Hydrogen - the synthetic fuel of the future?

In the ever-growing demand for energy in everyday life the quest to find the ultimate fuel is still on. How far have we gone with the idea of storing the energy in the form of the hydrogen molecule and what is the state-of-art in this field? 

When one thinks of hydrogen energy, the first thing that comes to mind is the hydrogen car. Some of the commercially available options are Toyota Miray, Hyundai Nexo, and the Honda Clarity, present on the market in the last few years. At the end of 2018, the global fuel cell electric vehicle stock reached 11 200 units, as reported by IEA. In 2019, further development of this market is seen, with Mercedes and BMW joining the race. Comprehensive studies predict that hydrogen cannot compete with the electricity on a small scale, meaning passenger cars, at the price of around 70 000 USD per vehicle is very noncompetitive. However, where hydrogen energy is expected to outperform batteries are applications that require high energy density  - some interesting examples are Pininfarina H2 speed, the hydrogen-fueled racing car made in Italy, and Nicola One semi-truck with custom-built hydrogen fuel cell-powered range extender (scheduled for release in 2020). 

Breaking news this year was an announcement of China’s plan to invest in developing the hydrogen society. Wan Gang, China’s science-and-technology minister, sometimes also called “the father of China’s electric-car movement”, in his interview on June 9th, stated that “the shift toward hydrogen is a natural step in realizing a vision of having electric cars dominate inner-city traffic, while buses and trucks filled with hydrogen tanks roam the nation’s highways for long-distance travel”. Europe is constantly working on widening its hydrogen fueling station network. Transport solutions rely, so far, on the high-pressure hydrogen tanks for hydrogen storage and fuel-cells for providing the electricity by oxidizing hydrogen. Safety risks combined with such a storing method, as well as the expensive catalysts needed for fuel-cell operation, rise the price of these systems. On the plus side, the only by-product of the working fuel-cell is water, consequently zero CO2 emission. But actually, ecological factors are quite disputable at this point - if one accounts for the environmental impacts of hydrogen production and vehicle manufacturing (which is also true for electric cars). Most of the hydrogen (over 90%) is obtained from fossil fuels - through steam reforming of natural gas and coal gasification. 

On a small scale, there are some interesting solutions to green hydrogen, such as the idea behind Tyrolysis energy startup. As they state, “A clean fuel made from dirty sources is not clean.”. They harness and use recycled aluminum to evolve hydrogen from water, claiming to be able to produce hydrogen and electricity at a cost competitive, not only with other renewables (solar, wind, etc), but also with fossil fuels. Other promising approach is making water splitting (decomposition of water to hydrogen and oxygen) as efficient as possible, while using either electricity from renewable sources or renewable sources directly. Researchers from Israeli startup H2Pro use an electrochemical thermally activated chemical water splitting to produce hydrogen in an efficient way. As they stated:

“Water splitting at nearly thermoneutral conditions is indeed possible, and we emphasize the many avenues that can be explored to further optimize this process. Approaches like these open the door to electrolytic chemical production with efficient energy utilization”

Hen Dotan et al. in Nature Energy, volume 4, pages 786–795 (2019)

Large investments in the research and development sectors, in both industry and academia, are still expected in this field. Hydrogen storage technologies, studied for a few decades now, yet fail to offer satisfying commercial solutions, and this can be the possible route for improvement. However, the real game-changer for the hydrogen industry would be technologically and economically feasible large scale method for hydrogen generation from renewable energy sources with zero CO2 emission. Otherwise, hydrogen as a fuel is just one more expensive option that still violates ecological balance, only during its production instead of consumption.