The alternative powered car; what was once a distant concept is now a production reality. There are probably several on the streets near where you live. Are they really the answer to the limited supply of oil and the growing environmental concerns? To answer this you must first understand the different types of environmentally friendly cars available:
The hybrid car is any vehicle which has two, or more, sources of power. In most cases this is a gasoline engine and an electric motor. The electric motor is powered by batteries which are charged by the engine. The electric motor will power all electrics on the vehicle to reduce the load on the engine and improve its efficiency. On some vehicles is will also connect to the drive train and power the vehicle a short distance. This technology is also used in start / stop automobiles; allowing the car to switch off and back on automatically. The hybrid does not end the use of gasoline powered engines but does provide better fuel efficiency and will make the oil derived products last longer.
The Electric Car
An electric car is powered by electricity! The most common electric car is equipped with several large batteries. These batteries are either charged at home or at special points in towns. The batteries power an electric motor which provides power to the wheels. An electric powered automobile is capable of speeds of up to 70mph but is limited in range; most are only able to do around 80 miles before needing recharging. These cars have no dependency on oil and so could be a viable option for the future. However, for them to take over from gasoline further developments will be needed to increase the range of these vehicles and improve the charging times. The vehicle itself has zero effect on the environment whilst being driven. There is an environmental impact depending on how the electricity needed for charging has been created.
The Hydrogen Car
Hydrogen and oxygen when mixed create a mixture of water. The byproduct of this is heat energy. This energy has been used to propel rockets into space and it is now possible to drive cars with it – although at significantly slower speeds! The hydrogen needs to be stored in a tank on-board the car whilst the oxygen can be taken from the air around the car. A computer carefully controls the mixture of the two and introduces a spark to ignite the fuel. The heat energy generated is used to charge batteries on the car which, in turn, power the wheels. The distance the car can travel is only limited by the amount of hydrogen available. The idea is to be able to top up the vehicle at normal service stations and it should only take a few minutes. At the moment there is not enough of an infrastructure to support the use of this car everywhere but this is slowly improving. The only emissions created by this car are water so the environmental impact is zero. However, as with the electric car there is an environmental impact on the creation of the fuel. Hydrogen is in abundant supply but it is mixed with other chemicals and needs to be extracted. There are green ways of doing this via wind power or water but it can also be done by using fossil fuels – the very thing that the new technologies are trying to move away from. Burning of these to create hydrogen will have an environmental effect.
The Air Car
This is a concept that fewer people have heard of but has been around for over one hundred years. The design is similar to the standard internal combustion engine with a few less parts. Normal air needs to be compressed and then is forced into the engine to move the pistons and drive the wheels. The only emission from this vehicle is cold air! Unfortunately the range of these automobiles is also limited by the amount of compressed air on board. There is no infrastructure yet for refilling compressed air tanks at your regular service station although this may happen in the future. The air needs to be compressed at a very high pressure and it may not be possible to complete this task at home, although there are some designers who are including compressors on the car to allow home charging. The environmental impact of this car is again zero except for the fuel production. As the air will need to be compressed by electricity the environmental impact will again come down to how this electricity is created.
For these vehicles to become viable the range and refueling options will need to be improved.
Will These New Technologies Save The World?
There is no doubt that scientists are working hard to explore new options. All of the above automobiles are not just theories they are all either already being produced or will be shortly. Unfortunately there are also flaws in each one. A hybrid still relies on gasoline whilst the electric, hydrogen and air cars all require a clean source of electricity to ensure there is no environmental impact. It is entirely possible that none of these vehicles are the long term solution for saving the planet. They do buy scientists time to trial other methods of propulsion or to provide renewable, constant clean electricity around the world – nuclear power has been discussed as an option for this but still requires mining for Uranium which is not a renewable resource.
Ultimately the hybrid car will probably be shelved and more work will continue on the other three types which do not require oil for power. Electric and hydrogen cars have the potential to work side by side depending on the length of the intended journey. It is unlikely that both hydrogen and compressed air will become available at refueling stations due to the costs involved. Perhaps the future involves a completely new, as yet undiscovered type of propulsion. For now the alternative fuel technologies may not save the planet but they will go a long way to prolonging its life.