What is Fuel Cell?

A fuel cell is an electrochemical energy conversion device. It produces electricity from external supplies of fuel (on the anode side) and oxidant (on the cathode side). These react in the presence of anelectrolyte. Generally, the reactants flow in and reaction products flow out while the electrolyte remains in the cell. Fuel cells can operate virtually continuously as long as the necessary flows are maintained.

How does a Fuel Cell Generate Electricity?

Fuel cells generate electricity through an electrochemical reaction, known as reverse electrolysis. This reaction combines hydrogen and oxygen to form water vapor, heat and electricity. All three of the by-products of this reverse electrolysis reaction can be further utilized by the fuel cell system. Waste heat can be utilized for space heating and cooling. The water vapor can be captured and used as the feedstock for additional hydrogen and the electricity is channeled into an external circuit where it is used by any electric appliance.

What is the difference between batteries and fuel cells?

In principle, a fuel cell operates like a battery. Unlike a battery however, a fuel cell does not run down or require recharging. It will produce electricity and heat as long as fuel and an oxidizer are supplied. Both batteries and fuel cells are electrochemical devices. As such, both have a positively charged anode, a negatively charged cathode and an ion-conducting material called an electrolyte. Fuel cells are classified by their electrolyte material. Electrochemical devices generate electricity without combustion of the fuel and oxidizer, as opposed to what occurs with traditional methods of electricity generation.

What are the Different Types of Fuel Cells?

There are four main types of fuel cells distinguished by the electrolyte used in the individual cells. The different types of fuel cells are; polymer electrolyte membrane or proton exchange membrane (PEM), molten carbonate (MCFC), phosphoric acid (PAFC) and the solid oxide fuel cell (SOFC).

What fuels do fuel cells use to produce electricity?

One advantage of fuel cells is their fuel flexibility. With the proper reforming technology, fuel cells can extract hydrogen from a wide variety of currently available fossil fuels (e.g. Natural gas, methanol, coal, etc.). From fossil fuels, fuel cells utilize one natural element as their fuel, hydrogen, the most abundant element on Earth. In addition to fossil fuels, hydrogen can be generated renewably from water and other photobiological means.

What are the Benefits of Fuel Cells?

• Environmental
  Fuel Cells achieve high fuel efficiencies while emitting extremely low emissions.

• Engineering
  Fuel cells operate on a wide variety of fuels, utilize electrochemical reactions and contain no moving parts. These features make them simple to operate, quiet and extremely reliable

Why aren't fuel cells everywhere?

In the near future, fuel cells will play an increasing roll in everyday life. Soon fuel cell powered cars and trucks will be cruising the streets of your town emitting nothing more than harmless water vapor. Fuel cells will find their way into cell phones and laptop computers whose battery life is measured in days instead of hours. Your house or office will have a fuel cell that replaces a conventional furnace, providing heat and electricity free from the disruptions associated with the utility's electric grid. Most of the companies planning to manufacture fuel cells are still in the research and development stage of production. Once their systems satisfy the manufacturers' stringent requirements for performance and safety, the fuel cell systems will be available to the general public.

What is the amount of hydrogen that is equivalent to a gallon of gasoline?

It would take about 10 Nm³ of hydrogen gas to equal the energy present in 1 gallon of gasoline or 8.3 pounds of coal.