Nowadays transportation is the sector which is in the second place in energy consumption. It means that it is also second place in emission of CO2. It happens because people drive their cars every day to work, fly or go by train to different countries, and ship their packages. In addition, all these types of transportation use fuel, usually petroleum, which costs a lot of money. For example, now a gallon of gasoline costs around $3.8 dollars in the US, and around $7 dollars in Europe. Therefore, many car industries have started developing new types of engines that consume less fuel, such as hybrid or electric engines.
Hybrid engines consist of two engines, one electric and the other gasoline; therefore, they combine benefits of electric motors and fuel engines, such as fuel efficiency and additional power. Some advanced technologies for hybrid engines that help to save fuel are regenerative braking, electric motor drive assist, and automatic start or shut off. With regenerative breaking, the electric motor applies resistance to the drivetrain, which causes the wheels to slow down. Then the energy from the wheels turns the motor, which functions as a generator, converting energy usually wasted during coasting or braking into electricity. This electricity is stored in batteries that use the electric motor. This function allows cars to save gasoline. In the past the electric motor charged from the gasoline one. Another function is the electric motor drive assist. Actually, the electric motor provides additional power for gasoline during acceleration, passing, and hill climbing. This is not new for hybrids; electric motor drive assist was the first feature for them. However, it saves a lot of fuel, and sometimes when you do not drive fast only the electric motor is working. The automatic start and shut off is used not only in hybrids, but also in regular engines. This relevantly new function turns off the engine when you come to a stop and starts it when you press the gas pedal. Some examples of hybrids are Toyota Prius, BMW 7, Lexus CT 200.
In addition, some cars work only on the electric engine. It makes these cars very efficient and environmentally friendly. It has the same regenerative breaking feature as a hybrid. Therefore, it converts around 60 % of electricity from the grid to power. In fact, this type of car does not emit CO2, so it is very ecologically friendly. Nevertheless, it uses electricity, which is mostly produced by oil plants, coal plants, and others. There are some advantages of the electric motor. It provides quiet, smooth acceleration, and needs less maintenance than the gasoline engine. It can be recharged from any plug; however, there are some difficulties with the charging process. To charge this motor takes from four to eight hours , depending on what kind. The big disadvantage of it is that you cannot drive for a long distance because you need to recharge the battery every 200 miles. One of the most well-known examples of this type of car is Tesla.
Click here to see video about Tesla http://www.youtube.com/watch?v=AOdsTuaJEfc&feature=player_embedded
Sources
“How Hybrids Work.” How Hybrids Work. N.p., n.d. Web. 10 Feb. 2013.
“Electric Vehicles.” Electric Vehicles. N.p., n.d. Web. 10 Feb. 2013.
“Transportation and Climate | OTAQ.” EPA. Environmental Protection Agency, n.d. Web. 10 Feb. 2013