Can Solid Stored Hydrogen Fuel Free Drones From Combustion Engines?

September 27, 2023 by John Nieman

Although drones offer flexibility and precision for industrial applications, current battery power options limit their range, and combustion engines can hinder performance. One fuel innovation using long-lasting hydrogen storage may overcome these limitations.

Engineers have helped advance the technology that supports electric unmanned aerial vehicles (UAVs), and as a result, UAVs offer considerable advantages for many possible applications, such as remote security surveillance and land surveying. 


Photo of a working Honeywell Drone.

Photo of a working Honeywell Drone. Image used courtesy of Honeywell


At present, neither batteries nor combustion engines can overcome problems that limit the use of UAVs.

The problem with existing battery options is that they can only facilitate short-range applications. Although the combustion engine does expand the range of the UAV, other problems arise. Issues with carbon emissions might limit drone deployment due to clean energy regulations, and the excessive noise of the combustion engine can make drones unusable for certain jobs. 

The National Renewable Energy Laboratory (NREL) has partnered with Honeywell Aerospace to pioneer a solution that combines solid stored hydrogen and an attached fuel cell that can generate electricity. This source of electricity can fuel UAV flight in a way that circumvents the challenges of previous battery and combustion options. 

The Versatility of Rapid Release Hydrogen from Solid Storage 

In developing drone technology, engineers are concerned about the power and energy of the drone, which can drastically limit its range and payload size. A drone that can only take 30-minute flights and carry five pounds will not add much value to any industry. 

UAV technology has come a long way since it was first introduced in its most primitive form. Engineers have made advancements in battery technology and the combustion engine, and recently, they have been trying to help commercialize hybrid gas-to-electric drones. But the NREL and Honeywell Hydrogen solution to drone fuel limitations is noteworthy because it overcomes challenges associated with previous battery, combustion, and hybrid options.

NREL and Honeywell have named this project Fuel Additives for Solid Hydrogen (FLASH) Carriers in Electric Aviation, and one primary goal they have achieved is to find a way to store and rapidly release hydrogen without diminishing UAV performance. 

In previous models, hydrogen has been stored on UAVs in large, cumbersome tanks that impede drone engineering and interfere with flight efficiency. FLASH, however, is pioneering the use of a cartridge containing solid materials that can store hydrogen and then rapidly release it to the attached fuel cell.

Hydrogen has been used in both liquid and gas forms to fuel UAVs, but this cartridge-based approach that uses a solid material for hydrogen storage has the long-range capabilities of the combustion option combined with the battery-sized versatility. This compactness facilitates drone structure engineering and avoids the burden of large tank cylinders or engines.  

The solid material-based storage system that FLASH has developed not only has a high capacity for hydrogen storage, but it can also withstand lower temperatures, which can be crucial for drones traveling at higher altitudes. Solid materials are also tunable, meaning they can be adapted for a diversity of applications.


UAVs Could Optimize Power Line Maintenance and Other Utility Labor  

Commercial utility providers still rely on traditional manpower for powerline maintenance and repair, leading to considerable labor costs and risk to human lives. Every year, 64% of deaths from electrocution are from workers repairing, maintaining, and installing electricity infrastructure. Drones powered by the FLASH cartridge could offer a novel alternative to having workers individually manage power line maintenance, thus saving money and lives. 


UAVs can be used to perform powerline inspections.

UAVs can be used to perform powerline inspections. Image used courtesy of Kansas State University


UAVs capable of performing maintenance labor operations would be valuable not only for power lines but also for solar farm and wind turbine maintenance, which can involve difficult terrain. The power community’s growing interest in offshore wind farms seems even more feasible if hydrogen-powered UAVs can offer maintenance support for remote ocean locations. 

Drone technology continues to advance, and the FLASH cartridge offers new potential for range and power that might transform the ability of UAVs to support electricity infrastructure and other forms of clean technology maintenance.