|
Car manufacturers have been continually improving the technology looking for a better automobile for a variety of reasons, one of which is that they are legally required to meet Corporate Average Fuel Economy Standards. The Energy Policy Conservation Act of 1975 was established to improve fuel economy in response to the 1973-74 Arab oil embargo.
The law required vehicles weighing less than 8,500 lbs. to average at least 27.5 miles per gallon (8.5 liters per 100 km) for a manufacturer's entire line of passenger cars, subject to fines for not meeting these standards. For 2004, the standard is 20.7 mpg for light trucks, vans and SUVs. Auto producers, however, can now balance the higher mpg of their hybrids with lower ratings on their luxury cars and still meet requirements. So adding a hybrid to their existing product line allows car manufacturers a broader range of products while still meeting policies.
In addition, some government regulations dictate certain emission standards, such as in California where the low emissions vehicle norm is 3.4 grams of carbon dioxide per mile. However, since the U.S. government has no guidelines for pollution control, car manufacturers are not required to address this issue. Yet to please the growing consumer demand for cleaner cars, automakers realize that cars burning more gas will emit more pollution, so reducing fuel usage by increasing fuel efficiency automatically cuts CO2 emissions. It is estimated that the current crop of hybrid cars cut dangerous pollutants by at least one-third from conventional cars.
Reports from the Environmental Protection Agency (EPA) indicating worsening pollution have also inspired the experimentation with alternative forms of power. Since cars are among the major contributors to this problem, purchasing emission-free vehicles is one way to reduce pollution while not having to give up driving. Initial recommendations for cleaner cars had suggested using other carbon-based fuels than oil, such as propane or natural gas.
Yet while they are cleaner than gasoline, they are still limited fossil fuels and they do pollute. The electric motor alternative, which is totally emission-free, was proposed using power from batteries, the sun or hydrogen fuel cells. Battery-powered cars, besides being cleaner, are more efficient and have less moving parts to wear out, however, their range is shorter and recharge time longer.
Although solar-powered cars, which are equipped with batteries that are charged by the sun have longer ranges, they are still dependent on batteries, which have size and
weight limitations. Hydrogen-powered fuel cells hold promise as a clean source of power for electric motors, without the limitations of batteries.
In a fuel cell, hydrogen is burned in a pollution-free chemical reaction where the fuel cell combines hydrogen and oxygen to produce electricity, water and waste heat. Since hydrogen is the most abundant element in the universe, it seems like the best replacement for more limited resources like oil. In addition, cars powered by hydrogen are 100% emission-free, lightweight and compact, three times as efficient as gas engines, have excellent ranges, easy refueling and are totally safe. To date, several auto manufacturers are testing fuel cell powered cars, such as Mazda, Mercedes-Benz and BMW.
|
