<a href="http://perpetualminds.com/wp-content/uploads/2011/07/Hydroelectric-Power.jpg"><img class="size-full wp-image-155 alignleft" title="Hydroelectric Power" src="http://perpetualminds.com/wp-content/uploads/2011/07/Hydroelectric-Power.jpg" alt="Hydroelectric Power" width="300" height="225" /></a>Hydroelectric power is the production of power by using the gravitational force of falling or flowing water, which is the most widely used form of renewable energy.

Most hydro electricity comes from dammed water which is released to drive a <a title="The Water Turbine" href="http://www.top-alternative-energy-sources.com/water-turbine.html" target="_blank">water turbine</a> and generator. The energy created by the moving water depends on the volume released, and on the difference in height between the water source and the turbine. The difference in height between the source and the turbine is called the head. The amount of potential energy which can be harnessed from the water is proportional to the head. To obtain very high head, water for a hydraulic turbine may be routed through a large pipe called a penstock. Most hydro electricity comes from dammed water which is released to drive a water turbine and generator. The energy created by the moving water depends on the volume released, and on the difference in height between the water source and the turbine.

Hydro power is considered to be a clean, renewable source of energy. It emits a very low level of <a title="The Greenhouse Effect" href="http://perpetualminds.com/2011/06/20/the-greenhouse-effect/" target="_blank">greenhouse gases</a> in comparison to fossil fueled plants. It has a low operating cost and can be highly automated. Power is generally available on demand as the flow of water can be controlled. Using this alternative energy has some major advantages and also disadvantages it offers to our economy.

<strong>Hydroelectric Power Advantages</strong>
There are many advantages to using hydroelectric power which include the following:

1. Once the dam is built, the energy is virtually free.
2. No waste or pollution produced.
3. Much more reliable than wind, solar or wave power.
4. Water can be stored above the dam and is ready to cope with peaks in demand.
5. Hydro-electric power stations can increase to full power very quickly, unlike other power stations.
6. Electricity can be generated constantly.

<strong>Hydroelectric Power Disadvantages</strong>
Despite the advantages to hydroelectric power, there are some disadvantages:

1. The dams are very expensive to build. However, many dams are also used for flood control or irrigation, so building costs may be shared.
2. Building a large dam will flood a very large area upstream, causing problems for animals that once lived there.
3. Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable.
4. Water quality and quantity downstream can be affected, which can have an impact on plant life.

As with other traditional energy sources, such as <a title="Natural Gas As An Energy Source" href="http://perpetualminds.com/2011/07/18/natural-gas-as-an-energy-source/" target="_blank">natural gas</a> and <a title="Coal Energy" href="http://perpetualminds.com/2011/07/25/coal-energy/" target="_blank">coal</a>, hydroelectric power is not an ideal solution for an energy source. Rather than rely on hydroelectric power as an energy source, we must seek out cleaner alternative energy.

Photo Credit: <a title="Lesson's From China's Three Gorges Dam" href=" http://japanfocus.org/-peter-bosshard/3262" target="_blank">JapanFocus</a>