Non-Conventional Sources of Energy

Non-conventional sources of energy refer to those energy sources that are replenished continuously by natural processes and are widely available. Till now, these sources are not used extensively in the world. They are infinite, natural and can be restored. For example, solar energy, wind energy, tidal energy, bio-gas, and more. They do not cause pollution so they can be used for generating clean energy with minimal waste.

Why is non-conventional energy needed?

The consumption of energy is growing day by day and we depend more on fossil fuels or conventional energy sources (coal, petroleum, etc.) than non-conventional energy sources for our energy requirements. If we keep using fossil fuels at this rate they will be depleted completely in the next few hundred years and their price will be more in the coming years. So, we need to rely more on renewable (non-conventional) sources of energy and need focus on the optimum use of non-renewable (conventional) sources of energy. The govt. of India also established a separate department for the effective exploitation of non-conventional (renewable) sources of energy.

Here is the list of some of the major non-conventional sources with their detailed description.

1. Tidal Energy

As the name suggests, it is the renewable or non-conventional energy that is produced from the natural rise and fall of ocean tides. In simple words, the flow of water during the tides produces tidal energy.

The tides are produced when Earth, the sun and the moon interact gravitationally. In Tidal power plants, the energy of tides is converted into electricity. These plants are set up in areas where the sea experiences frequent waves and tides.

Advantages of Tidal Energy

• The occurrence of tides is predictable and is uniform due to gravitational forces. Whether the tide is high or low is needed to assess only. So, efficient systems to generate tidal energy can be designed easily.
• Continuous advancement in technology will make generating tidal energy cheaper and more efficient.
• It helps prevent coastal flooding. For example, a tidal lagoon can bear 1 in 500 storm surges and waves in a year.
• The equipment and machinery used in the tidal lagoon last longer and are more cost-effective than other equipment used in other non-conventional energy-based power stations.
• Tidal power plants do not release greenhouse gases while generating electricity.
• Water is denser than air, so a large amount of electricity can be generated through tidal power plants.

Tidal Energy Disadvantages:

It also has some limitations that prevent from making the most of tidal energy, such as;

• The construction of tidal power plants is very expensive as of now.
• It also causes some environmental issues such as habitat change due to tidal barrages.
• The repair and maintenance of tidal power plant are not costly and not easy.
• The production of energy is predictable but it is not steady.

2. Wind Energy

It is the energy that is obtained from the wind. The kinetic energy of wind can be used by converting it into mechanical energy such as in a windmill. In ancient times, wind energy was used in propelling ships. Today, wind energy is used for various purposes such as electricity generation wherein the kinetic energy of wind is used to move a wind turbine, a device that uses wind energy to generate electricity. The wind moves the blades of a turbine that are connected to a rotor, which spins a generator to produce electricity.

Advantages of Wind Energy

• It is renewable energy that can be used extensively.
• It does not pollute the air or cause global warming as it does not release any harmful gas.
• It requires less land surface and land between windmills can be used for other purposes such as agriculture, horticulture, etc.

Disadvantages of Wind Energy

• It requires a specific location to set up a windmill, also it can be installed only where there are strong winds.
• Its repair and maintenance are costly and are not easy.
• It is prone to damage caused by storms and cyclones.
• Wind sites are located in remote locations very far from the cities where electricity is required.
• Wind plants may affect local wildlife and turbines may also cause noise pollution.

3. Solar Energy

It is the energy that we get from the sun, which is the biggest source of energy for us. Sun radiates very high energy constantly. Solar energy is widely harnessed in solar plants wherein solar energy is converted into electrical energy or used to generate electricity. Life on earth is not possible without solar energy, for example, green plants need sunlight to prepare their food through photosynthesis. It is clean energy as it does not cause any pollution and is also abundantly available.

Uses of Solar Energy

• It is used in solar heaters to heat water.
• Solar cells convert solar energy into electricity.
• The solar cooker that is used to prepare food also uses solar energy to generate heat.

Advantages of Solar Energy

• Solar panels or cells need less maintenance and can last up to 25 years.
• They can store electricity produced from solar energy.
• It is very important for space missions as all satellites use solar energy.

Disadvantages of Solar Energy

Silicon is used in solar cells. Although it is abundantly available, the premium quality silicon is very costly due to this the cost of installing solar panels is very high.

4. Geothermal Energy

It refers to the energy obtained from the heat produced deep inside the Earth. It is present in the rocks and fluids present beneath the surface of Earth. The hot molten rock called magma also produces this heat. This underground source of heat can be used to generate energy such as electricity.

Advantages of geothermal energy

• It is free and abundantly available. It is limitless renewable energy with an estimated lifespan of 4 billion years.
• It is non-polluting as it does not release any harmful gases, unlike fossil fuels. Further, it does not leave any residue or by-products behind.
• Its use generates employment, and a large number of the skilled and unskilled workforce is required at geothermal power plants.
• It can be used directly. For example, in cold countries, it is directly used for melting ice on roads, heating houses, heating water for bathing or washing purposes, and more.

Disadvantages of geothermal energy

• The transportation of geothermal energy is not easy. It can be used effectively only in nearby areas. Further, during transmission, it may release harmful gases into the atmosphere.
• Its installation of geothermal power plants is very expensive as it requires huge investment-related to machinery and manpower.
• Extensive research is required before installing a geothermal power plant. The underground site may run out of heat over a period of time due to a fall in the temperature due to the irregular inlet water supply.
• The process of drilling to reach deep under the earth may release toxic gases into the nearby atmosphere, which may also affect the health of workers involved in this work.

5. Biomass Energy

It is the energy obtained from living or once-living organisms. The commonly used biomass for energy are plants, woods, animals, etc. This energy can be burned to produce heat or can be converted into electricity. Biomass is organic material as it contains carbon compounds and comes from living organisms for example waste and dead remains of plants and living organisms.

Further, biomass chemical composition is different in different species, however, mostly it comprises 25% lignin and 75% carbohydrates (sugars).

Biomass energy is in use since ancient times when cavemen first made fire from wood for cooking and keeping warm. Today also, humans burn wood and cattle dung for cooking purposes. However, it is not environmentally friendly as it produces smoke and harmful gases that pollute the atmosphere.

Advantages of Biomass Energy

• It makes use of organic waste for energy such as fuels.
• It makes us less dependent on fossil fuels which may increase the life of fossil fuels.
• The use of biomass to produce energy is very cost-effective and requires less maintenance.
• It is environmentally friendly as carbon is not released into the atmosphere when fossil fuels are burned such as biogas. However, if we burn bio-waste, carbon is produced.

Disadvantages of Biomass Energy

• It produces methane gas which leads to the greenhouse effect and global warming.
• It is less effective than fossil fuels.
• It requires more space to set up a biogas plant.