The
discovery
of
electricity
Renewable Energy:
How Hydro
Stations Work
Hydropower is produced by the movement of
freshwater from rivers and lakes. The most common
form of hydropower plant uses a dam on a river to
store water in a reservoir. Enormous quantities of
water are involved and a large hydro-electric power
system requires a very large dam, or a series of dams.
1
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing
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How Hydro
Stations Work continued
<Hydro-electric power> is based on the simple principle of using falling
water to spin a shaft connected to an electric generator.
The greater the FALL of water, the more power it has to spin a shaft.
The greater the QUANTITY of water, the greater the number and size
of the shafts that may be spun and the greater the electricity output.
The amount of power that can be produced depends on two factors:
• the FLOW (quantity of water passing)
• the HEAD available (vertical distance of water can be made to fall).
The flow is measured in terms of cubic metres a second. The head is
expressed in metres. It may be natural (e.g. the Kiewa River), or it
may be artificially created by building a dam to raise the level of a lake
or river.
Every hydro-electric generating unit consists of a hydraulic or water
turbine to convert the energy of falling water to mechanical energy,
connected by a shaft to an electric generator to convert mechanical
energy into electric energy.
CONTROL BOARD
EXCITER
GENERATOR
GOVERNOR
TURBINE
RELIEF VALVE
DRAFT TUBE
TAIL RACE
Diagram of Clover Power Station
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2
How Hydro
Stations Work continued
Water for a hydro-electric power station is conveyed under pressure
(the head) through tunnels or pipes to the turbine where it hits the
turbine runner. The runner starts spinning when water hits it, and this
spins the generator shaft. When the water has given up its energy to
the turbine runner, it is discharged through the tailrace of the power
station to join the main stream of the river.
Victorian hydro-electric installations can be found at Kiewa, EildonRubicon, Dartmouth, Cairn Curran (Newstead), Cardinia Dam (Menzies
Creek), and a number of other small installations.
The Snowy Mountains Hydro-electric Scheme is one of the most
complex integrated water and hydro-electric power schemes in the
world. Snowy Hydro currently provides over 70% of all renewable
energy that is available to the eastern mainland grid of Australia.
<Energy from
moving water
activity>
Hydro-electricity uses no <fossil fuel> (coal, oil or gas) in any of
the generation process. Although it is a renewable energy source,
hydropower does carry a greenhouse gas penalty due to the
production of methane, which arises from the rotting of underwater
vegetation. The extent to which methane is produced in a hydroelectric dam depends on a variety of factors, including the original
vegetation on the dam site, water temperature, and the area of the
dam. <source>
3
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Click here to find out
more about
<generation
of electricity>
More information
Alternative energy sources
<http://www.greenpeace.org.au/climate/solutions/index.html>
<http://www.darvill.clara.net/altenerg/index.htm>
<Wind power>
<Solar power>
<Hydro power>
Nuclear power
<http://www.energyquest.ca.gov/story/chapter13.html>
<http://www.greenpeace.org.au/climate/solutions/nuclear.html>
<http://www.greenpower.gov.au/pages/Facts-Sheets.php>
Wave energy and hydro power
<http://www.energyquest.ca.gov/story/chapter14.html>
<http://www.reslab.com.au/resfiles/wave/text.html>
<http://www.alpinediscoverycentre.com.au/hydro/index.htm>
Hydro power
<http://www.darvill.clara.net/altenerg/hydro.htm>
<http://www.snowyhydro.com.au/>
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4
Energy from moving water
Activity
Make a poster based on the topic “Energy from moving water”.
Your poster should have:
• a minimum of 5 key scientific facts or concepts about
generating energy from moving water
• a clear explanation of the scientific and technical
principles involved
• at least 4 annotated pictures or diagrams that summarise
the scientific concepts and principles involved
• advantages and disadvantages of generating energy
in this way
• a maximum of 500 words
• a list of references used.
5
Renewable Energy:
How Hydro
Hydropower is produced by the
movement of freshwater from rivers
and lakes. The most common form
of hydropower plant uses a dam on
a river to store water in a reservoir.
Enormous quantities of water are
involved and a large hydro-electric
power system requires a very large
dam, or a series of dams.
<Hydro-electric power> is based on the
simple principle of using falling water to spin
a shaft connected to an electric generator.
The greater the FALL of water, the more
power it has to spin a shaft. The greater
the QUANTITY of water, the greater the
number and size of the shafts that may be
spun and the greater the electricity output.
The amount of power that can be produced
depends on two factors:
•
the FLOW (quantity of water passing)
•
the HEAD available (vertical distance
of water can be made to fall).
The flow is measured in terms of cubic metres
a second. The head is expressed in metres. It
may be natural (e.g. the Kiewa River), or it may
be artificially created by building a dam to raise
the level of a lake or river.
Every hydro-electric generating unit consists
of a hydraulic or water turbine to convert
the energy of falling water to mechanical
energy, connected by a shaft to an electric
generator to convert mechanical energy into
electric energy.
Water for a hydro-electric power station is
conveyed under pressure (the head) through
tunnels or pipes to the turbine where it
hits the turbine runner. The runner starts
spinning when water hits it, and this spins
the generator shaft. When the water has
given up its energy to the turbine runner,
it is discharged through the tailrace of the
power station to join the main stream of
Stations Work
the river.
Victorian hydro-electric installations can be
found at Kiewa, Eildon-Rubicon, Dartmouth,
Cairn Curran (Newstead), Cardinia Dam
(Menzies Creek), and a number of other
small installations.
The Snowy Mountains Hydro-electric
Scheme is one of the most complex
integrated water and hydro-electric power
schemes in the world. Snowy Hydro
currently provides over 70% of all renewable
energy that is available to the eastern
mainland grid of Australia.
Hydro-electricity uses no <fossil fuel> (coal,
oil or gas) in any of the generation process.
Although it is a renewable energy source,
hydropower does carry a greenhouse gas
penalty due to the production of methane,
which arises from the rotting of underwater
vegetation. The extent to which methane is
produced in a hydro-electric dam depends
on a variety of factors, including the
original vegetation on the dam site, water
temperature, and the area of the dam.
<source>
Oscillating Water Column
This device consists of water column that
is open to the sea at the base. Incoming
waves force the water up the column forcing
the enclosed air through a turbine located
about the water surface.
This type of system incorporates several
hours of energy storage. However, it does
occupy a large area and suitable coastal
sites are not as readily available as those for
oscillating column systems.
More information
Alternative energy sources
<http://www.greenpeace.org.au/climate/
solutions/index.html>
<http://www.darvill.clara.net/altenerg/index.
htm>
<Wind power>
<Solar power>
<Hydro power>
Nuclear power
<http://www.energyquest.ca.gov/story/
chapter13.html>
<http://www.greenpeace.org.au/climate/
solutions/nuclear.html>
<http://www.greenpower.gov.au/pages/
Facts-Sheets.php>
Wave energy and hydro power
<http://www.energyquest.ca.gov/story/
chapter14.html>
<http://www.reslab.com.au/resfiles/wave/
text.html>
<http://www.alpinediscoverycentre.com.
au/hydro/index.htm>
Hydro power
<http://www.darvill.clara.net/altenerg/hydro.
htm>
<http://www.snowyhydro.com.au/>
Tapered Channel
This system focuses waves into a rock
gully 60 metres wide leading to a concrete
channel which tapers from 3 metres to 0.2
metres over a 90m metre length. The waves
spill over the channel sides into a reservoir
3 metres above mean sea level. The water
is returned to the sea through a turbine
coupled to a generator.
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing