Below are furhter equations used for calculations involving this kind of power station:

Gross plant capacity (G.C):

$G.C={\frac {E_{potential}}{sec}}$ (in Watts) ... Equation 3.5

The firm capacity (F.C) will therefore be:

$F.C=G.C\times {\eta }$(in Watts) ... Equation 3.6

Thus the yearly gross out put:

$Y.G.O=F.C\times 8760Hrs$(in kWh) ... Equation 3.7

We can also estimate the volume of flow per annum:

$V_{annum}=Catchment_{.}Area\times Annual_{.}Rainfall\times Yield_{.}Factor$

(in kWh) ... Equation 3.8

Where:

- η = Efficiency
- m = mass (in Kg)
- g = constant ≈$9.8m.s^{-2}$
- h/H = water head height (metres)
- ρ = density of water ($m^{3}$)