Hydro-power+Plants

=Hydro-Power Plants= Hydro-power or hydroelectric power is generated by using electricity generators to produce energy from moving water, such as rivers and streams. Turbines are used to capture the kinetic energy of water by converting it to electricity as the falling water spins the turbine. Hydropower plants may be located below reservoirs or built in rivers (run-of-the-river units) with no water storage capacity. Hydropower is considered a renewable source of energy, as it relies on water which is continuously renewed through the natural water cycle. Hydro-power plants have low running cost, near-zero emissions, and ability to be dispatched quickly to meet peak electricity demand.

**How it works?**
The water stored in the dam is released through pipes that run through turbines that turn generating dynamos. The force of the water is very strong, so large and powerful generators can be used. With a network of dams, the falling water can be used to produce electricity a number of times during its descent. Because the flow of water can be quickly and easily adjusted, the generation of hydro electricity can be quickly increased or decreased as demand requires. Snowy Hydro currently provides over 70 percent of all renewable energy that is available to the eastern mainland grid of Australia, as well as providing fast response power to light up the morning and evening rush hours of Sydney, Brisbane, Canberra, Melbourne and Adelaide.

**In Australia**
 Australia has a number of large hydroelectric schemes, the most famous being the Snowy Mountains Hydro-Electric Scheme. In terms of total electricity generation, hydro electric power represents 10% of Australian production.Hydro electricity currently accounts for 97% of Australia's renewable energy consumption - solar, wind, biomass and geothermal account for the remaining 3%.

The Snowy Mountains Hydro-electric Scheme is one of the most complex integrated water and hydroelectricity schemes in the world. The Scheme collects and stores the water that would normally flow east to the coast and diverts it through transmountain tunnels and power stations.The water is then released into the Murray and Murrumbidgee Rivers for irrigation.The Snowy Mountains Scheme comprises sixteen major dams, seven power stations (two of which are underground), a pumping station, 145 km of inter-connected trans-mountain tunnels and 80 km of aqueducts. The Snowy Mountains Hydro-electric Scheme provides around 70 per cent of all renewable energy that is available to the eastern mainland grid of Australia, as well as providing peak load power (Snowy Hydro 2007).

 http://www.snowyhydro.com.au/levelTwo.asp?pageID=289  __http://www.snowyhydro.com.au/levelTwo.asp?pageID=66 __

Impoundment
The **most common** type of hydroelectric power plant is an impoundment facility. An impoundment facility, typically a large hydropower system, uses a dam to store river water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level.

Diversion
A diversion, sometimes called run-of-river, facility channels a portion of a river through a canal or penstock. It may not require the use of a dam.

Pumped Storage
When the demand for electricity is low, a pumped storage facility stores energy by pumping water from a lower reservoir to an upper reservoir. During periods of high electrical demand, the water is released back to the lower reservoir to generate electricity.

(Source: http://www1.eere.energy.gov/windandhydro/hydro_plant_types.html)



Plant Sizes
Based on their capacities, hydro-power plant facilities range in sizes from large power plats that supply many consumers with electricity to micro plants that can be operated by individuals for their own energy needs. The plants can be categorised by the following:

Large Hydro-Power Plants
Large hydro-power plants are defined as facilities that have a capacity of more than 30 megawatts.

Low Hydro-Power Plants
Low hydro-power plants are defined as facilities that have a capacity of 1 megawatt to 30 megawatts.

Small Hydro-Power Plants
Small hydro-power plants are defined as facilities that have a capacity of 100 kilowatts to 1 megawatt. Small Hydro-electric plants can feed electricity into the grid or supply electricity to isolated communities

Micro Hydro-Power Plants
Micro hydro-power plants are defined as facilities that have a capacity of less than 100 kilowatts. A small or micro-hydroelectric power system can produce enough electricity for a home, farm, ranch, or village.

Plant Costs & Running Costs
Hydroelectric plants are generally less expensive to run than other generating plants, however the construction of hydroelectric plants is expensive.

Global Facts
Currently, 808,000 megawatts of hydropower generation capacity are in operation or under construction around the world. Globally, hydropower accounts for about 17 percent of total electricity generation and nearly 90 percent of renewable electricity generation. As regions, Central and South America generate nearly 70 percent of their electricity from hydropower, and many countries, including several large countries such as Canada and Brazil, rely on hydropower for more than half of their electricity. China currently obtains about 17 percent of its electricity from hydropower; from 1990 to 2006, Chinese hydropower generation grew at a compound annual growth rate of 8 percent (compared to 1.5 percent for the rest of the world), with the increase in Chinese hydropower generation over this period accounting for 36 percent of the global increase in hydropower generation.

SWOT Analysis

 * **Strengths:** || ===Weaknesses:=== || **Opportunities:** || ===Threats:=== ||
 * Hydroelectricity is a renewable energy resource || Hydropower can impact water quality and flow || Research and development to improve efficiencies, reduce costs and negative environmental impacts || Building hydroelectric plants can have serious consequences for both the environment and people, i.e. flooding and the consequent loss of flora and fauna ||
 * Hydroelectricity is one of the most efficient energy sources because most of the kinetic energy of the water is converted to electrical energy || Hydroelectric plants are site specific || Improve reliability and durability || Dam construction unavoidably results in areas of land being flooded, with other areas being set aside for infrastructure development and catchment conservation areas. ||
 * No greenhouse gases or other dangerous gases are produced || The construction of hydroelectric plants is expensive || Integration of hydropower systems with other renewable sources for electricity generations (developing hybrid systems) || Construction of hydro-power plants, especially in tropical and sub-tropical regions, can in cases have adverse health impacts on people in the immediate catchment area and downstream of the construction site ||
 * Hydroelectric plants are generally less expensive to run than other generating plants || Energy expansion not possible for small and micro hydro plants as the size and flow of small streams may restrict future site expansion as the power demand increases || Improve equipment || Some vector borne diseases can be associated with reservoir development, for example malaria and schistosomiasis, and schemes constructed in malaria prone areas have the potential to increase transmission of this disease ||
 * Electricity can be stored for later use by using excess production to pump water to a higher altitude facility until it is released again to generate electricity || In many locations stream size will fluctuate seasonally, during the summer months there will likely be less flow and therefore less power output ||  || People subject to resettlement can be more at risk from health problems where stresses are created by the new project development; i.e. a poorly managed project could result in lack of jobs or income, poor sanitation, or contaminated water supplies ||
 * Hydroelectric plants only need a turbine and generator where as coal-fired stations need a furnace, boiler, condenser, cooling towers etc. || In times of drought, a common occurrence in Australia, water supplies can be reduced drastically thereby reducing the amount of electricity that can be generated ||  || Loss or contamination of traditional food sources and access to traditional fisheries would exacubate project-induced health issues ||
 * Plants can operate for 50 years of more without major displacement ||  ||   || Anaerobic decay processes in large reservoirs has in some cases increased levels of contaminants such as mercury in fish through bio-accumulation. ||
 * Hydro-power generation flexibility enables hydropower to meet sudden fluctuations in demand or help to compensate for the loss of power from other sources; hydro-power can be used for both baseload and peak generation ||  ||   ||   ||

Video Clip - Bogong Hydro-Power Project, VIC: @http://youtu.be/2okm58HSxvo @http://youtu.be/ISJRLW0omcU

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