Hydroelectric energy (dams)
By. Minki Seo 6WR
Hydroelectric energy is created by using the water flow, gravitation, and nowadays,
advanced technology.” Hydro” comes from the Greek. It means “water”. Hydro electric energy is
clean, renewable and relatively safe. Hydropower was used in ancient times to move simple
machines. For example, to crush the seeds or wheat grains. The first electrical generator was
invented in late 19th century. The first hydroelectric power plants were built in the beginning of
20th century. Today, almost 150 countries produce hydro power. The biggest producers are
China, Canada, Brazil and USA. They make huge hydro dams to produce electricity. The biggest
dams are in China, Brazil and Paraguay.
To produce large amount of hydro energy we need hydro plants and dams. Dams hold
the water by creating a large reservoir. This is called storage energy. Then, when there is
enough water, the dam gates open and the
gravity pulls the water through the penstock,
which leads to the turbine. As the water
flows down to the turbine, it builds up
pressure. The higher the dams are and
wider opened gate, more amount of water
flows with more pressure. This means more
energy. From turbine, water goes up to the
generator. Generator produces electric
power. The “used” water is either pumped
up to the dams again or re-enters the river
down-stream. Flowing water moving the
turbine blades is a kinetic energy. The power
made by generator is mechanical
energy.
Benefits
1. Dams provide recreation such as
boating, skiing, camping, picnic areas
and boat launch facilities.
2. It stores water for preventing floods
and uses the water when it is need like
droughts.
3. It produces energy.
Drawbacks
1. When constructing dams, it has to be
very high quality. So it would be very
expensive, or else, the dams would
collapse very easily.
2. The village that’s in the valley floods by
the dam which means they have to
move out. This means that the villagers
lose all their farms and business.
Sometimes, they make the villagers
move forcibly.
3. If it fails, the villages below the dams
would get flooded away.
The hydropower plant can have good and bad impact on environment. The best thing
about hydro energy is that it is clean and renewable. Water is free. Hydro plants don’t create
any kind of waste or pollution. In some countries dams are used to support agriculture and
prevent flood. Reservoirs can be used to breed fish or as recreation sites. Unfortunately dams
and hydro plants affect and often damage natural habitats .Dams’ area change the surrounding
environment, forcing animal and plant to adapt new situation or leave. Building dams often
affect the water temperature and river’s flow. Dams destroy a balance between the water
sources and ecosystems which depend on them. Whole ecosystems might be (and they usually
are) destroyed. Large areas of wetland, forest, grassland etc. must be flooded. All kinds of
wildlife in these areas are affected. Changes affect fish migration and population the most. Fish
can’t move upstream through the dams or move downstream to the ocean. Engineers try to
solve these problems by building fish ladders. In tropical countries, high water temperature and
lack of natural water current can create an environment for the mosquitos, snails and flies, to lay
their eggs. Increased amount of these animals can cause several serious diseases such as Malaria,
Schistosomasis and River Blindness.
To sum up everything, hydroelectric energy has its pros and cons. Out of hydro, solar and
wind, hydroelectric power is the most profitable .It is also the most stable and predictable.
Hydroelectricity can be produced 24/7. To maintain hydro plants is not difficult and doesn’t
involve a lot of “men sources”, however building a hydro plant and dam is a very long and
expensive process. It requires high advanced technologies and well qualified staff. Dams’
constructions not only affect environment, but also force people to relocate. That often causes
social and political conflicts in areas where dam is planned to build. (Recently in Vietnam, many
of hydro plants’ projects have been paused or banned, due to environmental and social
concerns). Beside all these problems and discussions about negative sides of hydropower, more
and more countries invest in this clean energy source. It is estimated that 16% of global electric
power comes from hydroelectric energy.
Citations
Works Cited
"Benefits of Dams | FEMA.gov." Benefits of Dams. 19 Feb. 2013. FEMA. 16 May 2013
<http://www.fema.gov/damsafety/benefits-dams>.
"Benefits of Dams to Society." USSD. 2011. Original site design and content copyright. 16 May
2013 <http://ussdams.org/benefits.html>.
Bonser, Kevin. "How Hydropower Plants Work." HowStuffWorks. 14 May 2013. © 1998-2013
HowStuffWorks, Inc. 16 May 2013
<http://science.howstuffworks.com/environmental/energy/hydropower-plant.htm>.
"Dam problems - Environmental impacts." WWF. © WWF. 16 May 2013
<http://wwf.panda.org/what_we_do/footprint/water/dams_initiative/problems/enviro
nmental/>.
"Energy and kids." Energy and kids. 2005. © 2005 ESD Bulgaria. 16 May 2013
<http://www.kids.esdb.bg/hydro.html>.
"Energy Matters: Hydroelectric Intro." ThinkQuest. Ed. Blair Cornelia. Oracle Foundation. 16
May 2013 <http://library.thinkquest.org/20331/types/hydro/>.
"Environmental impact of reservoirs." Wikipedia. 15 May 2013. Wikimedia Foundation. 16 May
2013 <http://en.wikipedia.org/wiki/Environmental_impact_of_reservoirs>.
"Environmental Impacts." Environmental Impacts. 16 May 2013
<http://www.mtholyoke.edu/~lpohara/Pol 116/enviro.html>.
"Environmental Impacts of Dams." Environmental Impacts of Dams. 16 May 2013
<http://www.arch.mcgill.ca/prof/sijpkes/arch374/winter2001/dbiggs/enviro.html>.
"Environmental Impacts of Dams." International Rivers. 16 May 2013
<http://www.internationalrivers.org/environmental-impacts-of-dams>.
"Environmental Impacts of Hydroelectric Power." Clean Energy. 3 May 2013. ©2013 Union of
Concerned Scientists. 16 May 2013.
"Hydro Power." Conserve Energy Future. 2013. Conserve Energy Future Copyright ©. 16 May
2013 <http://www.conserve-energy-future.com/Disadvantages_HydroPower.php>.
"Hydro vs. Wind vs. Solar Power?" Electrical Engineering Portal RSS. 11 Dec. 2010. © 2013 EEP Electrical Engineering Portal. All Rights Reserved | Privacy Policy. 16 May 2013
<http://electrical-engineering-portal.com/hydro-vs-wind-vs-solar-power>.
"Hydroelectric energy." - National Geographic Education. 16 May 2013
<http://education.nationalgeographic.com/education/encyclopedia/hydroelectricenergy/?ar_a=1>.
"Hydroelectric power station." Wikipedia. 05 Jan. 2013. Wikimedia Foundation. 16 May 2013
<http://en.wikipedia.org/wiki/Hydroelectric_power_station>.
"Hydroelectricity." EPA. 30 Apr. 2013. Environmental Protection Agency. 16 May 2013
<http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.html>.
"Hydroelectricity." Wikipedia. 14 May 2013. Wikimedia Foundation. 16 May 2013
<http://en.wikipedia.org/wiki/Hydroelectricity>.
"Hydropower." Energy KIDS. U.S. Energy Information Administration. 16 May 2013
<http://www.eia.gov/kids/energy.cfm?page=hydropower_home-basics>.
"Hydropower energy resource harvesting in Vietnam - News VietNamNet." Hydropower energy
resource harvesting in Vietnam - News VietNamNet. 16 May 2013
<http://english.vietnamnet.vn/en/environment/20537/hydropower-energy-resourceharvesting-in-vietnam.html>.
"Hydropower Facts - Creating Electricity with Water & Gravity." Hydropower Facts - Creating
Electricity with Water & Gravity. 7 May 2013. Science Kids ©. 16 May 2013
<http://www.sciencekids.co.nz/sciencefacts/energy/hydropower.html>.
"Hydro-power plants halted over eco-fears - News VietNamNet." Hydro-power plants halted
over eco-fears - News VietNamNet. 16 May 2013
<http://english.vietnamnet.vn/fms/environment/68463/hydro-power-plants-haltedover-eco-fears.html>.
"Hydropower." Water Home. 16 May 2013 <http://water.worldbank.org/topics/hydropower>.
"NAVIGATION." WellHomecom The Pros and Cons of Hydropower Comments. July 2012.
Copyright WellHome 2011 - All right reversed. 16 May 2013
<http://www.wellhome.com/blog/the-pros-and-cons-of-hydropower/>.
Painter, Tammie, and Demand Media. "History of Hydroelectric Power." Green Living on
National Geographic. 16 May 2013. © 1996-2013 National Geographic Society. 16 May
2013 <http://greenliving.nationalgeographic.com/history-hydroelectric-power20128.html>.
Perlman, Howard. "Hydroelectric power: How it works." Hydroelectric Power: How it works,
USGS Water-Science School. 6 Mar. 2013. 16 May 2013
<http://ga.water.usgs.gov/edu/hyhowworks.html>.
Press, Associated. "Three Gorges Dam has caused urgent problems, says China." The Guardian.
19 May 2011. Guardian News and Media. 16 May 2013
<http://www.guardian.co.uk/environment/2011/may/19/china-three-gorges-dam>.
"Solar power." Wikipedia. 14 May 2013. Wikimedia Foundation. 16 May 2013
<http://en.wikipedia.org/wiki/Solar_power>.
"Solar Vs Hydro Vs Wind." Solar Vs Hydro Vs Wind. 16 May 2013
<http://www.solaralaska.com/primer/solvs.htm>.
V, Rian. "Advantages and Disadvantages of Hydropower." Advantages and Disadvantages of
Hydropower. © 2005 - 2009. 16 May 2013
<http://www.technologystudent.com/energy1/hydr2.htm>.
"Wind power." Wikipedia. 14 May 2013. Wikimedia Foundation. 16 May 2013
<http://en.wikipedia.org/wiki/Wind_power>.
Criterion D: Reflecting on the impact of science - Generating Green Electricity
Maximum 8
Outline and
summarize
 How well did you
describe how
science is applied in
the technology you
chose to generate
green electricity?
1-2
Implications
 How well did you describe how
your green electricity
technology interacts with one
of the following factors
social – economic – political –
environmental – moral
 How might your technology
cause new or different
problems?
 How well can you
apply scientific terms
to correctly
communicate your
understanding?
 How clear is your
writing?
 How factual is your
writing?
Documentation
 How organized is your
works cited?
 Did you cite all your
sources?
attempts to state
the ways in which science is applied and used to address generating
green energy
attempts to state
a solution to green energy production and how it is linked to one of the
One World factors: social – economic – political – environmental- moral
attempts to state
attempts to apply
with limited effectiveness
scientific language to communicate his or her understanding
attempts to
document sources correctly
is able to state
3-4
Communication
states
states
applies
but is not clear and effective
the ways in which science is applied and used to address generating
green energy
a solution to green energy production and how it is linked to one of the
One World factors: social – economic – political – environmental- moral
scientific language to communicate his or her understanding
states
with errors
outlines
outlines
5-6
7-8
document sources correctly
the ways in which science is applied and used to address generating
green energy
a solution to green energy production and how it is linked to one of the
One World factors: social – economic – political – environmental -moral
outlines applies
but is inconsistent or
not clear or precise
states
mostly correct
outlines and summarizes
outlines and summarizes
outlines and summarizes
scientific language to communicate his or her understanding
document sources correctly
the ways in which science is applied and used to address generating
green energy
a solution to green energy production and how it is linked to one of the
One World factors: social – economic – political – environmental- moral
scientific language to communicate his or her understanding
Consistently applies
Clearly and precisely
Consistently
document sources completely