Could hydrogen fuel cells be a solution for poor drone battery life?
HES in the News - 14 August 2018
HYCOPTER, hydrogen-powered multi-rotor developed by HES Energy Systems.
WeTalkUAV produces endless articles and videos expounding the virtues of drones and showing you all the ways the cool and interesting ways they are changing the world.
One of the biggest drawbacks of this technology, however, is the poor life of their lithium ion batteries. Few drones, whether commercial or consumer, can fly for more for longer than 15-30 minutes. There are models capable of longer flight times but they tend to be far more expensive and primarily exist in the commercial arena.
Many negative implications stem from this poor battery life fact. For the personal user; it’s a massive buzz kill than having your drone controller notify you’ve only got a few minutes of flight time left, particularly when there are no spare batteries round. For the commercial operator: having to change batteries regularly takes up a lot of time that could and should be spent on the job at hand.
So why don’t they just add more batteries to existing drones? Unfortunately, because batteries increase the weight of any given UAV, the drone needs to generate more power to stay in the air. So – unless you can produce much lighter batteries, it makes zero sense to add additional weight in the form of batteries to our current generation of drones.
How can hydrogen help?
Hydrogen is the most abundant element in the universe and we’ve had the ability to power cars with hydrogen for decades. Unlike a battery, which stores power, a hydrogen fuel cell is, in essence, a device that uses chemical reactions to generate electricity. Hydrogen fuel cells combine hydrogen and oxygen produce water and energy in the form of electricity. Hydrogen cells are very environmentally friendly, producing only water as a byproduct.
Last year, a Singaporean-based company produced a hydrogen-powered quadcopter that could continuously for four hours. H3 Dynamics group made the Hycopter, which you can see in action in the clip below. They managed to make this particular drone for an astonishing four hours!
Likewise, a team of researchers at the University of Sydney have worked to improve the flexibility and robustness of hydrogen fuel cell-based hybrid power systems in drones.
Lead researcher, Andrew Gong told DroneLife: “Hydrogen power provides much greater range and endurance compared to existing small electric unmanned aircraft. In the future, this may be useful for extended-duration inspection or surveillance tasks, such as surveying large agricultural properties or inspecting pipelines and other infrastructure.”
The promise of hydrogen-powered drones has been around since at least 2013 as this Popular Mechanics article shows. It just still hasn’t quite got to a point of being competitive with the lithium-ion market.
Are there other methods that keep drones flying for longer?
One way to keep drones in the air for a much longer time is to tether them to the ground. Being constantly attached to a power supply equals a big increase in flight time. On the other hand, being tethered gives many limitations, not least of which is you can kiss the portability of your drone goodbye. A cable long enough to allow the drone to fly hundreds of meters is probably going to be a bit unwieldy.
What about solar power? Couldn’t it be an unlimited free source of energy for drones if they had little solar panels? Well, that could work – but only in instances where the sun is out (which is not given). We should continue to develop the solar-powered drone technology but it’s unlikely to be viable, at least given current capabilities.
If hydrogen fuel powered drones are so great, why aren’t they more popular?
There are several reasons for this. Firstly, lithium-ion technology has continued to improve over the past decade, although gradually. I may have started the article bagging the shitty battery life of current drones, but they have been getting slightly better year-on-year. Secondly, changing to a completely new method of powering drones would require an extensive overhaul of current technology and often the force of momentum will keep an old technology chugging along, even if it’s not necessarily the best way of doing things.
As it stands, hydrogen fuel cells have been known to generate a lot of heat when operating. This can spell huge trouble for drones, especially because they are mostly made of plastic which may end up bending or even melting if the cell gets too hot.
So – the hydrogen technology is certainly improving but is not yet ready for large-scale rollout. We hope the testing and improvements keep on coming because we need better ways of powering drones and fast!