Import ASCII weather data

[sailerthomas]

I tried to import own measured meteorological data using the “Import ASCII meteo file” tool. Available parameters are daily irradiance on module plane (Wh/m²) und daily temperature (°C). I generated a Format protocol file to define the corresponding column.

I used the button “Global on tilted plane” in the conversion tool to define the irradiance on the tilted plane. I used “Ambient temperature” to define temperature. Furthermore i clicked on “Energy (e.g. Wh/m², kJ/m²,…)” in the “Irradiance given in” box. I defined tilt and azimuth in the “Plane orientation” box to define the module plane.

Performing the conversion of the meteo file produces a *.MET file without problems. But regarding at the file shows, that the conversion did not work properly. The yearly global horizontal irradiance and also the global irradiance on collector plane have a value of about 10.6 kWh/m²*a and 9.2 kWh/m²*a respectively. Temperature nevertheless seems to be correct.

Are my settings correct? What is the problem?

Thanks in advance,

Thomas

[André Mermoud]

The time of your data are probably not matching the time of PVsyst.

And you have probably not followed the advice of PVsyst for checking the data quality when importing your data.

Please analyze your meteo file in "Databases > Meteo Tables and graphs", page "Check data quality".

Here you have performant tools for the analysis of your imported data, and you can press F1 for a complete explanation in the help.

[sailerthomas]

Dear Andre Mermoud.

I have tried several times to import irradiances from a tilted plane. Unfortunately i never suceeded. My settings can be seen in the pictures. Also i double checked all values using the PVsyst "Meteo tables and graphs" tool. The results can also seen in the picture.

Irradiance values of 0.026 kWh/m²*day are calculated. The tool says that "The Clearness index of the best clear days is very low by respect to the clear day model Please check the units or the solarimeter calibration.Nevertheless the data source is correct!

Can you tell me if my settings are incorrect or if the tool does not work?

Rgards,

Thomas

[sailerthomas]

Anybody any idea how to solve the problem?

[André Mermoud]

The Irradiance units are not correct.

However it is not possible to import POA data in daily values. The retro-transposition model only works on an hourly basis.

[sailerthomas]

Now it works.

Thanks!