Fuel cells are not always environmentally friendlyStaff writer ▼ | July 16, 2015
Fuel cells are regarded as the technology of the future for both cars and household heating systems, but are fuel cells always more environmentally friendly?
Green energy The fuel is the key to ecology
In the future, we might be driving fuel-cell cars that burn solar-generated hydrogen. This would make the "zero emissions car" a reality. At the same time, small combined heat and power units - also based on fuel cell technology - could be placed in our cellars at home. They convert natural gas and biogas into electricity while generating heat as an added "bonus" to warm the building.
Although this is technically possible, does it also make sense for the environment? Empa researcher Dominic Notter teamed up with colleagues from Greece and Brazil to analyze the life cycle assessments for the use of fuel cells: From their production, throughout their entire service life, all the way to their eventual recycling.
The result was conclusive: Fuel cells for cars are only ecologically sound if they are able to run on hydrogen from renewable energy sources. It doesn't make any sense to draw electricity from the European power grid, use it to produce hydrogen via hydro-electrolysis and fuel cars with it; the CO2 emissions per kilowatt hour of electricity would be far too high using this method.
At present, industrial hydrogen is predominantly obtained directly from natural gas. However, the fuel cell does not really have any environmental advantages with this kind of fuel, either. A car with a combustion engine currently has the edge: The production of conventional cars is less harmful for the environment.
Nor does the fuel cell stand a chance in the eco-comparison with electric cars for now: First of all, electricity is needed to generate hydrogen, which the car tanks up on. Electricity is then produced from hydrogen again in the car. This double conversion significantly reduces the efficiency level.
People who use the same electricity to charge the battery in their electric cars directly travel more economically and thus in a more environmentally friendly way. ■