Development of Mineral and Energy Resources Thermal Power Sources, Hydel Power Resources Part 7

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Thermal Power Sources

In thermal power, the major source of energy is coal, diesel, and natural gas that are used for generation of electricity. It is the largest source of power supply in the country. The installed capacity of thermal power stations is about three times the installed capacity of the hydel power. During 2004-05 the share of thermal power was about 80,903 MW out of 1, 18, 419 MW of electricity produced in the country. This is approximately 68% of the total electricity produced in India. The share of thermal electricity increased very rapidly after creation of the National Thermal Power Corporation (NTPC) in the year 1975. Presently, NTPC has to its credit 13 coal based super thermal power projects and seven gas/liquid fuel based. During the 2004-05, NTPC produced 24,435 MW which is about 30% of the all India thermal production during the same period. Coal based thermal power units have been set up near the coal mines to avoid transport costs. Transmission of power over long distances is relatively cheaper despite some loss of energy in transit.

Thermal and Nuclear Plants In India

Image of Thermal and Nuclear Plants in India

Thermal and Nuclear Plants In India

Super Thermal Power plants have been established mainly very close to big coal mines. These are Singrauli in Uttar Pradesh, Korba in Chhattisgarh, Ramagundam in Andhra Pradesh, Farakka in West Bengal, Vindhyachal in Madhya Pradesh, Rihand in Uttar Pradesh, Kawas and Gandar in Gujarat, and Talcher in Orissa. Most of these power plants have improved their efficiency and profitability through improved plant load factor (78% against the national average of 63%) with the electrification of trunk routes railways have also set up their own super thermal power stations in the regions lying away from major coal fields. In Tamil Nadu there is a big thermal power plant at Neyveli which is fed by local lignite coal field.

Besides coal based thermal power plants, the latest trend is to encourage diesel and natural gas based thermal power plants. Such plants can be set near the distribution or market centres. The gestation period of oil or gas-based plants is generally the shortest. These plants are also found to be more efficient than coal-based plants. The oil and gas pipes have to be laid for continuous supply of petroleum and natural gas for such power plants.

As India is poor in its mineral oil and proven gas resources, it has to import these raw materials including naptha etc. from Middle East countries. The new Dabhol Thermal Power plant of Maharashtra on the Konkan coast is based on such imported raw material. This plant is an indicator of the new trend.

Petroleum based power units have been set up in the remote areas of north-east and Himalaya region. It is very interesting to note that Karnataka and Kerala states in South have not a single thermal power plant till now.

Hydel Power Resources

Water power resource is a renewable or inexhaustible resource. It is pollution free. Its recurring or maintenance coast is minimal. However, this source of energy has two major drawbacks. Firstly, it calls for huge financial layout particularly in those regions where water is to be impounded in huge quantity to ensure free flow of water all the year round. Secondly, in most cases its gestation period is too long.

With the water power potential of 41000 MW, India ranks fifth in world after Congo, Russia, Canada, and the U.S.A.

Hydroelectric Power: The development of hydroelectric power started in the last decade of the 19th century with the establishment of a hydroelectric plant for supplying electricity to Darjeeling in 1897. In 1902, another hydropower plant was erected at Sivasamundram waterfall on Kaveri River in Karnataka. Later, a few plants were erected in the Western Ghats to meet the requirements of Mumbai. Hydropower plants were also commissioned in Uttar Pradesh, Himachal Pradesh in the north, and Tamil Nadu and Karnataka in the south in 1930s. Total power generation capacity reached to 508 MW in 1947. Massive efforts were made to develop waterpower during the Five-Year Plans and several multipurpose projects were commissioned.

Total installed capacity of hydroelectricity increased to 25219.55 MW at the end of 2000-01, which was nearly 1/4th of the total installed capacity of electricity. In spite of being cheaper, pollution free and renewable source of power, the significance of hydroelectricity has declined in post-independence period. Its share in total power generation declined from 49 % in 1950-51 to only 14.9 % in 2000-01. Nevertheless, hydroelectricity plays a very significant role in northern, western, and southern grids. The north-eastern grid is primarily dependent on hydel power.

In context of the energy crisis in the country, hydroelectric power has assumed pivotal significance. Indian rivers drain 1677 billion cubic metres of water to the sea every year. The Central Water and Power Commission estimated the potential of hydroelectric power at about 40 million kW at 60% load factor from these rivers. Central Electricity Authority re-estimated this potential at 84,000 MW at 60% load factor. It is equivalent to about 450 billion units of annual energy generation. Basin-wise distribution of the potential is given in Table.

India: Basin-wise Estimated Potential of Hydropower (potential in thousand MW at 60 % load factor)

India: Basin-Wise Estimated Potential of Hydropower
Title: India: Basin-wise Estimated Potential of Hydropower

Basin

Potential

% of Total

Indus

20.0

23.8

Brahmaputra

35.0

41.7

Ganga

11.0

13.1

Central Indian Basins

3.0

3.6

West Flowing Rivers

6.0

7.1

East Flowing Rivers

9.0

10.7

Total

84.0

100.0

This potential depends on several physical and economic factors. Among them, river regime, volume of river water, regularity in river flow (all these are dependent on rainfall pattern), nature of terrain, availability of other sources of power, level of economic development creating demand, and technological status are important. Regular flow of sufficient water with high velocity provides favourable condition for the development of hydroelectricity. The amount and regularity of flow depends on nature of rainfall while slope determines the velocity of flow. Since these conditions vary throughout the country, the distribution of hydropower potential is also very uneven.

Major Hydel Power Stations In India

Image of Major Hydel Power Stations in India

Major Hydel Power Stations In India

The rivers originating from the northern mountainous region are the most important ones in this respect. They have their sources in glaciers and snowfields, therefore, they are perennial and their flow of water is regular throughout the year. Velocity of flow is high because of dissected terrain and the competition for use of water for other purposes is low. The north-eastern part of this mountainous region, constituting the Brahmaputra basin has the largest power generating potential. The Indus basin in the north-west is at second place. The Himalayan tributaries of the Ganga have a potential of 11,000 MW. Thus, 3/4th of the total potential is confined in the river basins originating from the northern mountainous region.

The rivers of peninsular India are comparatively poor in this respect. They depend entirely on the rainfall for their flow, and therefore, their flow is very erratic exceptionally high flow during the monsoon period followed by a long period of lean flow. Storage of water is essential to regulate the flow. The bulk of the potential in this part is confined in the hilly regions along the middle and upper reaches of various river systems. The topographical features in these reaches are seldom favourable for development of irrigation. Consequently, development of hydroelectric sites would not clash with other priority uses of water. The Western Ghats, north-western Karnataka, Nilgiri and Anamalai hills, and upper Narmada basin are major areas of concentration of potential in peninsular India. Despite this, potential of hydropower has been comparatively more developed in southern states because these states are far away from coalfields of the north-eastern plateaus.

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