This document discusses hydroelectric power generation. It describes factors to consider when selecting a generation site, such as topography and geology. It also outlines different types of hydroelectric power plants, including run-of-river, pumped storage, and impoundment. The document explains how hydroelectric power is generated by harnessing the kinetic energy of flowing water using dams, turbines, and generators to produce electricity. It notes both advantages, such as being renewable and reliable, and disadvantages, such as high construction costs and potential environmental impacts.
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Hydro electric power generation
1.
2.
3. This is the generation of power by harnessing the
energy of flowing water.
This presentation will focus on;
* Factors considered when selecting the generation site
* Types of hydro-electric power plants
* How power is generated using this method
* Advantages and Disadvantages of this method
4. • The dam’s, bed and walls must sustain the
hydraulic pressures of water hence the
following should be considered;
*Good topographical location along the river
(wide and flat valley)
*Right geological structure (strong & stable rock
structure)
*Availability of sufficient water (flow of the
river should accommodate for evaporation in the
dam)
5. • Before development of a station the expected
power is computed as follows;
The measure of mechanical energy=THP
THP= (Q * H) /8.8
Q=flow rate[m3/s] , H= head[m] , 8.8=constant
Expected power is given by conversion 1THP= 746W
6. These power stations have different capacities
of power varying from each size;
* Large Hydropower (more than 30MW)
* Small Hydropower (100 kW to 30 MW)
* Micro Hydropower (up to 100 kW)
8. • It is a method of keeping water in reserve for
peak period power demands by pumping
water that has flowed through the turbines
back up a storage pool at a time when
customer demand for energy is low i.e.
(during the middle of the night).
9. * A run-of-water-project(diversion), facility channels a
portion of a river through a canal or penstock.
* It may not require the use of a dam.
An example of diversion
hydro-power plant in
Alaska
10. • This is most common type of
hydroelectric power plant.
• It is a large hydropower system, that uses
a dam to store river water in a reservoir.
11.
12. • The dam stores water behind it in the reservoir.
• Gravity causes the water to fall through the intake
into the penstock inside the dam.
• The moving water turns the turbine propeller at
the end of the penstock.
• The turbine shaft spins the generator.
• As the generator rotor spins the magnets, a flow of
electrons is created in the coils of the stator.
• The produced electricity is stepped up and
transmitted to consumers.
• The water continues past the propeller into the
river.
13. The key tech element involved in the energy
conversion process is mechanical-to-electrical.
The major components are;
1.Turbines
(a) impulse turbine:-applicable were high head of
water is available.
(b) reaction turbine:-used for head below 450m
15. * No pollution
* Renewable energy source
* Very reliable energy source
* Not expensive to maintain
* Can increase or decrease the plant’s production
whenever there is high or low demand
respectively
* Water can be stored, waiting to be used in peak
times
16. * Building the dam is expensive and time taking
* Silt deposits can shorten the operational
lifespan of hydroelectric reservoirs
* Relocation of the people living were the dam
is to be built
17. • Hydro-electric power is an important part of
the world's electricity supply, providing
reliable, cost effective electricity, and is
expected to continue to do so in the future.
• Hydro power has less negative environmental
impacts which are very different from those of
fossil fuel power plants.