Researchers at the Council for Scientific and Industrial Research (CSIR) have demonstrated hydrogen fuel cell-propulsion for unmanned aerial vehicles (UAVs) in a hardware-in-the-loop (HWIL) simulation.
CSIR researchers used a simulation of a hybrid fixed-wing, vertical take-off and landing (VTOL) UAV (H2UAV) for the demonstration in May last year. The HWIL simulation included the fuel cell module and hydrogen storage vessel, and amongst others simulated in a laboratory the electrical loads that would be experienced in flight. Future tests will simulate fuel cell performance in different environmental conditions.
The aviation industry still largely relies on fossil fuels for propulsion, the Council noted. The benefits of hydrogen propulsion for UAVs include longer flight times than electric propulsion due to higher fuel energy density, zero-emission potential, faster refuelling, and increased payload capacity.
“While the hydrogen fuel cell research is still in the development stage, once completed, a commercially viable fuel cell-propulsion system and the hydrogen-powered UAV will be licensed to a local partner for industrialisation and commercialisation,” the CSIR said.
The H2UAV is designed from the outset for hydrogen propulsion and is currently under development at the CSIR. Weighing less than 35 kg, with a four-meter wingspan, the vertical takeoff and landing UAV will handle a 5 kg payload and have a flight time of approximately 10 hours or more. It will be able to operate in adverse conditions, including light rain and temperatures ranging from -19 to +45 degrees Celsius.
Image: CSIR
A modular design will allow for rapid payload reconfiguration, making it adaptable for different mission types, such as patrolling, monitoring or surveillance. As the hydrogen-powered UAV will operate quietly, it will be ideal for surveillance and reconnaissance missions.
The multi-year project was initiated and funded by the Department of Science, Technology and Innovation (DSTI). Development of the H2UAV is a first step in a roadmap towards the expanded use of hydrogen in South African aviation including general aviation aircraft and regional airliners. This is in line with the DSTI’s Hydrogen Society Roadmap that aims to develop a sustainable and competitive hydrogen economy in South Africa by 2050.
Kevin Jamison, Head Engineer: Aerospace Systems at the CSIR, told DefenceWeb that when it comes to decarbonising aviation, it is easier to start somewhere affordable. From a risk management point of view, it is easier to start small and then scale up, with hydrogen fuel powered regional airliners and manned aircraft the end goal.
Katleho Ramotsabi, Senior Project Manager: Aerospace Systems at the CSIR, said the Council’s role in the Hydrogen Society Roadmap is to establish and localise manufacturing towards the ultimate goal of decarbonising the transport sector. The Roadmap covers the mining, air mobility, and heavy-duty transport sectors. The CSIR has also initiated work with regulators around hydrogen generation, filling, storage and transportation.
Ramotsabi noted that there is big demand for hybrid VTOL UAVs, with market forecasts predicting around 20% compound annual growth over the next five years, and demand coming from multiple key sectors such as commercial, military, law enforcement, and government.
The CSIR Impact Area Manager for Aerospace Systems, Biko Managa, reiterated his team’s intent to push the boundaries of propulsion in aviation for the local industry. “We are working to position South Africa as a leader in hydrogen-based aviation technologies, reducing reliance on fossil fuels and contributing to a cleaner future for aerospace,” he said.
“The pursuit of hydrogen alternatives is not only about reducing gas emissions that harm the environment but at the CSIR, we also view it as an opportunity for exploring new fields of science, developing new skills, creating jobs, fostering partnerships and driving up exports of South African products,” he added.
The project is benefitting from work being done by Hydrogen SA (HySA), a DSTI initiative, through its Centres of Competence (CoCs), which has amongst others developed a portable on-site hydrogen generator that can produce 2.5 kg of hydrogen a day. The system weighs 850 kg. HySA Infrastructure has also developed a storage vessel weighing 1.7 kg and able to store 4.7 litres of hydrogen.
Jamison said the government is very interested in fuel cells because they require platinum in their catalyst – and South Africa is a major producer of platinum. Although hydrogen has its pros and cons, it is a promising green energy alternative. Although funding for the fuel cell and H2UAV project has been inconsistent, the CSIR is putting together a funding framework and there is renewed focus on getting the project going again, Jamison said.
There is already interest in the H2UAV from the South African Army, and the Department of Trade, Industry and Competition has approached the CSIR noting interest from the Border Management Authority in a long-endurance quiet UAV. Jamison believes there are many potential customers for a fuel cell-powered UAV, such as the Department of Forestry, Fisheries and the Environment, which would like such an aircraft for anti-pollution patrols.
