- The power to be supplemented by the storage or standby unit to
obtain a firm power of 15 MW is the area abc (Fig. 12.23)17.76 MW
month. Therefore the storage required is
17.76 106 30 24 60/10009.81 20 0.92.6 108 m^3.
With no storage, the firm power available is 7.95 MW. Therefore the
capacity of the standby unit is 15 7.957.05 MW.
534 HYDROELECTRIC POWER DEVELOPMENT
Worked Example 12.2
The monthly flows of a stream over the period of the driest year on record
are as shown below:
Month J F M A M J J A S O N D
Flow 4.0 2.25 5.0 1.25 0.5 0.75 0.5 0.75 1.25 1.25 5.0 6.25
( 106 m^3 )
- Estimate the maximum possible uniform draw-off from this stream,
and determine the reservoir capacity to achieve the uniform draw-off
and the minimum initial storage to maintain the demand.
- If the reservoir has only a total capacity of 8 106 m^3 with an initial
storage of 4 106 m^3 , determine (a) the maximum possible uniform
draw-off and (b) the spillage.
Fig. 12.23 Flow–power duration curve
