Hydrogen fuel cells with great difficultyare moving forward as an energy source for ground electric vehicles, but many are beginning to look for alternative ways to drive without emissions. The new air taxi startup, Alaka’i Technologies, this week introduced an electric aircraft for five passengers, powered by liquid hydrogen, which, according to the creators, will be more efficient and powerful than aircraft powered by batteries that many competitors are developing.
What is more efficient: electricity or hydrogen?
The company to create a "flying car"is located in Massachusetts and is run by people from NASA, Raythein, Airbus, Boeing, and the Department of Defense. The other day, she presented a mockup of an aircraft with six screws called Skai in Los Angeles, in the office of BMW Designworks, with which she collaborated on the design of the aircraft. Alaka’i says that the final product can fly up to four hours and cover 600 kilometers per load of fuel, which can be replenished in 10 minutes at a hydrogen filling station. According to the company, it has created a functional full-scale prototype, which will make its first flight “in a short time”.
This will not be the first hydrogen powered aircraft.fuel cell; Boeing made it back in 2008. But he will be the first of its kind. The box-shaped configuration of the Skai does not have an aerodynamic appearance, as in the prototypes from Lilium, Bell and, yes, Boeing. It reaches a speed of only 224 km / h, while other eVTOL concepts (electric vehicles for vertical take-off and landing) promise a speed of up to 270 km / h. Skai was developed more for efficiency, which is more important than maximum speed, if you dozens of short jumps every day.
"Our task was to make itsimple and we focused on creating a specific image of a reusable image during the day, ”says NASA veteran Bruce Holmes, who is on the board of directors of Alaka’i.
The argument for fuel cells comes down toenergy density: a pound (almost half a kilogram) of compressed hydrogen contains 200 times more energy than a pound of batteries, says Alaka’i founder Brian Morrison. This means that Skai can satisfy the requirements for speed, range and carrying capacity, which, in the opinion of Alaka’i, will make it competitive, while at the same time allowing it to significantly save weight - the main consideration for everything that flies. Although the company did not disclose the specifics of the power supply system, it states that it and its fuel cell supplier (which is also not disclosed) managed to make a “breakthrough” in the technology providing the desired performance.
Hydrogen fuel cells prove theirthe ability to significantly increase the operating time of transport systems: some small unmanned aerial vehicles have switched from 30–45 minutes of battery life to 2–4 hours of working with fuel cells, says Thomas Valdez, chemical engineer at Teledyne Energy Systems. And they offer safety benefits by eliminating the risk of thermal acceleration of the battery. Even a broken tank is not a problem. “Hydrogen will dissipate very quickly in the air under pressure, so it will not accumulate or ignite like conventional fuels,” says Valdez.
Of course, as with all startups related toby air taxi, Skai has a lot of problems. The main one is to ensure the timely receipt of the FAA certificate, which is not guaranteed, given the installation of a new propulsion system in the apparatus of a new type. Holmes believes that a simple construction will help them here.
“We have significantly fewer spare parts forcompared with traditional aircraft and half the requirements that the FAA should test, ”he says. Skai does not have a tail rotor, and a ballistic parachute means that it does not need to rely on an auto-turn for a safe landing if power drops. The six screws that produce 450 horsepower are in a fixed position and do not rotate before a vertical or horizontal take-off.
To cope with this task, Alaka’iplans to skip the air taxi service at an early stage, focusing instead on emergency services, search and rescue missions and cargo transportation. These roles do not require the same certification standards as passenger flights. Holmes is extremely optimistic: certification will take only a few months (and will be completed by the end of 2020) instead of the standard five to ten years.
Hydrogen, of course, has a disadvantage, namelythe fact that its not so much around. The lack of refueling infrastructure makes it difficult for land-based vehicles to run on hydrogen, but airplanes may be easier. Instead of relying on gas stations at every corner, airplanes may have more centralized refueling centers supplied by tankers.
Equipment costs can be another potential obstacle.
"Hydrogen fuel cells are used inspacecraft for quite some time. This is a proven technology, ”says Charles Eastlake, an honorary professor of aerospace engineering at the University. Embry-Riddle. "But cost prevents them."
He notes that one creation projectThe electric aircraft, which the university undertook in 2011, included a fuel cell that would have cost $ 250,000 on the open market, all to power a relatively small 40-horsepower electric motor. Although technologies have only improved since then, but the cost is falling, it will not fall much, considering that most of the dollars spent on R & D are transferred to batteries.
Alaka’i says that the first will be launched firstthe plane, and only then a highly automated and fully autonomous mode was implemented. The startup focuses on the price of about $ 200,000, although the first models are likely to be much more expensive. Production will be about 10,000 per year. This is a huge number: none of the manufacturers produce more than 700 aircraft.
Ultimately, Alaka’i wants to create versionsaccessible to all citizens, only in the price category, as luxury cars. The key difference, of course, is that these cars can fly.
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