Generate missing data when importing PVsyst standard format

[ckoessler]

Hy,

I want to use hourly measurements to simulate power outcome of our projects. Concerning missing data ,the help file for PVsyst standard file imports says the following:

The PVsyst simulation requires complete data (for relevant monthly or yearly sums).

Missing data should be -99, they will be replaced by modeled values (synthetic generation).

Here my question:

- Do I need to execute the synthetic generation? I am asking because when checking the imported data, there are still the "-99" values when data is missing.

I tried to use imported data with ' hourly synthetic generation'. Bus this is using my monthly values to generate a new hourly data set rather than to just replace the "-99".

What is the right way to generate just the missing data?

Tank you a lot!

[ckoessler]

Juste one additional information:

- I actually replaced missing date with "-99" before importing it...when using the imported data for simulation ,the "-99" values hadn't been replaced, which brings down power outcome....

[André Mermoud]

Which tool are you using for importing these data ?

Which value are you replacing (GlobH, DiffH, temp) ?

How much values are to be replaced ?

I think I have indeed not developed this replacement of values by a synthetic generation in the general ASCII importing tool.

I have only done this with specific importing formats (like HelioClim or SolarAnywhere if I remember well).

This means that the help is probably erroneous.

However if you are not interested in the "integrated" results, you can either put null values, or simply suppress the concerned records in the ASCII source file and reimport it.

[ckoessler]

Which tool are you using for importing these data ?

--> Import meteo data (external data source: PVsyst standard format) (PVsyst standard format for hourly meteo data)

Which value are you replacing (GlobH, DiffH, temp) ?

--> We got only hourly global values and hourly temperature values.

How much values are to be replaced ?

we use yearly data sets --> 8760 values. Depending on the data set, between 1 and 250 of values are missing. These values would need to be generated

--> Keeping "-99" values brings down power outcome. replacing missing values with 0 is not the best way of handling things. What would the synthetique generation look like? Simple curve fitting?

As PVsyst simulation requires complete data (for relevant monthly or yearly sums) I cannot suppress the concerned values???

Kind regards

[André Mermoud]

The replacement of data is indeed not implemented in this tool.

I have done this for the next version 6.36, to be released soon.

The missig values will be replaced by an average of the corresponding values of the previous and the next day.