Weather file upload
You can upload custom weather files to Solesca. We only accept TMY3-formatted CSV files currently. The files must also be UTF-8 encoded to be processed properly. The weather files must have the top two rows of the resource description and the following columns within the third row onwards. The data can be in hourly, 15min, or 5min intervals and the columns can be in any order.
| Column | Column Name | Unit | Notes |
|---|---|---|---|
| A | Year | - | May vary for TMY files, which use multiple years' data. |
| B | Month | - | 1-12 |
| C | Day | - | 1-31 |
| D | Hour | - | 0-23 |
| E | Minute | - | Represents the minute of the hour. Either in 5min, 15min, or hour intervals |
| F | GHI | W/m² | (Global Horizontal Irradiance): The total amount of solar radiation that hits a horizontal surface on Earth. |
| G | DNI | W/m² | (Direct Normal Irradiance): The amount of radiation that hits the plane perpendicular to the sun. |
| H | DHI | W/m² | (Diffuse Horizontal Irradiance): Solar radiation received from the sky in all directions. |
| I | Temperature | ÂşC | - |
| J | Relative Humidity | % | 0-100 |
| K | Pressure | mbar | - |
| L | Wind Direction | Âş(degrees) | - |
| M | Wind Speed | m/s | - |
| N | Albedo | - | 0-1 |
Error Parsing Weather File ("Weather file upload failed")
Solesca requires weather data in a specific layout. If your upload fails, you can quickly fix it by copying your values into our template:
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Download and open our template in a spreadsheet editor of your choice (e.g. Excel, Google Sheets, Numbers, etc.):
Solesca Weather File Template
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In row 2, fill in the metadata columns:
- Source: Your data provider’s name (e.g. NSRDB)
- Latitude
- Longitude
- Elevation: in meters
- Local Time Zone: UTC offset (negative for west of Greenwich)
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Paste your time-series values under the matching headers. Refer to the table above for column descriptions.
Once your data matches this format, save as a CSV and re-upload the file.
For an example filled template, download this: Example Filled Weather File (CSV)
Confirm weather file time format
When we run our energy simulation, all timestamps must be in local time.
- If your file is already in local time, we’ll use it as-is.
- If it’s in UTC, we’ll automatically shift every timestamp by the “Local Time Zone” offset in the weather file.
How to tell if your data is UTC or local
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Inspect the DNI sunrise transition Find the first timestamp where Direct Normal Irradiance (DNI) jumps from 0 to a positive value (i.e. dawn).
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Compare it to your expected local sunrise
- If it falls around a reasonable local sunrise hour (e.g. 6–8 AM), your file is probably in local time.
- If it’s offset by your UTC zone (for example, sunrise at 14:30 when you’re at UTC –7), it’s almost certainly in UTC.
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When in doubt, verify with your provider If you’re still unsure, check directly with whoever supplied the weather data.