Energy Concepts and Resources in Environmental Science

Introduction to Energy

  • Energy: Capacity to do work or move matter.
  • Work: Transfer of energy to or from an object.
  • Power: Rate of energy flow; rate at which work is done.
  • 1 Watt = 1 Joule/second.
  • Kilowatt-hour (kWh): Amount of energy delivered in one hour.

Forms of Energy

  • Radiated Energy: Energy travelling in waves.
  • Thermal (Heat) Energy: Energy of moving atoms or molecules.
  • Mechanical Energy: Energy from an object's motions and forces acting on them.
  • Kinetic Energy: Energy due to motion.
  • Potential Energy: Energy due to position.

Types of Potential Energy

  • Chemical Energy: Stored in chemical bonds.
  • Electrical Energy: From charged particles (e.g., electrons).
  • Nuclear Energy: Stored in the atomic nucleus due to strong forces.
  • Gravitational Energy: Energy stored due to height in a gravitational field.
  • Elastic Energy: Energy stored in objects that can be stretched or compressed.

Major Energy Resources

Renewable Energy Sources
  • Hydropower
  • Solar Energy
  • Wind Energy
  • Geothermal Energy
  • Biomass Energy
Non-Renewable Energy Sources
  • Fossil Fuels: Derived from the incomplete decomposition of biomass through heat and pressure over millions of years.
  • Includes oil, coal, and natural gas.

Fossil Fuels

Coal Formation
  • Formed from giant plants that died in swamps millions of years ago, buried under water and dirt, turning into coal due to heat and pressure.
  • Types of Coal:
  • Lignite: 25-35% carbon content.
  • Sub-bituminous Coal: 35-45% carbon content.
  • Bituminous Coal: 45-85% carbon content.
  • Anthracite: >85% carbon content.
Petroleum (Oil)
  • Formed from tiny marine plants and animals buried under layers of silt and sand over millions of years, transforming into oil and natural gas.
  • Products from crude oil:
  • 47% gasoline, along with lubricants, plastics, etc.
Natural Gas
  • Formed during the maturation of oil, primarily composed of methane (CH₄) along with propane (C₃H₈) and butane (C₄H₁₀).
  • Extraction methods include hydraulic fracturing (fracking) which has risks such as groundwater contamination and high water usage.

Advantages and Disadvantages of Fossil Fuels

Advantages

  • Established technology with existing infrastructure.
  • Easily accessible and affordable.
  • Reliable energy source.
  • Creates employment opportunities.

Disadvantages

  • Environmental issues such as emissions and climate change.
  • Health hazards due to pollution.
  • Finite resources that are being depleted faster than they are formed.

Nuclear Energy

  • Chemical Energy: Energy stored in chemical bonds.
  • Nuclear Energy: Energy resulting from nuclear reactions, specifically fission.
  • Nuclear Fission: Splitting of heavy atomic nuclei (e.g., Uranium-235) into lighter nuclei, releasing a significant amount of energy.
  • Advantages include low emissions (mainly steam), high energy value per mass, while disadvantages involve radiation risks and the challenge of nuclear waste disposal.

Renewable Energy

  • Defined as energy obtained from natural and persistent flows of energy (sun, wind, water).
Primary Sources
  • Solar energy
  • Wind energy
  • Hydroelectric power
  • Geothermal power
  • Biomass and tidal energy.
Advantages and Disadvantages of Renewable Energy

Advantages

  • Infinite and sustainable energy sources.
  • Lower harmful emissions compared to fossil fuels.
  • Opportunities for remote energy supply.

Disadvantages

  • Reliability issues (cannot be 100% controlled).
  • Typically newer technology, potentially leading to hidden environmental costs.

Energy Issues in the Philippines

  • High fuel and generation costs.
  • Expensive renewable technologies.
  • Aging infrastructure.
  • Energy distribution inequities leading to frequent blackouts, especially in rural areas.