29-06-2013, 11:59 AM
MINI & MICRO HYDRO POWER GENERATION
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INTRODUCTION
Think of the energy and power in a giant waterfall. Now
imagine being able to use that energy to make electricity.
That is hydroelectric power. A hydroelectric plant uses the
flow of water from a higher to a lower elevation to generate
power. It accomplishes this by taking control of a river,
usually through the construction of a dam. Hydroelectric
plants provide about 20% of the world’s electricity. Only oil,
coal, and natural gas generate more electricity worldwide.
HYDROLOGY
The science which deals with analysis of
rainfall and run-off and their nature.
Generally it’s a habbit that practiced from
the prehistoric period.
EVAPORATION
Water is transferred from
the surface to the
atmosphere through
evaporation, the process
by which water changes
from a liquid to a gas.
Approximately 80% of all
evaporation is from the
oceans, with the remaining
20% coming from inland
water and vegetation.
PRECIPITATION
Precipitation is the
primary mechanism for
transporting water from
the atmosphere to the
surface of the earth.
There are several forms
of precipitation, the most
common of which for the
United States is rain.
GROUNDWATER
Groundwater is all the water that has penetrated the
earth's surface and is found in one of two soil layers.
The one nearest the surface is the "zone of aeration",
where gaps between soil are filled with both air and
water. Below this layer is the "zone of saturation", where
the gaps are filled with water. The water table is the
boundary between these two layers. As the amount of
groundwater water increases or decreases, the water
table rises or falls accordingly
ADVANTAGES
Hydroelectric power is long-established as a clean, safe
method of making electricity. It does not add carbon dioxide
(CO2) to the environment, and it uses a renewable power
source, water.
Hydroelectric power has other benefits as well. Dams and
hydroelectric plants last a long time. This means that once
the costs of building are paid off, a hydroelectric plant
becomes a relatively inexpensive source of electricity.
DISADVANTAGES
High capital cost
It depends on availability of water
Usually these plants are away from load
centres Takes long time for erection