By Vaibhav Agrawal
The energy resource can alter the course of wars, forging alliances, and compelling countries to develop new research and development areas. The US Navy has recognised this fact and has begun efforts to diversify its resources, including nuclear-powered aircraft carriers, fleets powered by biofuels, and hydrogen-solar-powered drones. It’s only a matter of time before the world witnesses the emergence of the first green hydrogen-powered navies, thanks to the introduction of ammonia-powered shipping.
China had reportedly started constructing a 300MW green hydrogen plant in Xinjiang, capable of producing 20,000 tonnes of green hydrogen annually. To counter China and establish India as the epicentre of green hydrogen, it is imperative to establish a presence in every sector that demands green hydrogen.
Why Hydrogen As Fuel?
Several fuel cell technologies are available, such as solid acid, solid oxide, and proton-exchange membranes (PEM). PEM is the most commonly used electrochemical cell in drones due to its high power density. Additionally, PEM cells operate at lower temperatures, resulting in more straightforward and less expensive construction and engineering, and they emit less heat, reducing their thermal signature.
Hydrogen fuel cells offer numerous advantages over battery-powered and internal-combustion engine drones. Fuel cells used in drones have a high energy density, which means they provide a greater energy output-to-mass ratio, making them especially beneficial for aviation and unmanned aerial vehicles. Hydrogen PEM fuel cells have demonstrated up to three times the endurance for equivalent aircraft and payload weights compared to drone battery systems.
Batteries have a relatively low energy density and require a long recharge, often several times the typical half-hour flight endurance they provide. On the other hand, hydrogen cylinders can be swapped out within minutes, enabling greater operational efficiency.
Fuel cell technology operates quietly compared to internal combustion engines, minimising any disruptive noise or vibration that may interfere with UAV sensors and payloads. Furthermore, fuel cells require less maintenance than their counterparts, which often have a lower MTBF (Mean Time Between Failures) and demand more spare parts and labour.
Hydrogen-powered drones outshine many internal combustion engine models regarding high-altitude performance, which experience derating due to reduced air density. In contrast, small internal combustion engines only operate at optimal fuel efficiency under specific conditions while simultaneously producing excessive noise, pollution, and thermal signatures.
PEM hydrogen fuel cell systems are primarily targeted towards small-to-medium-sized UAVs. One can install hybridised systems that merge hydrogen cells with a compact battery to supply additional power during high-demand phases of flight, such as take-off, swift ascent, and high wind resistance, thus compensating for the low power density disadvantage mentioned earlier. During periods of low demand, the hybrid battery can be recharged.
Drone fuel cell systems are designed for reliable operation even in extreme environments, enhancing mission endurance and range. This could increase efficiency for BVLOS (beyond visual line of sight), ISR (intelligence, surveillance, and reconnaissance), and long-range mapping and surveying UAS missions.
HevenDrones, a company focused on developing and commercialising actionable drones, recently introduced its first commercial-grade hydrogen-powered drone, the H2D55. With 5 times greater energy efficiency than drones powered by traditional lithium batteries, the H2D55 can fly for up to 100 minutes and carry a payload of 7kg.
HevenDrones’ hydrogen product line launch addresses the challenges of flight endurance and payload capacity associated with battery-powered lithium drones and the long-term environmental impact linked to lithium mining. With no need to frequently replace batteries, hydrogen fuel cells can also reduce the long-term ownership costs for organisations deploying drone technology at scale.
Over the next nine months, a lineup of three hydrogen-fueled drones is planned for release, with the H2D55 being the first among them. The other models will increase payload capacity while maintaining longer flight endurance.
In addition to being lightweight, the H2D55 has a control system that contains multiple gyroscopes and supporting algorithms that significantly extend the operating limits of stable flight.
The Global Green Race
The significance of energy sources like oil is still evident in demand today, exemplified by the presence of US military bases in the Middle East, China’s pursuit of influence in oil-rich regions, and the development of new energy supply routes such as Gwadar. Nevertheless, the emergence of solar, wind, hydro, nuclear, and the more recent green hydrogen has paved the way for new possibilities in energy.
Renewable energy offers the potential for more cost-effective and efficient military machinery. In 2016, the US Navy deployed the “Great Green Fleet,” which included the USS Makin Island featuring a hybrid electric-diesel propulsion system powered by a blend of diesel-biofuel. The vessel could go three times longer without refuelling than a conventional vessel, resulting in an estimated savings of $248 million in energy costs over its lifetime.
Moreover, the demonstration of the Hybrid Tiger drone, a hydrogen-powered UAV, by the US Navy further highlights the potential benefits of renewable energy sources. This drone utilises solar and hydrogen fuel cells as its only power source, enabling it to remain airborne for up to 24 hours and operate silently, in contrast to conventional drones that consume gallons of expensive jet fuel and generate distinct noise.
India: The Future Hub For Green Hydrogen Energy
The Green Hydrogen Mission recently announced by the state is poised to establish New Delhi as a hub for this eco-friendly fuel in India. As the cost of Green Hydrogen is expected to decline from its current range of $4-$7 per kg to approximately $2 per kg by 2030, Indian forces will have the opportunity to explore this emerging fuel source in cutting-edge technologies like UAVs. This fuel will be produced entirely within India, eliminating the need for the country to rely on external sources for energy supply.
In addition, India’s emergence as a Green Hydrogen hub may lead to the signing of various logistical agreements with allies and strategic partners, potentially boosting the export potential of this eco-friendly fuel to unprecedented levels.
As an alternative fuel, ammonia – derived from hydrogen – is increasingly gaining traction in the global shipping industry. Given the need for climate-friendly options to power large vessels, cargo shipping companies are exploring diverse options. One significant advantage of ammonia is its widespread availability and usability, as it can be utilised by fuel cell and internal combustion engine technologies without requiring high-pressure tanks for storage. By producing Green Ammonia using Green Hydrogen, the possibility of a shipping industry powered by eco-friendly fuels is rapidly becoming a viable reality.
According to the IEA’s net zero analysis, Ammonia is expected to power 45% of the shipping industry by 2050. Once this technology gains traction, major powers such as the USA and China will likely adopt it for their Navies without hesitation. Therefore, India should keep pace with these developments to stay caught up.
Given that the Indian Navy is already diversifying its energy sources through nuclear-powered submarines, it may be well-suited to spearhead efforts to explore the potential of Green Hydrogen for military purposes. As militaries worldwide continue to diversify their energy options, demand for Green Hydrogen is expected to rise. By positioning itself as a leader in this emerging field, India can enter into agreements with major navies, further establishing itself as a hub for Green Hydrogen.