Hydraulic Losses

Hydraulic loss can also be referred to as head loss and is used to represent the friction losses in the penstock. ResSim uses net head (the difference between the pool elevation and the tailwater elevation) in the power equation to calculate generating capacity. When you specify a hydraulic loss, you are describing a loss to the head, which results in a reduction in the plant's generating capacity.

You can specify the head loss as a constant or as a function of flow through the penstock (entering the powerhouse):

Constant Hydraulic Losses ("Figure: Power Plant - Hydraulic Losses - Constant")—enter the hydraulic loss as a constant value of distance (ft or m).

Function of Release ("Figure: Power Plant - Hydraulic Losses - Function of Release")—enter a table of values to specify the relationship between Release and Loss to describe the head loss as a function of flow through the outlet. The thumbnail plot will reflect the data you enter in the table.