What are the advantages of fuel cells They mainly result from the type of fuel they use hydrogen It allows us to store electricity produced from renewable sources by means of electrolysis without harmful emissions and use it as needed This is particularly important in terms of emissions across the energy chain from production to fuel tank to wheel Experts refer to this as well to tank and tank to wheel or well to wheel when looking at the entire chain Whereas the major losses and emissions of ICE powertrains occur in the vehicle itself electric powertrains operate with zero emissions irrespective of whether the traction power is supplied by a battery or a fuel cell The lion s share of an electric vehicle s losses and emissions is incurred during power generation and storage However both of these aspects are negligible if the power is produced from renewable energy sources What is a fuel cell A fuel cell is a device that converts the chemical reaction energy of a supplied fuel and an oxidation agent into electrical energy Consequently unlike most fuels that produce energy as the result of a combustion process hydrogen the ideal fuel for use in fuel cells is not burned in the cell Its energy density of 33 3 kWh kg 15 1 kWh lb is nearly three times higher than that of diesel 11 9 kWh kg 5 4 kWh lb Plus in a hydrogen oxygen bond known as water it is available in practically unlimited supply After all 70 percent of the Earth s surface is covered by water Moreover pure hydrogen contains no bound carbon so the emissions of fuel cells contain no CO2 Fuel cells can operate with all hydrogen containing gases such as methanol coal gas and natural gas However unlike hydrogen these gases always emit CO2 as part of the transformation process into electricity and water The oxygen from the ambient air serves as the oxidation agent How does it work A fuel cell transforms the energy bound in a fuel directly into electrical energy The composition of a low temperature PEM proton exchange membrane fuel cell currently the preferred technology is similar to that of a battery an electrolyte in this case a membrane instead of a liquid separates two plate shaped electrodes anode and cathode referred to as bipolar plates in the context of fuel cell technology from each other This membrane is able to conduct protons but is otherwise impermeable It is coated with catalytic materials that promote the fi ssion of hydrogen into electrons and protons The electrons fl ow as usable electric current to the cathode via a conductor The protons also fl ow through the membrane to the cathode where they meet with oxygen ions that have formed as a result of the absorption of the electrons that have migrated to the cathode Both react into water vapor and water Energy H2 Air H H H2 H2 O2 O2 O2 O2 H2O Wa te r Electricity H O electrolysis Filling station Anode CathodeElectrolyte membrane Direct current 63 Here and now

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