JM2 Group

Hi JM2 Group. There has been a lot of things done with water or hydroelectric power - you should be able to find a lot of information! As we get started, ‍‍‍‍‍‍‍I'll add comments in red.‍‍‍‍‍‍‍


  1. Hydroelectricity is generated by the conversion of free-falling water to electricity. the potential energy from the weight of the water falling through a vertical distance is converted into electricity. P=Qh/k where P is the amount of electric power. Q is the volume of water and h is the height through which the water falls. The amount of electricity which can be generated at a hydroelectric plant is dependent upon two factors. Head is once factor or the distance through which the water falls. the other factor is the flow rate, measured per unit of time. The electricity produced is proportional to the product of the head and the rate of flow.
    1. Hydroelectric power continued: ▪ Dam - Most hydropower plants rely on a dam that holds back water, creating a large reservoir .
    2. Intake - Gates on the dam open and gravity pulls the water through the penstock , a pipeline that leads to the turbine. Water builds up pressure as it flows through this pipe.
    3. Turbine - The water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine
      Generators - As the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons.
      Transformer - The transformer inside the powerhouse takes the AC and converts it to higher-voltage current.
      Power lines - Out of every power plant come four wires: the three phases of power being produced simultaneously plus a neutral or ground common to all three.
      Outflow - Used water is carried through pipelines, called tailraces , and re-enters the river downstream.
  2. History of Hydroelectric Power:
    Around 200 B.C., roughly 2000 years ago these ancient civilizations acquired the use of water power
    1. Romans-aqueducts
    2. Egyptians-irrigation and water wheels
    3. Greeks-water wheels to grind wheat into flour
    In the 1700's water power was being used throughout the world for irrigation. In 1882, the first water wheel to generate electricity was built in Wisconsin. After, more plants were produced in Niagara Falls. In 1903 6 major dam projects were approved. In 1911, the Roosevelt dam was constructed. It was not until the 1930's, when larger dams began to be constructed, that the dams affected the environment around them.
  3. There are 5 types of hydroelectric power: Conventional, Pumped Storage, Run of the River, TIde and Underground.
  4. Conventional: Most hydroelectric power comes from the potential energy of ‍‍‍‍‍dammed water ‍‍‍‍‍driving a water turbine and electrical generator. The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head. The amount of potential energy in water is proportional to the head. A large pipe (the penstock) delivers water to the turbine. ‍‍‍‍‍Conventional is the most common source of hydroelectric power. It is also the most effective. ‍‍
  5. Pumped Storage: A resevoir is This method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand, excess generation capacity is used to pump water into the higher reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine. Pumped-storage schemes currently provide the most commercially important means of large-scale grid energy storage and improve the daily capacity factor of the generation system.
  6. Run of the River: Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that the water coming from upstream must be used for generation at that moment, or must be allowed to bypass the dam.
  7. Tide: A tidal power plant makes use of the daily rise and fall of ocean water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, can also be dispatchable to generate power during high demand periods. Less common types of hydro schemes use water's kinetic energy or undammed sources such as undershot waterwheels.
  8. ‍‍‍‍Underground:‍‍‍‍‍‍‍‍‍‍‍ An underground power station makes use of a large natural height difference between two waterways, such as a waterfall or mountain lake. An underground tunnel is constructed to take water from the high reservoir to the generating hall built in an underground cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway.
  9. Advantages:Fuel is not burned so there is minimal pollution Water to run the power plant is provided free by nature. Hydropower plays a major role in reducing greenhouse gas emissions: Although only 33% of theavailable hydroelectric potential has been developed, today hydroelectricity prevents the emission of GHG corresponding to the burning of 4.4 millionbarrels of petroleum per day worldwide. Improves the air we breathe. Relatively low operations and maintenance costs. The technology is reliable. It's renewable. Most dam are used to regulate flooding and control water supply.
  10. Disadvantages of hydroelectric power: There are high investment costs. Hydrology dependent (precipitation). In some cases, inundation of land and wildlife habitatIn some cases, loss or modification of fish habitat. Fish entrainment or passage restriction. In some cases, changes in reservoir and stream water quality. Insome cases, displacement of local populations
  11. Political Influence ie China:Media reports demonizing China's hydropower projects have misled the public and even influenced some decision-making departments of the government. However, hydropower has had systemic influence in developing countries. According to The Economist, countries' support for dams are growing because of two factors; global warming, economic meltdown hitting poorer countries. Climate change is increasing the amount of floods and droughts. This makes it essential to store water. Furthermore, developing countries have the potential to develop hydro energy, store water and benefit financially. Opposition to hydropower by NGO's is moderating. The financial status of the hydroelectric industry is generally healthy due to long equipment life and low maintenance and operating costs. Hydroelectric facilities in the United States had total capital value in 2000 of about $159 billion based on average new facility costs compiled by DOE.

  1. Largest sources of Hydroectric power:
1) The Three Gorges Dam in China
2) TheItaipu Hydroelectricity Power Plant
3) The Guri Dam
4) Tucuruí Dam
5) The Grand Coulee Hydroelectric Power Plant
6) The Sayano–Shushenskaya Dam
7) The Krasnoyarsk Hydroelectric Power Plant
8) The Robert-Bourassa Hydroelectric Power Plant
9) The Churchill Falls Generating Station
10) The Longtan Dam

12. Fun Facts:
  • 7percent of total power is produced by hydroelectric plants.
  • Hydropower is the most important and widely-used renewable source of energy.
  • ‍‍‍‍Hydropower represents 19% of total electricity production.‍‍‍‍
  • China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States Approximately two-thirds of the economically feasible potential remains to be developed.
  • ‍‍‍‍‍Untapped hydro resources are still abundant in Latin America, Central Africa, India ‍‍‍‍‍and China
  • Supplies about 305 of all electricity needs.
  • U.S. department of Energy estimates 1 5 in the efficiency of existing hydroelectric plants could generate enough energy to power 283,000 households.
  • Only 2400 of the existing 80,000 dams in the United States are used to generate power. Many of these “untapped’ dams could be fitted with turbines and generators.

13. Future of Hydroelectric power:

The actual amount of electricity that will ever be generated by hydropower will be much less than its potential. Much of the remaining hydro potential in the world exists in the developing countries of Africa and Asia. In North America and Europe, a large percentage of hydropower potential has already been developed. The public will most likely oppose further construction of hydro schemes. Small-scale and low head hydro capacity will probably increase in the future as research on low head turbines and standardized turbine production reduces the costs of hydroelectric power at sites with low heads. In the future, new computerized control systems and improved turbines may allow more electricity to be generated from existing facilities. Furthermore, increased fuel prices in the future could result in older hydropower facilities being refurbished.

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Bibliography/Sources used:

Drs. Simpson, Ghazzi, and Brest - your research looks good, but I'm not sure if I understand how the energy can be stored when not needed. Is it changed into electricity and then stored/used? Is there a way that we can take advantage of natural weather occurrences that allow the rivers to increase their flow? As you further your research, I'd like to see some information/ideas on implementation and future planning along with meeting the needs of consumers and a cost evaluation.
Hydropower facilities offer a range of additional benefits. Many dams are used to control flooding and regulate water supply, and reservoirs provide lakes for recreational purposes, such as boating and fishing.