About Energy!!!

About Energy!!! Physics

Project

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What Is Energy??? Energy, from the Greek word ‘energia’, meaning "in-work," is the capacity for doing work. Energy can be measured in terms of mechanical work, but because not all forms of energy can be converted into useful work, it is more precise to say that the energy of a system changes by an amount equal to the net work done on the system. The units of energy are the same as those of work. These units may be ergs, joules, watt-hours, foot-pounds, or foot-poundals, depending on the system of units being used. 2

Different Types of Energy Energy

Renewable Sources

Non-Renewable Sources

Biomass, Solar Energy, Wind Energy, & Geothermal Energy

Fossil Fuel, Charcoal, Trees 3

Renewable Sources 1. 2. 3. 4. 5. 6.

Biomass Wind Energy Solar Energy Geothermal Energy Nuclear Energy Tidal Energy 4

1. Biomass This term is applied to all plant products which are used to produce energy. It is used to generate electricity, fuel and produce heat for industries and gas for domestic purposes. Direct burning of biomass is done is villages which is not very economical. The methane produced in the biogas digester is a clean fuel with which bio-fertilizer is also produced. Some ways in which biomass produces energy: • Wood and other agricultural waste is used for heating. • Fermentation of grains produces ethanol which mixed is with petrol and used as fuel. • Gasification converts decaying biomass into methane. 5

1. Biomass Production of Biogas

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2. Solar Energy It is the energy produced by the sun. It is the oldest and most efficient form of energy. Even in the ancient times it was used to keep hoses warm, dry clothes and preserve food. Some ways in which Solar energy helps us: • Used to produce electricity with the help of photovoltaic cells which is non-polluting. This energy is used to run various electronic gadgets and even to run vehicles. • Used for cooking food in pots • Used to boil water

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Solar Energy Solar Panel Solar cooking Pots

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3. Wind Energy Winds are caused by uneven heating of Earth. Today Windmills called wind turbines are used to produce electricity. Its blades catch the wind, changes its direction form horizontal to vertical. A turbine is then engaged and electricity is produced. The turbines can be as tall as ten storeys. Large no. of turbines are placed together in an area which is called wind farms. Wind turbines are noisy but non-polluting. 9

Wind Energy

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Geothermal Energy

Geothermal energy is the heat energy that occurs naturally within the Earth. The word GEO means earth and THERMAL means heat. Geothermal reservoirs are formed by rain water seeping through earth’s crust into porous hot rocks. These reservoirs contains a mixture of very hot water and steam. Such reservoirs form a renewable source of energy which is non polluting. Iceland gets most of its energy from geothermal sources. 11

4. Geothermal Energy

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