BIMODAL wind distribuition

[CA1]

Hi

I am trying to simulate with WASP a site with a bimodal wind distribution

As I have checked, WASP is always understimating the energy output

Any idea to simulate and obtain an accurate energy output?

Thanks in advance

[Duncan]

Do you know why the distribution is bimodal? Is there strong seasonality in the time series data?

[CA1]

Yes there are two periods

First period from October to January high wind speeds and form June to September low wind speeds

The wind farm is located in Oaxaca (Mexico) flat terrain (RIX =0) maybe it can be give you an idea

Also I have found this article http://www.sciencedirect.com/science/article/pii/S0960148104000618 where explains that there is an understimation of the wind resource

I am totally lost about it ¡¡¡¡ maybe with a CFD simulation ?¿

Thanks

[CA1]

Another idea

What about to simulate in 2 steps

1) October-March ( high wind speed period)
2) April-Sept (low speed period

We obtain two productios that have to be weighted

[YOCUI]

Hi ,

just one assumption , that have you try to increase the sector number to see the sectorwise fitted distribution ? i think for those special climate with strong seasonality the wind direction sould be some kind of variation with season change , and since wasp use sectorwise weibull for AEP calculation and if we can store different wind into different sector and then may still can get a well fitted sectorwise weibull .and this won't change the AEP ,although the overall fiting looks bimodal .

[CA1]

Hi Yocui

Its a good idea but in this project I have only one wind prevailing direction (NNW) and I have considered 16 sector

Thanks for your idea

[YOCUI]

Hi ,

you are welcome .

i have not see such trick issue before , i think your idea is worth to try. and i saw that you mentioned the site is flat right ?if the terrain feature and roughness not variaed much at the NNE ,then i have an idea that may be we can add a for example 10 degree of direction offset to one set of seasonality effected wind data ,and then you can seperate the bimodal by increase the sector numbers , if the terrain and roughness not changed a lot within these few tens of degrees then the deviation of aep would be very small .what is your opinion to this ?