CBSE Class 10 Science Notes Chapter 14 Sources of Energy

To learn about renewable and non-renewable energy, fuel efficiency, and how they affect the environment, read the cbse class 10 sources of energy notes. This resource is a great explanation of cbse class 10 sources of energy because it covers fossil fuels, solar electricity, and nuclear energy.

As the global population grows, our demand for power increases every day. Understanding where this power comes from is a critical part of the class 10 science chapter 14 notes. The learner must learn to tell the difference between old ways, like burning coal, and new ways, like using solar energy. Use this article to quickly review cbse class 10 science chapter 14 or to learn more about the physics of power.

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CBSE Class 10 Science Notes Chapter 14

CBSE Class 10 Science Notes Chapter 14 is a great revision tool for CBSE Class 10 students about to appear for their CBSE class 10 science exams. Here are the detailed notes with simple explanations:

Energy and Its Sources

Energy is the inherent ability to carry out tasks or the collective power obtained from our natural reservoirs. It manifests in diverse forms, capable of transformation between different states. Usable energy, when employed, disperses into less usable forms within the environment. Predominantly sourced from natural elements like the sun, oceans, fossil fuels, and wind, energy undergoes conversion into electrical forms integral to our daily activities. This conversion process facilitates the harnessing of energy from its primary origins, ensuring its applicability for various needs. In essence, the dynamic nature of energy allows it to exist in multiple forms, sustaining life and powering human activities through its continuous transformation and utilisation.

Renewable and Non-Renewable Sources of Energy

Energy can be broadly categorised into two main types: renewable and non-renewable. Non-renewable resources, such as coal, nuclear energy, and oil, are finite and require extended periods to replenish. These sources are limited and can lead to depletion over time. On the other hand, renewable energy sources, often referred to as clean energy, are continually replenished by natural processes. Examples of renewable energy include solar and wind energy, which harness the power of the sun and wind, respectively.

Unlike non-renewable sources, renewable energy has the advantage of being sustainable and doesn't deplete over time. The utilisation of renewable energy aligns with environmentally conscious practices, offering a more sustainable and eco-friendly alternative to non-renewable sources. As the world faces increasing concerns about resource scarcity and environmental impact, the promotion and adoption of renewable energy sources become crucial for a sustainable energy future.

A Good Source of Energy

Sources can be categorised as renewable and nonrenewable. A good source of energy doesn't get used up quickly and is often called renewable.

What Is Good Fuel?

An ideal source of energy should be easily available, simple to store and transport, capable of doing a lot of work per unit mass and volume, and economical.

Conventional Sources of Energy

Energy sources that have been in use for a long time or widely adopted globally are conventional sources. Wood and coal are common sources of heat energy. Examples: Fossil fuels, hydropower. Conventional sources are commercial and non-commercial.

Fossil Fuels

Fossil fuels form from the compression of dead organic matter over millions of years. We heavily depend on them for our work. However, they are non-renewable and finding alternatives is crucial to avoid an energy crisis.

Disadvantages of Burning Fossil Fuels

Burning fossil fuels produces byproducts causing air pollution, leading to acid rain and the greenhouse effect. Gases emitted contribute to global warming.

Thermal Power Plants

These plants burn fossil fuels to produce electricity. Steam generated from burning coal moves turbines, generating electricity. They are often located near coal or oil fields for easier transmission.

Hydropower Plants

Hydropower plants harness energy from flowing water by strategically positioning turbines, which convert the kinetic energy of the water into electricity. These plants are commonly situated in close proximity to dams or waterfalls, where the natural movement of water is substantial and efficiently utilised to generate electrical power.

Turbines

Turbines are mechanical devices that harness kinetic energy by rotating. They efficiently convert this energy into useful work, typically accomplished through a dynamo. Essential components in power plants, turbines play a crucial role in electricity generation by utilising various energy sources to drive their rotation and produce electrical power.

Dams

Dams are constructed as barriers to impound water, creating reservoirs. The stored water's gravitational potential energy is harnessed to generate hydroelectricity. As water is released, it flows through turbines, converting kinetic energy into electrical energy. Dams play a crucial role in sustainable energy production by facilitating the controlled release of water, ensuring a continuous and reliable source for hydroelectric power generation.

Fuels

Biomass is derived from living things. In India, cow dung is used for fuel due to the abundant livestock population. Biogas is produced by decomposing cow dung and plant matter in a digester.

Wind Energy

Wind energy is an environmentally friendly source generated by harnessing the kinetic energy of wind using windmills.

Advantages and Limitations of Wind Energy

Advantages: Environment-friendly, efficient, renewable. Limitations: Requires constant wind speeds, backup storage, large land areas, high initial costs, and regular maintenance.

Solar Energy

Solar energy is light and heat from the sun. Solar cookers and water heaters use solar energy. Solar cells convert solar energy into electricity. Advantages: No moving parts, require little maintenance, can be set up in remote areas. Disadvantages: Requires special-grade silicon, uses expensive silver for interconnections.

Energy from the Sea

Seas and oceans are sources of kinetic and potential energy.

Tidal Energy

Tides, caused by the moon's gravitational pull, produce tidal energy. Dams constructed near sea openings harness this energy.

Wave Energy

Wave energy captures the kinetic energy generated by ocean waves, converting it into electricity. This method is effective in regions with robust wind patterns that produce substantial wave activity. However, the practical implementation of wave energy is constrained to locations where strong winds consistently generate significant wave power.

Ocean Thermal Energy

Ocean Thermal Energy exploits temperature variations in ocean water to generate power. By utilising the contrast between surface and deep-water temperatures, this renewable energy source taps into the natural heat gradient of the oceans. Warm surface water is used to vaporise a substance, typically ammonia, which then drives turbines to produce electricity. As the vapour condenses with cold deep-sea water, a continuous cycle is created. This eco-friendly method harnesses the immense thermal potential of the ocean, providing a sustainable energy solution with minimal environmental impact.

Geothermal Energy

Geothermal energy taps into Earth's internal heat by utilising steam produced from underground hotspots. This steam, emerging from the Earth's interior, is employed to drive turbines, converting the thermal energy into electricity.

Nuclear Energy

Nuclear energy harnesses the power of nuclear fission within reactors to generate electricity. In this process, the nucleus of a heavy atom, such as uranium or plutonium, is bombarded with neutrons, causing the atom to split and release an immense amount of energy. The released energy manifests as heat, which is then used to produce steam from water. This steam, in turn, drives turbines connected to generators, ultimately generating electricity. Nuclear fission stands out as a highly efficient means of electricity production due to the substantial energy release from a single fission event. However, it comes with challenges, including the management of radioactive waste and concerns over safety. Despite these issues, nuclear energy contributes significantly to global electricity generation, providing a continuous and reliable power source with a minimal environmental footprint compared to certain fossil fuels. The controlled nature of nuclear fission in reactors enables a consistent and potent supply of electricity to meet the demands of various industries and households.

Disadvantages of Using Nuclear Energy

The drawbacks of utilising nuclear energy are multifaceted. Firstly, the management of nuclear waste poses a significant hazard, given its radioactive nature, necessitating secure long-term disposal solutions. Secondly, the establishment and maintenance of nuclear facilities involve substantial costs, making nuclear energy economically challenging. Furthermore, the finite availability of uranium, a key nuclear fuel, raises concerns about long-term sustainability. Additionally, the potential for the destructive misuse of nuclear technology, such as in the development of weapons, adds a critical layer of global security apprehension. These disadvantages underscore the need for stringent safety measures, effective waste management strategies, and continuous exploration of alternative, more sustainable energy sources.

Nuclear Fusion

Nuclear fusion is a process where lighter atomic nuclei, typically isotopes of hydrogen, combine to form a heavier nucleus, releasing a substantial amount of energy. Unlike nuclear fission, which involves splitting heavy nuclei, fusion harnesses the same powerful reaction occurring in the sun. The most prevalent fusion reaction involves isotopes of hydrogen, deuterium, and tritium, fusing to create helium and releasing energy. The key advantage of nuclear fusion lies in its potential for generating vast amounts of clean and sustainable energy. It produces minimal radioactive waste compared to nuclear fission, reducing environmental concerns. The fusion process mimics the sun's energy production, making it an abundant and virtually limitless source. Combining lighter nuclei to produce a heavier nucleus releases a vast amount of energy. The mass deficit is given by Einstein's equation E=mc2.

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What is a Good Source of Energy in Class 10 Chapter 14?

Before categorising energy, we must define what makes a source "good." According to the sources of energy class 10 notes, an ideal source of energy should possess the following qualities:

• High Calorific Value: It should produce a large amount of heat per unit mass or volume.

• Easy Accessibility: It should be easy to obtain and transport.

• Economical: The cost of extraction and use should be low.

• Eco-friendly: It should produce minimum smoke or toxic residues.

Classification in Chapter 14 Sources of Energy

There are two main groups of energy sources based on how they are used and how easy they are to get.

1. Conventional Sources of Energy

These are traditional sources that have been there for a long time and can't be used again.

• Fossil Fuels: Natural gas, coal, and oil are fossil fuels. They take millions of years to produce and are limited. One big problem with cbse class 10 sources of energy notes is that burning them makes the air dirty and warms the planet.

• Thermal Power Plants: These make steam from fossil fuels, which powers turbines to make electricity.

• Hydro Power Plants: Hydroelectric power plants turn the potential energy of falling water into electricity. While it is renewable, building large dams can disturb local ecosystems.

• Biomass: Using organic matter like wood and cow dung. Modern versions include Biogas, which is an excellent fuel with high heating efficiency.

2. Non-Conventional (Alternative) Sources

As fossil fuels deplete, we turn to these renewable alternatives:

• Solar Energy: Solar energy is the process of turning sunlight directly into electricity using solar cookers or solar cells made of silicon.

• Wind Energy: Making electricity with wind turbines in places where the wind blows at least 15 km/h.

• Tidal and Wave Energy: Using the movement of the water to create energy.

• Geothermal Energy: Geothermal energy is the heat that is trapped inside the Earth's crust.

• Nuclear Energy: Energy released through nuclear fission or fusion. While highly efficient, it carries risks of radiation leaks and waste disposal issues.

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Energy Transformation Summary Table of Chapter 14 Sources of Energy

Let’s have a summary to understand the energy transformation from the source to a new form and the advantage & disadvantage of doing the same. 

Environmental Consequences in CBSE Class 10

A key part of any sources of energy class 10 summary is the impact on our planet. No source of energy is 100% "clean." For example, while solar cells are clean during use, their manufacturing involves chemicals. Similarly, while wood is renewable, large-scale cutting leads to deforestation. The goal of modern science is to find a balance where we meet our needs while minimising the damage to the environment.

How Long Will Energy Sources Last?

We can also classify sources as:

1. Renewable: Sources that can be replenished (Sun, Wind, Water).

2. Non-renewable: Sources that will eventually run out (Coal, Petroleum, Natural Gas).

Students should focus on cbse class 10 science chapter 14 revision notes that highlight the transition from non-renewable to renewable energy as a necessity for a sustainable future.

Read More: NCERT Solutions for Class 10 Science Chapter 14 Sources of Energy

CBSE Class 10 Science Notes Chapter 14 FAQs

1. Why is Biogas considered an excellent fuel?

Biogas (mostly methane) burns without smoke, leaves no residue like ash, and has a high heating capacity. It is a brilliant way to manage farm waste.

2. What are the limitations of solar energy?

The main limitations are the high cost of silicon used in cells and the fact that it is not available at night or during cloudy weather.

3. What is the minimum wind speed required for a wind energy farm?

To maintain the required speed of the turbine for electricity generation, the wind speed should be higher than 15 km/h.

4. How is nuclear energy generated?

It is generated via nuclear fission, where the nucleus of a heavy atom (like Uranium) is split into lighter nuclei, releasing a tremendous amount of energy.

5. What is the "Greenhouse Effect" mentioned in sources of energy class 10 notes?

The greenhouse effect is caused by the accumulation of gases like carbon dioxide (from burning fossil fuels) in the atmosphere, which traps heat and leads to global warming.