IntroductionAn increase in carbon pollution around the world has necessitated better options for the future of automobiles. The two types of automotive options being developed are hydrogen fuel cell vehicles and battery electric vehicles. Both of these have advantages and disadvantages within the system, in terms of environment and cost. Hydrogen Fuel Cell Vehicles A hydrogen fuel cell is an electrochemical cell that directly converts the chemical energy of hydrogen and oxygen into electricity with pure water (Figure 1). Generally, fuel cells have a similar arrangement consisting of an electrolyte and two electrodes, but there are many types of fuel cells classified by the type of electrolyte used (DOE Energy Efficiency, 2006). An electrolyte is a liquid or gel that contains ions and can be broken down by electrolysis and is present in a battery. The hydrogen fuel cell pathway involves three conversion stages: converting electricity to hydrogen, converting hydrogen back to electricity, and finally, converting electricity to mechanical energy (Stephen Eaves, James Eaves , N/A). A polymer electrolyte membrane (PEM) fuel cell is widely considered the most promising for light transportation. The hydrogen gas flows through channels to the anode, where a catalyst causes the hydrogen molecules to split into protons and electrons, increasing energy production (DOE Energy Efficiency, 2006). The polymer electrolyte membrane also operates at a temperature of 50 to 100 ºC and has an electrical efficiency of 50 to 60%. (Bill Siuru, 2007) As the process of generating electricity is direct via an electrochemical device in a fuel cell, it never goes through the stage of being a high temperature gas according to the standard..... . middle of paper.... Hydrogen vehicles were to be used more widely, methods to produce hydrogen cost-effectively would need to be developed, and producing enough to power an everyday car would also be a challenge (U.S. Dept. of Energy 2010).ConclusionFuel cells are clean, fuel efficient and fuel flexible. Any hydrogen-rich material can serve as a potential fuel source for this developing technology. Although it will reduce carbon emissions, further research will need to be carried out to ensure it becomes cost-effective for everyday users. Battery-powered cars are the most viable and cheapest option at the moment, but the carbon emissions add to an already increasingly degraded atmosphere. By implementing hydrogen fuel cells as an alternative for large modes of transportation, there will be a significant reduction in greenhouse gases for everyday transportation users..