Hydroelectric+Power

=Advantages=

__**Moderate to High Net Energy**__ One advantage of large-scale hydropower is that it can produce moderate to high net energy. Currently, there are three facilities that generate over 10 GW of energy, which are the Three Gorges Dam (above picture) (22.5 GW), Itaipu Dam (14 GW), and Guri Dam (10.2 GW). To give you an idea of how much energy that is, New York City uses about 10.5 GW. Large-scale hydroelectric power stations out-generate any of the largest renewable power plants in the world, including wind, solar, and geothermal power plants. In fact, hydroelectric plants generate the most electricity in the world. Of the largest non-renewable power plants in the world, the Kashiwazaki-Kariwa Nuclear Power Plant in Japan dominates at 8.212 GW, which is still less than half of the energy generated by the Three Gorges Dam in China. In addition, hydroelectric power has a large, untapped potential for supplying more energy. Large-scale hydroelectric projects also encompass wave and tidal power, areas of renewable energy that have been receiving more attention in the recent years and that hold a lot of promise. (Scientists estimate that ocean and tidal power can supply 10% of US total energy demand.)



Sources: [] [] [] []

=Disadvantages=

__**Environmental Costs**__ While there are many advantages to large-scale hydropower, there are also several environmental costs. First, large-scale hydropower disrupts natural, beneficial floods that occur on many rivers. The sediment trapped behind the dam can fertilize floodplains below and flood waters remove debris and satiate dry land. Second, dam construction results in the destruction of riparian, or stream-side, habitat. The elimination of this particular habitat results in a loss in biodiversity and a decline in water quality, which furthers biodiversity loss. Third, ecological alterations can cause other species to proliferate, such as snails. While seemingly innocuous, snails are hosts of parasites that cause schistosomiasis or “snail fever”, a disease that infects over 200,000 people worldwide and is ranked as the second most devastating parasitic disease (1st=malaria). Schistosomiasis has spread in many places with dam construction, such as the Akosombo Dam in Ghana, the Kariba Dam in Zimbabwe, and the Kainji Dam in Nigeria (above picture).



Sources: [] [|http://www.clearwaterconservancy.org/RCP - McCoy Dam.htm] [] []