Photovoltaic and Fuel Cells

Photovoltaic (PV) cells are devices that convert sunlight into electricity. These cells power many of the small calculators and wrist watches we wear everyday. The bigger and more complicated systems power communications equipment, lighting to houses, and even our appliances. A PV cell is made up of the cover glass, transparent adhesive, the anti-reflecting coating, negative and positive semiconductors, and front and back contact. Sunlight enters and passes through the cover glass, transparent adhesive, and anti-reflecting coating. Here the sunlight goes through the negative semiconductor and positive semiconductor where it is converted into an electric current. From this point the front and back contact act like bridges so that the electric current may flow to an external circuit.

A fuel cell is like a battery except that a fuel cell does not need recharging as long as fuel is supplied. It is simply two electrodes sandwiched around and electrolyte. Hydrogen enters through the anode while oxygen enters through the cathode. When sparked by a catalyst, hydrogen splits into a proton and an electron. The proton passes through the electrolyte and the electron creates its own path were it is used for energy before returning to the cathode. At the cathode electrons are reunited with hydrogen and oxygen to form a water molecule. There are many types of fuel cells such as phosphoric acid, proton exchange membrane or solid polymer, molten carbonate, solid oxide, alkaline, direct methanol fuel cell, and regenerative fuel cells.

The benefits from both photovoltaic and fuel cells are low operating costs, reliable, clean and efficient, they create economic growth, and are modular. Over the years costs for photovoltaic cells has come down more than twenty fold since the 1970’s. Vehicles today consume 6 million gallons of oil everyday, if 20 percent of cars used fuel cells; oil imports would be cut by 1.5 million everyday (Energy Educators of Ontario, 1993). Research still continues on several different technologies to reduce costs to acceptable levels.

In the world today fossil fuel consumption is increasing everyday and the supply is depleting. Photovoltaic and fuel cells are the best substitute to our fossil fuel reserves. They will aid us in keeping our environment clean and suitable for living.