A REPORT EDUCATIONAL TOUR TO
HYDRO ELECTRIC POWER STATIONS Submitted to Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad In Partial Fulfilment of Requirements For the award of Degree of
BACHELOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING
By
SUDEEP MISHRA (07K31A0347)
DEPARTMENT OF MECHANICAL ENGINEERING ROYAL INSTITUTE OF TECHNOLOGY & SCIENCE
(Affiliated to Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad) Damergidda(V),Chevella (M), R.R. Dist, Andhra Pradesh
2010-2011 HISTORY OF HYDROPOWER
Humans have been harnessing water to perform work for thousands of years. The Greeks used water wheels for grinding wheat into flour more than 2,000 years ago. Besides grinding flour, the power of the water was used to saw wood and power textile mills and manufacturing plants.
For more than a century, the technology for using falling water to create hydroelectricity has existed. The evolution of the modern hydropower turbine began in the mid-1700s when a French hydraulic and military engineer, Bernard Forest de Bélidor wrote Architecture Hydraulique. In this four volume work, he described using a vertical-axis versus a horizontal-axis machine.
During the 1700s and 1800s, water turbine development continued. In 1880, a brush arc light dynamo driven by a water turbine was used to provide theatre and storefront lighting in Grand Rapids, Michigan; and in 1881, a brush dynamo connected to a turbine in a flour mill provided street lighting at Niagara Falls, New York. These two projects used direct-current technology.
Alternating current is used today. That breakthrough came when the electric generator was coupled to the turbine, which resulted in the world's, and the United States', first hydroelectric plant located in Appleton, Wisconsin, in 1882.
HYDROELECTRIC POWER / HYDROELECTRICITY
Hydro means "water". So, hydropower is "water power" and hydroelectric power is electricity generated using water power. Potential energy (or the "stored" energy in a reservoir) becomes kinetic (or moving energy). This is changed to mechanical energy in a power plant, which is then turned into electrical energy. Hydroelectric power is a renewable resource.
In an impoundment facility (see below), water is stored behind a dam in a reservoir. In the dam is a water intake. This is a narrow opening to a tunnel called a penstock.
Water pressure (from the weight of the water and gravity) forces the water through the penstock and onto the blades of a turbine. A turbine is similar to the blades of a child's pinwheel. But instead of breath making the pinwheel turn, the moving water pushes the blades and turns the turbine. The turbine spins because of the force of the water. The turbine is connected to an electrical generator inside the powerhouse. The generator produces electricity that travels over long-distance power lines to homes and businesses. The entire process is called hydroelectricity. TYPES OF HYDROPOWER PLANTS
There are three types of hydropower facilities: impoundment, diversion, and pumped storage. Some hydropower plants use dams and some do not. The images below show both types of hydropower plants.
Many dams were built for other purposes and hydropower was added later. In the United States, there are about 80,000 dams of which only 2,400 produce power. The other dams are for recreation, stock/farm ponds, flood control, water supply, and irrigation. Hydropower plants range in size from small systems for a home or village to large projects producing electricity for utilities.
IMPOUNDMENT
The most common type of hydroelectric power plant is an impoundment facility. An impoundment facility, typically a large hydropower system, uses a dam to store river water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which in turn activates a generator to produce electricity. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level. DIVERSION
A diversion, sometimes called run-of-river, facility channels a portion of a river through a canal or penstock. It may not require the use of a dam.
PUMPED STORAGE
When the demand for electricity is low, a pumped storage facility stores energy by pumping water from a lower reservoir to an upper reservoir. During periods of high electrical demand, the water is released back to the lower reservoir to generate electricity.
Pumped storage hydro-electricity works on a very simple principle.Two reservoirs at different altitudes are required. When the water is released, from the upper reservoir, energy is created by the downflow which is directed through high-pressure shafts, linked to turbines.
In turn, the turbines power the generators to create electricity.Water is pumped back to the upper reservoir by linking a pump shaft to the turbine shaft, using a motor to drive the pump. The pump motors are powered by electricity from the National Grid - the process usually takes place overnight when national electricity demand is at its lowestA dynamic response - Dinorwig's six generating units can achieve maximum output, from zero, within 16 seconds.Pump storage generation offers a critical back-up facility during periods of excessive demand on the national grid system.
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SIZES OF HYDROELECTRIC POWER PLANTS
Facilities range in size from large power plants that supply many consumers with electricity to small and micro plants that individuals operate for their own energy needs or to sell power to utilities.
Large hydropower Although definitions vary, the U.S. Department of Energy defines large hydropower as facilities that have a capacity of more than 30 megawatts.
Small hydropower Although definitions vary, DOE defines small hydropower as facilities that have a capacity of 100 kilowatts to 30 megawatts.
Microhydropower A microhydropower plant has a capacity of up to 100 kilowatts. A small or microhydroelectric power system can produce enough electricity for a home, farm, ranch, or village.
TURBINES INSTALLATION LAYOUT OF HYDROELECTRIC POWER PLANTS
Hydroelectric power plants convert the hydraulic potential energy from water into electrical energy. Such plants are suitable were water with suitable head are available. The layout covered in this article is just a simple one and only cover the important parts of hydroelectric plant.The different parts of a hydroelectric power plant are
(1) Dam
Dams are structures built over rivers to stop the water flow and form a reservoir.The reservoir stores the water flowing down the river. This water is diverted to turbines in power stations. The dams collect water during the rainy season and stores it, thus allowing for a steady flow through the turbines throughout the year. Dams are also used for controlling floods and irrigation. The dams should be water-tight and should be able to withstand the pressure exerted by the water on it. There are different types of dams such as arch dams, gravity dams and buttress dams. The height of water in the dam is called head race.
(2) Spillway
A spillway as the name suggests could be called as a way for spilling of water from dams. It is used to provide for the release of flood water from a dam. It is used to prevent over toping of the dams which could result in damage or failure of dams. Spillways could be controlled type or uncontrolled type. The uncontrolled types start releasing water upon water rising above a particular level. But in case of the controlled type, regulation of flow is possible.
(3) Penstock and Tunnel Penstocks are pipes which carry water from the reservoir to the turbines inside power station. They are usually made of steel and are equipped with gate systems.Water under high pressure flows through the penstock. A tunnel serves the same purpose as a penstock. It is used when an obstruction is present between the dam and power station such as a mountain.
(4) Surge Tank Surge tanks are tanks connected to the water conductor system. It serves the purpose of reducing water hammering in pipes which can cause damage to pipes. The sudden surges of water in penstock is taken by the surge tank, and when the water requirements increase, it supplies the collected water thereby regulating water flow and pressure inside the penstock.
(5) Power Station Power station contains a turbine coupled to a generator. The water brought to the power station rotates the vanes of the turbine producing torque and rotation of turbine shaft. This rotational torque is transfered to the generator and is converted into electricity. The used water is released through the tail race. The difference between head race and tail race is called gross head and by subtracting the frictional losses we get the net head available to the turbine for generation of electricity.
NATIONAL HYDROELECTRIC POWER CORPORATION
NHPC Limited (Formerly National Hydroelectric Power Corporation), A Govt. of India Enterprise, was incorporated in the year 1975 with an authorised capital of Rs. 2000 million and with an objective to plan, promote and organize an integrated and efficient development of hydroelectric power in all aspects. Later on NHPC expanded its objects to include other sources of energy like Geothermal, Tidal, Wind etc.
Market Value
At present, NHPC is a schedule 'A' Enterprise of the Govt. of India with an authorized share capital of Rs. 1,50,000 Million . With an investment base of over Rs. 2,20,000 million Approx. In 2009-2010 NHPC made a profit after tax of Rs2090 crores . A increase of 94% than the previous year profit of 1050 crores. NHPC is among the top ten companies in India in terms of investment. Department of Public Enterprise, Govt. of India recently conferred prestigious Miniratna status to NHPC.
Initially, on incorporation, NHPC took over the execution of Salal Stage-I, Bairasiul and Loktak Hydro-electric Projects from Central Hydroelectric Projects Control Board. Since then, it has executed 13 projects with an installed capacity of 5175 MW on ownership basis including projects taken up in joint venture. NHPC has also executed 5 projects with an installed capacity of 89.35 MW on turnkey basis. Two of these projects have been commissioned in neighbouring countries i.e. Nepal and Bhutan.
On-going Work
Presently NHPC is engaged in the construction of 11 projects aggregating to a total installed capacity of 4622 MW . NHPC has planned to add 5322 MW during 11th Plan period. 10 projects of 9981 MW are awaiting clearances/Govt. approval for their implementation. Detailed Projects report or Feasibility Report are being prepared for 7 projects of 5755 MW.
Since its inception in 1975, NHPC has grown to become one of the largest organizations in the field of hydro power development in the country. With its present capabilities, NHPC can undertake all activities from concept to commissioning of hydroelectric projects.
This is a list of major hydroelectric power plants in India.
GENERATOR STATIOM COMMUNITY OPERATOR CAPACITY (MW) UNITS
Srisailam Dam Andhra Pradesh APGenco 6 × 150, 7 × 110 1,670 1 X 110, 7 X 100.8,
Nagarjunasagar Andhra Pradesh APGenco 965 5 X 30
Sardar Sarovar Gujarat SSNNL 6X200, 5X140 1,450
Baspa-II Himachal Pradesh JHPL 3 X 100 300
Nathpa Jhakri Himachal Pradesh SJVNL 6 X 250 1,500
Bhakra Dam Punjab BBMB 5 X 108, 5 X 157 1,325
Dehar Himachal Pradesh BBMB 6 X 165 990
Baira Suil Himachal Pradesh NHPC 3 X 60 180
Chamera-I Himachal Pradesh NHPC 3 X 180 540
Chamera-II Himachal Pradesh NHPC 3 X 100 300
Pong Himachal Pradesh BBMB 6 x 66 396 Uri Hydroelectric
Jammu & Kashmir NHPC 4 X 120 480
Dam
Dulhasti Jammu & Kashmir NHPC 3 X 130 390
Salal Jammu & Kashmir NHPC 6 X 115 690 Sardar Sarovar[5] 400
10 X 103.5, 2X27.5, Sharavathi Karnataka KPCL 1,469 4 X 60
Kalinadi Karnataka KPCL 2X50, 2x135, 4X150, 3X50, 1,225 3X40
Linganamakki Dam Karnataka 55
Idukki Kerala KSEB 6 X 130 780
Bansagar Dam Madhya Pradesh 425
Bargi Dam Madhya Pradesh 105
Madikheda Dam Madhya Pradesh 60
Omkareshwar Madhya Pradesh NHPC 8 X 65 520
Indira Sagar Madhya Pradesh NHPC 8 X 125 1,000
Loktak Manipur NHPC 3 X 35 105
Khuga Dam Manipur
Koyna Maharashtra MahaGenco 18 X 106.67 1,920
Mulshi Dam Maharashtra 150
Jayakwadi Dam Maharashtra 12
Kolkewadi Dam Maharashtra
Rangeet Sikkim NHPC 3 X 20 60
Teesta-V Sikkim NHPC 3 X 170 510
Tanakpur Uttarakhand NHPC 3 X 40 120
Dhauliganga-I Uttarakhand NHPC 4 X 70 280
Loharinag Uttarakhand NTPC 4 X 150 600
THE FOLLOWING HYDRO ELECTRIC POWER PLANTS WERE VISITED DURING THE EDUCATIONAL TOUR .
1. NAGARJUNA SAGAR DAM ² ON 29TH NOVEMBER, 2010
2. SRISAILAM HYDRO POWER PLANT ² ON 30TH NOVEMBER, 2010
1. NAGARJUNA SAGAR DAM
FACTS AND FIGURES
Official name Nagarjuna Sagar Dam
Nalgonda District, Andhra Location Pradesh, India
16°36ĻN 79°20ĻE / 16.6°N Coordinates
79.333°E
Construction began 1956
Opening date 1960
Construction cost 1300 crore rupees
DAM AND SPILLWAYS
Length 1,450 metres (4,757 ft)
Height 124 metres (407 ft) from river level
Impounds Krishna River
RESERVOIR
Creates Nagarjuna Sagar Reservoir
Capacity 11,472 million cubic metres
Catchment area 215000 km² (83012 sq mi) Nagarjuna Sagar Dam is the world's largest masonry dam built across Krishna River in Nagarjuna Sagar,Nalgonda District of Andhra Pradesh, India. It is downstream to the Nagarjuna Sagar reservoir with a capacity of up to 11,472 million cubic metres which is the world's largest man-made lake with a concrete wall of that measures 6 ft (1.8 m). thick. The dam is 490 ft (150 m). tall and 16 km long with 26 gates which are 42 ft (13 m). wide and 45 ft (14 m). tall.It is one of the earliest irrigation and hydro-electric projects in India. The dam provides irrigation water to the Nalgonda District, Prakasam District, Khammam District and Guntur District.
HISTORY
The proposal to construct a dam to use the excess waters of the Krishna river was put forward by the British rulers in 1903. Siddeswaram, Hyderabad and Pulichintala were identified as the suitable locations for the reservoirs. The perseverance of the Raja of Muktyala paved way for the site identification, design and construction of the dam.
PROJECT CONSTRUCTION
The dam water was released by the then Prime Minister's daughter, Indira Gandhi in 1967.[5] The construction of the dam submerged an ancient Buddhist settlement, Nagarjunakonda, which was the capital of the Ikshvaku dynasty in the 1st and 2nd centuries, the successors of the Satavahanas in the Eastern Deccan. Excavations here had yielded 30 Buddhist monasteries, as well as art works and inscriptions of great historical importance. In advance of the reservoir's flooding, monuments were dug up and relocated. Some were moved to Nagarjuna's Hill, now an island in the middle of the reservoir. Others were moved to the mainland.
EFFECT OF THE PROJECT
Nagarjuna Left Canal
The project benefited farmers in the districts of Guntur, Prakasam, Krishna, Nalgonda and Khammam. The right canal (a.k.a Jawahar canal) is 203 km long and irrigates 1.113 million acres (4,500 km²) of land. The left canal (a.k.a Lalbahadur Shastri canal) is 295 km long and irrigates 0.32 million acres (800 km²) of land in Nalgonda and Khammam districts of Telangana region. The project transformed the economy of above districts. 52 villages were submersed in water and 24000 people were affected. The relocation of the people was completed by 2007.[4]
POWER GENERATION
The hydroelectric plant has a power generation capacity of 815.6 MW with 8 units (1x110 MW+7x100.8 MW). First unit was commissioned on 7 March 1978 and 8th unit on 24 December 1985. The right canal plant has a power generation capacity of 90 MW with 3 units of 30 MW each. The left canal plant has a power generation capacity of 60 MW with 2 units of 30 MW each.[7]
The dam is constructed on the border of Guntur and Nalgonda districts. The dam also provides drinking water to the Nalgonda town. 2. SRISAILAM HYDRO POWER PLANT
FACTS & FIGURES
Location Srisailam, India
16°05Ļ13ļN Coordinates 78°53Ļ50ļE / 16.08694°N 78.89722°E
Construction began 1960
Opening date 1981
DAM AND SPILLWAYS
Length 512 m (1,680 ft)
Height 241 m (791 ft)
Impounds River Krishna
Reservoir
Creates Srisailam Reservoir
Catchment area 206,040 km2 (79,550 sq mi)
Surface area 800 km2 (310 sq mi)
POWER STATION CAPACITY
6 × 150MW (left bank) Turbines 7 × 110MW (right bank)
Installed capacity 1,670 MW
The Srisailam Dam is a dam constructed across the Krishna River at Srisailam in the Kurnool district in the state of Andhra Pradesh in India and is the 2nd largest capacity hydroelectric project in the country.
The dam was constructed in a deep gorge in the Nallamala Hills, 300 m (980 ft) above sea level. It is 512 m (1,680 ft) long, 240.79 m (790.0 ft) high and has 12 radial crest gates. It has a huge reservoir of 800 km2 (310 sq mi). The left bank hydroelectric power station generates 6 × 150 MW of power and right bank generates 7 × 110 MW of power. the dam also surrounded by thick forests and beautiful sceneries.
The Srisailam project began in 1960, initially as a power project, across the Krishna, near Srisailam in Andhra Pradesh. After several delays, the main dam was finally completed twenty years later in 1981. In the meantime the project was converted into a multipurpose facility with a generating capacity of 770 MW by its second stage which was expected to be completed in 1987. The dam is to provide water for an estimated 2,000 km2 (770 sq mi) with its catchment area of 206,040 km2 (79,552 sq mi) and water spread of 1,595 km2 (616 sq mi). Under the right branch canal 790 km2 (310 sq mi) in Kurnool and Cuddapah districts will have assured irrigation. From the initial modest estimate of Rs.384.7 million for a power project the total cost of the multipurpose project was estimated to cross Rs.10 billion in its enlarged form. The 143 m (469 ft) high and 512 m (1,680 ft) wide dam has alone cost Rs.4.04 billion together with the installation of four generating sets of 110 MW each.
The right branch canal is estimated to cost Rs.4.49 billion and the initial investment of Rs.1.4 billion has been provided by the World Bank. The projected cost-benefit ratio of the project has been worked out at 1:1.91 at 10% interest on capital outlay.On 2 October 2009, SriSailam dam experienced a record inflow which threatened the dam.
Srisailam Hydel Power Project Important Dates
Project Status: Completed Project Type/Scale: New Unit Industry: Electricity Generation - Hydel Based Investment/Estimated Cost: Rs. 2,500.00 Crores / USD 625.00 Million Monday, September 01, 1986 Planning Commission approval received Wednesday, May 31, 1995 Initial commissioning date Tuesday, December 31, 1996 Expenses incurred till 1 (Rs. 1,123.63 Crores) Wednesday, February 28, 2001 Expenses incurred till 1 (Rs. 2,300.00 Crores) Friday, April 27, 2001 First unit commissioned Monday, October 29, 2001 Second Unit Commissioned Sunday, April 21, 2002 Third Unit Commissioned Friday, November 29, 2002 Fourth Unit Commissioned Friday, March 28, 2003 First unit commissioned Thursday, July 31, 2003 Sixth unit completion by Thursday, September 04, 2003 Sixth Unit Commissioned Tuesday, September 30, 2003 Completed Friday, October 31, 2003 Completion by
Future Project :- Srisailam Mini Dam
Company: Andhra Pradesh Power Generation Corpn. Ltd. Ownership: State Govt. - Commercial Enterprises Project Location: 14.5 kms down main Srisailam dam,Srisailam, Kurnool district, Andhra Pradesh, India
Project Status: Active Project Type/Scale: New Unit Industry: Storage & Distribution Investment/Estimated Cost: Rs. 100.00 Crores / USD 25.00 Million Thursday, January 01, 2004 Date of announcement Saturday, July 31, 2004 Initial commissioning date
ADVANTAGES AND DISADVANTAGES OF HYDROPOWER
Hydropower offers advantages over other energy sources but faces unique environmental challenges.
ADVANTAGES
Hydropower is a fueled by water, so it's a clean fuel source. Hydropower doesn't pollute the air like power plants that burn fossil fuels, such as coal or natural gas.
Hydropower is a domestic source of energy.
Hydropower relies on the water cycle, which is driven by the sun, thus it's a renewable power source.
Hydropower is generally available as needed; engineers can control the flow of water through the turbines to produce electricity on demand.
Hydropower plants provide benefits in addition to clean electricity.
Impoundment hydropower creates reservoirs that offer a variety of recreational opportunities, notably fishing, swimming, and boating. Most hydropower installations are required to provide some public access to the reservoir to allow the public to take advantage of these opportunities. Other benefits may include water supply and flood control.
DISADVANTAGES
Fish populations can be impacted if fish cannot migrate upstream past impoundment dams to spawning grounds or if they cannot migrate downstream to the ocean. Upstream fish passage can be aided using fish ladders or elevators, or by trapping and hauling the fish upstream by truck. Downstream fish passage is aided by diverting fish from turbine intakes using screens or racks or even underwater lights and sounds, and by maintaining a minimum spill flow past the turbine.
Hydropower can impact water quality and flow. Hydropower plants can cause low dissolved oxygen levels in the water, a problem that is harmful to riparian (riverbank) habitats and is addressed using various aeration techniques, which oxygenate the water. Maintaining minimum flows of water downstream of a hydropower installation is also critical for the survival of riparian habitats.
Hydropower plants can be impacted by drought. When water is not available, the hydropower plants can't produce electricity.
New hydropower facilities impact the local environment and may compete with other uses for the land. Those alternative uses may be more highly valued than electricity generation. Humans, flora, and fauna may lose their natural habitat. Local cultures and historical sites may be impinged upon. Some older hydropower facilities may have historic value, so renovations of these facilities must also be sensitive to such preservation concerns and to impacts on plant and animal life.