Question

a) What is hydroelectric power?
b) Explain the mechanism of electricity generation in a hydropower station.
c) What is the need to construct a dam over a river in a hydropower station?

Answer 1

(a)

1. Hydroelectric power, also called hydropower, is electricity produced from generators driven by turbines that convert the potential energy of falling or fast-flowing water into mechanical energy.
2. Hydropower can supply large amounts of low-carbon electricity on-demand, making it key to many secure and clean electricity grids.
3. With a dam and reservoir, it is also a flexible source of electricity, since the amount produced by the station can be varied up or down in seconds or minutes to adapt to changing energy demands.
4. Once a hydroelectric complex is constructed, the project produces no direct waste, and it almost always has a considerably lower output level of greenhouse gases than fossil fuel-powered energy plants.

(b)

1. Hydroelectric power is produced with moving water because the source of hydroelectric power is water, hydroelectric power plants are usually located on or near a water source.
2. The volume of the water flow and the change in elevation—or fall, often referred to as head—from one point to another determine the amount of available energy in moving water.
3. In general, the greater the water flow and the higher the head, the more electricity a hydropower plant can produce.
4. At hydro power plants, water flows through a pipe, or penstock then pushes against and turns blades in a turbine to spin a generator to produce electricity.
5. 

(c)

1. A hydroelectric dam is one of the major components of a hydroelectric facility.
2. A dam is a large, man-made structure built to contain some body of water.
3. In addition to construction for the purpose of producing hydroelectric power, dams are created to control river flow and regulate flooding.
4. In some rivers, small-scale dams known as weirs are built to control and measure water flow.
5. Dams are just one component of a complete hydroelectric facility but are one major, visible component in the system.
6. The purpose of a hydroelectric dam is to provide a place to convert the potential and kinetic energy of water to electrical energy by using a turbine and generator.
7. Dams act as the place where water is held back and released in a controlled manner through hydraulic turbines, enabling the mechanical energy of the water to be transformed into electrical energy.
8.