|Fuel Cells | Fuel Cell Construction | The Chemistry behind Fuel Cells | Different Kinds of Fuel Cells | Applications of Fuel Cells | Obstacles for Fuel Cells to Over Come|
A new form of energy production has been in the works since the space race in the 1950'0s. It’s not quite a battery, but it isn’t quite a combustion engine either. Fuel cells seem to be the wave of the future for electricity production.
Electricity is nothing more than flowing electrons. That means that
power generation is nothing more than finding out how to free electrons.
Fuel cells rely on hydrogen for its
electrons. There are many different fuel cells for every kind of application.
fuel cell has the same essentials. They all have an anode (negative electrode)
The fuel cell works by injecting molecular hydrogen (H2) molecules into the anode. The hydrogen molecules react with the catalyst. The catalyst is usually a thin coat of powdered platinum on carbon paper. This breaks up the hydrogen into a proton and an electron. The proton goes across the electrolyte, (remember, it only accepts protons) while the electron is fed through the circuit and goes to work, whether it be powering your oven or providing horsepower to your new ustang.
Upon finishing their job, the electrons return to the cell through the cathode. There, the catalyst assists the oxygen molecules, the hydrogen protons and the hydrogen electrons in making water. The chemical reactions are the following:
The whole reaction ends up looking like this:
This reaction only creates about 0.7 volts. Because of this, there are several cells built into a stack. This multiplies the voltage up to useable levels.
Fuel cells differ in two ways. The most important difference is the electrolyte. Different electrolytes provide different voltages and different properties. The fuel cell destined to appear under car hoods is called a Proton Exchange Membrane Fuel Cell. The stacks that will be used to fuel the car are about the size of an average sized printer.
Other fuel cells are much bigger (ranging in size from a large central air conditioning unit to a compact car.) These cells are stationary and can provide electricity to an apartment complex, an office building or 60 family homes. These include phosphoric-acid, solid oxide and molten carbonate fuel cells. All of these fuel cells are large and take a relatively long time to heat up (or “prime the hydrogen pumps”) which is why they are not suitable for automobiles. These large-scale fuel cells operate at high temperatures as well, (they range from about 1,000° F to 1,800° F) which allows engineers another way of producing energy. The heat from the fuel cells can be used to boil water (perhaps the water it produces) and turn steam turbines for even more electricity.
Fuel cells have the potential to slip into every kind of electronic device. A few applications could include:
It is important to remember that fuel cells are not batteries. While they share similar
Hydrogen can be extracted from several different fuels:
Currently, hydrogen costs are about $3.00 a gallon. But by 2010, the
Department of Transportation promises to reduce the cost to under a dollar.
The cost of the hydrogen is
dependent mostly on the delivery system of the hydrogen. Hydrogen can
through pipe lines (this is already employed in industrial settings).
Hydrogen can also be
drawn from the above fuels and carried on-board the cars just as gas
is in combustion
engines. The best alternative would be for fueling stations to be powered
by solar, wind,
or hydroelectric power and use that electricity to separate hydrogen
from water using
electrolysis. There are already two such stations working in southern