Thursday, 26 January 2012

Green Renewable Energy Development–Greece

Hellenic Post of Greece remind the importance of Renewable Energy in the world by issued the stamps set features Green Renewable Energy Development on April 26, 2010. The image   on each stamps  presented Solar Energy,Hydro Power, Wind Power, Self Contained Man, Wave Power, and Bio Energy.

          Solar Energy                            Hydro power

Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.
Hydro power is power that is derived from the force or energy of falling water, which may be harnessed for useful purposes.Since the early 20th century, the term is used almost exclusively in conjunction with the modern development of hydro-electric power, the energy of which could be transmitted considerable distance between where it was created to where it was consumed.
             Wind Power                            Self Contained Man
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships.
A large wind farm may consist of several hundred individual wind turbines which are connected to the electric power transmission network. Offshore wind power can harness the better wind speeds that are available offshore compared to on land, so offshore wind power’s contribution in terms of electricity supplied is higher.
            Wave Power                          Bio Energy
Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work like : electricity generation, water desalination, or the pumping of water (into reservoirs). Machinery able to exploit wave power is generally known as a wave energy converter.In general, larger waves are more powerful but wave power is also determined by wave speed, wavelength, and water density.
Bio Energy is renewable energy made available from materials derived from biological sources. Biomass is any organic material which has stored sunlight in the form of chemical energy. The organic material may composed of  wood, wood waste, straw, manure, sugarcane, and many other byproducts from a variety of agricultural processes.

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