7A+Hydroelectric+power

= **Hydroelectric Power** = By Ji-Won and K.K.

Introduction
The overuse of fossil fuels to create energy is polluting the Earth day and night, and now many countries are using renewable sources of energy, one of them being hydroelectric power. Known for its cheap price and efficiency compared to other methods in creating electricity, hydroelectric power is produced by the energy of water passing through dams, which is how it got its name.

How does it work?
The creation of hydroelectric power starts when water, its potential source of energy, is trapped in dams. These dams are much thicker at the bottom because the flow of water increases in depth. As water flows through the dams, creating kinetic energy, the turbines start to activate the generator producing electrical energy. Electricity is sent through wires to our homes, passing two or three transformers, reducing the voltage of electricity.

How widespread is it?
About 145 countries in 6 continents use hydroelectric power, with China using this renewable method the most, producing 721 terawatts per hour in 2010. In Africa, 38 countries - Mozambique, Egypt, Zambia, Nigeria, The Democratic Republic of Congo, Ghana, Zimbabwe, Cameroon, Kenya, Ethiopia, Angola, Morocco, Namibia, Cote D'ivoire, United Republic of Tanzania, Sudan, Uganda, South Africa, Malawi, Gabon, Madagascar, Reunion, Guinea, Congo, Mali, Algeria, Lesotho, Swaziland, Tunisia, Rwanda, Burundi, Central African Republic, Togo, Burkina Faso, Mauritius, Mauritania, Sao Tome and Principe use hydroelectric power. In the world, 19% of global electricity is produced using hydropower and 16% of global electricity is consumed.

How efficient is it?[[image:total-cost-electricity-production-per-kwh.jpg width="506" height="314" align="right"]]
Generally, 96MW ([|proportion in Wikipedia-Calculating the Amount of Available Power] ) of electricity is produced by hydro power although it may differ depending on the types of dams and methods such as conventional hydroelectric, run-of-the-river hydroelectricity, small hydro, micro hydro and pumped storage hydroelectricity. These different types of methods and dams can also affect the amount of energy that goes into the process of creating electricity through hydroelectricity power. The cost in building a hydroelectric dam, including construction, parts for electricity generation and others engineering and ground property, is dependent on the river it crosses, its storage lake and so on. For example, Hoover Dam cost roughly 690 million dollars in this current age and the Three Gorges Dam in China cost about 30 billion dollarsto build in 2006.

**Benefits of Hydropower**

 * No emissions, no waste or pollution
 * Reliable
 * Electricity generated constantly
 * Renewable (hydrologic cycle)
 * Power stations can increase to full power quickly than others
 * Ready to use at any time
 * Cheap potential energy source (water always exists)
 * Plentiful sources of water

**Drawbacks of Hydropower**[[image:dam_construction.jpg width="254" height="214" align="left"]]

 * Expensive dams (High investment costs)
 * Threaten areas in vicinity by flooding
 * Effect on water quality due to diversion of rivers
 * Rare suitable places to build dams
 * Dependent on precipitation
 * In some cases, cause displacement of local population

Role in the Future
From our research on hydroelectric power, we think that it will become more widespread in the future. Although building dams can be expensive, the price of using its potential energy and others not relating to the construction are cheap, and also it has advantages overpowering other renewable energies like solar power, wind power and so on. Hydropower is always ready to use at any time and its power stations can increase to full power quickly than others. As human population increases, the use of hydroelectric power will increase as well because more production of electricity would be necessary. Since hydropower always has water, its potential source of energy, it is always ready to use, unlike solar power, wind power etc. Even though an increase in another method might trespass the advantages of hydroelectric power and decrease its use, a decrease in another method will surely increase the use of hydropower because there will be lesser options in trying to reduce CO2. Despite all these advantages, water used to generate hydropower might become less available since hydropower is dependent on rivers and precipitation. But there may be a way to fill in this disadvantage of hydroelectric power: it is to use the water from the vast oceans, like tidal power.

Images
[] [] [] [] [|http://www.bettertrades.org/sectornomics/energy/hydro.as] [] []