1. RENEWABLE ENERGY SOURCES
What is renewable energy?
Energy exists freely in nature. Some of them exist infinitely (never run out, called
RENEWABLE), the rest have finite amounts (they took millions of years to form,
and will run out one day, called NON-RENEWABLE)
Let's look at these types of energy in the diagram above.
You will notice that water, wind, sun and biomass (vegetation) are all available
naturally and were not formed. The others do not exist by themselves, they were
formed. Renewable energy resources are always available to be tapped, and
will not run out. This is why some people call it Green Energy.

2. What is Biomass ?
Biomass fuels come from things that once lived: wood products, dried
vegetation, crop residues, aquatic plants and even garbage. It is known as
'Natural Material'. Plants used up a lot of the sun's energy to make their
own food (photosysnthesis). They stored the foods in the plants in the
form of chemical energy. As the plants died, the energy is trapped in the
residue. This trapped energy is usually released by burning and can be
converted into biomass energy.

3. How is biomass converted into
energy?
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Burning
This is a very common way of converting organic matter into energy.
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Decomposition
Things that can rot, like garbage, human and animal waste, dead animals
and the like can be left to rot, releasing a gas called biogas (also known as
methane gas or landfill gas).
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Fermentation
Ethanol can be produced from crops with lots if sugars, like corn and
sugarcane. The process used to produce ethanol is called gasification.

4. What is Wind Power?
The earth's surface has both land and water. When the sun comes up, the air over
the land heats up quicker than that over water. The heated air is lighter and it rises.
The cooler air is denser and it falls and replaced the air over the land. In the night
the reverse happens. Air over the water is warmer and rises, and is replaced by
cooler air from land.
The moving air (wind) has huge amounts of kinetic energy, and this can be
transferred into electrical energy using wind turbines. The wind turns the blades,
which spin a shaft, which connects to a generator and makes electricity. The
electricity is sent through transmission and distribution lines to a substation, then
on to homes, business and schools.

5. Water power
Water power scheme
Moving water has kinetic energy. This can be transferred into useful energy in
different ways. Hydroelectric power (HEP) schemes store water high up in dams.
The water has gravitational potential energy which is released when it falls.
Sluice Gates: These can open and close to regulate the amount of water that is
released into the pipes.

6. Geothermal
Geothermal energy scheme
In some places the rocks underground are hot. Deep wells can be
drilled and cold water pumped down. The water runs through fractures
in the rocks and is heated up. It returns to the surface as hot water and
steam, where its' energy can be used to drive turbines and electricity
generators.
Geothermal energy is called a renewable energy source because the
water is replenished by rainfall, and the heat is continuously produced
by the earth.

7. Solar power
Solar
"Solar" is the Latin word for "sun" and it's a powerful source of energy. Without
it, there will be no life. Solar energy is considered as a serious source of
energy for many years because of the vast amounts of energy that is made
freely available, if harnessed by modern technology.
It is renewable!
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solar energy kidsThe technology used to convert the sun's power into
electricity does not produce smoke (carbon dioxide and other air pollutants).
Tapping the sun's energy does not usually destroy the environment.
Unfortunately, the sun does not available in the night, and in some days, clouds
and rains and other natural conditions prevent the sun's powerful rays to reach
us. This means that it is not always available. This a why we cannot rely on
solar energy alone.

8. Solar Panels
Solar panels do not generate electricity directly. Instead they heat up water
directly. A pump pushes cold water from a storage tank through pipes in the
solar panel. The water is heated by heat energy from the Sun and returns to the
tank. They are often located on the roofs of buildings where they can receive
the most sunlight.