Tuesday, 26 November 2013

Hydroelectric Environmental Impact

In 2011, Ontario emitted 170.6 megatonnes of greenhouse gases (GHGs), second in Canada only to Alberta. Greenhouse gases are any gases that contribute to the greenhouse effect and deteriorate the earth’s atmosphere. The great thing about hydroelectric power is that no fuel is being burnt and so it does not contribute to Ontario’s greenhouse gas output. The only pollution from hydropower comes from the construction of the power plants, as well as methane being released when vegetation and trees are removed to create reservoirs and redirect rivers towards generating stations. An environmental benefit of hydropower is there are no waste disposal issues like there are in plants run by nuclear or fossil fuels.


There are however, environmental consequences that come from using hydropower as well. Fish habitats can be altered not only from rivers being dammed for hydro plants, but also from the change in river patterns caused by having the dam there, and the mass amounts of water can trigger geological events such as earthquakes. People are sometimes forced to relocate and leave their houses and business due to flooding of dams as well.  

Benefits of Hydroelectricity

Main Benefits of Hydroelectric Generation:

·         - Electricity can be produced at a constant rate.
·        -  Water flow can be easily controlled to the turbines by means of sluice gates.
·        -  Water can be stored in reservoirs for times of higher electricity demand.
·        -  Hydro generation sites are designed to last for decades. 
·        -  The damns can be used as a tourist attraction to educate the public and generate a secondary income.
·        -  The lake water can be used for agricultural irrigation.
·        -  Hydroelectric sites don’t produce greenhouse gases.

·         - The cost for installation is only 5.1 – 11.3 cents/ KWH.

A Brief History of Hydroelectricity


Nearly 2000 years ago, Greeks used water wheels to grind wheat into flour; this is the beginning of hydropower. In the 1700s, hydropower was used all over for milling of lumber and grain, as well as for pumping irrigation water. Appleton, Wisconsin became the first operational hydroelectric generating station in the United States in 1882, producing 12.5 kW of power. The total electrical capacity generated was equivalent to the power used by 250 lights. Within the next 20 years, approximately 300 hydroelectric plants were operational worldwide. The invention of the hydraulic reaction turbine created the sudden expansion of hydropower. By the early 1900s, 40% of the US’s electricity was provided by hydro. The largest and last masonry dam built by the US Bureau of Reclamation was the Roosevelt Dam in Arizona between 1905 and 1911; its power has since increased from 4,500 kW to 36,000 kW. In 1933, the Tennessee Valley Authority Act was enacted into law. In 1937, the Hoover Dam first began generating power, producing 130 MW. By the 1940s, hydroelectric power supplied roughly 75% of the electricity used in the western United States and approximately one-third of the United States’ total electrical energy. However, by 1997, around 10% of the United States’ electricity came from hydroelectric power.