MP Board · Class 10 · Science · Sources of EnergyWhat are non-conventional sources of energy? Why is there a growing emphasis on shifting from conventional to non-conventional energy sources? Discuss any three non-conventional energy sources in detail.

Introduction to Non-Conventional Sources of Energy\nNon-conventional sources of energy are those energy sources that are renewable, inexhaustible, eco-friendly, and generally derived from sources like the sun, wind, biomass, tides, and geothermal heat. Unlike conventional sources (such as coal, petroleum, and natural gas), they do not deplete with continuous usage and cause little to no environmental pollution.

Need to Shift from Conventional to Non-Conventional Sources\nThe growing emphasis on shifting to alternative energy sources is driven by several critical factors:

• Depletion of Fossil Fuels: Conventional sources like coal and petroleum are exhaustible and will eventually run out within the next few decades.
• Environmental Pollution: Burning fossil fuels releases harmful greenhouse gases like carbon dioxide, sulfur dioxide, and nitrogen oxides, which cause global warming, acid rain, and severe respiratory health issues.
• Energy Security: Many countries depend heavily on imported fossil fuels, making their economies vulnerable to price fluctuations. Non-conventional sources are locally available and enhance energy independence.
• Sustainability: Non-conventional sources provide a clean, continuous, and sustainable supply of energy for future generations.

Detailed Discussion of Three Non-Conventional Energy Sources

1. Solar Energy:

   • Source and Principle: The sun is the ultimate source of energy on Earth. Solar energy is harnessed directly using photovoltaic (PV) cells (solar cells) made of silicon, which convert sunlight directly into electricity.
   • Applications: Used in solar cookers, solar water heaters, street lighting, and calculators. Large-scale solar power plants generate electricity for remote and urban areas.
   • Advantages: It is abundantly available, infinite, and maintenance-free once installed.

2. Wind Energy:

   • Source and Principle: High-speed winds possess kinetic energy. When wind blows over the blades of a wind turbine, it rotates the turbine connected to an electric generator, producing electricity.
   • Applications: Wind farms are established in coastal areas, open grasslands, and hilltops where wind blows steadily. Used for pumping water and generating electricity.
   • Advantages: Completely pollution-free and generates electricity without consuming water.

3. Biomass Energy:

   • Source and Principle: Biomass refers to organic matter derived from plants and animal waste (cow dung, agricultural residues, crop waste). In a biogas plant, anaerobic microorganisms break down biomass in the absence of oxygen to produce biogas (mainly methane) and high-quality manure.
   • Applications: Used extensively in rural areas for cooking and lighting, substituting firewood and LPG.
   • Advantages: It provides an efficient way of waste disposal, reduces pollution, and produces excellent organic fertilizer as a byproduct.