2. CONTENTS
1)Why do we need Electrical energy?
2)Energy resources.
3)Power stations
4)Conventional ways of generating electricity.
5)Fossil fuels & Their alternatives.
6)Types of Energy Sources.
7)Conclusion.
3. Why do we need electrical energy?
• We need electrical energy to power
the appliances in our homes.
• Electrical energy powers
factories in order to make things.
• Without electricity we wouldn’t
have technology as we know it
today.
4. Energy Resources
• There are a number of sources of energy that we could
use to generate electricity.
• The most common are called fossil fuels.
• Power stations use fossil fuels to
generate electricity.
•We burn fossil fuels to release heat
energy.
•The heat energy is used to heat water
to produce steam.
•The steam drives a turbine and then a
generator which converts the kinetic
energy of the turbine into electrical
energy.
6. Oil – Burning oil also releases Carbon Dioxide and
Sulphur Dioxide.
Gas – Burning gas releases Carbon Dioxide gas.
• Fossil fuels consist of Coal, Oil
and Gas.
Conventional Ways of Generating Electricity
Coal – Burning coal releases Carbon
Dioxide (a Greenhouse gas) and
Sulphur Dioxide.
•Both of these gases dissolve into the
clouds and create acid rain.
7. Alternatives to Fossil Fuel?
• If both Nuclear fuel and Fossil fuels
will eventually run then it makes sense
to replace them with something else.
• Also, it makes sense to replace them
with something which does not pollute
the Earth!
8. Types of energy sources
Non Renewable
• Coal
• Oil
• Gas
• Nuclear
Renewable
• Solar
• Wind
• Hydroelectric
• Geothermal
• Biomass
Non-renewable
will not be
replaced.
Renewable are
being replaced all
the time.
9. SOLAR ENERGY
• The Sun can be described as
our ultimate source of
energy.
• Energy to grow our food
comes from the Sun.
(Photosynthesis converts light into plant
food)
• The Sun heats the Earth.
• The energy from the Sun drives the weather which gives
us wind, waves and rain.
10. We can change sunlight to
Electricity by using solar
Photovoltaic cells. This electrical
Energy can then be used directly in
the home or in larger scale projects
as shown.
Solar Cells are quite expensive & required large area to generate a
substantial amount of power, also, they do not produce a constant
supply of power. e.g. at night.
Despite this, they are often the best energy source
for producing electricity in remote locations
e.g. on a satellite or when only small amounts of
electricity are needed.
11. WIND ENERGY
Wind is another kind of
energy that makes things
work. You can’t see the wind,
but when it blows on a windy
day you can feel it push
against your body.
Some areas of the world
have areas that are windy
most of the year, but the
amount of electricity
produced always changes
with the strength of the
wind.
12. Blowing wind spins the blades on a wind
turbine. The spinning blades turn a
generator that makes electricity.
Some people say that ‘wind farms’ look
unsightly and that they produce a lot of noise as
they turn around. This could cause are a
nuisance to people living nearby. This is called
visual and noise pollution.
13. HYDROELECTRIC ENERGY
Moving or falling water can be used to do work. Years ago moving
water turned wooden wheels to grind flour. Today moving water is
used to make electricity in HYDROELECTRIC POWER STATIONS.
14. GEOTHERMAL ENERGY
Geothermal means “earth heat” and is as old as the world itself. Deep
underground the earth is very hot and this can be used to heat water.
15. Around 3000m below the earths surface
the rock is molten.
Water sometimes comes close to this rock
and turns into steam.
This water can reach temperatures of
more than 230degrees Celsius (Remember
water boils at 100 degrees)
In some areas of the
world there is enough
steam produced to turn a
Turbine and produce
Electricity.
16. BIOMASS
Another sustainable energy
resource is plant matter which
is called Biomass.
Forests and certain crops can
be cultivated to provide fuel for
burning.
The fuel is burnt to
release heat. The heat
boils water to produce
steam which turns a
generator. The generator
converts the KE of the
steam into electricity.
17. Conclusion
In order to protect our
environment it is better to use
Renewable sources to generate
power.
