Introduction

• Energy is the ability to do work.
• A good source of energy is essential for daily activities such as lighting, cooking, transportation, and running industries.

• To identify an efficient energy source, certain characteristics must be met.

Characteristics of a Good Source of Energy

A good source of energy should:

• Have High Calorific Value:
  • It should produce a large amount of energy per unit mass or volume.
  • Example: 1 kg of coal produces more energy than 1 kg of wood.

• Be Economical:
  • It should be cheap and easily available to everyone.
  • Example: Solar energy is free after installation.

• Be Easily Accessible:
  • The energy source should be easy to transport, store, and use.
  • Example: Electricity can be transmitted through wires over long distances.

• Cause Minimal Pollution:
  • It should have low environmental impact, producing little or no pollution.
  • Example: Wind and solar energy are clean sources of energy.

• Be Safe to Use:
  • The energy source should be safe to handle, with minimal risk of accidents.
  • Example: LPG is safer compared to coal or kerosene.

• Be Renewable and Sustainable:
  • It should be renewable (replenished naturally) to ensure long-term availability.
  • Example: Solar, wind, and hydro energy are renewable.

• Have High Efficiency:
  • It should provide maximum energy output with minimum wastage.
  • Example: Electricity and natural gas are highly efficient.

Types of Energy Sources

• Conventional Sources of Energy:
  • Energy sources that have been used for a long time.
  • Examples:
    • Fossil fuels: Coal, Petroleum, Natural gas
    • Firewood

• Non-Conventional Sources of Energy:
  • Modern, renewable, and eco-friendly sources of energy.
  • Examples:
    • Solar energy
    • Wind energy
    • Hydroelectric energy
    • Geothermal energy

Comparison of Energy Sources

Criteria	Fossil Fuels	Renewable Energy
Availability	Limited (non-renewable)	Unlimited (renewable)
Pollution	Causes pollution	No pollution
Cost	Relatively cheaper	High initial setup cost
Sustainability	Unsustainable	Sustainable
Energy Output	High	Moderate to High

Examples of Good Energy Sources

• Solar Energy:
  • Derived from sunlight, clean and renewable.

• Wind Energy:
  • Generated by wind turbines, eco-friendly.

• Hydroelectric Energy:
  • Produced from water flowing in dams.

• Natural Gas:
  • Cleaner than coal and petroleum, with high calorific value.

Why Should We Shift to Renewable Energy?

• Fossil fuels are depleting at a fast rate.
• Burning fossil fuels causes air pollution and global warming.

• Renewable sources are sustainable and reduce environmental damage.
• The future relies on clean energy to ensure environmental balance.

Key Terms to Remember

• Calorific Value: The amount of heat energy produced by burning 1 kg of fuel.

• Sustainable: Energy sources that do not get depleted over time.

• Renewable Energy: Energy that is naturally replenished.

• Non-Renewable Energy: Energy sources like coal and oil that are limited.

Conclusion

A good source of energy should be efficient, economical, accessible, and eco-friendly. Shifting to renewable energy sources is essential for a sustainable future.