Subject: Max Turbine Flow Posted: 4/17/2014 Viewed: 14070 times
Usually the available data for hydropower scheme is the plant capacity in MW. How can this be used to get the max turbine flow input that WEAP requires to operate the HP plant?

Stephanie Galaitsi

Subject: Re: Max Turbine Flow Posted: 4/22/2014 Viewed: 14029 times
In order to ensure your hydropower plant in WEAP can produce its MW capacity, you must use the following set of equations to enter the correct parameters in WEAP under the “hydropower” tab for your reservoir or run-of-river hydropower.

The gigajoules (GJ) of energy produced in a month (which can be converted to MW) are calculated using the following equation:

EnergyFullMonthGJ = VolumeThroughTurbine x HydroGenerationFactor

The VolumeThroughTurbine value can’t be higher than the Max. Turbine Flow (under the hydropower tab) to ensure that the plant will has an engineering limit that equals its MW capacity. So to calculate what the Max. Turbine Flow in an optimized hydropower operation, set the equation equal to:

EnergyFullMonthGJ = Max. Turbine Flow x HydroGenerationFactor

And solve for Max. Turbine Flow using the equation for HydroGenerationFactor:

HydroGenerationFactor = 1000 (kg / m^3) * DropElevation x PlantFactor x PlantEfficiency * 9.806 / (1,000,000,000 J / GJ)

Where the variables PlantFactor and GeneratingEfficiency are entered into WEAP by the user (so you have full control over their values), and you are left with the variable for DropElevation. For the purpose of estimating the Max. Turbine

Flow parameter for the model, assume that DropElevation is at its maximum (the elevation when the reservoir is full and could have max turbine flow). If you’re modeling a run-of-river hydropower plant, DropElevation equals the Fixed Head variable you entered in the hydropower tab, so make sure that gives you the results you want.

You can find out more information about the energy calculations in the Help Manual under Calculation Algorithms/Hydropower

Devaraj de Condappa

Subject: Re: Max Turbine Flow Posted: 5/7/2014 Viewed: 13865 times
Dear Mohamed,

As Stephanie wrote, the basic equation is

Pth = ρ x q x g x h x PlantEfficiency

where

Pth = the power in W
ρ = water density (kg/m3) (~ 1000 kg/m3 for water)
q = water flow (m3/s)
g = acceleration of gravity (9.81 m/s2)
h = falling height, head (m)
PlantEfficiency = capacity to transform gravity energy into electrical energy (the same you enter in WEAP)

Since we are talking about the capacity of the plant (in MW), it is the maximum power production capacity of the plant so as Stephanie wrote q should be the Max. Turbine Flow you enter in WEAP and h should be the maxi head when the reservoir is full.

However, unlike Stephanie, I don't think you should use the Plant Factor, as we are talking about the capacity of the plant, not its actual production.