The US military has been scouting electric aircraft for new opportunities to improve performance and operational resiliency. Along with battery-electric aircraft, hydrogen fuel cell technology is also in play, as demonstrated by a small business startup called Hydroplane, helmed by a CEO with a 16-year NASA track record to her credit.
Hydrogen Fuel Cells For Zero Emission Aircraft
Whether powered by batteries or fuel cells, electric aircraft are considerably quieter than their jet-fueled cousins.
Cost is another consideration, and that helps explain why Hydroplane caught the eye of the US military. The company centers its business model on a soup-to-nuts modular drop-in hydrogen fuel cell propulsion system complete with power distribution, thermal management, hydrogen storage, and associated electronic equipment.
Hydroplane has already developed a 120-kilowatt version of the system under contract with the Air Force Agility Prime program, which aims to support innovation in the area of zero emission vertical lift aircraft.
The next step is a more powerful 500-kilowatt fuel cell system capable of heaving the Army’s vertical lift aircraft into the air. The plan got a leg up last May, when Hydroplane earned a prize from the US Army’s xTechSearch 8 competition. The company’s pitch to xTechSearch included a modular fuel cell system for auxiliary power, as well as a drop-in propulsion system for aircraft.
As part of the competition, Hydroplane was invited to apply for Small Business Innovation Research funding. The SBIR program runs on a phased-in approach, with Phase I focused on setting expectations. “If awarded, that will allow Hydroplane to collaborate with the Army to define performance, durability, and operations requirements,” Hydroplane explained back in May.
The fabrication of a prototype doesn’t come along until an SBIR applicant receives Phase 2 funding for development and testing. If the performance is satisfactory, the applicant can move on to Phase 3, which provides funding for commercial production.
The US Navy Wants A Hydrogen Fuel Cell For Ground Power, Too
While that is going on, the US Navy awarded a Phase 1 Option SBIR contract to Hydroplane, enabling it to move forward with the development of a lightweight ground power unit, based on its fuel cell technology.
The focus on stationary power was not a difficult stretch for Hydroplane. “As a small business we have the agility and innovation mindset to rapidly bring cutting edge technology from research to product,” explains founder and CEO Anita Sengupta, PhD.
The “Option” part of the contract refers to a continuation of an initial Phase 1 contract awarded by the Navy earlier this year, aimed at developing a ground power unit for the US Marine Corps. Hydroplane announced the new contract in September, emphasizing that the funding supports a fuel cell ground power unit for the Marine Corps to deploy in “a contested logistics environment.”
In addition to military use on the ground, Hydroplane anticipates that the fuel cell can replace diesel generators at airports to help decarbonize aviation operations.
Producing Hydrogen On Site For The Fuel Cell Of The Future
The reference to a “contested logistics environment” is brings up an important point about fuel cells. They produce electricity from a reaction between hydrogen and ambient air, sparked by a catalyst. The hydrogen fuel has to come from somewhere. If it has to travel long distances in a war zone, the hazards add up, just as they do for any other fuel transportation operation.
Right now, the global hydrogen supply chain relies heavily on extracting hydrogen from natural gas. In terms of encountering logistical complications and hazards, that puts fuel cells in the same league as any other power system that depends on fossil energy.
On the bright side, a holistic approach to onsite power generation has been emerging. The Navy and other branches of the armed services are on the prowl for durable, resilient systems that produce hydrogen for fuel cells locally, without relying on fossil resources from distant facilities.
One option under consideration by the Office of Naval Research is a modular system that generates hydrogen from a reaction between aluminum pellets and water. “Any form of water works in the chemical reaction: salty ocean water, river water, even urine,” ONR explains, emphasizing that the system can be deployed under a wide variety of conditions.
The pellets need to be recharged periodically, but the system does avoid the risks and hazards associated with transporting flammable gases and liquids over long distances.
“Additionally, since steam is leftover after the hydrogen fuel creation process, it’s available to be distilled and used for drinking and hydration,” ONR points out.
“Hydrogen gas is also compatible with fuel cell usage, which does not generate the noise and heat signature associated with internal combustion engines,” they add.
More Locally Produced Hydrogen For Fuel Cells
A more familiar approach to local sourcing is green hydrogen produced by electrolysis. An electrolysis system stands fuel cell technology on its head, deploying electricity to jolt hydrogen gas from water with the help of a catalyst. Paired with onsite wind turbines or solar panels, a transportable or mobile electrolysis system could accompany modular fuel cell power stations to remote areas, contested or not.
The Army, for example, is currently testing a modestly-sized solar-equipped electrolysis system on wheels, aimed at generating hydrogen to refuel fuel cell rescue vehicles. The US military is also testing hydrogen fuel cells in microgrids, and for use as backup power systems in case of emergency.
Keep an eye on the US Navy for a next-level development. Conventional electrolysis systems require purified water, but the Navy has engaged researchers at the University of South Carolina to explore the potential for ships to produce hydrogen on board, from seawater. The electrolysis systems could run on wind or solar power if available, or on batteries if not.
“The hydrogen could produce ammonia for long-term energy storage, run through a fuel cell to produce power and clean water for drinking, or be burned directly for power generation,” explains the school.
In terms of drinking water, the project builds on the Navy’s longstanding interest in water purification systems. The project got under way in July on a three-year timetable, so stay tuned for more news about that.