water power

1. water power Created by: Tymoteusz Zadeberny Michał Kucharski

2. How we receive power from water??? We also have coal or other things that people used to get power in past, but at last they will finish, so we have tried to find some new things which we could use to get power, endless things. To sum up, people found energy in sun, water, wind, biomass etc. And now we will look at power of water. All of us know that water is 71% of our Earth.It’s powerful but getting power from water is more difficult than filling up a bucket of water.

3. Types of hydroelectric power plants - Non-reservoir flow plants - the quantity of produced water by this power plants depends on the quantity of water which is flowing in riverbed at that moment; - Regulatory low (reservoir) flow plants - there is a pondage accumulating water in front of the power plant; - Pumped-storage power plants - water circulation is driven artificially by pumping water successively from the lower- to the higher-elevation reservoir, and then flowing it back through the plant to the lower reservoir.

4. Flow plants Water uses gravity and differences of potential energy in upper and lower river reaches to convert potential energy into kinetic energy. If we put the turbine on the way of water, we would intercept, then use some of energy.

5. Water turbine Water turbine - A water turbine is a device directly akin to a water wheel. Thanks to a rotor complete with blades, it converts water energy into rotary movement. In the case of a hydroelectric power plant, a turbine drives a generator which produces electricity (a kind of power generator). A water turbine can directly capture energy stored in water of a river (or other watercourse). This is how small hydro plants (SHP) work. Larger plants with pondage use dammed up water (serving at the same time as flood control systems and flow regulators). When the energy system reports demand for more electricity, more water is released from the reservoir.

6. Pumped-storage power plant A pumped-storage power plant is an interesting type of a hydro plant. It can supply energy to the power grid or store it. The basic components of such a plant are two reservoirs (upper and lower), which are connected by huge pipes. At times when electricity demand is low and electricity is much cheaper (e.g. at night or in summertime), water is pumped from the lower to the upper reservoir. Electric power is thus converted into potential gravity energy. When more power is needed (and when it is more expensive), the process is reversed – water is released from the upper reservoir to the lower one through a reversible turbine assembly. The devices can be used as pumps (moving water from the lower to the upper reservoir) or as ordinary water turbines.

7. Advantages 1. Once a dam is constructed, electricity can be produced at a constant rate. 2.If electricity is not needed, the sluice gates can be shut, stopping electricity generation. The water can be saved for use another time when electricity demand is high. 3. Dams are designed to last many decades and so can contribute to the generation of electricity for many years / decades. 4. The lake that forms behind the dam can be used for water sports and leisure / pleasure activities. Often large dams become tourist attractions in their own right.

8. More advantages:) 5. The lake's water can be used for irrigation purposes. 6. The buildup of water in the lake means that energy can be stored until needed, when the water is released to produce electricity. 7. When in use, electricity produced by dam systems do not produce green house gases. They do not pollute the atmosphere. Like all, hydro power plants have disadvantages too

9. Disadvantages 1. Dams are extremely expensive to build and must be built to a very high standard. 2. The high cost of dam construction means that they must operate for many decades to become profitable. 3. The flooding of large areas of land means that the natural environment is destroyed. 4. People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcibly removed so that hydro-power schemes can go ahead.

10. More disadvantages:( 5. The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earthquakes and has depressed the earth’s surface at its location. 6. Although modern planning and design of dams is good, in the past old dams have been known to be breached (the dam gives under the weight of water in the lake). This has led to deaths and flooding. 7. Dams built blocking the progress of a river in one country usually means that the water supply from the same river in the following country is out of their control. This can lead to serious problems between neighbouring countries.