Page 84 - Sonbeel Utsab 2024

Power and energy
Power is the rate of producing energy. Power is measured in Watts (W) or kilowatts
(kW).The maximum hydropower output is mainly dependent on how much head
and water flow is available. In hydroelectric power and potential energy of water is
utilized to generate electricity [9-10]. Power is proportional to the product of head
and flow rate. The general expression for any Hydro power Generation is:

P= m x g x H x η
net
Where
P = the power measured in Watts (W)
η = the overall efficiency of power plant
g = the acceleration due to gravity [9.81 m/s²]

H =
net

The net head [m]. This is the gross head physically measured at the site, less head
losses. To keep things simple head losses can be assumed to be 10%, so

H =H x0.9
net gross
m = the mass flow rate in kg/s (numerically the same as the flow rate in litres /second
because litre of water weighs 1 kgs.)
The expression clearly shows that the total power that can be generated from the
hydroelectric power plants depends on two major factors

·The flow rate of water or volume of flow of water and height or head of water.
·More the volume of water and more the head of water more is the power
produced in the hydroelectric power plant.

The metric prefixes are given
1 Watt [W] = 1 Watt
1 Kilowatt [kW] = 1,000 Watt
1 Megawatt [MW] = 1,000,000 Watt
1 Gig watt [GW] = 1,000,000,000 Watt

EFFICIENCY
Turbine efficiency ratings are important to compare different turbine types and their
performance under conditions of reduced flow. Hydro power efficiency includes the
efficiency of the turbine, generator, and transformer. Generally, in a hydropower
system the different parameters of following efficiency are available [5].
Turbine efficiency= 85-95%
Transformer efficiency = 95-100% Generator efficiency= 95-100%
Therefore in the present investigation, we have considered the parameters of
following efficiency
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