Hydrogen Fuel Cell Basics

• A hydrogen fuel cell car is powered by an electrochemical process. Hydrogen, which is stored in an on-board tank in a compressed form, is exposed to oxygen from the air in a series of fuel wells. The reaction releases electrons, which are stored as electricity in a battery pack. Batteries power an electric motor, which drives the vehicle. The by-product of the chemical process is water, along with some heat, which is expelled from the car's exhaust system as water vapor.
  
  

Plug-In Electric Basics

• Plug-in electric cars are commonly cited as an alternative form of powering automobiles for which the necessary technology is already available. Sometimes known as extended range hybrids, plug-in electric vehicles use a battery pack and electric motor to provide power. The car can be recharged by plugging it into a household electrical outlet, or with a specially designed charging station. A small gasoline engine is included on most plug-in electric cars. This engine is only used when the batteries are depleted and require additional power, using the gasoline engine as a generator to extend the range of the car.
  
  

Advantages

• The biggest advantage of both hydrogen fuel cell cars and plug-in electric cars is the ability to drive without the need for gasoline. Plug-in electric cars will not require any gasoline to be used when they are driven within their electric range, which may be up to 100 miles depending on the storage capacity of the batteries. For longer trips, gasoline usage is still minimal. Hydrogen fuel cells use no fuel other than hydrogen and produce no emissions other than water, making them an environmentally ideal solution to the production of harmful carbon emissions.
  
  

Disadvantages

• For hydrogen fuel cell vehicles, the largest disadvantage is the complexity of the process by which hydrogen can be produced for fuel. Isolating hydrogen atoms is a difficult and energy-intensive process. In fact, the production of hydrogen fuel can actually use more energy and produce more pollution than will be saved by a car that does not need gasoline. In the case of plug-in electric cars, the true environmental impact is only felt wherever the electricity that is put into the car is produced. Since it draws from the standard electric grid, the power may come from coal burning power plants or other problematic sources.
  
  

Future Evolution

• Hydrogen fuel cell cars are currently being tested by a variety of automakers in real-world scenarios. For them to come into widespread use, engineers will need to find better, easier ways to produce hydrogen fuel. It will also be necessary to improve the efficiency of fuel cells so that less hydrogen fuel is needed in the first place. Plug-in electric cars are rapidly coming to the market. For them to truly be efficient and clean, more municipal power authorities will need to switch to renewable forms of producing electricity, such as wind, solar and biomass.