Page 305 - Electrician - TT (Volume 2)

ELECTRICIAN - CITS

The components of a tidal power station are :
1 A barrage : a barrage is a small wall built at the entrance of a gulf in order to trap water behind it. It will either
trap it by keeping it from going into the gulf when water levels at the sea are high or it will keep water from
going into the sea when water level at the sea is low.
2 Turbines : They are the components responsible for converting potential energy into kinetic energy. They are
located in the passage ways that the water flows through when gates of barrage are opened.

3 Sluices : Sluice gates are the ones responsible for the flow of water through the barrage they could be seen
Fig 2.
4 Embankments : They are caissons made out of concrete to prevent water from flowing at certain parts of the
dam and to help maintenance work and electrical wiring to be connected or used to move equipment or cars
over it.

Advantages of tidal power generation
There are many advantages of generating power from the tide; some of them are listed below.
• Tidal power is a renewable and sustainable energy resource.
• It reduces dependence upon fossil fuels.
• It produces no liquid or solid pollution.

• It has little visual impact.
• Tidal power exists on a world wide scale from deep ocean waters.
Disadvantages and constraint to tidal power generation
Unfortunately, there are also disadvantages and limitations to generating tidal power. Some of these are;

• At the present time both tide and wave energy are suffering from orientation problems, in the sense that neither
method is strictly economical (except in few locations throughout the world) on a large scale in comparison
with conventional power sources.

Fig 2

Power generation by solar energy

Objectives: At the end of this lesson you shall be able to:
• explain the basic principle and construction of the solar cell.

Solar electricity

When sunlight strikes on photovoltaic (PV) solar panel, the electricity is produced. The method of generating the
electrical energy from the solar panel (cells) is termed as solar energy generation.
Generation of electricity by using solar energy depends up on the photovoltaic effect in some specific materials.
There are certain materials that produce electric current when these are exposed to direct sun light. This effect
is seen in combination of two thin layers of semiconductor materials. One layer of this combination will have a
depleted number of electrons.
When sunlight strikes on this layer, it absorbs the photons of sun light ray and consequently the electrons are
excited and jump to the other layer. This phenomenon creates a charge difference between the layer and resulting
to a tiny potential difference between them.

292

CITS : Power - Electrician & Wireman - Lesson 106-116