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Inside China's Silicon Valley and One Quest to Power Drones with Hydrogen Fuel Cells

Has the full potential of LiPo batteries been exhausted?

July 11, 2017

Drones have a serious problem with flight time, and I spent 14 hours inside a cramped aluminum tube to see if I could find a solution. After testing a bunch of drones at the Roswell Flight Test Crew over the past several years, I came to the inexorable conclusion that battery-powered platforms max out at about 20 minutes. Tinkering with different airframe materials, motor designs, and propeller sizes might help a little bit, but, as an industry, we’re only going to achieve serious improvements through a more fundamental change.

Thus, the aluminum tube I mentioned earlier: an Airbus A330, which would carry me very nearly halfway around the globe from my home in Portland, Oregon, to Shenzhen, China. Known as the Silicon Valley of Hardware, Shenzhen went from a sleepy fishing village of 20,000 people to a sprawling megalopolis of more than 20 million in just two decades. It is home to literally hundreds of drone companies, including the most recognized drone brand in the world: DJI.

However, my ultimate destination was not the headquarters of that global titan, a glittering tower of glass and steel rising high above the tree-lined streets. Instead, I visited one of the scrappy upstarts dwelling in its shadow: MicroMultiCopter Aero Technology (MMC). MMC makes large, weatherproof drones for use in industrial and public safety applications. Almost unknown in the U.S., its products are widely used across China and other countries in Southeast Asia, which account for nearly 50% of the world’s population.

Of course, I’d seen plenty of industrial birds before this trip, but MMC had created something unique. The drone company is developing an onboard hydrogen fuel cell that’s powerful enough to keep a multirotor aloft not for 20 minutes, or for an hour — but for three hours, and perhaps a good deal longer as the technology continues to mature.

Maxed out

But before I set off to China, I had to know: Have we already achieved maximum flight time based on current battery technology? I put that question to David Ainsworth, the CTO of OXIS Energy.

Based in the U.K., OXIS was founded in 2004 at the Culham Science Centre in Oxfordshire, where lithium-ion battery technology was developed and prototyped. The company’s specialty is battery chemistry: the artful science of combining different elements to create new types of cells with improved storage capacity.

“The lithium-polymer battery is a class within lithium-ion battery technology and is based on the same active materials for the cathode and then anode,” he says. “For any given cathode and anode, there is a ‘theoretical capacity’ and, thanks to 25 years of development, they are approaching their practical limits.”
For those of us who aren’t scientists, he means there is only so much energy you can store inside a LiPo battery given the specific materials involved. Try to go beyond those limitations and bad things can happen, as Samsung so ably demonstrated last September with the flameout of the Note 7 smartphone.

“The large-scale lithium-ion cell manufacturers, such as Samsung, LG, Panasonic, and Sony have not made any significant progress on energy density over the last five years,” Ainsworth says.

After talking to Ainsworth, I went straight to Wikipedia to find out what I could about batteries. It turns out, for something so simple in looks, how a battery works is anything but. Here’s what you need to know:
  • A battery is a device that turns chemical energy into electrical energy.
  • Each cell within a battery is divided into two pools of chemicals, one consisting of negatively charged ions, and the other with positively charged ions.
  • The ions are attracted to each other. The flow of particles from the anode (the negative side of the battery) to the cathode (positive side) creates the electrical current that you can use to power your quad.
Satisfied that we aren’t going to be squeezing more juice out of our LiPos anytime soon, I applied for my Chinese entry visa, packed my bags, and walked down the jetway to the waiting A330.
The alleyways of Shenzhen’s suburban area evoke the dystopian sci-fi classic Blade Runner far more than the sunny suburbs of Modern Family. Patrick Sherman
Stranger in a strange land

The photos you see of Shenzhen in the media depict a thoroughly modern city, with towering office buildings and lush, green parks. Having seen it with my own eyes, I can report that those images accurately reflect the city — but not the whole city. During its development, the government mandated that the factories be relocated to what is referred to as the “suburban area.”

In the mind of a typical American, the word suburban conjures up images of single-family homes, white picket fences, and carefully tended lawns. In China, not so much.

The suburbs of Shenzhen are more urban than most of the urban areas of Portland. The predominant features are towering factory buildings and high-rise apartments. At street level, the buildings along the main thoroughfares host small shops selling street food, cell phones, clothing, groceries, and household supplies — along with internet
gaming parlors and driving schools.

Carts selling live fish and crabs, fresh cuts of meat and whole, plucked birds, crowd the alleyways hard up against men playing dominoes and smoking cigarettes. The roads are navigated by a mix of pedestrians, bicyclists, motorcycles, cars, and heavy trucks.

The whole scene was at once hardscrabble and vibrant. Exploring the neighborhood around my hotel, I halfway expected Rick Deckard (Blade Runner, hello) to push past me in desperate pursuit of a wayward replicant (again, Blade Runner).
To provide a level surface for the final assembly of its aircraft and components, MMC uses an enormous slab of marble, which doesn't respond to changes in temperature and humidity.
Patrick Sherman
Made in China

For most of my life, the words “Made in China” have carried the connotation of cheap manufactured goods, often designed to imitate products made in the U.S., Europe, or Japan. However, even before my trip to Shenzhen, the drone industry had forever transformed my perception of China and its goods.

It was February 2012 — 35 drone years ago, assuming that each terrestrial year delivers seven years’ worth of growth and progress in the drone industry — and at the Roswell Flight Test Crew, we were struggling to cobble together reliable aircraft for our early missions alongside firefighters and hot air balloonists. The state-of-the-art flight management system in those days made use of accelerometers and gyroscopes scavenged from Nintendo Wii controllers.

What made the “MultiWii” so special was that drone operators could return the aircraft to a level orientation all on its own when the radio’s right stick was centered: a primitive form of what we now call Attitude Mode. That was an enormous leap forward from the previous generation of controllers, which, like today’s racing quads in Rate Mode, required constant input from the pilot to maintain straight and level flight.

Searching for a better solution, we stumbled across an online video demonstrating a new flight controller with a peculiar name — NAZA — made by a Chinese company called Da-Jiang Innovations.

Of course, Da-Jiang Innovations is known today as DJI and the NAZA became the bedrock upon which the company built its category-defining personal drone: the Phantom. However, that was still a few years away when I plunked down a couple of hundred bucks for a mysterious plastic box.

When the NAZA arrived direct from China, we installed it on our home-built flagship hexacopter — RQCX-3 Raven — and it worked magnificently. We started referring to the NAZA as the “Make-It-Fly” box, because you seemed to be able to mount it on any multirotor and it flew perfectly.

Blogging about this wondrous discovery, I was bothered by the name. I kept asking myself: “What is a NAZA, anyway?” I started digging around on DJI’s website and found that the names of many of its products — such as its first multirotor kit, the Flame Wheel — were drawn from Chinese mythology. That’s when it hit me: If you create something, you get to name it. And many times culture serves as a reference point for understanding it. Having grown up reading about the Mercury, Gemini, and Apollo astronauts, along with the XB-70 Valkyrie, the F-16 Fighting Falcon, and many others, it came as quite a shock that anything that flies could take its name from source other than European mythology or the birds of North America. In that moment, I realized that the Chinese weren’t just participating in the drone revolution — they were leading it — and it was foolish or delusional to think otherwise.
Fun Fact
DJI stands for Da-Jiang Innovations!
Enter the dragon

Arriving for the first time at the MMC factory, that revelation was very much in the forefront of my mind. I fully expected to see cutting-edge systems and innovative, new products. But to get the most out of my visit, I needed to understand what my hosts said.

Unfortunately, I arrived in China with precisely two Chinese words at my command: ni hao, which means hello, and xiè xiè, which means thank you. I left China having added one more word to my vocabulary: shì de, which means yes.

There was considerable variation in English-speaking fluency between the individuals I met — ranging from fair to non-existent — but the employees at MMC tackled this problem with a pragmatic tenacity that seems to be a hallmark of Shenzhen’s ethos. While they might not have every resource that would be ideal for the project at hand, such as perfect command of spoken English, they never stop trying. They come back at a problem again and again until they see it accomplished.

The MMC factory itself embodied this same spirit. I cannot imagine how a U.S. Occupational Safety and Health Administration inspector would react during a tour of the facility: I haven’t seen so many trip hazards since the last time I was aboard a Navy vessel. As best I could tell, there wasn’t an elevator anywhere in the four-story structure. To conserve electricity, lighting and air conditioning were powered up only as needed, and they appeared to be absent altogether from communal spaces, such as hallways.

It was Spartan by U.S. standards, possibly more than the law would allow in some cases. And like nearly every other building I visited in the suburban area, it evinced a gritty practicality: Its appearance mattered far less than its function.
In each managers office there was a tea table. Here I am about ready to enjoy some tea! Patrick Sherman
With that said, it was tidy and well organized. The employees wore uniforms bearing the MMC logo and the walls were covered with hand-painted murals encouraging them to work hard and be an effective member of the team. These, I determined, were the equivalent of those motivational posters found in break rooms across America, with mountain climbers standing triumphantly on snow-capped peaks, highlighting virtues like achievement, greatness, and perseverance — albeit with a decidedly sterner tone.

One thing that had no equivalent in any U.S. business that I’ve ever visited was the tea table that each manager maintains in his office. About the same size as a coffee table, they were typically surrounded by couches and chairs, and managers use them to entertain visitors, like me, or to hold team meetings.

These tables incorporate a built-in water reservoir, two electric burners, and a basin. The manager brews tea and serves it with a unique style to guests in tiny cups. I discovered that tea tables weren’t unique to MMC, but typical of the culture of Guandong Province, where Shenzhen is located. The company’s Chief Designer Shiqian Deng, respectfully referred to as Mr. Deng by other employees, impressed me the most with his tea service. Obviously refined over many years of practice, he nimbly washed the rims of his cups with the first batch of tea using only chopsticks to avoid scalding his hands. With that accomplished, he made a second pot for drinking with tea leaves from his home province.
I couldn’t get a photo of the MMC hydrogen fuel cell, but Intelligent Energy shared an image of one of its prototype designs fitted to a DJI Matrice 100. Intelligent Energy
Drones at work

Adjacent to its factory, MMC maintains a walled courtyard where it performs quality assurance tests on all of its drones before they are shipped out to customers. That was where I had the opportunity to see its interchangeable payloads in action. In just a few seconds, without the use of any tools, an electro-optical camera with a 30x zoom lens can be swapped for an intelligent drop mechanism, a searchlight, or even a loudspeaker.

In all, MMC makes more than 200 different payload modules, enabling its drones to do jobs that I had never considered before my visit. In the U.S., inspecting power lines is an application receiving a lot of attention. Right now, in Indonesia, MMC drones are being used for stringing power lines. These are serious machines doing serious work, and U.S. companies looking to build out their drone fleets would be well-advised to take a close look at what they can do.

Of course, any application that can be accomplished in 20-minute increments is an application that would be more efficiently and easily accomplished in three-hour increments — which is what led me to a secure laboratory inside the factory where the company is developing its hydrogen fuel cell technology.

My hosts requested that I leave my camera on the other side of the security door, so I can only describe what I saw for you: a box (about the size that could house a pair of ankle boots) with four cooling fans on one side, and what looked to me like an air filter on the other side. This was connected by a hose to a lightweight pressure cylinder, like the ones firefighters wear as part of their breathing apparatus, which contained the hydrogen gas. The device was controlled by a fairly intricate looking circuit board, and the only exhaust produced was tiny droplets of water.

It was astounding: The fuel cell drove a dummy load set up on the work bench, and if its readout was accurate, the system was entirely capable of powering a large multirotor — large enough to lift the fuel cell itself, the pressure cylinder, and quite a substantial payload, while sustaining it in the sky for hours.

Of course, as a journalist, I was trained to be skeptical. I immediately reflected on Carl Sagan’s wise words of caution: “Extraordinary claims require extraordinary evidence.”
In addition to hydrogen fuel cells, MMC makes lightweight aircraft that operate using conventional LiPo batteries — and the company claims it can achieve flight times approaching one hour.
Patrick Sherman
Hydrogen explosion

To verify the credibility of what I had seen, I contacted Julian Hughes, the senior vice president for North America at Intelligent Energy. The U.K.-based company has offices in Japan, India, China, Singapore, the U.S., and France. Intelligent Energy specializes in the development of hydrogen fuel cells for a range of applications, including automobiles. Hughes began by confirming that yes, indeed, a hydrogen fuel cell can power a drone — as his own company had recently demonstrated.

“A fuel cell can be more than twice as efficient as an internal combustion engine,” he explained in an email. “A conventional engine burns fuel to create heat and in turn converts heat into mechanical energy and finally electricity. In contrast, a fuel cell produces electricity, water, and heat directly from hydrogen and oxygen.”

Hughes went on: “Fuel cells are like batteries in that they are electrochemical devices, but unlike batteries, they do not need recharging and will continue to operate as long as they are provided with fuel in the form of hydrogen, and an oxidant — oxygen, taken from the air.” Of course, hydrogen gas and aviation have a decidedly mixed history. NASA has been using fuel cells on its spacecraft since the 1960s. On the other hand, there was the unfortunate incident involving a certain German airship trying to dock at Lakehurst Naval Air Station in New Jersey, in 1937. So, I asked Hughes if drones could safely carry hydrogen fuel.

“Hydrogen is no more or less dangerous than other flammable fuels, including petrol and natural gas,” he said. “In fact, some of hydrogen’s properties actually provide safety benefits compared to petrol or other fuels. For example: It dissipates very quickly and is much less likely to explode in open air because of its high buoyancy and diffusivity. This contrasts sharply with much heavier gasses such as natural gas and gasoline vapor.”

Hughes pointed out that hydrogen, with more than 50 million tons produced annually, has an excellent safety record. However, he warned that hydrogen and all flammable fuels must be handled responsibly.

“Like petrol and natural gas, hydrogen can behave dangerously under specific conditions,” Hughes said. “Hydrogen can be handled safely when appropriate guidelines are observed and the user has an understanding of its behavior.”

Beyond any doubt, MMC had offered me a glimpse of the future. In spite of the potential of this technology to rewrite the industry’s most fundamental assumptions regarding multirotor drone performance, especially in heavy-duty commercial applications, I’m not sure it was the hydrogen fuel cell that impressed me most during this journey. Rather, it was the people I met, and the appreciation I gained for the culture in this crucial part of the world: a city summoned up out of the jungle that has in just two decades achieved profound global influence.

The people who live and work here are intrepid and endlessly striving, relentlessly practical, eager to learn, and excited to make new friends. They are optimistic without being starry-eyed and proud without being conceited. In the end, it is that bright and engaging culture that may be their most important contribution to the drone industry and world, rather than any particular piece of hardware.

Note: A version of this story appeared in the March/April 2017 issue of Drone360 magazine.
Featured image: Patrick Sherman