Energy Resources

Energy Resources Overview

  • Earth has natural resources such as energy, water, and soil that are harnessed for sustainability.

Learning Targets

  • Explain how heat from inside Earth is tapped as a source of energy.

  • Explain how energy is harnessed from alternative sources such as water and geothermal heat.

  • Address environmental concerns related to energy use.

  • Recognize water distribution on Earth.

  • Explain human impact on water quality and availability.

  • Suggest ways to conserve and protect water resources.

  • Describe how people generate different types of waste in everyday life.

  • Cite ways to reduce waste at home, school, and community.

Energy Resources Types

Renewable Energy Sources

  • Governed by RA 9513 (Renewable Act of 2008) in the Philippines.

  • Includes:

    1. Biomass

    2. Solar

    3. Wind

    4. Hydropower

    5. Geothermal

    6. Ocean

Hydropower

  • Utilizes the kinetic energy of falling or running water to turn a generator.

  • Output energy depends on the flow and height of the water.

Hydropower Mechanism

  • Dams serve as reservoirs of water.

  • Gravity converts potential energy into mechanical energy as water falls through a penstock.

  • Moving water strikes turbine blades, rotating the generator.

Pros and Cons of Hydropower

  • Pros:

    • Non-polluting.

  • Cons:

    • Requires a dam and reservoir.

    • Obstructs fish migration.

    • Alters natural water systems.

    • Affects wildlife and agricultural lands.

    • Can displace local populations.

Ocean Power

Types of Ocean Energy

  1. Wave

  2. Tide

  3. Ocean Thermal Energy Conversion (OTEC)

Ocean Power Details

  • Kinetic Energy from Waves:

    • Pros:

      • Nonpolluting, free, and little land space needed.

    • Cons:

      • High cost, storm vulnerability, potential aquatic life disturbances.

  • OTEC Mechanism:

    • Utilizes the temperature difference between surface and deep ocean water.

    • Low-boiling point fluid vaporizes, expands, and spins a turbine.

OTEC Pros and Cons

  • Pros:

    • Available year-round and produces freshwater.

  • Cons:

    • Not feasible in all regions, high costs.

Geothermal Energy

Geothermal Gradients

  • Direct relationship between temperature rise and depth within the Earth.

Types of Geothermal Energy Systems

  1. Dry Steam - Directly uses geothermal steam.

  2. Flash Steam - Most common, uses high-pressure hot water that turns into steam.

  3. Binary Steam - Uses lower temperature water to heat another liquid.

Geothermal Energy Advantages

  • Minimal land and freshwater use,

  • Nearly zero emissions.

Environmental Concerns

  • Potential for environmental damage from certain materials.

Solar Energy

Methods of Harnessing Solar Energy

  1. Photovoltaic Cells - Directly convert sunlight into electricity.

  2. Concentrated Solar Power - Uses sun's energy as heat source to drive steam turbines.

Solar Energy Pros and Cons

  • Pros:

    • Limitless, free, noise-free, low maintenance.

  • Cons:

    • Inconsistent, high costs, requires large areas, environmental pollutants.

Wind Energy

Wind Energy Mechanism

  • Air motion creates pressure gradients that power wind turbine generators.

Wind Energy Applications

  • Hybrid Systems: Combine wind with photovoltaic cells.

  • Wind Pumps: Transform kinetic energy to lift water.

Wind Energy Pros and Cons

  • Pros:

    • Unlimited supply, low maintenance, no greenhouse gases.

  • Cons:

    • High initial investment, impact on bird populations.

Nonrenewable Energy

Overview

  • Nonrenewable sources do not replenish within a human time frame:

    • Coal

    • Natural Gas

    • Petroleum

Coal Energy

  • Comprised of sedimentary rocks of organic materials.

  • Mainly burnt in boilers to produce steam that drives generators.

Natural Gas

  • Composed mostly of methane and cleanest among fossil fuels.

  • Forms from ancient microorganisms and organic matter.

Petroleum

  • Formed from diatoms, involving kerogen and bitumen processes.

Environmental Impact of Nonrenewables

  • Degradation of atmospheric quality due to emissions such as sulfur oxide and carbon dioxide.

Environmental Laws on Renewable Energy

  1. RA 913 - Promotes development and utilization of renewable energy for self-reliance and emission reduction.

  2. RA 8749 - Philippine Clean Air Act aimed at pollution prevention and healthy ecology.

Exam Questions Highlights

  1. Advantage of Renewable Energy Sources:

    • d) Generate electricity without greenhouse gas emissions.

  2. Renewable Energy Source from Ocean Tides:

    • a) Tidal Energy.

  3. Reason Nonrenewables are Still Used:

    • a) Reliability and ease of storage and transport.

  4. Nonrenewable Energy Source for Transportation:

    • d) Petroleum.