Sources of Energy. pp.145-151. Nearly all the energy on Earth comes originally from the sun. Plants get energy for photosynthesis from sunlight. Animals get energy from food, including plants. Over time plant and animal remains changed into coal, oil and natural gas.
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Coal, oil and natural gas are called fossil fuels because they take millions of years to be created, like fossils.
Fossil fuels are nonrenewable resources because we are using them much faster than they can be replaced.
They will run out!
Burning fossil fuels releases pollution into the air.
Coal comes from plants alive millions of years ago.
Oil and natural gas come from animals and bacteria from millions of years ago.
Nuclear energy comes from releasing the energy that holds the nucleus of a uranium atom together.
This releases lots of heat (thermal energy).
The nuclear fuel is still radioactive for millions of years after it’s removed from the power plant.
Uses the potential energy of water to generate electricity.
The water has to be stored by a dam. Then it passes through the dam’s generators.
Hydroelectricity is a renewable resource because the source can be replaced.
Inexhaustible means they can never run out!
Examples include solar power, wind power and geothermal energy.
These are also called alternative resources.
Limited amounts left
Need large amounts of fuel
Releases lots of pollution
Leaves lots of ash/residue
Limited amounts of uranium
Leaves radioactive waste
Can harm fish swimming upstream
Drought can lower water level too low to generate power
Expensive to build
Need sunlight (night, clouds)
Needs large spaces
Depends on weather
Needs large spaces
Can kill birds
Not pretty to look at
Not available everywhere