Category
📚
LearningTranscript
00:00Hi kids! Today we will learn about another renewable source of energy, hydroelectricity.
00:11So let's start! Hydro means water, and hydroelectricity is electricity produced using water. But how?
00:26Let's see. Hydroelectricity is mostly produced in big structures known as dams. Dams are
00:36big structures made on rivers that store a huge quantity of the river's water in a reservoir.
00:47And these reservoirs are too large and possess great height. And when they release water
00:57from such great heights, the water falls with a great force, which is sufficient to rotate
01:05big turbines that ultimately run big engines to generate electricity. Let's learn advantages
01:15of using hydroelectricity. First and foremost advantage is it is clean energy. That is,
01:27it does not pollute environment in any way. And no fossil fuels are burnt to produce electricity.
01:36Secondly, it can be a domestic source of energy. That is, any state can produce its own electricity
01:47without relying on international fuel sources. A hydropower plant is capable to provide electricity
01:56at a constant rate throughout the year. The big reservoirs created in the process of making
02:06dams also serve the purpose of recreational activities like water sports and makes it a
02:14tourist destination. Now let's learn some of the disadvantages of hydropower. Firstly,
02:24dams are very expensive and time-consuming to build. People in the flood regions of the dams
02:33are forcibly moved to other locations. Construction of dams also causes geological
02:43damages. For example, the construction of Hoover Dam triggered many earthquakes.
02:49Dams also arises international conflicts. If a dam is built on a river that passes
03:01from more than one countries, the country that builds a dam gets the control of the flow of the
03:08river and the other country has no control over it. So it can be flooded if the other
03:16country opens the gates of the dam. Now let's learn about another renewable source of energy
03:25and it is geothermal energy. A lot of energy is stored beneath the earth in the form of hot molten
03:37matter and this energy can be trapped through various means. Example, steam of lava is trapped
03:46and used to run turbines which in turn produces electricity. It is a clean and sustainable source
03:55of energy. This heat energy of molten matter can be trapped from a few miles beneath the earth's
04:02surface using a geothermal heat pump system and can be used to keep our home warm. It helps to
04:13melt the snow from the sidewalk to provide us hot water throughout the year. In many countries,
04:22most of the buildings and even big swimming pools are heated with geothermal hot water.
04:29Advantages of geothermal energy. Geothermal energy can be extracted without burning fossil fuels such
04:42as coal, gas or oil. So it's a clean source of energy. Unlike solar energy and wind energy which
04:53are not evenly available throughout the year. Geothermal energy is always available that is
05:01365 days of the year. It is least expensive compared to wind energy, solar energy and other
05:12sources of energy. Now let's learn some of the disadvantages of geothermal energy. The main
05:21and one of the most important disadvantage is that it releases hydrogen sulfide which is a gas
05:32that smells like rotten egg. Next disadvantage is that if you use the same geothermal site for years,
05:43eventually it may cool down. So you cannot rely on one source as a permanent source of energy. So
05:54kids today we learned about two renewable sources of energy and they are hydroelectricity and
06:04geothermal energy. Now you may go ahead and take a quiz to learn more. Bye-bye.