As drone technology continues to evolve, fuel cells appear to be becoming more practical as power sources. Although still expensive and slower to respond to load changes, fuel cells have power-to-weight ratios currently two to five times higher than standard lithium ion batteries. And in the past couple of months, several projects have surfaced that point to significant advancements in the technology and its applications.
The first comes from HES Energy Systems. The Singapore-based company recently announced that it’s manufacturing hydrogen fuel cells for drones that, according to HES CEO Taras Wankewycz, are the smallest and lightest for the power delivered or energy stored in the world. As an example of the applications of the ultralight fuel cells, he points out in an interview with Commercial UAV News that HES fuel-cell technology was used to power a drone that set an FAI World Record for distance for a lighter-than-5kg UAV.
On the larger side of the drone market, Germany’s Lange Research Aircraft is developing a surveillance aircraft called the Antares E2. The company says the drone’s six methanol fuel cells can keep it in the air for up to 40 hours. The Antares E2, which can operate manned or unmanned, can also haul a payload of about 440 pounds.
Taking a best-of-all-worlds approach, researchers at the University of Sydney are testing out a triple hybrid approach. By powering a propulsion system with a hydrogen fuel cell, a battery and a supercapacitor the research team says it hoped to balance the limitations of each. They report that the design was able to improve peak power and load response in the propulsion system.
As discussed in an earlier podcast from the Sustainable Aviation Symposium, fuel cell technology presents interesting possibilities for manned aircraft as well. The hydrogen-fuel-cell-powered HY4, which flew for the first time in September 2016, can carry four. Though not yet ready to compete with most gas-powered four seaters, the zero-emission HY4 has reached a maximum speed of about 108 knots and has a max range of about 810 nautical miles. The project was developed by the DLR Institute of Engineering Thermodynamics in partnership with Hydrogenics, Pipistrel, H2FLY, the University of Ulm and Stuttgart Airport.
Also in the works for manned applications is the Zodiac Aerospace-led HYCARUS project. The HYCARUS team is developing a fuel cell system designed to power non-essential equipment and act as a secondary power source on business and commercial aircraft. The project, which includes partner companies from France, Germany, Belgium, Spain and the Czech Republic, has been running since 2013.