Notes On Sources of Energy - CBSE Class 10 Science
 We cannot imagine the world without energy. The source of energy is important as well. There are various sources of energy available today to the mankind. On a broad sense, sources of energy can be categorized into non-renewable and renewable. Wood, coal, oil, natural gas are some of the non-renewable sources as they cannot be renewable. These are also called the conventional sources of energy. Nuclear fuels like uranium produce energy by fission process. Nuclear energy from sun is obtained by nuclear fusion process.   Conventional fuels and sources of energy cause a lot of pollution to mankind and hence there is a need for looking towards alternate sources of energy, which are most likely to be renewable. Solar energy, energy from wind, hydro energy, geothermal energy and energy from biomass are some of the alternate sources of energy. Wind energy can be harnessed by using wind mills that can be erected at suitable locations. Hydroelectric plants make use of hydro energy. In most of the rural areas biomass is utilized.   Characteristics of a Good Source of Energy        •  Enables us to do a large amount of work per unit volume or mass.        •  Is easily accessible.        •  Is easy to store and transport.        •  Is economical. Burning coal or petroleum products causes acidic oxides to be released. Thermoelectric production of electricity involves turbines. In thermal power stations, fossil fuels are burned to produce steam, basically a form of heat energy. This steam runs a turbine, which rotates a generator to produce electricity. In hydroelectric power stations, the kinetic energy of flowing water, which is actually the potential energy of water stored at a height, is converted into electricity. Plant and animal products, wood and cow-dung cakes, are used as fuels. The source of these fuels is called bio-mass. Burning a given mass of charcoal generates more heat than burning an equal mass of wood. Cow-dung, crop residue, garbage and sewage are decomposed in the absence of oxygen to produce bio-gas. Advantages of Bio-Gas:        •  It is an excellent fuel with 75% methane.        •  It burns without smoke.        •  It has a high heating capacity.        •  It is also used for lighting. Wind is another freely available resource that is used for generating energy. Alternative or Non-Nonventional Sources of Energy:        •  Energy from the sun        •  Energy from the sea        •  Geothermal energy        •  Nuclear energy Black surfaces absorb more heat when compared to white under identical conditions.   Three Types Energy From the Sea:        •  Tidal energy        •  Wave energy        •  Ocean thermal energy Molten rock in the earth’s crust is pushed upward and trapped in certain regions called hot spots. Nuclear energy is produced either by nuclear fission or nuclear fusion. Exploiting various sources of energy causes disturbances in the environment.

#### Summary

 We cannot imagine the world without energy. The source of energy is important as well. There are various sources of energy available today to the mankind. On a broad sense, sources of energy can be categorized into non-renewable and renewable. Wood, coal, oil, natural gas are some of the non-renewable sources as they cannot be renewable. These are also called the conventional sources of energy. Nuclear fuels like uranium produce energy by fission process. Nuclear energy from sun is obtained by nuclear fusion process.   Conventional fuels and sources of energy cause a lot of pollution to mankind and hence there is a need for looking towards alternate sources of energy, which are most likely to be renewable. Solar energy, energy from wind, hydro energy, geothermal energy and energy from biomass are some of the alternate sources of energy. Wind energy can be harnessed by using wind mills that can be erected at suitable locations. Hydroelectric plants make use of hydro energy. In most of the rural areas biomass is utilized.   Characteristics of a Good Source of Energy        •  Enables us to do a large amount of work per unit volume or mass.        •  Is easily accessible.        •  Is easy to store and transport.        •  Is economical. Burning coal or petroleum products causes acidic oxides to be released. Thermoelectric production of electricity involves turbines. In thermal power stations, fossil fuels are burned to produce steam, basically a form of heat energy. This steam runs a turbine, which rotates a generator to produce electricity. In hydroelectric power stations, the kinetic energy of flowing water, which is actually the potential energy of water stored at a height, is converted into electricity. Plant and animal products, wood and cow-dung cakes, are used as fuels. The source of these fuels is called bio-mass. Burning a given mass of charcoal generates more heat than burning an equal mass of wood. Cow-dung, crop residue, garbage and sewage are decomposed in the absence of oxygen to produce bio-gas. Advantages of Bio-Gas:        •  It is an excellent fuel with 75% methane.        •  It burns without smoke.        •  It has a high heating capacity.        •  It is also used for lighting. Wind is another freely available resource that is used for generating energy. Alternative or Non-Nonventional Sources of Energy:        •  Energy from the sun        •  Energy from the sea        •  Geothermal energy        •  Nuclear energy Black surfaces absorb more heat when compared to white under identical conditions.   Three Types Energy From the Sea:        •  Tidal energy        •  Wave energy        •  Ocean thermal energy Molten rock in the earth’s crust is pushed upward and trapped in certain regions called hot spots. Nuclear energy is produced either by nuclear fission or nuclear fusion. Exploiting various sources of energy causes disturbances in the environment.

#### Activities

Activity 1 childrensuniversity.manchester.ac.uk has developed an interactive online simulation which explains how electricity is generated from various sources. In this one gets to build a wind turbine by assembling the components given. An interactive quiz is given at the end to test the understanding of the topic covered. Go to Acivity Activity 2 childrensuniversity.manchester.ac.uk has created an interactive learning material which gives information about renewable and non-renewable sources of energy. It also gives a quiz to test one's knowledge on various energy sources like sun, biomass, coal, waves, wind, etc. Go to Activity Activity 3 science-animations.com has created an interactive learning material which gives information about engines. Go to Activity Activity 4 eschooltoday.com  has developed an interactive online simulation which explains how electricity is generated from various sources Go to Activity