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SAI INTERNATIONAL SCHOOL, BHUBANESWAR.

                                Class VIII: SOCIAL STUDIES – GEOGRAPHY

                           CHAPTER - 3- MINERAL AND POWER RESOURCES
                                               (VIRTUAL CLASSES)



                              NOTES FOR CHAPTER-3- Mineral and Power Resources

        SUBTOPIC- Non-Conventional Sources


              Non-conventional sources of energy are renewable and unlimited in nature but are more
               expensive since they need technological upgradation.
              Energy from the sun, wind and tides, nuclear energy, energy from the earth and from decayed
               organic matter are called non-conventional sources of energy.

        Solar energy
              is an inexhaustible and non-polluting form of energy
              is the heat/light of Sun which is the primary source of all energy on the earth
              Solar panel, made up of a number of solar cells that absorb solar energy and convert it into
               electricity, are used to convert solar energy into heat and electrical energy
              can be effectively used in tropical countries that receive abundant sunlight
        Wind energy
              is the energy generated from winds
              is renewable, low-cost, safe and clean source of energy
              Wind mills are used to produce electricity
              Disadvantages of wind energy are
              it contributes to noise pollution
              can be harmful to birds
        Tidal energy
              is the energy generated from tides which are caused by the gravitational pull of the moon and
               the sun and the rotation of the earth
              is a non-polluting and inexhaustible source of energy
        Nuclear energy
              is the energy stored in the nuclei of radioactive elements like uranium and thorium
              is produced during nuclear fission when the nucleus is split
              During nuclear fission huge amount of heat and light energy is released.
        Geothermal energy
              Geo = earth and thermal = heat
              is the heat energy stored inside the earth
              is clean and eco-friendly
              can be seen dissipated on the earth’s surface in the form of hot springs, natural geysers and
               volcanoes
         Biogas
              is also a renewable source of energy which is produced from biomass that includes wood from
               trees, matter from dead plants and animals, waste from other plants, animal dung and kitchen
               waste
              can be used to generate electricity, light, heat, motion and fuel
              is a low-cost source of energy, easy to operate, and uses bio-waste.
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