Energy Resources

Introduction

• Energy is defined as the capacity to do work. It exists in various forms such as solar, chemical, mechanical, electrical, thermal, and nuclear energy. All life processes depend on energy. On Earth, the Sun is the ultimate source of energy, directly or indirectly supplying the energy needed for plants, animals, humans, and natural cycles.
• Solar energy drives photosynthesis in plants, producing food, oxygen, and biomass. It powers the water cycle by evaporating water from oceans and lakes, forming clouds and rain. Even fossil fuels originated from prehistoric forests that grew using solar energy. Thus, every energy form can ultimately be traced back to the sun.
• As civilization advanced, humans learned to convert natural energy sources into usable forms. Chemical energy stored in food is released in our bodies. Manual labour and domestic animals still supply energy in many rural Indian agricultural systems. Electrical energy produced from hydropower, thermal power, and nuclear stations powers households, industries, and transportation today.

Types of Energy Resources

a) Solar Energy

• Solar energy comes directly from the sun’s radiation.
• Captured through solar panels, solar thermal collectors, and photovoltaic cells.
• Used for electricity, heating water, drying grains, and solar cookers.
• Advantage: Abundant and pollution-free.
• Limitation: Dependent on sunlight; requires high installation cost.

• Wind Energy
• Generated by converting the kinetic energy of wind into electricity using wind turbines.
• Works best in coastal areas, deserts, and open plains.
• Advantage: Clean, safe, and renewable.
• Limitation: Irregular wind speed; requires large land area.

• Hydropower (Hydroelectric Energy)
• Produced by the force of flowing or falling water turning turbines.
• Based on the water cycle, which is driven by the sun.
• India has major hydropower plants like Bhakra Nangal, Tehri, Sardar Sarovar.
• Advantage: Low operating cost, high efficiency.
• Limitation: Dam construction causes displacement, ecological impacts.

• Biomass Energy
• Derived from organic materials like: Wood, Cow dung, Crop residues, Agricultural waste
• Used for cooking, heating, and producing biogas.
• Advantage: Easily available in rural areas.
• Limitation: Excessive use of wood causes deforestation; incomplete burning produces smoke.

• Geothermal Energy
• Comes from the heat inside the Earth’s crust.
• Used for electricity generation and heating.
• Advantage: Very reliable and available 24×7.
• Limitation: Found only in selected regions (Iceland, Japan, parts of India like Manikaran).

• Tidal Energy
• Generated from the rise and fall of sea tides.
• Tidal energy plants convert tidal motion into electricity.
• Advantage: Predictable and consistent.
• Limitation: Very high cost; limited to coastal regions with strong tides.

General Advantages of Renewable Resources

• Environmentally friendly
• Pollution-free or low pollution
• Reduce greenhouse gas emissions
• Promote sustainable development
• Reduce dependence on fossil fuels

Limitations of Renewable Resources

• High initial cost (solar panels, wind turbines, dams)
• Require advanced technology
• Seasonal or location-specific (solar, wind, tidal)
• Energy storage challenges (batteries increase cost)

Non-Renewable Resources

Non-renewable resources are energy sources that exist in limited quantities and take millions of years to form. Once exhausted, they cannot be replenished within a human lifetime. These resources currently supply the major share of global energy but cause high environmental pollution and are responsible for climate change.

Non-renewable resources include fossil fuels and nuclear fuels.

• Coal

Formation: Formed from prehistoric plants buried under heat and pressure for millions of years. Known as a fossil fuel.

Types of Coal

• Anthracite (highest carbon, best quality)
• Bituminous
• Lignite
• Peat (lowest grade)

Uses

• Electricity generation in thermal power plants
• Industrial fuel for steel, cement, and brick industries
• Used in trains historically (steam engines)

Limitations

• Produces CO₂, SO₂, NOx, and particulate matter
• Causes global warming, acid rain, and severe air pollution
• Mining causes land degradation and deforestation

• Petroleum (Crude Oil)

Formation: Formed from marine plants and animals buried under sediment layers for millions of years.

Uses

• Major source for:
  • Petrol, diesel, kerosene
  • LPG, aviation fuel
  • Lubricants, waxes
  • Petrochemicals (plastics, fertilizers, synthetic fibers)

Importance: Backbone of transportation, automobiles, and industrial chemicals.

Limitations

• Reserves are limited and rapidly depleting
• Highly polluting (CO₂ emissions)
• Oil spills damage marine ecosystems
• Geo-political tensions over oil-rich regions

• Natural Gas

Composition

• Mainly methane (CH₄)
• Found with oil deposits or in gas fields

Uses

• Cleaner fuel for:
  • Cooking (PNG)
  • Electricity generation
  • Fertilizer industry (for manufacturing urea)
  • Industrial heating
  • CNG vehicles (reduced emissions)

Advantages: Burns cleaner than coal and oil. Produces less CO₂ and no ash

Limitations

• Still non-renewable
• Can cause methane leakage (potent greenhouse gas)
• Transport requires pipelines

• Nuclear Fuel (Uranium & Thorium)

Source: Uranium-235 and Thorium-232 (India has large thorium reserves)

Uses

• Used in nuclear reactors to produce electricity
• Nuclear fission releases a large amount of energy

Advantages

• Very high energy output from a small quantity of fuel
• No greenhouse gas emission during electricity production

Limitations

• Radioactive waste is extremely dangerous
• Risk of nuclear accidents (Chernobyl, Fukushima)
• Waste remains hazardous for thousands of years
• High cost and advanced technology needed

Growing Energy Needs

Energy use is directly linked to economic development. Modern strategies for development have measured progress using energy consumption as an index. However, high energy consumption has long-term negative environmental impacts.

Important global facts:

• Between 1950–1990, global energy demand increased fourfold.
• The world’s electricity demand doubled in the last 22 years.
• In 2000, global energy use was 9096 million tons of oil equivalent (MTOE)—an average of 1.5 tons per person.
• The Asia–Pacific region surpassed North America in energy consumption by 2005, and by 2020 consumes 40% more energy.

Energy demand continues to rise due to:

• Population growth
• Industrial expansion
• Urbanization
• Mechanized agriculture
• Increasing transportation needs

Global Energy Consumption Pattern

At the end of the 20th century, global commercial energy share was:

• Oil – 39%
• Coal – 24%
• Natural Gas – 24%
• Nuclear – 7%
• Hydro/Renewables – 6%

Oil remains the dominant global energy source.

Need for Sustainable Energy Use

To ensure long-term availability:

• Promote renewable energy (solar, wind, biogas, small hydel).
• Increase energy efficiency in appliances and industries.
• Reduce transmission losses.
• Adopt clean technologies in coal and oil industries.
• Encourage public transport instead of private vehicles.
• Educate people about energy conservation (switching off unused appliances).
• Develop effective systems for nuclear waste management.
• Promote energy-efficient agriculture (less chemical fertilizer use).