Types of Renewable Energy:
All the FACTS

Although several types of renewable energy have been with us since a long time, we probably did not have the right tools for harnessing them for practical purposes. For instance, the sun and the wind as also the foliage and plant life (biomass) are no newfound discoveries but people never imagined that sunlight could help create electricity through photovoltaic cells. Similarly, wind as a renewable energy was mainly used by sailing ships or was employed to run windmills for grinding corn. Today the same wind is employed to generate electricity in average homesteads.

Although there are quite a few types of renewable energies available, Hydropower seems to be the single largest source of such energies. It provides almost 11% of America’s total electric power. As much as 77,000 megawatt of hydropower today provides electricity for the nation’s 35 million homes. Hydro-electric power is derived from the force of flowing water stored in large dams or water bodies where river water is primarily stored and then allowed to run in cascades to rotate turbines that are coupled to generators. However, geo-scientists are currently discarding the notion of arresting river water in this form as they consider such actions are unnatural and may seriously disturb the ecological balance in the region.

Geothermal energy is also considered to be another useful renewable energy. It is produced from naturally occurring hot water or steam (as from the Old Faithful in the Yellowstone National Park in USA) emanating from under the earth’s surface and is responsible for 2,800 megawatt of energy in the US. As a matter of fact, steam is employed to rotate a turbine that is coupled to a generator that generates electricity.

And now let us come to wind as a form of renewable energy that is currently sweeping the United States like never before. Although two internationally famed people like the great Italian painter, Leonardo da Vinci and Christopher Columbus, the great explorer had predicted about its tremendous potentiality long ago, nothing much was heard about this till wind turbines had hit the market only recently. Among the many scientific sketches that were found in da Vinci’s collections, one depicted a wind machine (aero plane) that could use wind power to lift it above the land. As for Columbus, he was so sure of wind power that he sailed for long on un-chartered seas in search of a new continent when his men eventually located land.

Apart from two isolated issues that related to early generation of electricity through wind power; one involving Prof. James Blyth of Glasgow who generated electricity with his fabric-sailed wind turbine in July 1887 and Charles F. Bush of Cleveland, OH who achieved the same result in 1900, nothing more was done about it for long period of time. Contemporary Wind Turbines generate electricity through devices that consist of a rotor fitted out with suitable blades and are coupled to generators that generate electricity when held against strong wind. With the help of battery banks and transformer-cum-converters, the DC output of the Wind Turbines is converted to usable 120V AC current. Today, large wind parks in the United States provide electricity to numerous homes in cities and suburbs. It is estimated that by 2020, most fossil-fueled generators in the country would be replaced by wind powered generators, thus reducing the emission of greenhouse gases and saving the world from the dangers of global warming.

Yet another ground-breaking invention uses solar energy (renewable energy) to produce electricity. The photovoltaic cells absorb sunlight, release their electrons from the atoms, as a result of which electricity is produced. Several PV cells are arranged in the form of a panel (called Solar Panel) to generate reasonable amount of power.

Nevertheless, researchers are busy finding out newer methods of harnessing the world’s renewable energies that are clean, unpolluted and are available free of cost all through the years.