This document provides an overview of grid interfaced tidal power plants. It discusses the history of tidal power usage dating back to tidal mills in medieval times. The advantages of tidal power include being clean, non-polluting, and producing a constant, predictable supply of electricity. Disadvantages include tidal power only being economically feasible in locations with a tidal range of over 5 meters and potential environmental impacts. The document describes how tides are formed by the gravitational pull of the moon and sun. It explains the process of harnessing tidal power using tidal barrages, which involve constructing a dam across an estuary with sluice gates and turbines.

1. GRID INTERFACED TIDAL POWER
PLANTS
By
Trisha Gopalakrishna
Zoish Hormusjee
Shashank Pathak

2. Introduction
• The earth is filled with almost 75% water and it is conceivable
that tides based on this pollution free source of energy would
be very cost-effective for generating electricity.
• Tidal energy exploits the natural rise and fall of coastal tidal
waters caused principally by the interaction of the gravitational
fields of the sun and the moon.

3. History
• Tidal mills were in use on the coasts of Spain, France, UK and
China during the medieval period, around 1100 AD.
• They remained in common use for many centuries, but were
gradually replaced by more convenient and cheaper sources
made available due to the industrial revolution.
• The principle used for harnessing this energy consisted of a
pond filled through sluice (rapid controlled gates) when tides
are high and emptying it during low tides via an undershot
waterwheel, producing mechanical power.

4. Advantages
• The energy produced is clean and non polluting.
• There is no carbon dioxide or any other by-products
released. It produces no greenhouse gases or other.
• There are two tides every day and they can be relied on.. So
the electricity supply is constant and efficient.
• Tides are definitely predictable.
• A plant is expected to be in production for 75 to 100 years.
• Uses an abundant, inexpensive fuel source (water) to
generate power
• May protect coastline against damage from high storm
tides and provide a ready-made road bridge

5. Disadvantages
• Economic recovery of energy from tides is feasible only at
those sites where energy is concentrated in the form of
tidal range of about 5m or more and the geography
provides a favorable site for economic construction of a
tidal plant. Thus, it is site specific.
• Changing tidal range in two week periods produces
changing power.
• The turbines are required to operate at variable head.
• Requirement of large water volume flow at low head
necessitates parallel operation of many turbines.
• Tidal power plants disrupt marine life at the location and
can cause potential harm to ecology.

6. Formation of tides
• The highest level of tidal water is known as FLOOD TIDE or HIGH TIDE
and the lowest level is known as LOW TIDE or EBB. The level
difference between the high and low tide id known as TIDAL RANGE.
• The moon exerts a larger gravitational force on the earth, as it is
closer than the sun. Surface water is pulled away form the earth on
the side facing the moon, and at the same time the solid earth is
pulled away from the water on the opposite side.
• Thus the ocean height increases at both the near and far sides of the
earth.
• The solid earth rotates with a period of one day underneath these
two bulges. These bulges are swept westward, due to the earth’s
rotation, as deep ocean waves lasting a period of 12 hours 25
minutes.
• The sun’s effect is similar but smaller in magnitude and with a period
of 12 hours.

8. • When the sun, earth and moon
are aligned in conjunction, the
lunar and solar tides are in
phase, producing net tides of
maximum range. These are
SPRING TIDES occurring twice per
lunar month at times of both full
and new moon.
• When sun-earth and moon-earth
directions are perpendicular, the
solar and lunar tides are out of
phase producing net tides of
minimum range. These are NEAP
TIDES that again occur twice per
month at times of half moon.

9. • The generation of electricity from tidal power can be achieved
using
(i) tidal barrages
(ii) tidal impoundments or lagoons
(iii) tidal stream turbines
• Usually tidal barrage type of plants are set up and hence
discussed further.

10. • The main components of a barrage type tidal plant are-
1. Dam, barrage or dyke- a barrier constructed to hold
water.
2. Sluice ways rapid controlled gates, used to fill a basin
during high tides or emptying it during low tides
3. A Special, bulb type power turbine generator set

11. • A huge dam (called a
"barrage") is built across a
river estuary. When the tide
goes in and out, the water
flows through tunnels in the
dam.
• The ebb and flow of the tides
can be used to turn
a turbine, or it can be used
to push air through a pipe,
which then turns a turbine.

12. Grid Interfacing
The energy harnessed in the form of
mechanical energy , it is converted to
electrical energy with the help of auxiliary
equipment such as submarine cables, a
protection system designed accordingly and
the electrical networks including various
connections and earthing.

14. Videos

16. THANK YOU