Non-Conventional Energy Archives

21. Which one of the following is a conventional energy source ?

Which one of the following is a conventional energy source ?

Tidal energy

Geothermal energy

Solar energy

Biomass energy

This question was previously asked in

UPSC NDA-1 – 2016

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Conventional energy sources are generally considered to be those that are well-established, widely used on a large scale, and often (though not always) exhaustible. This category typically includes fossil fuels (coal, oil, gas), nuclear energy, and large-scale hydropower. Non-conventional or renewable energy sources are those that are naturally replenished and often rely on newer technologies for large-scale exploitation, such as solar, wind, tidal, geothermal, and modern biomass.
Among the given options, Tidal, Geothermal, and Solar energy are unequivocally classified as non-conventional/renewable energy sources. Biomass energy, particularly in the form of traditional uses like burning wood for fuel, has been used by humans for millennia and represents a long-established energy source, though often referred to as ‘traditional non-commercial’ energy. While modern biomass energy (e.g., bioelectricity, biofuels) is considered renewable/non-conventional, the term ‘biomass energy’ can encompass traditional use. In the context of the options provided, biomass has the longest history of widespread conventional use compared to the other listed sources, making it the most likely intended conventional source among these options, despite modern classifications.

– Conventional energy sources: Fossil fuels, Nuclear, Large Hydro.
– Non-conventional/Renewable energy sources: Solar, Wind, Tidal, Geothermal, Biomass, Small Hydro.
– The classification can sometimes be nuanced, especially regarding traditional biomass use versus modern biomass technologies.

Biomass energy refers to energy derived from organic matter. Its use ranges from traditional burning of wood and agricultural waste (especially in rural areas) to modern technologies like biogas plants, biomass power plants, and biofuel production. The long history of traditional biomass use contrasts with the relatively recent large-scale development of solar, wind, tidal, and geothermal power generation technologies. This historical context likely explains its inclusion as a potential ‘conventional’ source in this specific question, even though it falls under the ‘renewable’ category in modern classifications.

22. Which one among the following is a source of non-renewable energy ?

Which one among the following is a source of non-renewable energy ?

Geothermal energy

Nuclear energy

Biomass

Hydropower

This question was previously asked in

UPSC Geoscientist – 2024

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Nuclear energy is considered a source of non-renewable energy because it relies on finite natural resources, primarily uranium, which is mined and processed. Once the usable uranium is depleted, it cannot be naturally replenished on a human timescale.

– Non-renewable energy sources are those that exist in a fixed amount or are consumed faster than they can be replenished naturally. Examples include fossil fuels (coal, oil, natural gas) and nuclear fuels (uranium).
– Renewable energy sources are replenished naturally over short periods. Examples include solar, wind, geothermal, hydropower, and biomass.

While nuclear energy is non-renewable, it is often considered a low-carbon energy source because the process of generating electricity does not produce greenhouse gases. However, concerns exist regarding nuclear waste disposal and potential accidents.

23. Which one of the following is not a non-renewable energy source?

Which one of the following is not a non-renewable energy source?

Coal

Oil

Sunlight

Nuclear fuel

This question was previously asked in

UPSC Geoscientist – 2023

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Sunlight is not a non-renewable energy source.

Non-renewable energy sources are those that exist in a fixed amount and are consumed much faster than nature can replenish them. Coal, Oil (Petroleum), and Nuclear fuel (like Uranium) are considered non-renewable. Sunlight, however, is a continuously available resource on a human timescale, making it a renewable energy source.

Renewable energy sources are replenished naturally and include solar, wind, hydro, geothermal, and biomass energy. They are considered sustainable alternatives to fossil fuels and nuclear energy.

24. Which one of the following is NOT a renewable source of energy?

Which one of the following is NOT a renewable source of energy?

Wind

Sunlight

Nuclear minerals

Biofuels

This question was previously asked in

UPSC Geoscientist – 2020

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The correct answer is Nuclear minerals.

Renewable energy sources are those that are replenished naturally on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Wind energy, solar energy (from sunlight), and biofuels (derived from biomass that can be regrown) are examples of renewable energy sources. Nuclear minerals, such as uranium, are finite resources extracted from the Earth’s crust and are consumed in nuclear fission reactions to produce energy, making nuclear power (based on fission) a non-renewable source.

While nuclear power is low-carbon once operational, the fuel source (uranium) is not renewable in the same way as solar or wind energy. Nuclear fusion power, if it becomes commercially viable, would use more abundant fuels like hydrogen isotopes.

25. Recently, India’s first green hydrogen-based advanced fuel cell electr

Recently, India’s first green hydrogen-based advanced fuel cell electric vehicle (FCEV) was launched. It has no tailpipe emissions other than

Hydrogen peroxide

Nitrogen

Oxygen

Water

This question was previously asked in

UPSC CDS-2 – 2022

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A fuel cell electric vehicle (FCEV) powered by hydrogen uses a fuel cell to convert hydrogen and oxygen into electricity, which powers the vehicle’s motor. The primary byproduct of this electrochemical reaction is water (H₂O). The tailpipe emission is essentially just water vapor.

– Fuel cells combine hydrogen (the fuel) and oxygen (from the air) in a chemical reaction to produce electricity, with water and heat as outputs.
– FCEVs are considered zero-emission vehicles at the tailpipe.

Hydrogen peroxide (H₂O₂) is a different chemical compound and is not produced in this process. Nitrogen is the main component of air but is not a product of the fuel cell reaction. Oxygen is consumed in the reaction, not emitted.

26. Which one among the following is a non-conventional source of energy?

Which one among the following is a non-conventional source of energy?

Petroleum

Coal

Radioactive elements

Solar energy

This question was previously asked in

UPSC CDS-2 – 2020

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Solar energy is considered a non-conventional or renewable source of energy.

Conventional energy sources are typically fossil fuels (coal, petroleum, natural gas) and nuclear energy, which are finite or use processes developed conventionally. Non-conventional sources are renewable and environmentally friendly, such as solar, wind, geothermal, tidal, and biomass energy.

Radioactive elements are used in nuclear power plants, which is often categorised as a conventional source due to its established technology and non-renewable fuel source (uranium).

27. Which one of the following statements about biogas is not correct ?

Which one of the following statements about biogas is not correct ?

It is mainly composed of methane gas.

It is a non-renewable source of energy.

It is formed by the decomposition of cow dung in the absence of oxygen.

It burns without smoke and leaves no residue.

This question was previously asked in

UPSC CDS-1 – 2022

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The statement that biogas is a non-renewable source of energy is incorrect. Biogas is considered a renewable source of energy.

Biogas is produced from the anaerobic decomposition of organic matter, such as cow dung, agricultural waste, and sewage. The process is continuous as long as organic waste is available. Its primary component is methane (typically 50-75%), along with carbon dioxide (25-50%) and trace gases. Biogas is a clean fuel that burns without smoke and leaves no residue.

Biogas generation helps in waste management and reduces greenhouse gas emissions compared to allowing organic waste to decompose naturally in open landfills. It can be used for cooking, heating, lighting, and generating electricity. Being derived from biomass which is replenished naturally, it is classified as renewable energy.