February 18, 2022

Class 10 Science Chapter 14 Sources of Energy

We have studied in earlier classes that energy is neither created nor destroyed. But, if this is true then why do we have the energy crisis? In class 10 science chapter 14 sources of energy, we will try to find out the answers to these questions, but the important thing that we will learn in this chapter is about the different sources of energy.

If total energy during physical or chemical processes is conserved as we have learned in the previous class, then why do we even have to pay the electricity bill. To understand this we must understand the other phase of this riddle i.e energy can neither be created nor destroyed, but, it can be converted from one form to another.

Class 10 Science Chapter 14 Sources of Energy

Let’s understand the above with an example. If we take 200 mL of water whose temperature is 70ºC and put it in a place where the temperature is 25ºC. We know that all the extra temperature or heat that the water has will be gone. This proves that the usable form of energy is dissipated to the surroundings in less usable forms.

In class 10 science chapter 14 sources of energy, what they are trying to explain to us is that any source of energy that we consume to do work cannot be used again. So, we must use energy sources wisely and responsibly.

# 14.1 — What is a good source of energy?

In order to use the energy sources wisely, we must first know how to select the source needed to obtain the energy in its usable form. The best approach to determine what source will suit, we need to ask ourselves the following questions:

  • When we burn it, how much heat will it release?
  • Is it going to produce too much smoke?
  • Is it easily available?

Depending on various factors, there can be a lot of other questions. The point here is that we must take into consideration the effect of energy sources on our environment and others.

# 14.1 — Conventional sources of energy

In this part of the class 10 science chapter 14 sources of energy, we will learn about the sources of energy that we have been using for quite a long time now.

14.2.1 — Fossil fuels

As we have learned in previous classes, fossil fuels are the energy sources that are formed by the remains of dead plants and animals. Fossil fuels are non-renewable sources of energy meaning they can be used only once, therefore, we need to conserve them as much as possible.

When we burn fossil fuels, acidic oxides are released which are very harmful to us. They create a lot of air pollution which leads to other problems like acid rain.

14.2.2 — Thermal power plant

Electricity is the most consumed energy form in the modern world, and we are opting for all sorts of methods to generate more and more electricity. One such method is a thermal power plant where electricity is produced by burning fossil fuels which produce steam that runs the turbine to generate electricity.

Often thermal power plants are set near the coal or oil fields as the transmission of electricity is much more efficient than transporting coal or petroleum.

Class 10 Science Chapter 14 Sources of Energy

Besides the conventional sources of energy that are mentioned above, there are many more sources from which the energy is being harnessed in modern times. In this part of class 10 science chapter 14 sources of energy, we will learn about more conventional sources of energy.

14.2.3 — Hydropower plants

Hydropower plants, unlike thermal power plants, use renewable sources of energy i.e water. Hydropower plants convert the potential energy of falling water into electricity. Almost a quarter of the energy requirement in India is met by hydropower plants.

The working of a hydropower plant is simple. First, we collect water from the river in the large reservoir that is built high. The water from the high level in the dam is then carried through a pipe to the turbine that is situated at the bottom of the dam. The turbine then rotates and generates electricity. Construction of dams needs large areas and obstruct rivers.

14.2.4 — Improvements in the technology for using conventional sources of energy

With advancements in technology, we humans have found better and more efficient ways to harness the more sources from which the energy can be harnessed. This section of class 10 science chapter 14 sources of energy is dedicated to those methods.


Biogas is one of the best energy sources available to us. It has up to 75% methane, burns without any smoke (preventing air pollution), leaves no residue like when we burn woods it leaves ash as residue. One of the great things about bio-gas is that it has a high heating capacity making them an efficient energy source.

Wind energy

Like biogas, wind energy is also one of the best energy sources that are currently available to us. We use large windmills to harvest wind energy. Essentially, a windmill is just like a fan, though there are many differences between a fan and windmill, the main differences are, windmills are way bigger, and instead of electric energy, they use the wind to rotate, and of course, the fact that they generate electricity instead of using it.

Class 10 Science Chapter 14 Sources of Energy

So far in this writeup, we have learned about the conventional sources of energy, but there is more to class 10 science chapter 14 sources of energy as you will see while reading the alternate sources of energy in this section of this article.

# 14.3 — Alternative or non-conventional sources of energy

As our demand for energy is increasing day by day with advancements in technology, we desperately need not only to utilize efficiently the available energy sources but also discover new sources of energy so that our ever-increasing demand for energy could be met.

14.3.1 — Solar energy

Sun is an enormous source of energy. It has been there for billion years and will remain for many more. So, it’s just logical that we utilize its energy. This is why we humans have developed devices like solar cells, solar heaters, solar cookers, etc.

14.3.2 — Energy from the sea

Oceans and seas have so much to offer, there are different methods by which we can utilize the potential of seas and oceans. In this part of class 10 science chapter 14 sources of energy, we will learn all those methods and how they work.

Tidal energy

Tidal energy can be harnessed by constructing a dam across a narrow opening to the sea. In this, a turbine fixed at the opening of the dam converts the tidal energy to electricity. The problem with this energy source is, there are limited places where the narrow opening of the sea can be found.

Wave energy

As we know, the strong winds blowing across the sea generate waves in the sea. This wave energy can be harnessed by trapping the kinetic energy of huge waves just like tidal energy to generate energy. Again, the limitation to this method is, it can only be used in places where waves are very strong.

Ocean thermal energy

When sun rays fall on the surface of the sea or ocean, it causes their surfaces to heat, but their deeper sections remain relatively cold. We can use this difference in temperature to generate electricity.

Class 10 Science Chapter 14 Sources of Energy

In this last section of class 10 science chapter 14 sources of energy, we will see some more energy sources which we can utilize. Also, we read about the consequences of harvesting energy from all the sources that are discussed in this chapter.

14.3.3 — Geothermal energy

Geothermal energy can be harnessed by exploiting hot springs. In this, the steam trapped in rocks is used to rotate the turbine which in turn generates electricity. There are very few places on earth where hot springs can be found making geothermal energy rare to harness.

14.3.4 — Nuclear energy

When the nucleus of a heavy atom can be split into lighter nuclei by bombarding it with low-energy neutrons. This process is called nuclear fission, and enormous energy is released during this process. Though nuclear plants give a tremendous amount of energy, these plants are very dangerous.

# 14.4 — Environmental consequences

So far we have seen so many energy sources and methods to produce energy from them. But, each method and source has its limitations, in one way or the other they cause harm to the environment. This proves the statement that we had made at the beginning of this article, ‘the usable form of energy is dissipated to the surroundings in less usable forms’.

# 14.5 — How long will an energy source last us?

If there is one thing that class 10 science chapter 14 sources of energy teaches us, it is that energy is precious, there is not much left of the fossil fuels that we are still so dependent on, and the new energy sources are not very efficient so far. So, we have to be very efficient while using the sources of energy.

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