Dams are barriers that divide and retain water for a number of purposes. They provide water for irrigation
and industrial applications, they improve navigation, generate electricity, control flood and provide recreational areas or habitat for fish and other wildlife. The worlds tallest dam
at 300 meters high is found in Tajikistan.
Origin of Hydroelectric Dams
Dams date back to the olden days with most of them found in Mesopotamia and the Middle East. The earliest known dam dated around 3000
B.C. is in Jawa, Jordan. For the record, the oldest dam in the world that still stands is the Quatinah barrage in Syria. The dam is believed to have
been constructed during the time of Egyptian pharaoh Sethi and was expanded during the Roman period.
Types of Hydroelectric Dams
Alternative Energy Articles
Dams are categorized based on their size, purpose and structure. Large dams, according to international standards, are those with a height of
more than 15 meters while major dams are more than 150 meters tall. Based on material and structure, they are either timber dams, arch-gravity
dams or masonry dams each of which has further subtypes.
By purpose, dams are of four types the overflow, check, dry and diversionary. An overflow dam is used to measure the flow of water. A check
dam is small in size and is aimed at reducing the flow velocity as well as control soil erosion. For flood control, a dry dam is used while a
diversionary dam, as its name suggests, is aimed at diverting all or a part of a river flow from its natural course.
A major application of dams is in producing hydroelectric energy to generate electricity. Hydroelectric power supplies 63 percent of the earths
renewable energy and an estimated 19 percent of the worlds electricity, according to 2005 statistics.
As fossil fuels have been found to cause harm to the environment through their emissions and as their prices go up, the use of
renewable energy is getting greater attention. And with many countries having large rivers, water has been tapped as a potential source of clean energy for
Dammed water is responsible for producing hydroelectric
power. The potential energy produced by the dam is what drives the water turbine and
generator that creates electricity. One type of dam makes use of pumped storage
hydroelectricity through reservoirs at different elevations. When
demand for electricity is low, excess generation capacity is used to pump water into the higher reservoir. As demand peaks again, water is
released back into the lower reservoir via a turbine.
Dams are best built in a narrow part of a deep river valley. At this location, the valley sides can even serve as the dams natural walls. The main
function of a dam is to fill the gap in the natural reservoir line left by the stream channel.
As an alternative source of
energy, hydroelectric power is considered less costly than wind
energy and nuclear power. Compared to wind, it is easier to
store water when necessary and generate electricity at high levels on demand. Additionally, well-designed hydroelectric dams that are
maintained properly are cheaper in the long run and more reliable.
This energy source is used in furnaces for homes and for heating swimming pools. Its major applications are in power plants, space ships and in running cars.
Solar Energy Information
One of the cleanest sources of energy, it is dependent on the weather and location, wind energy is very helpful in a lot of ways specifically in generating electricity through the use of windmills.
Wind Energy Information
Hydroelectric energy utilizes the potential energy existing in the water and helps in generating cheaper electricity
Geothermal Energy comes from the earths core where temperatures are high and constant all year round. This is ideally used in home heating systems