Custom File Import
PVsyst includes a programmable tool designed to handle external data sources, such as weather or measured data, producing a .MET file that can be used in simulations.
The main requirements for the external weather or measured data file:
- The file must be in CSV format
- Each line must represent the data for one time step
- Time steps must be hourly or sub-hourly
- Dates can either be read from the file or generated sequentially.
The tool enables the definition of import protocols (separators, skipped lines, variables, date format, etc.) and allows configurations to be saved and reused for similar files.
The weather data import assistant guides the user through the steps of generating a healthy and coherent .MET file. The assistant is accessible from the Databases dialog.
Available variables
All the following weather variables can be imported. Please note that only POA or GHI can be imported at the same time. PVsyst recommends importing GHI, DHI and ambient temperature.
| Name | Available units | Description |
|---|---|---|
| GlobHor | W/m², MJ/m²/h | Global Horizontal Irradiance |
| DiffHor | W/m², MJ/m²/h | Diffuse Horizontal Irradiance |
| GIPMeas | W/m², MJ/m²/h | Measured Global Irradiation on Plane, also known as plane of array (POA) irradiance. Plane orientation should then be defined (fixed or tracker) |
| DNIMeas | W/m², MJ/m²/h | Measured Direct Normal Irradiance |
| BeamHor | W/m², MJ/m²/h | Horizontal Beam Irradiation |
| T_Amb | °C | Ambient Temperature |
| WindVel | m/s, km/h | Wind Velocity |
| TArrMes | °C | Measured Module Temperature |
| PrecWat | mm, cm, in | Precipitable Water Column |
| RelHum | ratio, %, ‰ | Relative Humidity (0–1) |
| Linke | ratio, %, ‰ | Linke Turbidity Coefficient |
| AoD | ratio, %, ‰ | Aerosol Optical Depth |
| Albedo | ratio, %, ‰ | Ground Albedo |
| T_DewPt | °C | Dew Point Temperature |
Data processing
Data processing steps are applied to your input data in the following cases:
- GIPMeas (POA) import : When importing the plane of array (POA) irradiance, a retro-transposition is applied to compute the GHI and DHI irradiance components. GHI and DHI are required for shading calculations. During the simulation, the POA irradiance (GlobInc) will be computed from the GHI and DHI.
- GlobHor only import : The DHI component (DiffHor) is computed using a diffuse irradiance model
- T_Amb missing : Ambient temperature can be generated synthetically when missing. However it is recommended to import an ambient temperature measurement.
- Time shift : see full page
- Missing data: see full page
- Quality control : see full page