Upload wind statistics

Wind statitics

ArchiWind aggregates long-term wind records into statistical summaries (wind roses, Weibull models, etc.) that are used to weight CFD simulations. By default it retrieves 5 years of hourly winds via the MeteoBlue History API (license holders) or Open-Meteo API (free trial users). These APIs provide global, high-resolution hourly wind data (speed and direction) for the site location. ArchiWind then bins this data by time period and direction to build wind roses and speed distributions. For example, all 5-year hours can be grouped by annual, seasonal or monthly periods and by azimuthal sectors (e.g. 8 or 16 compass directions). Each wind rose shows how often the wind blows from each direction and at what speeds. Such roses are a standard meteorological summary: “a wind rose gives a succinct view of how wind speed and direction are typically distributed at a particular location” . In practice, ArchiWind computes, for each period, the frequency of winds in each direction sector and the associated speed statistics. These wind-rose frequencies are then used as weights when averaging CFD results. In other words, CFD runs are performed for representative directions/speeds and the results (pressures, flows, etc.) are combined proportionally to the wind-rose frequencies.

Advanced Wind statitics settings

User-Provided EPW Files

As an alternative data source, ArchiWind allows users to upload EnergyPlus Weather (EPW) files. EPW is a standard format for building simulation weather data . An EPW file is comma-separated text: the first ~8 header lines hold location info (station name, lat/lon, elevation, etc.), and the rest is a time series of hourly records (typically 8760 lines for a full year). All values are in SI units. Crucially, EPW includes two key fields for wind: wind direction and wind speed. According to the EPW specification, “Wind Direction in degrees where North = 0.0, East = 90.0…If calm, direction = 0.0” , and “Wind Speed in m/s at the time indicated”  (values range 0–40 m/s; missing data are flagged as 999).

The upload of the EPW file is performed when initialising a new simulation under the “Advanced settings”

CSV Wind Data from the Israeli GovMap Portal

ArchiWind supports uploading wind data from the GovMap Wind Atlas — a public resource developed by the Israeli government to provide long-term wind potential estimates across the country.

This data can be downloaded as a CSV file, which contains wind statistics for specific points on the map. These files are based on simulations covering a 30-year period and are meant to support decisions related to wind turbine placement, but can also be used for pedestrian wind comfort studies.

What’s in the GovMap CSV?

Each CSV includes detailed wind data at several heights (typically 30 m, 60 m, 100 m, and 150 m above ground), and contains the following fields: • Wind Speed [m/s] • Power Density [W/m²] • Weibull A and K Parameters — used to characterize wind speed distributions • Directional Frequency [%] — how often wind comes from each direction • Air Density (relative to standard) • Annual Energy Production (AEP) and Capacity Factor at 100 m (for wind turbine reference)

Wind directions are grouped into sectors: • Direction 0 = omnidirectional • Directions 1–12 = sectors every 30° (e.g. 0°–30°, 30°–60°, etc.)

The values are provided monthly (January to December) and annually, allowing for seasonal analysis and accurate input for CFD simulations.

Using GovMap CSV in ArchiWind

When submitting a simulation, you can upload a GovMap .csv file instead of relying on the default weather API. ArchiWind will automatically: • Parse the file and validate its format • Extract directional wind statistics • Use the directional frequencies and Weibull distributions to generate a wind rose

This process ensures your simulation reflects realistic Israeli wind conditions specific to your site of interest.

⚠️ Make sure you download the CSV directly from the GovMap portal, without modifying its format. ArchiWind is designed to recognize and process the original structure.