A Fuel Cell converts the chemicals hydrogen and oxygen, obtained from natural gases and alcohol, and oxides, and converts them into water. During this process, it produces electricity. But the batteries we use do so as well; so what’s the difference? Because the batteries convert the chemical stored inside them into electricity, they go dead. But fuel cells use fuels provided as external sources and thus they do not need to be recharged. Thus if they are given a constant supply of hydrogen and oxygen, they continuously produce electricity. Though hydrogen is the most abundant element in the universe, it is not found in its pure form on Earth and energy is consumed in extracting pure hydrogen. If Fuel cell uses pure hydrogen then its efficiency in producing electricity is 80%. However, it still needs to be converted into mechanical work. This process has an efficiency of 80% as well. This gives a total of 64% efficiency. If hydrogen is not available in its pure form then Fuel Cell Vehicles use a device called a reformer which breaks down hydrocarbons and alcohol to give out hydrogen. However, it still has impurities and thus the efficiency of the fuel cell is affected.
Now, what are the benefits of this great invention? Why was it needed to have another fuel when gas, petrol and Diesel were doing just fine? According to The Independent, the Earth is facing an energy crisis and all these fuels are predicted to be dried up in a mere four decades. There is a need of renewable fuels which can be reproduced to ensure a reliable source of energy. As stated earlier, hydrogen is the most abundant element in the universe. It is also renewable. Depending on how it’s produced, hydrogen is completely environmental friendly because it produces no chemicals at all. The by-products of a fuel cell are water vapours and heat. It does not produce any harmful chemicals.
However, it is also stated that it is difficult to find hydrogen in its solitary state and it must be extracted from alcohol or hydrocarbons. Extracting it from water is extremely expensive. It is cheaper to use non-renewable fossil fuels and natural gasses for the purpose, but, then again, it is a danger to our natural supplies. Also, the amount of carbon dioxide produced in extracting hydrogen from fossil fuels cancels out the environmental friendliness of fuel cells. The hydrogen gas that escapes during its production is so harmful that scientists have declared that it can completely wipe out the ozone layer. Storing hydrogen is also a problem because it is low in density and therefore must be compressed. But this makes it massive and impractical. It is also highly flammable. Leaks in hydrogen tanks can not be detected because of its being scentless and colourless.
Thus, unless an inexpensive and environmental friendly method is derived to produce pure hydrogen, there are no practical uses of fuel cells in autos. However, prototypes of fuel cell cars have been produced by companies such as:
- Hyundai Tucson-ix35 FCEV (2010)
- BMW 1 series-fuel cell hybrid (2010)
- Mazda 5Hydrogen RE Hybrid (2009)
- Fiat Panda-HyTRAN (2009)
- Audi Q5-FCEV (2009)
- Nissan X-Trail-FCV (2009)
- Volkswagen Caddy-Maxi HyMotion (2009)
- Mercedes-Benz B-Class-F-Cell (2009)
Though they are not produced for commercial use.