1. A Report On,
Hydro Power
Plant
Created By,
Gaurav S. Maniar
Karan S. Raithatha
Electronics & Communication Department,
Dasrshan Institute Of Engineering & Technology
2. CHAPTER 1: INTRODUCTION
1.1 Introduction
Energy is the most important thing in this world. All living plants, animals (organisms)
on this earth require energy to perform any type of work. The capacity to do a work is
energy. The energy may require in smaller amount or in larger amount depending
upon the nature of work to be performed.
The different things from which we get the energy are called as Energy Sources. This
is the simplest meaning of energy sources.
Hydropower, hydraulic power, hydrokinetic power or water power is power that is
derived from the force or energy of moving water, which may be harnessed for useful
purposes. Prior to the development of electric power, hydropower was used
for irrigation, and operation of various machines, such
as watermills, textile machines, sawmills, dock cranes, and domestic lifts.
In hydrology, hydropower is manifested in the force of the water on the riverbed and
banks of a river. It is particularly powerful when the river is in flood. The force of the
water results in the removal of sediment and other materials from the riverbed and
banks of the river, causing erosion and other alterations.
1.2 Conventional OR Non-Renewable Energy Sources
The energy sources, which we are using from long time and which are in danger of
exhausting, are called as Conventional OR Non-Renewable Energy Sources. They are
not renewed by Nature and they are perishable, are going to get exhausted one day.
e. g. coal, petroleum products, nuclear fuels etc.
1.3 Non-Conventional OR Renewable Energy Sources
These are the energy sources whose utilization technology is not yet fully developed.
These are the sources, which can be recovered and reused. i. e. they can be used again
and again to generate energy because of the renewal of their energy.
We are going to consider one of the ways of generation of energy from non-
conventional energy namely hydroelectric energy.
As name suggest, it is the energy obtained from water. The main principle used in this
type is the kinetic energy of falling water is converted into electric energy using
turbines.
Hydroelectricity is the term referring to electricity generated by hydropower; the
production of electrical power through the use of the gravitational force of falling or
flowing water. It is the most widely used form of renewable energy.
3. 1.4 History
Fig 1. Irrigation Water Wheel
A water wheel is a machine for converting the energy of free-flowing or falling
water into useful forms of power. A water wheel consists of a large wooden or metal
wheel, with a number of blades or buckets arranged on the outside rim forming the
driving surface. Most commonly, the wheel is mounted vertically on a
horizontal axle, but the tub or Norse wheel is mounted horizontally on a vertical
shaft. Vertical wheels can transmit power either through the axle or via a ring
gear and typically drive belts or gears; horizontal wheels usually directly drive their
load.
4. CHAPTER 2: Hydro Energy
Fig. 2 Hydrological Cycle
The total amount of water on the earth and in its atmosphere does not change but the
earth‟s water is always in movement. Oceans, rivers, clouds and rain, all of which contain
water, are in a frequent state of change and the motion of rain and flowing rivers transfers
water in a never-ending cycle. This circulation and conservation of earth‟s water as it
circulates from the land to the sky and back again is called the „hydrological cycle‟ or
„water cycle‟.
The hydrologic cycle begins with the evaporation of water from the surface of the ocean.
As moist air is lifted, it cools and water vapor condenses to form clouds. Moisture is
transported around the globe until it returns to the surface as precipitation. Once the water
reaches the ground, one of two processes may occur;
1) some of the water may evaporate back into the atmosphere or
2) the water may penetrate the surface and become groundwater. Groundwater either
seeps its way to into the oceans, rivers, and streams, or is released back into the
atmosphere through transpiration. The balance of water that remains on the earth's
surface is runoff, which empties into lakes, rivers and streams and is carried back to
the oceans, where the cycle begins again.
5. CHAPTER 3: Power Plants
There are 5 different ways to generate electricity from hydro energy.
3.1 Conventional Dam
Most hydroelectric power comes from the potential energy of dammed water driving
a water turbine and generator. The power extracted from the water depends on the
volume and on the difference in height between the source and the water's outflow.
This height difference is called the head. The amount of potential energy in water is
proportional to the head. A large pipe delivers water to the turbine.
Fig.3 Conventional Dam
6. 3.2 Pumped Storage
This method produces electricity to supply high peak demands by moving water
between reservoirs at different elevations. At times of low electrical demand, excess
generation capacity is used to pump water into the higher reservoir. When there is
higher demand, water is released back into the lower reservoir through a turbine.
Pumped-storage schemes currently provide the most commercially important means of
large-scale grid energy storage and improve the daily capacity factor of the generation
system.
The method stores energy in the form of water, pumped from a lower elevation
reservoir to a higher elevation. Low-cost off-peak electric power is used to run the
pumps. During periods of high electrical demand, the stored water is released
through turbines to produce electric power. Although the losses of the pumping process
makes the plant a net consumer of energy overall, the system increases revenue by
selling more electricity during periods of peak demand, when electricity prices are
highest. Pumped storage is the largest-capacity form of grid energy storage now
available.
Fig. 4 Pumped Storage Power Plant
7. This system may be economical because it flattens out load variations on the power
grid, permitting thermal power stations such as coal-fired plants and nuclear power
plants and renewable energy power plants that provide base-load electricity to continue
operating at peak efficiency, while reducing the need for "peaking" power plants that
use the same fuels as many base load thermal plants, gas and oil, but have been
designed for flexibility rather than maximal thermal efficiency. However, capital costs
for purpose-built hydro storage are relatively high.
Along with energy management, pumped storage systems help control electrical
network frequency and provide reserve generation. Thermal plants are much less able
to respond to sudden changes in electrical demand, potentially causing frequency
and voltage instability. Pumped storage plants, like other hydroelectric plants, can
respond to load changes within seconds.
3.3 Run Of The River
Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so
that the water coming from upstream must be used for generation at that moment, or
must be allowed to bypass the dam. A dam – smaller than used for traditional hydro – is
required to ensure there is enough water to enter the “penstock” pipes that lead to the
lower-elevation turbines.
Run-of-the-river hydroelectricity is ideal for streams or rivers with a minimum dry
weather flow or those regulated by a much larger dam and reservoir upstream. A dam,
smaller than that used for traditional hydro, is required to ensure that there is enough
water to enter the "penstock" pipes that lead to the lower-elevation turbines. Projects
with poundage, as opposed to those without poundage, can store water for peak load
demand or continuously for base load, especially during wet seasons. In general,
projects divert some or most of a river‟s flow through a pipe and/or tunnel leading to
electricity-generating turbines, then return the water back to the river downstream.
8. Fig. 5 Run of the River
ROR projects are dramatically different in design and appearance from conventional
hydroelectric projects. Traditional hydro dams store enormous quantities of water
in reservoirs, necessitating the flooding of large tracts of land. In contrast, most run-of-
river projects do not require a large impoundment of water, which is a key reason why
such projects are often referred to as environmentally-friendly, or "green power."
The use of the term "run-of-the-river" for power projects varies around the world and is
dependent on different definitions. Some may consider a project ROR if power is
produced with no storage while a limited storage is considered by others. Developers
may mislabel a project ROR to sooth public image about its environmental or social
effects.
9. 3.4 Tidal Power
A tidal power plant makes use of the daily rise and fall of ocean water due to tides; such
sources are highly predictable, and if conditions permit construction of reservoirs, can
also be dispatchble to generate power during high demand periods. Less common types
of hydro schemes use water's kinetic energy or undammed sources such as
undershot waterwheels.
Tidal power is extracted from the Earth's oceanic tides; tidal forces are periodic variations
in gravitational attraction exerted by celestial bodies. These forces create corresponding
motions or currents in the world's oceans. The magnitude and character of this motion
reflects the changing positions of the Moon and Sun relative to the Earth, the effects of
Earth's rotation, and local geography of the sea floor and coastlines.
Fig. 6 Working
A tidal generator converts the energy of tidal flows into electricity. Greater tidal variation
and higher tidal current velocities can dramatically increase the potential of a site for tidal
electricity generation.
Tidal stream generators make use of the kinetic energy of moving water to power
turbines, in a similar way to wind turbines that use wind to power turbines.
Tidal barrages make use of the potential energy in the difference in height between high
and low tides. Barrages are essentially dams across the full width of a tidal estuary.
10. Fig. 7 Schematic
3.5 Under Ground
An underground power station makes use of a large natural height difference between
two waterways, such as a waterfall or mountain lake. An underground tunnel is
constructed to take water from the high reservoir to the generating hall built in an
underground cavern near the lowest point of the water tunnel and a horizontal tailrace
taking water away to the lower outlet waterway.
Fig. 8 Working of Underground Plant
12. CHAPTER 4: Classification Of Turbines
Flowing water is directed on to the blades of a turbine runner, creating a force on the
blades. Since the runner is spinning, the force acts through a distance. In this way, energy
is transferred from the water flow to the turbine. Water turbines are divided into two
groups; reaction turbines and impulse turbines. The precise shape of water turbine blades
is a function of the supply pressure of water, and the type of impeller selected.
There are mainly two types of turbines used in hydro electric power plant to generate
electricity. Classification of turbine is given below.
Turbine
Impulse Reaction
Turbine Turbine
Water
Pelton Turgo Francis Tyson Kalpan
Wheel
4.1 Impulse Turbine
Impulse turbines change the velocity of a water jet. The jet pushes on the turbine's
curved blades which changes the direction of the flow. The resulting change in
momentum causes a force on the turbine blades. Since the turbine is spinning, the force
acts through a distance and the diverted water flow is left with diminished energy.
Prior to hitting the turbine blades, the water's pressure is converted to kinetic energy by
a nozzle and focused on the turbine. No pressure change occurs at the turbine blades,
and the turbine doesn't require a housing for operation.
Impulse turbines are most often used in very high head applications.
Newton's second law describes the transfer of energy for impulse turbines.
13. 4.2 Reaction Turbine
Reaction turbines are acted on by water, which changes pressure as it moves through the
turbine and gives up its energy. They must be encased to contain the water pressure (or
suction), or they must be fully submerged in the water flow.
Newton's third law describes the transfer of energy for reaction turbines.
Most water turbines in use are reaction turbines and are used in low and medium head
applications. In reaction turbine pressure drop occurs in both fixed and moving blades.
14. CHAPTER 5: Important Points
5.1 Advantages
Renewable source of energy thereby saves scares fuel reserves.
Economical source of power.
Non-polluting and hence environment friendly.
Reliable energy source with approximately 90% availability.
Low generation cost compared with other energy sources.
Indigenous, inexhaustible, perpetual and renewable energy source.
Low operation and maintenance cost.
Possible to build power plant of high capacity.
Plant equipment is simple.
Socio-economic benefits being located usually remote areas.
Higher efficiency, 95%to98%.
Fuel is not burned so there is minimal pollution.
Water to run the power plant is provided free by nature.
It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always
there.
5.2 Disadvantages
Susceptible to vagaries of nature such as draught.
Longer construction period and high initial cost.
Loss of large land due to reservoir.
Non-availability of suitable sites for the construction of dam.
Displacement of large population from reservoir area and rehabilitation.
Environmental aspect reservoirs verses river ecology.
High cost of transmission system for remote sites.
They use up valuable and limited natural resources
They can produce a lot of pollution.
Companies have to dig up the Earth or drill wells to get the coal, oil, and gas.
For nuclear power plants there are waste-disposal problems.
15. CHAPTER 6: References
Domkundwal
Maps Of India
Wikipedia
Google Images
Indian Energy Portal
International Energy Association Data