When it comes to alternative power sources for engines, to the mind of the general public, the fuel cell battery currently lags behind. Yet experts believe that hydrogen fuel cell cars will catch up in the future. But how does the technology work? What are the pros and cons? All you need to know
Fewer pollutants, less noise – these are among the many great hopes for electrically powered vehicles. When it comes to electromobility, most people think of vehicles with a large battery that you charge from a wall outlet. Yet there is another propulsion technology that traffic experts are expecting a lot from. Including an alternative to long charging times.
The technology in question is the hydrogen engine. It is also known as the fuel cell electric vehicle, or FCEV. Before we discuss the pros and cons of hydrogen fuel cell cars, as well as the costs and risks involved, we’ll first briefly outline how this technology works.
6 questions about hydrogen fuel cell cars: you’re just a click away from the answers
1. How does a hydrogen engine work?
Hydrogen fuel cell cars are powered by an electric motor and are therefore classified as e-cars. The common abbreviation is FCEV, short for “Fuel Cell Electric Vehicle,” in contrast to a BEV or “Battery Electric Vehicle.”
There is one crucial difference between hydrogen fuel cell cars and other electric vehicles – hydrogen cars produce the electricity themselves. So, unlike in fully electric or plug-in hybrid vehicles, the vehicle doesn’t get its power from a built-in battery that can be charged from an external power source (➜ Read more: Electric cars and plug-in hybrids explained). Instead, hydrogen cars effectively have their own efficient power plant on board: the fuel cell.
In fuel cell technology, a process known as reverse electrolysis takes place, in which hydrogen reacts with oxygen in the fuel cell. The hydrogen comes from one or more tanks built into the FCEV, while the oxygen comes from the ambient air. The only results of this reaction are electrical energy, heat and water, which is emitted through the exhaust as water vapor. So hydrogen-powered cars are locally emission-free – more about that in a minute.
It can also recover or “recuperate” braking energy
The electricity generated in the fuel cell of a hydrogen engine can take two routes, depending on the demands of the specific driving situation. It either flows to the electric motor and powers the FCEV directly or it charges a battery, which stores the energy until it’s needed for the engine. This battery, known as a Peak Power Battery, is significantly smaller and therefore lighter than the battery of a fully electric car, as it’s being constantly recharged by the fuel cell.
Like other e-cars, hydrogen vehicles can also recover or “recuperate” braking energy. The electric motor converts the car’s kinetic energy back into electrical energy and feeds it into the back-up battery.