Live and Forecast API

Irradiance, Weather and PV Power data for the solar powered future

Data Specifications

Our Live and Forecast data spans from 7 days ago to +14 days ahead, at 5 to 60 minute granularity, anywhere on Earth. Includes probabilistic forecast estimates of PV power and all types of irradiance. Actuals available in real-time. Historical data also available.

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Live and Forecast Data Specifications

Geographic coverage


Temporal coverage

-7 days to +14 days

Time resolution

5, 10, 15, 20, 30 & 60 minutes (period-mean values)

Spatial resolution

2km (irradiance, PV power, snow soiling and cloud parameters, over all non-polar continental areas and nearby islands)
27km (other parameters, and polar or remote oceanic regions)

Update frequency

Every 5 to 15 minutes* (irradiance, PV power, snow soiling and cloud parameters, over all non-polar continental areas and nearby islands) Every 4 to 6 hours (other parameters, and polar or remote oceanic regions)

* Every 15 minutes over Europe, Africa, Middle East, West Asia and India. Every 10 minutes over East Asia, Australia, North & South America. Every 5 minutes over Hawaii, California & Nevada.

Data parameters

The following data parameters are available. In the case of forecasts, which span from the present time up to 14 days ahead, probabilistic 10th and 90th percentile values are also available for the parameters denoted with an asterix (*). Irradiance parameters also have clearsky values available (i.e. accounting for aerosols and water vapour, but with no clouds in the sky), these are denoted with a caret (^).

  • Global Horizontal Irradiance*^ (GHI) (W/m2)
  • Direct Normal Irradiance*^ (DNI) (W/m2)
  • Diffuse Horizontal Irradiance*^ (DHI) (W/m2)
  • Global Tilted Irradiance*^ (GTI) (W/m2)
  • Advanced PV Power Output*^ (MW)
  • Rooftop PV Power Output*^ (kW)
  • Cloud Opacity* (%)
  • Air Temperature (°C)
  • Solar Zenith Angle (°)
  • Solar Azimuth Angle (°)
  • Albedo Daily
  • Wind Speed (10 & 100m) (m/s)
  • Wind Direction (10 & 100m) (°)
  • Relative Humidity (%)
  • Surface Pressure (hPa)
  • Precipitable Water (kg/m2)
  • Precipitation Rate (mm/h)
  • Dewpoint Temperature (°C)
  • Snow Depth Water Equivalent (cm)
  • Snow Soiling Loss - Rooftop (%)
  • Snow Soiling Loss - Ground Mounted (%)
View detailed data parameter definitions
Advanced PV model

The Advanced PV Model, which produces the above listed data parameter "Advanced PV Power Output"" is designed for large PV plants where system specifications are typically available, and where accuracy of production estimates and forecasts are important.

Solcast's Advanced PV model is based on the open source pvlib-python library, with several proprietary extensions added by the Solcast team. To use the model, user sites must be created, manually via the Solcast API Toolkit web portal or programmatically via the API.

These sites exist to store, list, and edit the PV plant specifications used by the model. API requests are made by reference to a site ID.

Read more about the Advanced PV Model

Rooftop PV model

The Rooftop PV Model, which produces the above listed data parameter "Rooftop PV Power Output" is an empirical PV model, designed for modelling fleets of rooftop PV systems with limited system specifications available.

This model is limited to four system specifications: system azimuth and tilt, AC capacity, and a bulk loss factor. Because of this limited specification, there is no need for the creation of sites as with the Advanced PV model. Users simply make their API requests by referencing the latitude and longitude. Some users cluster nearby systems (<5km) together, using known or assumed average values of these specifications.

Read more about the Rooftop PV Model

Data access

Via the Solcast Web Toolkit and Solcast API.

File formats

JSON and CSV (CSV not recommended for automation)