Fuel Cells
What is a fuel cell?
Fuel cells are the future of electric vehicles. While an electric vehicle has to be charged for long periods of time to be used a fuel cell vehicles produces electricity while it is running through the separation of an atoms composition of protons and electrons. A fuel cell is an electrochemical device that splits the fuel, which is generally hydrogen, by using a catalyst (National Renewable Energy Laboratory, 2008). The fuel cell used by general transportation today is called a PEM which is abbreviated from polymer electrolyte membrane or proton exchange membrane (US Department of Energy, 2007; Wikipedia, 2008).
How does it work?
PEM fuel cells are fuelled by pure hydrogen (US Department of Energy, 2007; National Renewable Energy Laboratory, 2008). First the hydrogen is fed into the fuel cell where it meets a platinum catalyst which is used to separate the atoms interior (US Department of Energy, 2007; Wikipedia, 2008). The protons pass through the catalyst while the protons pass in a circuit to provide power (US Department of Energy, 2007; Wikipedia , 2008; National Renewable Energy Laboratory, 2008). More specifically Wikipedia states that the electrons enter on the anode and pass to the cathode to rejoin with the hydrogen protons. Between the anode and the cathode the electricity is used to power an electric motor which moves the vehicle. Wikipedia also says that where the electrons meet the protons oxygen is fed in and takes place in a chemical reaction to form water. This means that the only waste is water and heat which is produced from the running temperature of 80oC (US Department of Energy, 2007; Wikipedia, 2008).
Disadvantages
Even though hydrogen fuel cells do not have toxic waste there are still some downsides. Firstly, hydrogen is low density which means that it is hard to store (US Department of Energy, 2007). The US Department of Energy also says that since there is not much hydrogen stored it is hard to travel far distances without having to refuel. Another problem as described by the US Department of Energy is that fuel cells can also be fuelled by gases like methanol and ethanol. Gases like these release carbon dioxide which is a greenhouse gas. This said the amount of pollution is still less than fossil fuels. Another disadvantage to using these gases is that to use them hydrogen gas must be extracted from the gases and then fed into the fuel cell. This means that there is other waste and also there must be an extractor onboard which ads to cost and weight (National Renewable Energy Laboratory, 2008).
