Types

• There are many different ways that cars can be more green. One of the most popular is hybrid electric cars, which run on gasoline but use electricity from a battery to boost their fuel efficiency. Cars can also be fully electric and get their power entirely from a battery. Some hybrids also have the option of running only on electric power but can switch to using gasoline mode for long trips or better horsepower.
  
  Cars can also be greener by using alternative fuels. Diesels can run on biodiesel, which is made from vegetable oil instead of petroleum, without requiring any modification. Biodiesel is less polluting than petro diesel, and it is made from a renewable resource. Diesel cars can also be modified to run on straight vegetable oil.
  
  Gasoline cars can be converted to run on ethanol or an ethanol blend, which is also made from organic materials instead of petrochemicals. Flex-fuel vehicles are another type of green car, which are designed to be able to run on gasoline or ethanol or any blend of the two.
  
  There are also hydrogen cars, which either burn hydrogen directly or use hydrogen to create electricity, and solar cars, which use solar panels to power an electric motor, but neither of these technologies is widely available.
  
  

History

• Electric transportation has been in use almost as long as electricity, although it has never become a commercial success. The first electric car was built in 1891 by William Morrison. In 1900, 28 percent of cars in the United States were electric, but in 1908 Henry Ford introduced the gas-powered Model T and made it available to the masses. There have been several attempt to revive electric cars, such as GM's EV1 and Toyota's RAV4 EV. By 2005, all major car manufacturers had discontinued their fully electric cars, although many were producing hybrids.
  
  Biofuels are another type of green car technology that have been in use since the invention of the car. Both diesel and gasoline engines were originally designed to run on biofuels. It wasn't until crude oil became widely and cheaply available that cars began using petrochemical fuels, and today car engines are designed to run most efficiently on specific fuels, either petroleum or petro diesel.
  
  

Considerations

• All green car technologies have challenges that have prevented them from becoming widely available. Fully electric cars can only run short distances before needing a charge because of the limited range of current battery technology. Biofuels such as ethanol, biodiesel and vegetable oil require a large quantity of biomass, and there is not enough agricultural land to grow enough plants to switch our entire fleet of cars over to biofuels. Also, ethanol can most easily and cheaply be manufactured from corn, and the popularity growth of ethanol in 2008 was a factor in the increase in corn prices that decreased food availability and exacerbated hunger in many parts of the world.
  
  

Benefits

• The main benefit of green cars is that they create less pollution. This includes CO2 and other global warming contributors as well as particulate emissions and toxic gases. Electric cars have no direct emissions, and so switching to electric cars would decrease smog and improve air quality in urban areas.
  
  

Potential

• The combined factors of global warming, pollution and problems with oil scarcity are all reasons why demand for green cars is increasing, and there is a strong likelihood that demand will only increase in the future. As green car technology improves, more and more manufacturers will build cars that use green technology.