Renewable energy is an alternative to oil worldwide dependence. Renewable energy is nowadays composed of a series of sources of big enough in quantity and powerful enough in energy to sustain modern high level of energy use. These are : wind power, solar power, geothermal power, hydroelectricity and of course biofuel. Wind power is collected and exploited through huge wind power plants. They are composed of a sort of enormous post at which’s top is placed an aircraft-like three-branches turbine. Their functioning is quite easy : the wind pushes the three helixes connected to the turbine which makes it turn, so the faster it turns the more energy is produced that’s why for maximum efficiency, this kind of power plant is placed at hilltop or in a place where there is a very strong wind force. Solar power, the most effective and reasonable choice for an alternative energy source, is collected and exploited through photon cells collection panels. Although solar power plants are still late in industrial application, the particular photon panels are popular in the market today and attract more and more private investment. What is really revolutionary about these particular panels is that each building can produce its own energy or a part of the total consummated energy eventhough this still depends on the size of its roof, the available place on the ground to place such panels if roof is not enough to do so etc. So the only real problem with “particular solar energy production” is the high cost and the surface. Geothermal power consists of using the groundwater’s steam generated through naturally produced heat in order to make power plant turbines turn (just like a classical steam engine). Eventhough financially viable, renewable and “clean” (the most stunning example of the use of such energy is Iceland), this power source suffers a very heavy handicap : its geographical and geological limits as it is a non-volatile source of energy like sunbeams or winds but is concentrated on certain geographical points making its exploitation, if not naturally produced phenomenon, impossible. Alike geothermal power, hydroelectrical energy depends grandly on the hydrography and more precisely this time on the hydrographical patterns of a country (to sum-up, the size of the rivers) as the more a river’s water stream is powerful and its bed is large the more the electrical production capacity of its dams is important ! This can extend to such scale that, for instance, the 50 billion US dollars planned dam of Inga in the Democratic Republic Of Congo (former Zaire) at the Congo River’s mouth is expected to be able to deliver enough power to light all of Africa ! But as seen in the previous example, hydroelectricity remains a high cost source of energy which is added to some environmental negative effects such as salt accumulation in the artificial lakes created after the construction of a dam (example of the Barrage Of Aswan in The Arab Republic Of Egypt). Finally, the most promising biotechnology capable of replacing oil, and on which even oil companies and corporation bet on, is biofuel. This kind of fuel, as its name implies, is totally made from organic bodies or contains a small percentage of crude oil-related material such as sugarcane, colza or corn extracted ethanol. The most illustrative example is Brazil’s. Indeed, in three years (2003 – 2006), nearly forty percent of Brazil’s gasoline consumption was lost in favour of sugarcane extracted ethanol fuel while cars using this kind of fuel went from three percent to seventy percent in the same period ! Of course new technology means new habits, the emergence of alternative propulsion led to a revolution within the biggest oil consuming sector in the world : automobile. As a result, cars are today divided in three categories which are hybrid vehicles (petroleum / electrical based vehicles), petro-free cars (total non use of petroleum) and petro-cars (petroleum and biofuel based vehicles).
