapable – but will we confront the problems of supply, economics, and acceptance in ways that will allow the achievement of a greener future without using more energy than we obtain in the process?


Will VW Take on Tesla?

Volkswagen just bought a five-percent stake in a startup company called QuantumScape, a commercial spinoff of work done at Stanford University’s Nanoscale Prototyping Laboratory for Energy Conversion and Storage.  The Labroratory’s head, Fritz B. Prinz, Finmeccanica Professor of Engineering and Robert Bosch Chairman of Mechanical Engineering, explains: “Our team creates, models, and prototypes nanoscale structures to understand the physics of electrical energy conversion and storage. We are exploring the relation between size, composition, and the kinetics of charge transfer. We are also interested in learning from nature, in particular by studying the electron transport chain in plant cells.”

(Note that the QuantumScape web site is curiously without detail, showing only four pretty pictures and making three or four non-controversial statements.  The most information comes on the Contact link.)

Stanford Labs' team of researchers

Stanford Labs’ team of researchers

Whatever they are doing, the Lab has caught the interest of not only Volkswagen’s CEO Martin Winterkorn, but produced a flood of often speculative articles from Bloomberg, EV World and other sources, an indication that people in the know seem to think something’s coming.  That something may be what QuantumScape calls, “A fundamental disruption in the field of energy storage.”  This type of provocative statement is a hallmark of Elon Musk, CEO of Tesla, and hearing similar ideas from other sources might be a prelude to a more serious contest.

This disruptive element may refer to the “All-Electron Battery” developed by the Lab.  The Lab’s description of the battery is also provocative, and despite its scholarly tone makes pretty impressive claims.  “The All-Electron Battery stores energy by moving electrons, rather than ions, and uses electron/hole redox instead of capacitive polarization of a double-layer. This technology uses a novel architecture that has potential for very high energy density because it decouples the two functions of capacitors: charge separation and breakdown strength. If successful, this project will develop a completely new paradigm in energy storage for electrified vehicles that could revolutionize the electric vehicle industry and establish U.S. leadership in advanced energy storage technology for electric vehicles.”

The promise of the green arrow to the right shows why VW would be enthusiastic about this development

The promise of the green arrow to the right shows why VW would be enthusiastic about this development, with both Watt-hours per kilogram and Watt-hours per liter topping anything currently available

VW would be a formidable competitor for Tesla, spending over $13 billion a year on research and development to Tesla’s $250 million through the first nine months of 2014. reports VW’s Wintercorn as telling a Stanford audience in November, “I see great potential in this new technology, possibly boosting the range to as much as 700 kilometers (430 miles).” He went on to say. “Electro-chemistry is a field of the greatest importance internationally and across industries…..[and is]…..a field where we can and must achieve progress.”

Green Car Congress breaks the history and technology down a bit more.

“In 2010 (also the year QuantumScape was founded), ARPA-E awarded Stanford, with Honda and Applied Materials as project partners, $1,498,681 for a two-year project to further the AEB.

“In patents awarded to Stanford, the Stanford researchers explained that the improved energy storage is provided by exploiting two physical effects in combination.”

One patent describes the all-electron battery as a capacitor with embedded inclusions in the dielectric structure between two electrodes.  “Electrons can tunnel through the dielectric between the electrodes and the inclusions, thereby increasing the charge storage density relative to a conventional capacitor.”

By carefully nano-structuring one or both electrodes, the researchers found ways “to provide an enhanced interface area relative to the electrode geometrical area.”  Such “area enhancement” can also reduce the self-discharge rate of the battery.

The patent explains that “charge and discharge rates and storage capacities of the devices can be selected by appropriate geometrical design and material choice.”  Changing internal geometry allows a wide variety of battery characteristics.

Green Car Congress takes a tentative approach to potential developments.  “If Volkswagen has invested in QuantumScape (and if QuantumScape is basing its technology on the Stanford AEB), then we may see relatively soon what types of design and optimization decisions the startup has made on top of the basic technology with an eye toward vehicle applications.”

In any case, VW and Audi have set goals of leading in battery-powered and other alternative energy vehicles.  The company’s size and willingness to spend on R&D could lead to some exciting developments.


Hydrogen: Are We There Yet?

Probably not, but we are edging closer to when H2-powered vehicles (including small aircraft) might be as ubiquitous as Prius’s or Leafs – but there are significant barriers to overcome.

Fuel cell-powered aircraft might make sense eventually from a physical and economic sense, and while new technologies show promise for EV use, hydrogen power still has barriers to overcome before we’re able to exploit the environmental benefits of hydrogen power.  The appeal of a fuel cell to burn hydrogen and leave behind only a light mist of water still dazzles, but teasingly eludes us, not so much from a technical standpoint – but from environmental and economic ones.

Two Most Practical Fuel Cells for Transportation

Fuel cells come in many varieties, with proton exchange membrane (PEM) and solid oxide fuel cells (SOFC) types heading the list for practical vehicle use.   PEM cells, according to, “operate at relatively low temperatures, have high power density, and can vary output quickly to meet shifts in power demand. PEMs are well-suited to power applications where quick startup is required, such as automobiles or forklifts. Single PEM units range from several watts to several kilowatts, and can be scaled into larger systems.”

The same source explains SOFCs.  “High-temperature SOFCs are capable of internal reforming of light hydrocarbons such as natural gas, but heavier hydrocarbons (gasoline, jet fuel) can be used, though they require an external reformer. There are two configurations of SOFC fuel cell systems: one type uses an array of meter-long tubes, and another uses compressed discs.”

Not That Many Full-Sized H2-Powered Aircraft So Far

Boeing engineers managed to fly the first fuel-cell-powered light aircraft in 2008.  The modified Diamond Dimona craft took off and climbed on a combination of fuel cells and batteries driving an electric motor.  Others followed, with Lange Aviation producing the H-2, an Antares motorglider with hydrogen pods under its wings.  A longer-range version, the H-3, is projected, and would have additional pods.  The company claims that its Antares is the first human-carrying, only hydrogen-powered aircraft, although it might be a close call between that and Gerard Thevenot’s cross-channel trike (see below).

The Antares DLR-H2 with Kallo and Lange, the aircraft's designer

The Antares DLR-H2 with Josef Kallo of the German DLR (much like our NASA) and Axel Lange, the aircraft’s designer

Two fuel cell aircraft were entered in the Berblinger competition in 2011, both having flown successfully on hydrogen and both having achieved firsts and records in their classes.

Professor Gulio Romeo, of the Technical University in Turin, Italy (POLITO), fielded his RAPID 200 Fuel Cell, which had been tested in six test flights up to the time of the contest.  Take-off and climb can from the 35 kilowatts (50 horsepower) combined fuel cell and battery power.  Level flight speeds up to 160 kilometers per hour (99.2 mph) were achieved on fuel cell power only.  Professor Romeo’s airplane set a world speed record of 135 km/hr. and an endurance of 39 minutes during several flights conducted under FAI observation.   The Berblinger people reported that the airplane had flown 2.5 hours up to December, 2010 and covered 237 kilometers (147 miles), all trouble free. Very little has been reported since 2011 on this aircraft.

Enfica 200 which cruised on hydrogen fuel cells, but required battery assist for takeoff, climb

Enfica 200 which cruised on hydrogen fuel cells, but required battery assist for takeoff, climb

Gérard Thevenot, flying a La Mouette hang glider “trike” with an Eck/Geiger HPD-10 motor is probably the first true H2 flier.  Quoted in an Aero-Expo write-up, he said, “We can fly for the first time without auxiliary battery alone with the power of the fuel cell.” He made it across the English Channel on the 100th anniversary of Bleriot’s crossing, using about 550 grams of hydrogen per flight hour.  A five-liter bottle of H2 would keep the 55 kilogram (121 pound) airplane aloft for about an hour.  Later, another pilot flew the trike from Cozumel to the Central American mainland, a 10 kilometer (6.2 mile) hop.

Gerard Thevenot flying La Mouette trike with five fuel cells driving Eck/Geiger motor, two hydrogen tanks feeding fuel cells

Gerard Thevenot flying La Mouette trike with five fuel cells driving Eck/Geiger motor, two hydrogen tanks feeding fuel cells

For whatever reason, nothing other than continued drone flights using H2 seem to have been reported since 2011 in the general aviation size range.  (This despite a Berblinger meeting in 2013 which seemed for focus on technology if not flight demonstrations or contests.)  Boeing and Aerovironment have produced and test flown larger hydrogen-powered craft, although the Phantom Eye by Boeing uses highly modified internal combustion engines to burn the fuel, rather than relying on electric motors powered by fuel cells.

With this static state of affairs in aircraft development, we will next turn to the production of hydrogen for vehicle use, and the issues facing its distribution and deployment.  We are about where gasoline-powered cars were when they began supplanting horses and buggies – up against the prevailing technology and confronted, in the present instance, by well-financed and increasingly entrenched completion.  Whether fuel cells are just the “BS” asserted by Elon Musk, or whether they will prove a formidable opposition to current tech, will provide a fairly turbulent and competitive coming decade, in this writer’s opinion.

Next: How we get H2 and how we might make it competitive with batteries.

{ 1 comment }

A Cheerfully Acknowledged Chastisement

If one writes things, occasional slip-ups creep in.  In this case, an unchallenged assertion of who is “first” drew this kind email from Klaus Savier, builder, tuner and pilot of a very slippery Long-Eze.  He’s flown from California to Florida and back on good old fossil fuels (with one fuel stop each way) in his highly modified Long-Eze and achieved 30 miles per gallon at 250 miles per hour true airspeed.  It would be interesting to see how little fuel the airplane would consume at Green Flight Challenge airspeeds.  His demonstrated 0.36 pounds of fuel per horsepower-hour is claimed by Klaus to be 40-percent lower than the commonly seen 0.60 pounds per horsepower-hour that engines without his Light Speed Engineering ignition system and more standard propellers manage.  It shows what a determined experimenter can accomplish.

His letter follows:

Hello Dean,

Thank you for the nice article you wrote in Kitplanes a while ago. So far that was the only publication of actual demonstrated performance of this machine. As most articles process hyperbole and fantasies these days, it was welcomed by many readers and I saw many quotes from that article on various experimental aircraft blogs. There are still a lot of readers who prefer facts over fantasy even though our reality can hardly compete with a good dream.

I am continually improving the airplane, there is a lot more to come and the performance has been advanced significantly already and the weight has been reduced further. You might have seen that I won the Bronze race at Reno this year, another Long EZ with a very special, much larger engine, turning 300 rpm more was 35 mph slower. As an engineer [a technical writer - or technically, a writer, actually], you know what that entails.

But that brings me to another point: They had only one trophy for first in the bronze. The guy behind me got second place. He received his own trophy for placing second. That is the way it works.

Once there is a “first”, there can’t be another first for the same claim!

So when I read the following from your blog post:

“For 50,000 euros ($62,000), these future ‘StratosVoyagers’ will live a unique experience, they will be the first passengers of a solar airplane.”  We know that this can’t be true! At best, they will be the 50th or something like that since you and I know that Eric has already flown more than a dozen passengers in his Duo.

Although Irena Raymond may not be the very first passenger in the Sunseeker Duo, she has gone on to solo the solar airplane she and Eric built together.

Although Irena Raymond may not be the very first passenger in the Sunseeker Duo, she has gone on to solo the solar airplane she and Eric built together.  They are definitely the first family of solar aviation.

Klaus concludes, “And here is a picture of the ‘FIRST passenger of a solar airplane’. There will be no other, only in a dream!”

Your editor appreciates the gentle nudge from readers like Klaus, and will attempt to be sharper with editorial discretion.  In the meantime, we can only appreciate and encourage all seekers of greener flight.


$70,000 is a sizable base price for a car.   That sum for the simplest of Tesla S sedans makes a bigger than average debt load for most of us, probably more than most can responsibly assume.   Even the much anticipated model “E” at half that price is more stunning than the average sticker shock these days.  What if, by some act of art or science, that $70,000 could be slashed to $14,000 for an electric vehicle that could travel 265 miles on a charge?  That tall order is the order of the day for the Joint Center for Energy Storage Research, started two years ago under Dr. Steven Chu, who was then U. S. Secretary of Energy.  He and his “teams” were charged with establishing the cooperative enterprise at “Argonne National Laboratory with a budget of $120 million over five years to create a battery five times more powerful and five times cheaper than today’s norms – all within five years.”  We’re two years into the program – so how’s it going?

A lead article in The Seattle Times Monday morning removed any concern about progress, and the cooperative’s web site should alleviate any doubt that tax dollars are being spent wisely and well.

Not only would the price of EVs decline significantly if the group is successful, but the benefits would spill over into consumer products such as cellphones, laptops and the home-based “Internet of things.”

To pull of their ambitious goals, J-CESR’s researchers are delving into four lines of study:

  1. Electrochemical Storage Concepts looks at materials such as magnesium or yttrium (there’s a Scrabble winner) that carry twice or triple the charge of lithium, with two or three times the energy storage potential; chemical transformations that store many times the energy of today’s batteries; and non-aqueous redox flow that will be of great use in grid storage.
  2. “Crosscutting Science” that uses recently-developed research techniques to “make new materials and characterize their performance at the atomic level for the three energy storage concepts.
  3. “Systems Analysis and Translation designs virtual batteries on the computer, projects their performance, identifies shortcomings, and communicates results to the Science and Concept teams.”  J-CESR is using high speed computers that will allow analysis at the femtosecond level (a quadrillionth of a second).  They’re investigating new battery architectures “needed to leapfrog existing designs, improve system performance, raise cycle lifetimes and approach the theoretical energy and power densities of new materials and designs. New architectures will integrate novel materials and components at the nano- to macroscale.”
  4. As a grand capper, and the step ensuring taxpayers see a payoff for their investment, “Cell Design and Prototyping delivers pre-commercial prototypes for grid and transportation applications.”
Big numbers from big sources.  What J-CESR will have to achieve to bring 100% clean energy to just the US

Big numbers from big sources. What J-CESR will have to achieve to bring 100% clean energy to just the US

Getting Their Actors Together

Now spread out among its 14 academic and commercial members, key players will come together in a new Berkeley Hub with a $54 million, 43,000 square foot General Purpose Laboratory, “bringing its battery scientists, chemists and engineers together under one roof for the first time.”

Center Deputy Director Venkat Srinivasan will head the team, which aims to “achieve revolutionary advances in battery performance — creating devices with up to five times the energy capacity of today’s batteries at one-fifth the cost by 2017” – the same aims expressed by Energy Secretary Chu five years ago.

Srinvivasan explains, “We want to go beyond and find the next generation of technology.  It’s clear to us that the batteries we have today are not meeting the needs.”

The Daily Californian reported Srinivasan’s remarks at the Center’s ribbon cutting.   “You put a bunch of scientists and engineers together and they start interacting, and you have products coming out of the other end,” Srinivasan said. “They have very different skill sets, and so very new products … are the result.

Moving Beyond Lithium?

Elon Musk will soon compete, in a sense, not only against the Chevy Volt, BMW, Audi, Toyota and Nissan for primacy in the EV market, but will face researchers looking for the next big thing past lithium-ion batteries.  The efforts of J-CESR point toward post-lithium developments.  With others striving to perfect the delivery and distribution of hydrogen for vehicles, the market will soon provide choices that all lead to greener transportation.

The long climb to achieve parity with gasoline in terms of energy storage

The long climb to achieve parity with gasoline in terms of energy storage

J-CESR reports, “George Crabtree, director of the project at Argonne National Laboratory near Chicago, said the federal government is pursuing the research to transform the two areas that consume two-thirds of all the energy generated in the United States — transportation and the energy grid.”

“’There’s a real opportunity for next-generation storage,’ Crabtree said. ‘You have to make a big step forward. Lithium-ion will not be able to make that step. … You need a big program and a group effort to make it happen.’”  He says researchers have narrowed things to about 100 chemistries, with a few in the prototype phase.

Berkeley’s battery research hub is next door to the Advanced Light Source building, where automaker Toyota has been researching magnesium-ion batteries, which promise double the charge of lithium at the same weight.  That kind of potential charges up Srinivasan. “For the same weight, you can have twice the charge — you’re doubling the amount of capacity.  That’s exciting.”

Sharing the lab will be principal investigator and Lawrence Berkeley staff scientist Brett Helms, focusing on the other charge for J-CESR, large-scale grid storage.  Doubtless, discoveries within each group will be shared and expanded on.

Argonne National Laboratory leads JCESR in partnership with four other DOE national laboratories, five universities, and four private firms.  Joining Argonne on the JCESR team are Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory, Sandia National Laboratories, and SLAC National Accelerator Laboratory.  Participating universities include Northwestern University, the University of Chicago, the University of Illinois at Urbana-Champaign, the University of Illinois at Chicago, and the University of Michigan, and private firms joining the effort are Dow Chemical Co., Applied Materials, Inc., Johnson Controls Inc., and Clean Energy Trust.


It’s (Green Aviation) Giving Tuesday, 2014

If you’ve managed to survive Gray Thursday, Black Friday, and a weekend of NFL games stuffed with blandishments to entice you to the nearest mall (Thanksgiving happened in there somewhere), you’re forgiven if you flinch at yet one more presumptuous tug at your purse strings.  But we’re talking about helping pioneers on the edge of green technology, crafting the stuff dreams are made of – and making those dreams a reality.  On this Giving Thursday, think about contributing to the dream makers who are taking us into a better future of flight.   We share a few suggestions here.

Solar Flight

Eric and Irena Raymond are the first family of solar-powered flight, now cruising Italian skies in the world’s first two-seat sun-powered airplane, the Duo.  To assist with further development of their splendid aircraft, including Sunstar, a high-altitude surveillance and communications craft, the couple is selling a beautiful calendar featuring their aircraft.  For $37 US or 29 euros plus shipping, you will receive a year’s worth of stunning photos taken by the Raymonds, both highly skilled camera-people.

Both Raymonds are professional photographers as well as aircraft designers and test pilots

Both Raymonds are professional photographers as well as aircraft designers and test pilots

Over several decades, Eric has accomplished a great deal, including having the most hours in the air on solar power – all on his own financial resources.  He and Irena would appreciate your support to further develop this exciting resource.

Solar Impulse 2

A significantly well-backed operation, the Solar Impulse Project will start an around-the-world flight on solar power early next year, moving the airplane from its home base in Payerne, Switzerland to Abu Dhabi.  They will start and finish their epic voyage there.

Solar Impulse HB-SIB on one of its last Swiss flights before being moved to Abu Dhabi

Solar Impulse HB-SIB on one of its last Swiss flights before being moved to Abu Dhabi

Solar Impulse has an array of products to help underwrite their flight.  You can purchase badges commemorating different highlights of both airplanes’ development, and even “own” a solar cell on the wing of HB-SIB, the newest craft.   Besides the commemorative and “practical” gifts that support SI-B, the team has a boutique-like web page with items of Solar Impulse apparel.

John McGinnis’s Synergy

Synergy’s advanced aerodynamics and as yet untested (in full scale) configuration have been the objects of curiosity and controversy since their inception, but the airplane is on the home stretch toward completion and test flying.

Those who have followed Synergy's development will appreciate the elbow room in the donated new hangar

Those who have followed Synergy’s development will appreciate the elbow room in the donated new hangar

John is doing a great job of promoting the airplane, having seen it featured in Popular Science and even National Geographic Kids.  He gave a brilliant Ted Talk on the development of the craft this year.   His Facebook page will keep us posted on the latest developments.

John welcomes your participation in helping his extraordinary design reach its final plateau as you find a button box labeled “I support you.”   His project truly deserves our support, having just moved the project to a large hangar that provides indoor plumbing for the first time in the airplane’s development.  Now, that’s pioneering in almost every respect.

The Perlan Project

Even with its good fortune of having Airbus join as a partner in its altitude record goals, Perlan still seeks donations from private individuals who would like to support its multiple goals.

The Perlan team at the official announcement of their new partnership with Airbus, AirVenture 2014

The Perlan team at the official announcement of their new partnership with Airbus, AirVenture 2014

Aeronautical exploration, aerodynamic far-reaching meteorological research and the chance to  share the knowledge gained in all areas with students at all grade levels make this an attractive program with potentially extraordinary benefits for science, technology, engineering and math (STEM) programs worldwide.

The organization explains that, “Perlan Project Inc. is a 501c3 not-for-profit aeronautical exploration and atmospheric research company utilizing sailplanes (gliders) designed to fly at extremely high altitudes.”  Their challenge, to reach 90,000 feet in the Polar Vortex, should give us a first-hand look at the composition of the atmosphere and the nature of the ozone hole in a way that is impossible with powered aircraft or rockets.

The CAFE Foundation

Another 501.c 3, CAFE is an all-volunteer organization that supports this blog, holds the annual Electric Aircraft Symposium, and managed the Green Flight Challenge three years ago – a competition that demonstrated electric aircraft capable of flying at over 400 passenger miles per gallon equivalent energy.  With over 34 years of flight testing experience, the organization looks forward to promoting and running a series of future Green Flight Challenges that will lead to the development of practical electrically-powered commuter aircraft that would bring low-cost flight to neighborhood airparks.  Its advisory board consists of experts in aerodynamics, power, and energy storage.

The CAFE Foundation Board: front row, L-R, Alan Soule, Larry Ford, Brien Seeley, John Palmerlee, Wayne Cook back row, L-R, Mike Fenn, Steve Williams, Jo Dempsey, Bruno Mombrinie

The CAFE Foundation Board: front row, L-R, Alan Soule, Larry Ford, Brien Seeley, John Palmerlee, Wayne Cook
back row, L-R, Mike Fenn, Steve Williams, Jo Dempsey, Bruno Mombrinie

The group maintains an ever-expanding on-line technical library that is an invaluable resource to those researching advanced aerodynamics, reduced noise signatures for aircraft, propeller design, short and vertical takeoff and landing, and increased safety and utility for personal aircraft.  Giving to this group helps promote the academic and professional underpinnings of the next generation of light aircraft.


SolarStratos is Raphael Domjan’s mission to reach the edge of space in an electrically-powered, solar-assisted two-seat aircraft – the first commercial two-seat electric airplane, he claims.  Flying an aircraft based on Calin Gologan’s PC-Aero designs, Domjan will carry scientists and adventurous passengers to the low stratosphere.

The SolarStratos team, including Raphael Domjan by aircraft nose, Calin Gologan to left of tail

The SolarStratos team, including Raphael Domjan by aircraft nose, Calin Gologan to left of tail

He explains his mission here: “Wouldn’t it be essential to go higher to show the capacity of renewable energy, here on the surface of our planet? Beyond this adventure, our project is to open a door on a commercial electrical or solar aviation on the edge of space, with the aim of achieving unique travel with private passengers or scientists.

“Imagine yourself aboard a solar-powered plane flying in total silence at more than 75’000 feet. At this altitude you can contemplate the curvature of the planet and observe the stars during the day.”

SolarStratos offers everything from a free newsletter subscription to a 50,000 euro ($62,000) flight to altitude in the airplane, probably including familiarization with pressure suits and high-altitude protocols.

Summing Up

All of these organizations and projects have the potential to lead to bigger things, including revolutionizing the design, construction and flight of aircraft we could not have imagined even a decade ago.  What the coming decades bring could well depend on our contributions today.


Researchers at the Vienna University of Technology have combined two semiconductor materials, each only three atomic layers thick. Adding one semiconducting layer of the photoactive crystal tungsten diselenide to a layer of molybdenum disulphide, and “creating a designer-material that may be used in future low-cost solar cells.”

Layered look of Vienna semiconductor sausage

Layered look of Vienna semiconductor sausage.  Thomas Mueller and colleagues combined slices of tungsten diselenide and molybdenum disulphide to create transparent solar collector with a weight of one gram for over 3,300 square feet

Having worked with graphene, that two-dimensional, atom-thick material that promises much for structures, batteries and solar cells, Thomas Mueuller, assistant professor of photonics, and his team “acquired the necessary know-how to handle, analyze and improve ultra-thin layers by working with graphene.”  The team applied their lessons learned with graphene to combining two ultra-thin semiconductor layers and are now studying their optoelectronic properties.

Mueller explains, ““Quite often, two-dimensional crystals have electronic properties that are completely different from those of thicker layers of the same material.”  In their present study, the Tungsten diselenide, a semiconductor consisting of three atomic layers; one layer of tungsten sandwiched between two layers of selenium atoms. Mueller adds, “We had already been able to show that tungsten diselenide can be used to turn light into electric energy and vice versa.”

To get around the problem of inserting “countless tiny metal electrodes tightly spaced only a few micrometers apart,” the researchers came up with an “elegant” solution, combining the tungsten diselenide with molybdenum disulphide, which also consists of three atomic layers.  The two three-layered slices can now form large-areas solar cells.

Vienna UT explains the interaction of the two layers: “When light shines on a photoactive material single electrons are removed from their original position. A positively charged hole remains, where the electron used to be. Both the electron and the hole can move freely in the material, but they only contribute to the electrical current when they are kept apart so that they cannot recombine.

(Left to right) Marco Furchi, Thomas Mueller, and Andreas Pospichil sort out how to combine multiple layer semiconductors

(Left to right) Marco Furchi, Thomas Mueller, and Andreas Pospischil sort out how to combine multiple layers of semiconductors

“To prevent recombination of electrons and holes, metallic electrodes can be used, through which the charge is sucked away – or a second material is added. ‘The holes move inside the tungsten diselenide layer, the electrons, on the other hand, migrate into the molybednium disulphide’, says Thomas Mueller. Thus, recombination is suppressed.”

To tune the layers for proper alignment, Florian Libisch and Professor Joachim Burgdörfer provided computer simulations to calculate how the energy of the electrons changes in both materials and which voltage leads to an optimum yield of electrical power.

Mueller noted the challenge of stacking the two layers. “If there are any molecules between the two layers, so that there is no direct contact, the solar cell will not work.”  In something like miniaturized vacuum bagging, researchers heated both layers in a vacuum and stacked them in ambient temperature, then reheated the layers to remove any water between the layers.

The resulting material allows incoming light to pass through it, and absorbs the rest, converting it into electricity.    Transparent, the material could be used for window glass or for coatings on almost anything else, it would seem.  Because it’s only a few atoms thick, 300 square meters (3,229 square feet, or about 32 sailplane wings) weigh a gram.

Researchers are now working on stacking more than two layers, which will reduce transparency but increase electrical power.  How many layers will it take to make this a still lightweight but extremely powerful solar energy producer?  We’ll anxiously await further developments from Vienna.


SolarStratos Construction to Begin in January

Just as we have competing teams working out their plans to cross the Atlantic on electrically-powered wings, several projects are aiming high, attempting to reach altitudes normally achieved only by SR-71 pilots.  With balloon jumps topping 130,000 feet and the Perlan Project in final stages of construction for test flights early next year, the latest entrant in stratosphere-busting climbs will attempt the mission on batteries and solar power.

SolarStratos on its five-hour climb to 80,000 feet.  Rendering by SolarStratos

SolarStratos on its five-hour climb to 80,000 feet. Rendering by SolarStratos

Raphael Domjan, a self-described “eco-adventurer” and founder of Mission SolarStratos, will attempt by 2017 to top 80,000 feet in a two-seat, twin-motored craft designed and built by Calin Gologan and his PC-Aero team.  The airplane, a long-winged derivation of Gologan’s Elektra Two Solar, will rely on recent developments between Gologan and his American Partner, George Bye.  They’ve formed the American Electric Aircraft Corporation, dedicated to building, testing and certifying a two-seat trainer.

Solar Stratos has a 24.4-meter (80.8 feet) wing, 7.4 meters (9.84 feet) longer than that on the longest-span Elektra Two.  Somehow, PC-Aero has managed to add only 50 kilograms (110 pounds) to the Elektra’s 350 kilogram (770 pound) maximum takeoff weight for the larger craft.  Part of this may come from Solar Stratus’ short conventional gear, which replaces the retractable system on the Elektra Two.  Additional area for solar cells will allow the airplane to fly on solar power alone at its maximum altitude, necessary because the energy needed five-hour climb to maximum altitude will probably drain the 80 kilograms (176 pounds) of lithium-ion batteries on board.

Seeing "the stars at noon" will be part of voyages into the stratosphere.  Rendering by SolarStratos

Seeing “the stars at noon” will be part of voyages into the stratosphere. Rendering by SolarStratos

Domjan hopes to take others aloft to see the stars at noon and the curvature of the earth’s horizon, but passengers will have to be hardy souls willing to train for the serious business of wearing a lightweight pressure suit, the airplane’s own light weight not allowing pressurization.  Solar Stratos might benefit from the Perlan Project’s experiences with loaned NASA space suits.  Einar Enevoldson and Steve Fossett had issues even going to their 50,671 foot altitude record in 2006.

Raphael Domjan practicing free falls in the Realfly facility in Sion, Switzerland.  Photo courtesy SolarStratos

Raphael Domjan practicing free falls in the Realfly facility in Sion, Switzerland. Photo courtesy SolarStratos

Domjan is in training himself, according to this week’s Solar Stratos press release, working out in free-fall sessions at Realfly in Sion, Switzerland and presumably with jumps from altitude.  Geraldine Fasnacht, heading up security for the SolarStrator and Realfly teams, has assisted in training and preparations for the long flights ahead.  Making “dozens of jumps in the space of a few months, Domjan has also tested biomedical telemetry systems developed by the Swiss Centre for Electronics and Microtechnology (CSEM), while in simulated free fall at Realfly.

With construction of SolarStratos starting soon, Domjan can look forward to test flights by 2016 and by 2017 attaining “an altitude of around 80,000 feet (over 24 kilometers or 14.88 miles), where temperatures of about -70 ° C prevail.”  By 2018, the team hopes to start commercial flights to altitude.

The press release noted the presence of an elite support team.  “To meet this challenge, Raphael was already surrounded by a team of specialists, such as Michael Lopez-Alegria, astronaut and Flight Director Calin Gologan, engineer and manufacturer of the aircraft, Géraldine Fasnacht, wingsuit pilot, professional and responsible for flight safety rider, as well as other experts in engineering, meteorology, computer science and communication.”

Others include “Edgar Mitchell, the sixth astronaut to set foot on the moon in 1971, and lunar module pilot on the Apollo 14 Mission; André Schneider, vice president of the Ecole Polytechnique Federale de Lausanne (EPFL); Cedric Borboën, deputy director and wealth manager at Lombard Odier & Cie SA in Geneva, Founder & President of the Economic Forum North Vaudois; Miroslaw Hermaszewski, the first Polish astronaut, to have made a single flight as experimenter aboard Soyuz 30 in 1978; Raphael and his team are pleased to welcome these new sponsors eco-adventure SolarStratos.”

Domjan and his team look next to “open a door” on solar electric flight and near-space commercial trips for passengers and scientists.  Jean Verne, the grandson of Jules Verne, and Marie-Vincente Latécoère (from the Pierre-Georges Latécoère Foundation) support the project.

“Several partners have joined the adventure. This is Solstis SA, Horus Networks Sàrl, CSEM, PC-Aero GmbH, the City of Lausanne, e-Management, and RealFly Heli-Lausanne.”

Domjan’s ecologically-inspired adventurous spirit conquered the world’s oceans between September 2010 and May 2012 as he and a five-man crew sailed around the world using the energy generated by 500 square meters (5,382 square feet) of solar cells to power PlanetSolar, the world’s largest solar-powered boat.  He hopes to inspire others with his environmentally conscious adventures, while testing his personal limits and the limits of current technology.

Those wanting to support the effort will find varying levels of support, from a free subscription to the organization’s newsletter to a high-altitude flight in SolarStratos itself.  Under the heading “Be With Us,” SolarStratos promises the following: “You can join the club “SolarStartos” and follow us in our new venture. Everyone can join in the fun, but there [are] still 10 places for people wishing to live the adventure of solar flight in SolarStratos and approach some of our star, in silence. For 50,000 euros ($62,000), these future “StratosVoyagers” will live a unique experience, they will be the first passengers of a solar airplane and become ambassadors of the potential of renewable energy. This prestigious club will also fund the early stages of the project “SolarStratos.”


“Inspired by nature’s own anti-turbulence devices – feathers,” researchers at RMIT University in Melbourne, Australia, have developed a system that emulates the movements of feathers with which birds control their flight path in the most turbulent conditions.

Dr. Case van Dam gave a talk at the 2014 Electric Aircraft Symposium on controlling aircraft in turbulence and providing smoother rides with Gurney flaps, jet flaps and micro tabs.  The RMIT team chose to mimic the motions of feathers on a bird’s wing to gain many of the same advantages.  The Unmanned Systems Research Team learned enough to file a provisional patent on the system, detecting disturbances in the air ahead of the airplane.  Both approaches might help the electric commuter aircraft proposed by Dr. Brien Seeley and Dr. Mark Moore as part of the hoped-for “pocket airpark” system.

Research supervisor Professor Simon Watkins explained the benefits of the University’s wind tunnel testing on a model of a small aircraft.   “By sensing gusts and disturbances in air flow through their feathers, birds are able to fly gracefully rather than bouncing around in turbulent air.  The system we have developed replicates this natural technology, with the aim of enabling planes to fly smoothly through even severe turbulence – just like birds.”

By sensing a flow disturbance in the air on the leading edge of the wing or even ahead of the wing, the system uses phase-advanced sensing, reacting to flow disturbances before they can affect the motion of the aircraft.

As with Dr. Van Dam’s systems,  “Professor Watkins said the system had great potential for all sizes of aircraft and could not only reduce the effects of turbulence on passengers but also reduce loads on plane wings, leading to lower fatigue and hence longer life.”

“’While we need to explore new sensor arrangements to apply this technology to larger and faster aircraft, we have proven the idea on the most challenging problem of keeping small, lightweight planes steady – since these are the ones that get bounced around the most,’ he said.”

Large model aircraft flies into wind-tunnel turbulence

Large model aircraft flies into wind-tunnel turbulence using the prototype anti-turbulence system developed at RMIT University

RMIT reports that the patent submission for a turbulence mitigation system for aircraft represents the successful outcome of PhD research by Abdulghani Mohamed, supervised by Professor Watkins and Dr. Reece Clothier in RMIT’s School of Aerospace, Mechanical and Manufacturing Engineering.  Mr. Mohamed’s contributions on turbulence theory and its effects on aircraft are acknowledged.

Earlier attempts to duplicate birds’ feathers reacting to turbulence or to provide flight control indicated some effects of the feathers on top of a bird’s wing enhancing control.  German experimenters attempted to duplicate this effect by applying a leather strip to one wing of a Messerschmidt Me-109 in 1938.  Later experiments titled “Separation Control on a Glider Wing with Artificial Bird’s Feathers” involved a section of a Stemme S10 that attempted to duplicate flight at low Reynolds numbers.

RMIT University (Royal Melbourne Institute of Technology) identifies itself as a global university, with campuses in Melbourne, Australia, two campuses in Vietnam, and an office in Barcelona, Spain.  The University also offers programs through partners in Singapore, Hong Kong, mainland China, Indonesia, Sri Lanka, Spain and Germany, and enjoys research and industry partnerships on every continent.


Dr. Seeley provided this link to a story from China Daily this morning.  The blog reported on this airplane last year following its public debut, but this year, two examples showed up at the 10th China International Aviation and Aerospace Exhibition, also billed as Airshow China.  Held in Zhuhai, Guangdong Province, the show featured daily flight demonstrations by one of the two aircraft on display.

RX1E on display at

RX1E on display at the 10th China International Aviation and Aerospace Exhibition

China Daily followed its headline with this optimistic kickline, “Huge markets are expected for the versatile, eco-friendly 2-seat RX1E, then reports, “China will soon put its first domestically developed electric aircraft into mass production, and designers expect a huge market at home and abroad.”

“First” may be a dubious claim, with Tian Yu’s Greenwing International (Yuneec in China) e430 having flown five years ago, and having resumed flight testing in the US last year.  It may be true in the sense that Yuneec International now only shows drones, action cameras and powered skateboards on its page, with all aviation activities apparently transferred to its operations in California.

RX1E being assembled by students

RX1E being assembled by students

Designed by members of Shenyang Aerospace University in Liaoning Province, the airplane is expected to receive its airworthiness certificate from the Civil Aviation Administration of China “before the end of this year,” and will enter production in 2015.  Yang Fengtian, “an academic” at the Chinese Academy of Engineering and President of the Aerospace University, is obviously proud of the accomplishment.  “This will be the first electric aircraft to be certified by our civil aviation authority.  The success of our plane means China has become a technology leader in this field.”

In Shenyang, construction has started on a plant that can produce 100 RX1Es each year within three years.   Whether that rate will be achieved remains a matter for conjecture, with a price of 1 million yuan, or $163,000.  This will require the 1,000 sales Yang predicts as a demand from Chinese general aviation, but he sees markets for police patrols, flight training, “entertainment,” and mapping surveys.  He also sees market possibilities overseas, even though America’s FAA has yet to approve two-seat electric flight.  Yang says “many foreign enterprises have contacted us to express an interest in it.”  We can hope that interest equates to action on the part of the different foreign regulatory agencies.

The RX1E has a maximum take-off weight of 480 kilograms (1,056 pounds) and a maximum cruising speed of 160 kilometers per hour (99.2 mph).  Able to fly 90 minutes or 230 kilometers (142.6 miles) on a full charge of its 10 kilowatt-hour battery packs, the airplane should provide low-cost flight, with a five yuan ($1.00) fee  for a 40-minute recharge, with total operational costs at 20 yuan per hour.  The video leaves some question as to how many battery packs the aircraft carries, and how long they would need to charge for longer flights, but based on Yuneec’s similar design, at least four packs would probably be needed for a 90-minute flight.

Roland Bosch, an aircraft exhibition organizer from Germany, attended the Zhuhai show to invite Yang and the RX1E to display at a general aviation show back home.  “The RX1E’s design and engine are very good.  I believe it will be a big success in the global market because it is one of the best electric aircraft to my knowledge,” he said.

During the show, Mr. He Jun, Deputy Director of Liaoning General Aviation Institute and Mr. Tong Jianhui, General Manager of AVICLUB, signed an order for the first of the aircraft, indicating that production will commence on demand from the market.

We hope to report more on this promising design as details become available.

{ 1 comment }