Here is a compilation of term papers on ‘Hydro Power Plant’ for class 7, 8, 9, 10, 11 and 12. Find paragraphs, long and short term papers on ‘Hydro Power Plant’ especially written for school and college students.
Term Paper on Hydro Power Plant
Term Paper Contents:
- Term Paper on the Introduction to Hydro Power Plant
- Term Paper on the Elements of Hydro Power Plants
- Term Paper on the Types of Hydro Power Plants
- Term Paper on the Classification of Hydro Power Plants Based on Installed Capacity
- Term Paper on the Selection of Site for Hydro Power Plant
- Term Paper on the Layout of a Hydro Power Installation
- Term Paper on the Calculation of Hydro Power Plant
- Term Paper on the Advantages of Hydroelectric Power Plants
- Term Paper on the Disadvantages of Hydro Power Plants
- Term Paper on the Control, Automation and Monitoring System in a Hydroelectric Power Plant
Term Paper # 1. Introduction to Hydro Power Plant:
To meet Irrigation demand water has to be spread over land which the crops utilise consumptively and the water gets lost. But in generation of hydro power only benefit is taken of potential energy of water. Once that potential is used water is available for other uses. Thus irrigation and power generation objectives can be combined gainfully.
Hydro power has been occupying an important place in power supply industry ever since its inception in the country. This has been mainly due to the fact that hydro power forms the cheapest source of power inspite of the technological advances that have taken place in the field of thermal and nuclear power.
India is blessed with numerous sites where hydro power can be generated economically. The surface water resource can be harnessed gainfully for power generation provided that continuous and abundant water supply with reasonable potential energy or head of water or drop is available at a particular site.
The water with sufficient potential energy is taken over the blades of a turbine which provides motive power for the generator directly coupled on a common shaft. The water then passes down and is disposed off suitably. Thus the basic objective of any hydro power project is to provide motive power to the generators which generate electricity.
A complete hydroelectric installation includes hydraulic structures for interception, collection and storage of water, for its diversion to the turbines and for its disposal after the use. In addition, it includes power house where turbines together with control apparatus and electricity generators with switch gear, transformers etc., are installed.
Term Paper # 2. Elements of Hydro Power Plants:
Hydropower plant generates electricity or mechanical power by converting the power available in flowing water of rivers, canals and streams. The objective of a hydropower scheme is to convert the potential energy of a mass of water flowing in a stream with a certain fall, called head, into electric energy at the lower end of the scheme, where the powerhouse is located. The power of the scheme is proportional to the flow and to the head.
Term Paper # 3. Types of Hydro Power Plants:
Depending upon the head of water available the hydro power plants can be identified as:
(i) Low-head Installation which operates under a head of a few metres;
(ii) High-bead installation where the head of water may go upto 2000 metres or so; and
(iii) Medium-head hydro-electric installations with intermediate head. The installations where dams create most or all of the head fall under this category.
It may be clear by now that the sites for high head plants are generally available in the upper reaches of the river valley. The advantage of the high head installation is that since the head is great, the quantity of water required to generate a fixed quantity of power is smaller as compared to low-head plants. As a result the cost of installation per kilowatt of generating capacity is less in high-head installations.
Alternatively depending upon the nature of the source of supply of water the hydro-power plants may be either:
(i) Run-of-river installation where power is generated on the basis of day-to- day flow in the river, or
(ii) Storage installation where sufficient storage is created to take care of seasonal variations in the run-off of the river or stream.
The third division of hydro power stations could be done on the operational basis.
Under this classification we may have following three types:
(i) Peaking Hydro Power Station:
Here the power station is operated only during fixed hours a day or season to meet the excess demand or the peaks which remain beyond the capacity of the power stations operating regularly to generate fixed amount of power.
(ii) Base-Load Installation:
When large and relatively uniform water supply is available the hydro power installation may run continuously and regularly to meet the base load or firm demand of power.
(iii) Micro Installation:
As the name suggests this type is a very small hydro power station capable of generating as low an output as 10 kW. This type is generally adopted in the sparsely populated and widely scattered hilly terrain.
Term Paper # 4. Classification of Hydro Power Plants Based on Installed Capacity:
Hydroelectric power plants can be classified on various basis such as type of Head available (low, medium or high head), based on load (base load peak load, etc.), and based on Quantity of water available (run of river without pond, run of river with pond, reservoir, etc.).
Apart from this classification, hydroelectric power plants on the basis of installed capacity can be categorized as:
Large hydro, Medium hydro, Small hydro, Mini hydro and Micro hydro, etc. Generally the Mini, Micro and Pico hydro come under the subcategory of Small hydro.
The description of these are as follow:
Large-Hydro – More than 100 MW and usually feeding into a large electricity grid
Medium-hydro – 15 -100 MW – usually feeding a grid
Small-hydro – 1-15 MW – usually feeding into a grid
Mini-hydro – Above 100 kW, but below 1 MW; either stand-alone schemes or more often feeding into the grid
Micro-hydro – From 5 kW up to 100 kW; usually provided power for a small community or rural industry in remote areas away from the grid
Pico-hydro – From a few hundred watts up to 5 kW
Apart from the above said classification, there is also a class of very large hydro power plants coming up these days worldwide with capacity ranging from more than 5000 MW up to 10,000 MW due to the large scale investment and better technology available.
However as far as Small hydro is concerned the upper and lower limits varies from country to country while defining the Small hydro. There is a general tendency all over the world to define small hydro by power output. Different countries are following different norms keeping the upper limit ranging from 5 to 50 MW.
In India, small hydro schemes are further classified by the Central Electricity Authority (CEA) as follows:
Term Paper # 5. Selection of Site for Hydro Power Plant:
The river flows are characterised by wide fluctuations during different seasons of the year and also during various years depending upon variations in prevalent rainfall.
As a result firm or uniform power generation mainly depends upon the extent to which the fluctuations in river flows can be minimised by constructing regulatory hydraulic structures. The factors which influence the choice of a site for constructing hydro- power station can be grouped under three categories namely, topographical, geological and hydrological factors.
The main considerations to be taken into account are the following:
(i) Topographical limitations of a river valley in affording suitable site constitute major consideration.
(ii) Geological limitations of sites for construction of regulating dams, and of water conductor systems for utilising the drops along the river course is also an important consideration.
(iii) Considering the increasing pressure of population on the land the feasibility of submergence of useful land under reservoir area.
(iv) Diversion of water for other priority uses like irrigation severely affects power potential.
(v) In case of storage installations other uses of water for example requirements for irrigation, flood control, industrial water supply often make competing claim on limited storage capacity thereby jeopardising power potential.
Term Paper # 6. Layout of a Hydro Power Installation:
The nature, size and arrangement of various structures which constitute hydro-power installation depend upon topographical, geological and hydrological factors. In principle, however, there is similarity in the types of structures required for generation of electricity from the water power.
A hydro power plant consists of the following works which form the nucleus of every installation:
1. A structure to intercept and to regulate the free flow of water. It may be in the form of a dam or a weir or a barrage.
2. Head race or intake conduit together with gates, trash racks, surge tank etc. to control the entry of water from the reservoir on to the turbines. The intake arrangement may be in the form of a tunnel, or open channel or penstock or combination thereof.
3. A power station where motive power obtained from water flow is utilised to generate electrical energy.
It houses:
(a) Turbines together with controlling devices, and
(b) Generators and other regulatory apparatus like switch gear, transformers etc. Transmission system is generally considered out of the purview of a hydro-power plant.
4. Tail race or exist conduit to lead the water back into the river or artificial channel for its subsequent use for irrigation or other purposes.
General arrangement of various types of work, have been shown in figures 20.1, 20.2, 20.3 and 20.4. It may be seen that in Fig. 20.1 water is taken from a reservoir, built in the upper reaches of a river valley in a remote place, by means of a pressure tunnel to the power house located down below at a suitable place to utilise the high head available at the site. The main conduit may run for several kilometres before it ends near the power house.
Alternatively when the situation permits an open headrace channel can be built with a flat gradient to bring the water down from the remote reservoir. The channel ends in a forebay or a head pond. From the forebay the water is taken down to the power house by penstock. After use the water is conveyed back to the river by a tail race channel.
In a medium head installation all the head is created by an intercepting dam. Fig. 20.2 shows the hydro power installation at a dam site with medium head. Here the main conduit is short and consists of penstock taken through the dam and the power is developed locally at the dam site.
In canals and lower reaches of the rivers where large discharges at very low heads are available low-head hydro power plants are constructed. Fig 20.3 shows a conventional low-head installation.
Recently a tubular type of turbine has been put in use on big canals in our country. It utilises large discharges at very low-heads of the order of 6 metres. Fig. 20.4 shows low-head installation with tubular turbines on an irrigation canal.
Term Paper # 7. Calculation of Hydro Power Plant:
The theoretical power available from falling water can be calculated using following formula.
where Pt = theoretical output in metric horse power
ρ = unit weight of water in kg/m3
Q = flow through turbine (or quantity of water available for hydro power generation) in cumec
H = head available in metres.
Note: 1 Metric H.P. = 75 kg. m/sec.
The actual useful or effective output depends upon the efficiency of the various parts of the installation. Assuming that efficiency of pipe lines, intake etc. (e1) as 94 to 98% and that of hydraulic turbine (e2) as 80 to 90%, the overall efficiency (e) will be equal to the product of e1 and e2 and may be taken as 75%.
Since the turbine and the generator are directly coupled on the common shaft the hydro electrical power available will be given by equation:
Pe = Pt × e (where Pe is effective out-put and e is overall efficiency)
= e. (ρ/75) Q.H (taking p = 1000 kg/m3)
Pe = 10 Q. H. metric horse powers
Since 1 metric horse power = 0.7355 KW
Available hydro power Pe in KW = 7.355 Q.H
Example:
A canal drop is 6 metres, and discharge available through turbine is 50 cumec. Find the electrical energy available.
Solution:
Pe = 7.355 × 50 × 6
= 2206.5 KW
Term Paper # 8. Advantages of Hydroelectric Power Plants:
The advantages that hydroelectric power-offer over thermal power plants are immense:
1. Hydropower is a renewable source of energy as it is generated by a combination of the unending rain cycle and the abrupt topography of the earth.
2. It is non-polluting and hence environment friendly.
3. Though hydroelectric power projects take a long time to be built, they have a very long life. The first hydro-project completed in 1897 is still in operation.
4. Cost of generation, operation and maintenance is lower than the other sources of energy.
5. Ability to start and stop quickly and instantaneous load acceptance/rejection makes it suitable to meet peak demand and for enhancing system reliability and stability.
6. Hydroelectric power plants offer higher efficiency (over 90 percent) as compared to thermal power (35 percent) and gas (50 percent).
7. Cost of generation is free from inflationary effects after the initial installation.
8. Storage based hydro schemes often provide additional benefits of irrigation, flood control, drinking water supply, navigation, recreation, tourism, etc.
9. Hydropower projects, being located in remote regions, lead to development of interior backward areas in terms of infrastructure facilities like educational institutions, health centers, roads, telecommunication, etc.
10. Hydroelectric turbine-generators can be started and put “on-line” very rapidly.
11. Unscheduled breakdowns are relatively infrequent and short in duration since the equipment is relatively simple.
Term Paper # 9. Disadvantages of Hydro Power Plants:
1. Very land-use oriented and may flood large regions.
2. The dams are very expensive to build. However, many dams are also used for flood control or irrigation, so building costs can be shared.
3. Capital cost of generators, civil engineering works and cost of transmission lines is very high.
4. Water quality and quantity downstream can be affected, which can have an impact on plant life.
5. Finding a suitable site can be difficult – the impact on residents and the environment may be unacceptable.
6. Fish migration is restricted.
7. Fish health affected by water temperature change and insertion of excess nitrogen into water at spillways.
8. Available water and its temperature may be affected.
9. Reservoirs change silt-flow patterns.
Though concerns remain over the drawbacks of hydroelectric power plants the advantages of hydropower are much more than the disadvantages.
However the large capital cost involved in the construction of dams and other disadvantages large hydroelectric power plants which involves large dams and reservoirs can be eliminated by harnessing the potential of small hydroelectric power plants.
Term Paper # 10. Control, Automation and Monitoring System in a Hydroelectric Power Plant:
Control, automation and monitoring system in a hydroelectric power plant is associated with start and stop sequence for the unit and optimum running control of power (real and reactive), voltage and frequency. Data acquisition and retrieval is used to cover such operations as relaying plant operating status, instantaneous system efficiency, or monthly plant factor, to the operators and managers.
Type of control equipment and levels of control to be applied to a hydro plant are affected by such factors as number, size and type of turbine and generator. The control equipment for a hydro power plant include control circuits/logic, control devices, indication, instrumentation, protection and annunciation at the main control board and at the unit control board for generation, conversion and transmission operation including grid interconnected operation of small hydro stations.
These features are necessary to provide operators with the facilities required for the control and supervision of the station’s major and auxiliary equipment. In the design of these features consideration must be given to the size and importance of the station with respect to other stations in the power system, location of the main control room with respect to the equipments to be controlled and all other station features which influence the control system. The control system of a power station plays an important role in the station’s rendering reliable service; this function should be kept in mind in the design of all control features.
Control function of control in a hydropower plant may be categorized into the following:
1. Turbine Control:
This is the speed/load control of turbine in which the governor adjusts the flow of water through the turbine to balance the input power with the load. With an isolated system; the governor controls the frequency. In interconnected system, the governor may be used to regulate the unit load and may contribute to the system frequency control. In case of micro plants in the range of micro hydel (100 kW unit size), load control is also used, where excess load is diverted to dummy load to maintain constant speed.
2. Generator Control:
This is the excitation control of synchronous generator. The excitation is an integral part of a synchronous generator which is used to regulate the operation of the generator.
The main functions of excitation system of a synchronous generator are:
Plant Control:
Plant control deals with the operation of the plant. It includes sequential operations like start-up of the machine, excitation control, synchronization, loading of unit under specified operating conditions, normal and emergency shutdown, etc. The mode of control may be manual or automatic and may be controlled locally or from remote location. Plant control usually includes monitoring and display of the plant conditions.