fuel cell technology :: essays research papers

Fuel cell technology 1 Running head: FUEL CELL TECHNOLOGY: TRANSPORTATION AND RESIDENTAL/ COMMERICAL APPLICATIONS Fuel Cell Technology: Transportation and residential/commercial applications   Ã‚  Ã‚  Ã‚  Ã‚   Monique University 2 A fuel cell is an electrochemical energy conversion device. A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. With a fuel cell, chemicals constantly flow into the cell so it never goes dead as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals. Fuel cell provides a DC (direct current voltage that can be used to power motors, lights or any number of electrical appliances. The fuel cell will compete with many other types of energy conversion devices, including the gas turbine in your city's power plant, the gasoline engine in your car and the battery in your laptop. Combustion engines like the turbine and the gasoline engine burn fuels and use the pressure created by the expansion of the gases to do mechanical work. Batteries converted chemical energy back into electrical energy when needed. Fuel cells should do both tasks more efficiently. Fuel cells improve battered powered cars and gasoline powered cars more efficiently. Fuel-cell-powered electric cars are powered with pure hydrogen. It has the potential to be up to 80% 3 efficient, and with today’s gas prices that would be wonderful. The efficiency of a gasoline-powered car is surprisingly low. All of the heat that comes out as exhaust or goes into the radiator is wasted energy. The engine also uses a lot of energy turning the various pumps, fans and generators that keep it going. So the overall efficiency of an automotive gas engine is about 20%. That is, only about 20% of the thermal-energy content of the gasoline is converted into mechanical work. The efficiency of an electric car is 72% for the car, 40% for the power plant and 90% for charging the car. That gives an overall efficiency of 26%. The overall efficiency varies considerably depending on what sort of power plant is used. If the electricity for the car is generated by a hydroelectric plant for instance, then it is basically free (we didn't burn any fuel to generate it), and the efficiency of the electric car is about 65%.   Ã‚  Ã‚  Ã‚  Ã‚   4 Efficiency is not the only consideration, however. People will not drive a car just because it is the most efficient if it makes them change their behavior.