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ENERGY RESOURCES
CHAPTER 7
THE ENERGY WE USE
• The sun which is about 150 million kilometers
away.
• The light we receive takes about 8 minutes to
get here.
• Plants absorb energy in the process of
photosynthesis.
• Animals are kept warm by it.
• Average temperature is about 15 degrees
Celcius.
CONSUMPTION OF ENERGY IN THE EARLY 21ST CENTURY
• Most of the energy we use comes indirectly
from the sun.
• Industrial countries consume large amounts of
energy from fossil fuels.
ENERGY DIRECT FROM THE SUN
Solar Panels – A device that absorbs sunlight to
heat water.
Solar Cells (Photocells) – An electrical device that
transfers the energy of sunlight directly to
electricity, by producing a voltage when light falls
on it.
WIND AND WAVE POWER
• There are many technologies for extracting
energy from the wind.
• Windmills are used for grinding and pumping.
• Wind turbines are used for generating
electricity.
• Wave technology uses the up and down motion
of waves to spin a turbine.
• Much harder to achieve.
BIOMASS FUELS
• Wood is one of the most important fuel in the world.
• When you burn wood you are releasing the stored energy that was captured from the sun.
• Biomass Fuels – a material, recently living, used as a fuel.
• Animal dung and Biogas
• Accounts for about one seventh of all energy consumption.
FOSSIL FUELS
Fossil Fuels – a material, formed from long-dead
material, used as a fuel.
• Oil, Coal, and Gas
• Fossil Fuels store energy as chemical energy.
• Many of the Earth’s coal reserves formed from
trees that lived in the Carboniferous era about
300 million years ago.
• Oil and Gas are formed in a similar way except
they come from the remains of tiny shrimp like
creatures called microplankton they were
formed about 100 million years ago.
NUCLEAR FUELS
• Fuel from for a nuclear power plant is usually
uranium or sometimes plutonium.
• The radioactive decay is speed up so that the
energy is released more quickly.
• Nuclear Fission – the process by which energy is
released by the splitting of a large heavy nucleus
into two or more lighter nuclei.
• Nuclear Energy – energy stored in the nucleus of
an atom.
WATER POWER
• Water or Hydroelectric Power, uses kinetic
energy of moving water to turn water wheels.
• Dams create hydroelectricity by holding water
behind a dam and releasing it to turn a turbine.
GEOTHERMAL ENERGY
• Geothermal Energy – the energy stored in hot rocks underground.
• These rocks are hot because of the presence of radioactive substances inside the Earth.
• Water is pumped down into the rocks and boiled and high pressure steam returns where it can be
generated into electricity.
• Iceland has many geothermal power plants because of volcanoes.
RENEWABLES AND NON-RENEWABLES
• Renewables – energy resource which, when
used, will be replenished naturally.
• Non-Renewables – energy resource which, once
used, is gone forever.
• Biomass, Wind, Solar
• Fossil Fuels
COMPARING ENERGY RESOURCES
ENERGY FROM THE SUN
• Fossil Fuels
• Radiation (light and heat)
• Wind
• Hydroelectricity
• Tides (actually from the moon)
• Nuclear
• Geothermal
THE SOURCE OF THE SUN’S ENERGY
• Nuclear Fusion - the process by which energy is
released by the joining of two small light nuclei
to form a new heavier nuclei.
In the sun two energetic hydrogen atoms collide
and fuse to form an atom of helium.
Very high temperatures close to 15 million degrees.
Pressure is high forcing the hydrogen close
together.