Alternate Sources Of Energy-Page 2

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Solar cell

  The process in which a material produces electric current upon exposure to light is called photoelectric effect.Solar cell is a device used to convert solar energy into electrical energy.


Biomass

  The organic matter obtained from plant and animal wastes used for energy conversion is called biomass.The energy obtained from biomass is called bio energy.
Advantages of bio energy:
1.It provides clean fuel
2.maintains environment to be clean
3.reduces carbon dioxide content in the atmosphere
4.improves the water retention capacity of soil.

Biogas

   Biogas is produced from biomass by anaerobic digestion.The major constituents of bio -gas are methane(about 70%) and carbon dioxide.In rural areas biogas is produced specifically using cowdung in gobar gas plant.It provides
a) cooking gas  b)manure c) gas for lighting d) fuel for running small engines


Energy conversion from biomass

   Biomass is converted into bio energy by three processes 1)combustion pyrolysis
2)Bio gasification 3)Fermentation

Pyrolysis 

 It is a chemical decomposition at high temperature in total or partial absence of air.It produces fuel gas,ethanol(ethyl alcohol)and charcoal.

Bio gasification

  This is similar to bio gas production from gobar gas.

Fermentation

 This process involves conversion of sugar from biomass and converting the sugar to alcohol by fermentation as as result of this ethane(combustible gas) and solid residual fuels are obtained.