Energy Resources Notes

Nonrenewable Energy Resources

  • Exist in limited quantities.

  • Cannot be replaced except over many years.

  • Examples:

    • Oil

    • Natural gas

    • Coal

    • Uranium

  • Fossil fuels:

    • Formed underground from the remains of once-living organisms.

    • Account for the great majority of the world’s energy use.

Renewable Energy Resources

  • Can be replaced in a relatively short period of time.

  • Most originate either directly or indirectly from the sun.

  • Not distributed evenly throughout the world.

  • Examples:

    • Hydroelectric

    • Solar

    • Geothermal

    • Wind

    • Biomass

    • Nuclear fusion

Solar Energy

  • Sun and Earth are constantly releasing large amounts of energy.

  • This energy could be used for generating electric power, heating buildings, or other purposes.

  • Sunlight converted into usable energy is called solar energy.

  • Passive solar designs: sunlight heats a building without using machinery.

  • Active solar energy systems: sunlight heats flat collection plates through which water flows.

  • Sunlight can also be converted directly into electrical energy by means of solar cells, also known as photovoltaic cells.

  • A few large solar electric plants use mirrors that concentrate sunlight to produce electricity.

  • The benefits of solar energy depend on the climate.

Geothermal Energy

  • Thermal energy beneath Earth’s surface.

  • In some regions, especially near volcanoes, geothermal energy is used to generate electricity.

  • Geothermal energy is non-polluting but is not widely available.

Other Renewable Resources

  • Biomass energy: The chemical energy stored in living things.

    • Biomass can be converted directly into thermal energy or converted into a high-energy alcohol fuel.

  • Hydrogen fuel cell: Generates electricity by reacting hydrogen with oxygen.

    • Hydrogen fuel cells can be used to convert energy from renewable resources.

  • Nuclear fusion:

    • A form of hydrogen is the most likely raw material.

    • The process of fusion will probably produce little pollution or radioactive waste.

    • Scientists have been working on sustained fusion for years, but many challenges remain.

Energy Conservation

  • Energy resources can be conserved by

    • reducing energy needs

    • increasing the efficiency of energy use.

  • Energy conservation: Finding ways to use less energy or to use energy more efficiently.

  • Making appliances, cars, and even light bulbs more energy efficient is a way of reducing energy use.

  • Energy-efficient purchases often cost more initially but can save money in fuel costs over time.