HYDROGEN: The future fuel for aviation?

In June 2023, Rowan Atkinson – the versatile English actor, comedian and writer – authored an opinion piece for the Guardian casting doubt on the environmental benefits of electric vehicles (EVs) powered by lithium-ion batteries.

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While the arguments and studies he based his arguments on have been debunked, he rightly argued for more focus on hydrogen-powered vehicles.

It, however, is too early for hydrogen vehicles since there currently are just 72,000 hydrogen-fueled vehicles on the planet. In comparison to the 14 million EVs sold the previous year alone, the hydrogen-vehicle numbers pale. It, however, is indisputable that hydrogen-fuelled vehicles will be one of the major players in the times to come.

Intelligent Energy, a start-up in Leicestershire, U.K., has started to roll off the hydrogen fuel cell units capable of powering cars, trucks and buses. BMW is heavily invested in hydrogen-powered vehicles and has started delivering its iX5 hydrogen vehicles to select partners in Europe, the U.S. and Asia. While the hydrogen-vehicle future is already here, there has been a keen interest in hydrogen as a fuel for the aviation industry.

The aviation industry is a vital part of global transportation and economic growth but its heavy dependence on fossil fuels and thereby greenhouse gas emissions is a severe problem.

Mudasir A. Yatoo, Ph.D.

—Research associate in the Materials Department at Imperial College London and freelance consultant at Outsmart Insight.

In order to tackle these challenges, hydrogen as a fuel is emerging as a promising solution.

One of the primary motivations for exploring hydrogen as an aviation fuel is its potential to reduce carbon emissions. When combusted, hydrogen produces only water vapor as a by-product, presenting a pathway to mitigate the aviation industry’s carbon footprint.

Hydrogen for aviation comes with benefits including environmental sustainability; energy efficiency; versatility in terms of production and scalability; and synergy with other renewable energy sources such as wind and solar energy.

Fuel cells and hydrogen storage systems are two such technologies that have the potential to provide the necessary energy density and power output for commercial aviation.

The ability to store significant energy in a small space is vital for long-range flights and heavy payloads. The energy content per unit mass of hydrogen is 120 MJ/kg, the highest, but its volumetric energy density is very low because of its exceptionally low density at ordinary temperature and pressure conditions.

Although hydrogen’s energy density per unit volume is lower than traditional jet fuels, advancements in fuel cell and storage technologies are making it increasingly feasible for commercial aviation.

However, major challenges in infrastructure, technological advancement and safety remain. Establishing a strong hydrogen infrastructure including the availability of hydrogen at airports worldwide is one such key challenge.

Developing and integrating hydrogen storage, transportation and refueling infrastructure into existing airports are crucial.

Hydrogen is highly flammable and requires careful handling to ensure safety. Adequate safety measures and regulations and learning lessons from existing hydrogen applications, such as fuel cell vehicles appear to be the way forward.

Therefore addressing safety concerns and public perception surrounding hydrogen in aviation should be prioritized.

Furthermore, a concerted effort is required: Collaboration among government bodies, industry stakeholders and research institutions is necessary.

The road to the hydrogen-based aviation industry is long, but world governments’ policy support and funding with a clear focus on emissions-reduction targets could very well catalyze the transition sooner than later.

Mudasir A. Yatoo, Ph.D., is a research associate in the Materials Department at Imperial College London and freelance consultant at Outsmart Insight.

Cool it, sunshine

The cause of climate change is a hot topic. From carbon output to single-use plastic waste to energy consumption, the list goes on. But in the UAE, where temperatures hit 50 degrees in summer, the sun’s heat and subsequent cooling requirements are an environmental conundrum. Now technology is helping the country harvest its more than 4,400 hours of annual sunlight to tip the scales in favor of the planet.

Global heating, ventilation and air-conditioning (HVAC) giant GREE, known in the market for its investments in research and development, announced at the COP28 in Dubai the launch of its solar-powered technology in the UAE through its business partner, NIA. The technology is variant refrigerator flow (VRF), and it is quick, responsive and adaptable. It also uses less energy than conventional air-conditioners.

“NIA is engaging key decision-makers that enable sustainable change for the communities in the UAE by promoting solar-powered air-conditioning adoption,” says Imad Hseino, NIA’s head of HVAC solutions.

GREE, headquartered in China and founded in 1991, is one of the world’s largest manufacturers of HVAC solutions.

The system won multiple awards, including the British RAC Cooling Industry Award, the International Quality Innovation Award, the GENEVE International Invention Gold Medal and the China Patent Gold Award.

The units look like traditional systems, but inside is a whole host of carbon-reducing goodness.

CAPTION: Imad Hseino, head of HVAC solutions-NIA IMAGE: NIA

The units harness and use direct solar power without the use of a solar inverter, eliminating the typical 15 to 22 percent loss of energy that occurs during the transmission process.

Typically, energy from solar panels goes through an inverter and a transformer that outputs it as air-conditioning. But GREE’s technology can accept DC energy directly from the solar panels at 99 percent power efficiency.

That’s a big number, but what does it mean?

Whenever there is an inversion process, a certain amount of energy is lost in the form of heat. Since no inverter is required, the GREE solar VRF operates at a maximum, the company says. With minimal environmental impact.

VRF, an extremely conducive and multifaceted form of cooling technology, allows for variance of the flow of cool air to individual spaces. Eliminating the need for an inverter reduces materials (and therefore cost), ensuring higher efficiency and fulfilling its purpose with zero-carbon output, zero electricity bills and zero wasted energy.

That’s a lot of zeros in a region where 80 to 85 percent of an average building’s energy usage goes to cooling.

And the designs are suited for both residential or commercial settings, with simple and cost-saving installation of up to 20 percent compared with other solutions. Units can be installed on a rooftop or ground floor.

Garden-variety VRF systems require not only an inverter but a human to manage them. GREE’s product, however, uses AI to do the work.

“It (the system) incorporates advanced monitoring and control technologies, including the GREE Energy Information Management System for real-time energy-flow monitoring and a self-developed AI algorithm for maximizing efficiency,” Hseino tells KUST Review.

Concerned about the monitoring of energy flow? Just check your phone.

Launching new technology in a new region often comes with challenges, and the UAE is no exception.

DEWA, the Dubai Energy and Water Authority, put the solar VRF through rigorous approval processes, particularly in the inverter category.

IMAGE: NIA

“This involved the submission of comprehensive test certificates that demonstrated the system’s performance and safety compliance,” Hseino tells KUST Review. “The primary challenges were to meet the high sustainability standard of the related authorities and obtain the necessary approvals from regulatory authorities.” Now DEWA hosts the product on its website.

It all sounds positive, but what happens when the sun is gone for the day but it’s still too hot to turn the air-conditioning off?

The system has a hybrid connection. During sunlight hours, it’s feeding off the solar energy.

But once the sun sinks, the connection automatically shifts to the power grid.

If you prefer to continue solar-energy use during sundown hours, however, GREE also offers varying capacities of storage solutions to box up that energy and store if for a rainy day. This means flexibility to maintain sustainable cooling 24 hours a day.

And as the planet heats up, cooling has become a necessity. In the UAE and all over the world.

The United Nations Cool Coalition addresses the provision of sustainable but necessary cooling and met in Denmark in 2019 to discuss environmental protection amid mounting heat.

Rachel Kyte, chief executive officer of Sustainable Energy for All, says in a United Nations Environmental Programme press release, “In a warming world, cooling is a necessity, not a luxury. … Hundreds of millions of people at risk today from extreme heat need protection and we must protect them in a way that also protects the planet from increased carbon emissions.”

The UAE has set itself an aligned, aggressive goal to reach net zero emissions by 2050 in its Clean Energy Strategy 2050.

The GREE Solar VRF system is estimated to save 11,130 kilograms of CO2 annually, in a typical house.