Importing climate data PVSOL - unrealistic oriëntation

[Jan K]

Good day, 

I'm trying to make a simulation using last years climate data, I managed to import the data, and everything looks good. But when I run the simulation I get barely any losses on "orientation and inclination of the modules surface". 

When I run the simulation with normal PVGIS-SARAH (Vijfhuizen) climate data I get 10,7% losses on orientation (the modules are 10° sloped facing north)
When I run the simulation with last years (Koole-Vijfhuizen3) data I get 1,7% orientation losses. 

Everything with last years data seems realistic (temp, irradiaton, location etc.) 

Do you know why I get these big differences?

Thank you in advance, 

Jan Kleppe

Generation Green

 

Koole-Vijfhuizen3.dat

Vijfhuizen_2005_2020.wbv

[developer_mo]

Hi Jan,

thanks for your question.

I have tried to reproduce your result but could not recreate the high difference like you experienced.

Perhaps I have misunderstood something. You can also post two example projects in which the difference you describe occurs, then I can try to find out what the problem is.

Kind regards

Mikio

[developer_bh]

Hello @Jan K,

thanks for reaching out.

Both climate datasets you submitted have problems. You can see this in the climate details dialog.

 

For the PVGIS file there are problems with the minute synthesis, most probably due to an offset in the timestamps. I'd recommend to use another file and/or source. Do not use this file in hourly-simulations.

 

The second file you sent has some major problems with the data too, maybe because of the timestamps.

 

I didn't do a deep dive yet, but thats most probably the cause. Offset means in that context that the global-radiation values over the daily course are not correlated with the sun-course, so f.e. if the GHI data starts one hour too early you will have unnatural peaks in the morning and too low data in the evening. PVSOL has an auto-correction for this in the minute simulation, but this fails when the offset is not regular or data is missing. That's what the error message means in the second climate file. In the first climate file the PVSOL auto-correction will kick-in in minutewise simulation, so if you want to keep this climate file, better use it in minute-simulations. Do not use the second until you repaired it, it will give you wrong results.

Hope this will help you fix the problem.

 

Best,

Ben