Problems downloading Wind Resource files by lat/long

Hi Paul,

I download latest weather data from NSRDB via API and then use wind farm model in matlab to estimate power output, since power curve data of those wind turbines are available on related website and wind farm model is not very complicated. The result is ok. Just remember to transfer wind speed data from 2 m to 100 m height.
(Btw, in wind part reference manual, wind speed is said to be at the height of 10 m, so without your clarification, I won't know they are actually just 2 m height. Thx again for your help.)


Best,
Yanda

Thanks for that information.

SAM's Wind Power model will only run with wind resource data measured within 35 meters of the turbine hub height to avoid introducing too much uncertainty from the wind shear estimates. You can override that behavior as you did by making the wind shear calculations yourself, but you should be aware that using 2 meter data for a 100 meter turbine will only give you a rough approximation of the wind resource at hub height.

The different NSRDB datasets (PSM, MTS1 (TMY2), MTS2 (TMY3) use different heights for the wind speed, so the reference you saw to 10 meters may be correct for the particular dataset it described. Can you point me to the document where you saw that mention?

Best regards,
Paul.

Hi Paul,

Do you mean the merra-2 wind speed is accurate and the problem of incorrect power output is caused during 2m --> 100 m transfer process? Is it possible this is caused by 50 km spatial resolution of merra-2? Besides, could you please tell me if solar irradiation is calculated by wind speed or vice verse? In another word, if I use wind toolkit data and PSM solar irradiation at same time but different locations for hourly simulation, will that cause problems? Waiting for your reply. Many thx in advance.


Best,
Yanda

Hi Yanda,

Yes, I mean that extrapolating wind speed from 2 meters to 100 meters adds uncertainty to the 100 meter data.

SAM's photovoltaic models use wind speed, irradiance, and ambient temperature to calculate cell temperature.

I would recommend using WIND Toolkit data for wind power systems, and NSRDB data for solar power systems.

Best regards,
Paul.

Yes, I have been experiencing similar problems and would be grateful if someone could share some feedback on solutions.

Thanks
G

WIND Toolkit downloads should be working after some web service updates.

We have included some updates to SAM's wind and solar resource download features in the next version of SAM, which we hope to release around the end of November 2020:

github.com/NREL/SAM/issues/353

Best regards,
Paul.