Robotic technologies are advancing rapidly, and with the advent of the Fourth Industrial Revolution, more advanced robots are expected. The necessity for an effective and dependable energy supply is one of the main challenges that robotic engineers face. Hydrogen, a clean and abundant fuel, is an excellent candidate for powering robots.
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Hydrogen is an odorless, colorless, and tasteless clean fuel that is the most abundant element in the universe and produces only water and heat when burned. As a result, hydrogen is a perfect fuel for robots, needing a consistent and clean energy source to function. Hydrogen may be created from various sources, including natural gas, coal, biomass, and even water, utilizing renewable energy sources such as solar or wind power.
Hydrogen Fuel Cell Technology
In a hydrogen fuel cell, the hydrogen splits at the hydrogen electrode into a positive hydrogen ion and an electron. Water and electricity are created when the positive hydrogen ions move from the oxygen electrode via an electrolyte membrane. The oxygen required for the electrochemical process can be found in the environment; therefore, the fuel cell only needs hydrogen fuel to function.
Comparing Traditional Batteries with Hydrogen Fuel Cells
In a traditional drone, the sizes and quantities of the cells employed determine the battery capacity. After a specific weight crossover is achieved, the additional batteries become heavier than the actual payload. As a result, the batteries carry their own weight, failing to provide drones with longer flight periods.
Hydrogen fuel cells may provide a high energy density and ecologically friendly power source for drones and robotics. Large drones with extended flight periods or other mobile devices, such as underwater autonomous vehicles (UAVs), can be more efficiently powered by fuel cells.
For instance, one investigation that compared the yearly operating and usage efficiency of drones powered by batteries to drones driven by fuel cells found that drones powered by fuel cells might be roughly half as expensive overall while providing higher output.
Advantages of Using Hydrogen Fuel Cells in Robots
Hydrogen fuel cells can constantly function as long as there is a supply of hydrogen, unlike batteries that often need recharging, making them advantageous for robots that must work nonstop for extended periods. In addition, hydrogen fuel cells are the best choice for compact, lightweight robots because of their high power density, allowing them to provide much power within a small space.
Conventional fossil fuels may significantly affect air quality and people's health because they emit dangerous pollutants such as carbon dioxide, nitrogen oxides, and sulfur dioxide. Hydrogen fuel cells produce only water and heat as waste, making them the perfect choice for robots working in confined places like factories or warehouses. Hydrogen fuel cells may also run in quiet settings like hospitals or research centers because of their low noise output.
Challenges and Recent Developments
Hydrogen storage is one of the difficulties in employing fuel cells to power robots. Although storing hydrogen as a liquid needs freezing temperatures, which may be challenging to maintain, storing hydrogen as a gas requires a high-pressure tank, which can be heavy and bulky.
The expense of hydrogen fuel cells is another issue. Despite recent price reductions, fuel cells are still more costly than conventional batteries. However, as the technology spreads and manufacturing procedures are optimized, hydrogen fuel cell prices are anticipated to decline even lower.
Refueling hydrogen-powered robots is also challenging. However, the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy is funding research and development for a robotic hydrogen fuelling system for mobile robots. The immediate objective is to speed up and shorten the process of refueling hydrogen-powered robots in commercial settings like warehouses.
According to NREL, every extra second spent refilling robots in the warehouse results in yearly operating cost savings of over $1,000 for medium-sized operations.
Hydrogen Powered Robot Ship
In the U.K., a £3.8 million government grant has been given to Acua Ocean, Unitrove, and consortium partners to create an autonomous ship and hydrogen fueling station. This hydrogen-powered robot ship will ferry 4-5 tonne cargo from Aberdeen to Orkney and the Shetland Islands after the £5.4 million project is completed in the fall of 2024.
In a study published in 2021, energy management for hybrid electric fuel cell drones was examined to reduce hydrogen consumption and increase the effectiveness of the power supply system. A frequency separation rule-based technique was initially suggested to enhance power management, and subsequently, an analogous consumption reduction strategy was put into practice for pursuing fuel efficiency.
To derive a true power profile for load demand modeling, experimental flight tests were performed. The suggested power management solutions enabled power sources to operate in their nominal region, prolonging their lives and causing a three percent reduction in hydrogen use, increasing the drone's endurance by the same amount as the fuel it was carrying.
Overall, hydrogen-powered robots have the potential to completely change a variety of sectors by offering a more effective, affordable, and sustainable means to power robotic systems. Therefore, future use of hydrogen-powered robots is predicted to increase as this field of study and development is furthered.
References and Further Reading
Boukoberine, M. N., Donateo, T., & Benbouzid, M. (2022). Optimized Energy Management Strategy for Hybrid Fuel Cell Powered Drones in Persistent Missions using Real Flight Test Data. IEEE Transactions on Energy Conversion. https://ieeexplore.ieee.org/abstract/document/9716756
Boukoberine, M. N., Zia, M. F., Benbouzid, M., Zhou, Z., & Donateo, T. (2021). Hybrid fuel cell powered drones energy management strategy improvement and hydrogen saving using real flight test data. Energy Conversion and Management. https://hal.science/hal-03460679/document
Millard, R. (2023). Liquid hydrogen-powered robot ship wins backing from taxpayer. The Telegraph. Available at: https://www.telegraph.co.uk/business/2023/02/22/liquid-hydrogen-powered-robot-ship-wins-backing-taxpayer/.
Shepard, J. (2021). Fuel-cell-powered robot platforms. Battery Power Tips. Availablt at: https://www.batterypowertips.com/fuel-cell-powered-robot-platforms-faq/#:~:text=Hydrogen%20fuel%20cells%20can%20provide,electron%20at%20the%20hydrogen%20electrode.