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EE|Times EUROPE 15

AUTOMOTIVE
EC to Bet on Hydrogen Fuel-Cell Vehicles

By Maurizio Di Paolo Emilio

n its push to become climate-neutral by 2050, the European
Commission has unveiled an industrial strategy called the Clean
Hydrogen Alliance. The public-private partnership among the EC,
IEurope’s fuel-cell and hydrogen industry, and research organizations
will drive the region’s efforts to ensure Europe’s energy independence
and develop zero-emission cars.
FROM ELECTRIC VEHICLES TO HYDROGEN-POWERED CARS?
Next-generation vehicles that produce less harmful substances and less
noise are universal goals, and as a result, the whole world is exper-
imenting with electric vehicles (EVs). But a drawback of EVs, which
belong to the electro-mobility sector, is their long charging times.
That’s a problem that might be solved by hydrogen fueling, also
called cell fueling. Hydrogen cells exploit the same energy used by Figure 2: Electric and hydrogen vehicle in comparison
spacecraft to reach Earth’s (Image: InsideEVs.com)
An environmental orbit. But how do hydrogen
argument for hydrogen- cars work? What are the
strengths and weaknesses?
powered vehicles is THE HARDWARE OF A
that they do not emit HYDROGEN VEHICLE
greenhouse gases. But Hydrogen vehicles con-
vert chemical energy into
hydrogen is not exactly mechanics. A hydrogen
internal combustion engine
a renewable resource; vehicle (HICEV) uses a
it must be produced. hydrogen-fueled version
of the traditional internal
combustion engine. Alterna-
tively, hydrogen can be used to cause a reaction with oxygen in a fuel
cell, thus producing electricity. This type of vehicle is called a fuel-cell
electric vehicle (FCEV), and in recent years, FCEVs have drawn the
attention of many manufacturers. FCEVs are powered by an electric
engine and have an on-board power plant to allow the production and
management of hydrogen.
An environmental argument for hydrogen-powered vehicles is that Figure 3: General block diagram of electrolysis
they do not generate polluting emissions; rather than greenhouse
gases and fine particles, they emit water vapor (Figures 1 and 2). How- on the energy source used to produce it. Hydrogen is the most abun-
ever, the overall environmental impact of hydrogen mobility depends dant chemical element in the universe, but not in natural form. For this
reason, it is not exactly a renewable resource and must be produced. If
you use renewable energy sources to produce hydrogen, the environ-
mental impact is minimal. Conversely, if fossil sources are used, the
environmental impact is much higher.
Hydrogen can be produced through two production processes and
technologies: reforming and electrolysis. Reforming has a higher
environmental impact because it involves the extraction of crude oil,
transportation, and refining. Electrolysis is the process of splitting H₂O
water molecules into individual hydrogen and oxygen atoms via the
chemical reaction induced by electricity. This production process does
not emit polluting gases but requires a large amount of power. The
electrolysis process consists of a low-voltage current that flows through
the water to release oxygen and hydrogen in a gaseous form.
One of the qualities of hydrogen is its very high specific energy
density, 40,000 Wh/kg, or 236× the specific energy of lithium-ion
batteries. This means that hydrogen-powered vehicles are lighter than
Figure 1: Block diagram of a hydrogen car. In the fuel cell, battery-powered vehicles and have a more extended range. Also, hydro-
hydrogen and oxygen generate electricity, which is conveyed to the gen refueling takes just a few minutes, compared with several hours for
electric motor and/or battery. (Image: BMW) battery-powered cars.

www.eetimes.eu | APRIL 2020