As engineers battle towards a Net Zero world, hydrogen is being increasingly recognised for its potential to reduce greenhouse gas emissions and help combat climate change – but it’s not without its challenges, says Eliska Krizova, fuel cell stack engineer, at Bramble Energy.
The global challenge of combating climate change is one of the most pressing issues of our time – and addressing it requires collective action on an unprecedented scale. As the world seeks solutions to transition to a sustainable energy future, hydrogen remains a key player in the mix and I am one of many engineers exploring its potential.
Not only is it one of the most prevalent chemical elements on Earth, but one of its key attributes is its ability to produce no greenhouse gases or other harmful emissions when used as a fuel. When it’s harnessed in fuel cell technology to generate electricity, the only byproduct is water, making it a clean and sustainable energy carrier.
Its high energy content per unit of mass – surpassing that of traditional fossil fuels like gasoline – also makes it perfect for energy-intensive applications, particularly in sectors that are challenging to electrify directly, such as heavy industry, long-haul transportation, and aviation
Roadblocks to a hydrogen future
While hydrogen’s list of pros goes on, it is far from a silver bullet. Unlocking its full potential is dependent on overcoming some big challenges – one of the biggest being the fact that the majority of hydrogen is still derived from industrial processes that aren’t green.
While ‘green hydrogen’, produced through electrolysis powered by renewable energy sources, is entirely clean and sustainable, as of 2020, it only constitutes 0.1 per cent of global hydrogen production.
Hydrogen production, especially green hydrogen produced through electrolysis powered by renewable energy, can also be expensive. The cost of renewable energy infrastructure, electrolysis equipment, and other technologies needs to decrease for hydrogen to become cost-competitive with other energy carriers.
Alongside a lack of hydrogen infrastructure – and a lack of investment to improve it – hydrogen is also challenging to store and transport efficiently due to its low density and high flammability.
Thankfully, the landscape is shifting and the number of hydrogen-based projects addressing some of these challenges is expanding rapidly. One of the top innovations emerging in this field right now is Hydrogen Polymer Electrolyte Membrane (PEM) fuel cells. They efficiently convert hydrogen and oxygen from the atmosphere into electricity through an electrochemical process, enabling the extraction of a significant portion of hydrogen’s stored energy. Not only can this power vehicles, generate electricity, and more, but when hydrogen serves as the fuel source in PEM fuel cells, the sole byproduct is water vapour.
While challenges such as durability and stability and the fact they don’t perform well in extreme temperatures are halting the widespread adoption and economic viability of hydrogen fuel cells, right now researchers and engineers are working on developing an effective strategy that enables reliable cold start and freeze tolerance as well as enabling operation in high temperatures. They are also focused on developing materials resistant to degradation, optimising cell design to reduce stress factors, and refining cell operation to extend fuel cell lifespan and decrease maintenance requirements.
By enhancing all facets of fuel cell design and operation, we can progress toward higher power densities, which is particularly crucial in applications where size and weight limitations are significant (unmanned aerial vehicles (UAVs), planes, and cars).
Another innovation making waves in the realms of hydrogen fuel cells is Printed Circuit Board (PCB) technology; a fundamental component of modern electronics. The substantial expenses tied to the fuel cell stack’s materials and the intricacies of the manufacturing process have posed a major hindrance to its commercialisation. But, by using PCB tech, we’re able to tap into the already established global PCB industry’s supply chain, making it possible to manufacture low-cost fuel cells anywhere in the world. It’s a real breakthrough in cost effectively manufacturing fuel cells, which opens the door to wider adoption.
Alongside the above, there are various other technologies currently being developed, including storage solutions, transportation methods, sensors for safety, and other advancements in hydrogen production methods.
Research is also underway to create synthetic fuels, such as ammonia and methanol, using hydrogen, which can be used as clean alternatives to traditional fossil fuels in various applications, while electrolysis is seeing significant advancements. These innovations are also not without their challenges, however. Electrolysis for example can be very energy-intensive, particularly when using electricity from non-renewable sources. Advancements such as proton exchange membrane electrolysis (PEM electrolysis) are focused on improving energy efficiency, and other ongoing research and development efforts are focused on improving affordability and scalability of electrolysis systems to accelerate the adoption of hydrogen.
Driving the hydrogen industry forwards
As well as a growing number of hydrogen projects and innovations, we’re seeing lots of work towards establishing supportive policies and regulatory frameworks, which will be critical in gaining public acceptance and confidence.
This is a great indication that the hydrogen industry is gaining momentum. However, the path to widespread adoption hinges on scaling up technologies and driving innovation – and for this, engineers’ continued efforts and expertise will be vital.