Calculate Power curve not matching SAM

[jmarquez-leal]

Hi,

I am comparing land based wind turbines, No financial model in PySAM and SAM and noticed the outputs were different for the power curves, while using the same parameters. Here is the code I've been using, any ideas on why i am receiving different different power curves?

`import csv
import PySAM.Windpower as wp

setting parameters

a = wp.new()
a.Resource.wind_resource_model_choice = 0
a.Turbine.calculate_powercurve(
turbine_size=3000,
rotor_diameter=90,
elevation=300,
max_cp=0.45,
max_tip_speed=80,
max_tip_sp_ratio=8,
cut_in=3.25,
cut_out=25.25,
drive_train=0,

)

Recieving power curve data

wind_speeds = a.Turbine.wind_turbine_powercurve_windspeeds
power_outputs = a.Turbine.wind_turbine_powercurve_powerout

Export to CSV

with open('power_curve2.csv', 'w', newline='') as f:
writer = csv.writer(f)
writer.writerow(["Wind Speed (m/s)", "Power Output (kW)"]) # Header
writer.writerows(zip(wind_speeds, power_outputs))

print(" Power curve exported to 'power_curve2.csv'")`

thank you,

[brtietz]

@jmarquez-leal Can you provide the versions of the SAM GUI and PySAM that you're using?

[jmarquez-leal]

I am using SAM 2025.4.16 and for nrel-PySAM it is version 7.0.0

@jmarquez-leal Can you provide the versions of the SAM GUI and PySAM that you're using?

[jmarquez-leal]

@jmarquez-leal Can you provide the versions of the SAM GUI and PySAM that you're using?

Hi, has there been any updates on this?

[cpaulgilman]

@jmarquez-leal Thank you for your patience. I think the difference may be due to a difference in the the elevation assumption in SAM and PySAM. I am investigating and will follow up when I learn more.

[jmarquez-leal]

We are also investigating elevation changes in PySAM and any input for elevation had no effect on the power curve. Meanwhile changing the hub height in SAM does affect the power curve.

[jmarquez-leal]

After going through the SAM inputs, we realized that there was a set elevation by one of the wind files. we didn't notice it until now but after testing multiple sites we saw changes the power curves. This meant that elevation is a contributor to the large differences in the power output. I am interested if there is a way to change the elevation for PySAM for hourly data as elevation only impacts the Weibull wind resource model? and also since there is no hub height for PySAM is there a set height depending on the other parameters?