Power Plant Engineering

1.8 RESOURCES FOR POWER GENERATION
The hydel power source plays a vital role in the generation of power, as it is a non-conventional
perennial source of energy. Therefore the French calls it “huile blanche”—white oil-the power of flow-
ing water. Unlike black oil, it is a non-conventional energy source. A part of the endless cycle in which
moisture is raised by the sun, formed into clouds and then dropped back to earth to feed the rivers whose
flow can be harnessed to produce hydroelectric power. Water as a source of power is non-polluting
which is a prime requirement of power industry today.
The world’s total waterpower potential is estimated as 1500 million kW at mean flow. This
means that the energy generated at a load factor of 50% would be 6.5 million kW-hr, a quantity equiva-
lent to 3750 million tonnes of coal at 20% efficiency. The world hydel installed capacity (as per 1963
estimate is only 65 million kW or 4.3% of the mean flow.

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8
POWER PLANT ENGINEERING
India has colossal waterpower resources. India’s total mean annual river flows are about 1675
thousand million cubic meters of which the usable resources are 555 thousand million cubic meters. Out
of total river flows, 60% contribution comes from Himalayan rivers (Ganga, Indus and Brahmaputra).
16% from central Indian rivers (Narmada, Tapti and Mahanadi) and the remaining from the rivers drainning
the Deccan plateau (Godavari, Krishna and Cauvery). India’s power potential from hydel source as per
the recent estimate is 41500 mW while its present hydel capacity is only 32000 mW. Still India has got
enough hydel potential to develop to meet the increasing power needs of the nation. The abundant
availability of water resources, its fairly even distribution and overall economy in developing this source
of energy enhanced its development in India, The other factors responsible in its rapid development are
indigenous technological skill, material and cheap labour. In the IX five-year plan; the Government
considering the importance of this source has included a number of hydro-projects. The major difficulty
in the development of hydroelectric projects is the relatively longer time required for it’s hydrological,
topographical and geological investigations. Lack of suitable. Site is an added problem for taking up
hydro-projects.
Hydropower was once the dominant source of electrical energy in the world and still is in Canada,
Norway and Switzerland. But its use has decreased in other countries since 1950s, as relatively less
expensive fuel was easily available. In USA, only 10% of the total power production is water-generated.
In the light of fuel scarcity and its up surging prices, the role of hydropower is again re-examined and
more emphasis is being laid on waterpower development. As per Mr. Hays (Manager of Hydro Projects
in USA), “It was less costly per mW to build a single 1000 mW thermal plant than 20 small hydro-
plants. But, with the increased fuel cost and high cost of meeting environmental criteria for new thermal
plants, interest in hydro is being revived”. Small hydro-projects ranging from 10 to 1500 kW are becom-
ing more feasible as standardization of major equipment reduces costs. India is yet to start in the field of
micro-hydro projects, which is one major way for solving the present power problem.
Hydro-projects generate power at low cost, it is non conventional, easy to manage, pollution free
and makes no crippling demands on the transportation system. But the major drawback is, it operates at
the mercy of nature. Poor rainfall has on a number of occasions shown the dangers of over dependence
on hydropower.
Let rivers flow and let rains shower the earth with prosperity is the ancient prayer chanted by
Riches and continued to be chanted even now.
The development of hydropower systems as a back up for thermal systems has significant advan-
tages. The flexible operation of hydraulic turbines makes them suitable for. Peak load operation. There-
fore, the development of hydropower is not only economical but it also solves the major problem of peak
load. The present Indian policy of power development gives sufficient importance for the hydel-power
development. The next important source for power generation is fuel in the form of coal, oil or gas.
Unfortunately, the oil and gas resources are very much limited in India. Only few power plants use oil or
gas as a source of energy. India has to import most of the oil required and so it is not desirable to use it
for power generation. The known resources of coal in India are estimated to be 121,000 million tonnes,
which are localized in West Bengal, Bihar, Madhya Pradesh and Andhra Pradesh. The present rate of
annual production of coal is nearly 140 million tonnes of which 40 million-tonnes are used for power
generation. The coal used for power generation is mainly low-grade coal with high ash content
(20-40%).
The high ash content of Indian coal (40–50%) is one of the causes for bad performance of the
existing steam power plants and their frequency outages, as these plants have been designed for low ash

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FUNDAMENTAL OF POWER PLANT
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coals. Due to the large resources of coal available in the country, enough emphasis has been given for
thermal Power plants in the IX plan period.
The location of hydel-power plants is mostly determined by the natural topography available and
location of thermal plants is dictated by the source of fuel or transportation facilities available if the,
power plant is to be located far from coalmines. For nuclear power plant any site can be selected paying
due consideration to safety and load. India has to consider nuclear generation in places remote from coal
mines and water power sites. The states which are poor in natural resources and those which have little
untapped conventional resources for future development have to consider the development of nuclear
plants.
The nuclear fuel which is commonly used for nuclear power plants is uranium. Deposits of
uranium have been located in Bihar and Rajasthan. It is estimated that the present reserves of uranium
available in country may be sufficient to sustain 10,000 mW power plants for its thorium into nuclear
Indian lifetime. Another possible nuclear power source is thorium, which is abundant in this country,
estimated at 500,000 tonnes. But the commercial use of this nuclear fuel is tied up with development of
fast breeder reactor which converts energy economy must wait for the development of economic meth-
ods for using thorium which is expected to be available before the end of twentieth century. The major
hurdle in the development of nuclear power in this country is lack of technical facility and foreign
exchange required to purchase the main component of nuclear power plant. Dr. Bhabha had envisaged
8000 mW of power from nuclear reactors by 1980–81 which was subsequently scaled down to a more
realistic level of 2700 mW by Dr. Sarabhai out of this only 1040 MW has materialized which is less than
1.5% of the country’s installed power capacity. Moreover the performance of nuclear plants has been
satisfactory compared to thermal plants.