Overview

Live Solar Data

Real-time situational awareness

High-frequency irradiance and PV power data keep your control room ahead of changing conditions.

Solcast Live streams “estimated actuals” for every point on Earth, covering the last seven days and updating every five minutes. High-resolution satellite imagery is processed within minutes, turning cloud movements into actionable solar data.

Grid operators, EMS providers and VPPs gain an up-to-the-moment view of solar output, letting them adjust dispatch, refine state-of-charge targets and avoid last-minute surprises.

CLOUD AND IRRADIANCE TRACKING

Tracking the world's clouds in the finest detail

Designed for Solar, from the ground up. Never rely on generic weather model data again. Solcast's real-time solar data tracks real clouds at a resolution of 1-2km and 5 minutes. Our irradiance data and PV power data is updated every 5 to 15 minutes, downscaled to 90 metre resolution. Aerosol and albedo effects are explicitly treated.

DATA SPECIFICATIONS

Data that actually meets your requirements

Live data spanning from 7 days ago to now, issued every 5 minutes, at 5 to 60 minute granularity, anywhere on Earth. Live cloud tracking provides high-resolution solar irradiance data, downscaled global weather data provides the most accurate actuals based on available data, as it becomes available.

ACCURACY

Proven, replicable accuracy levels

Solcast Live data achieves a low bias of +0.05% with a standard deviation of ±2.05%, validated against high-quality irradiance site measurements. By processing satellite observations every 5–15 minutes and modeling real cloud movement at 1–2 km resolution, Solcast delivers reliable, real-time solar data that keeps your control room ahead of changing conditions.

Data Access

Access via API or web browser download

Ready to integrate solar API directly into your systems via json or csv. Relied upon by power system operators on four continents. API uptime of >99.99%, with very low latency. Bulk API requests available. SLAs available.

Product specifications

Geographic covereage

Global (note: far ocean and polar regions are coarser resolution)

Temporal coverage

-7 days to -5 minutes

Temporal resolution

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

Spatial resolution

90 meters (irradiance, PV power, snow soiling, cloud parameters, and other parameters across all regions)

Data parameters

The following data parameters are available.

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Irradiance Parameters


  • Global Horizontal Irradiance*^ (GHI) (W/m2)
  • Direct Normal Irradiance*^ (DNI) (W/m2)
  • Diffuse Horizontal Irradiance*^ (DHI) (W/m2)
  • Global Tilted Irradiance*^ (GTI) (W/m2)

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Solar Parameters

  • Advanced PV Power Output *^ (MW)
  • Rooftop PV Power Output *^ (kW)
  • Solar Zenith Angle (°)
  • Albedo Daily
  • Snow Soiling Loss – Rooftop (%)
  • Snow Soiling Loss – Ground Mounted (%)

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Weather Parameters


  • Cloud Opacity * (%)
  • Air Temperature (°C)
  • Wind Gust (m/s)
  • 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 Depth (cm)
  • Snowfall Rate (cm/h)
  • Thunderstorm Potential – CAPE (J/kg)

^ Clear-sky scenarios also available for these parameters

Data access

API or Web download

Download wait time

API: synchronous requests. Web download: seconds.

File formats

CSV, JSON, PVsyst, SAM, TMY3

Data formats

Solcast standard, PVsyst (60 minute only)

Time zone

UTC, longitudinal, or user-specified fixed offset.

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See how Solcast Live and Forecast data stack up — region by region, metric by metric — in our detailed performance validation.

Frequently Asked Questions

What is live solar irradiance data?

Live solar irradiance data refers to real-time data of solar energy received per unit area at a specific location. Solcast live data covers a time frame from 7 days ago up to the present time, and is updated every 5 minutes. This data set is also referred to as “actuals” as it represents the modeled actual weather conditions at the location.

How is live solar irradiance data generated?‍

Solcast’s live solar irradiance data is generated using a combination of satellite observations and weather models. Solcast processes these data sources using advanced algorithm models that account for atmospheric conditions, such as cloud cover and aerosol levels. Real cloud movements are tracked and forecast at a resolution of 1-2km and 5 minutes, which is then downscaled to 90-meter resolution to produce accurate, real-time solar irradiance values.

How often is live solar irradiance data updated?

Solcast’s live solar irradiance data is updated every 5-15 minutes, depending on the frequency of satellite observations available. Temporal resolutions available are 5-60 minutes. Data for each new period is added as soon as the time period passes, and is available through the Solcast API. This allows for real-time data access and timely information for accurate, immediate decision-making.

What is the difference between solar live irradiance data and solar forecast irradiance data? 

Solcast’s live irradiance data primarily relies on real-time satellite observations to provide real-time actuals up to the present moment. While forecast irradiance data combines satellite imagery and weather models to predict irradiance from now up to 14 days ahead. Live data is crucial for real-time grid management, operational adjustments, and performance monitoring, whereas forecast data is used for planning, energy production estimates, and scheduling maintenance activities in both utility-scale solar farms and distributed solar installations.

What is the accuracy of Solcast's irradiance data?

Solcast data has low bias of +0.05% with a standard deviation of ±2.05%, validated against high-quality site measurements. This means that estimates of total accumulated energy production are highly accurate.

Solcast has best-in-class accuracy on a wide variety of metrics including bias, RMSE (root-mean squared error), MAE (mean absolute error), MAPE (mean absolute percentage error), Pearson’s R value, and others. This accuracy has been independently validated against high-quality irradiance site measurements. Solcast achieves this accuracy with a combination of quality input data, processes using advanced algorithm models, calibrated data built for solar that outperforms more generic datasets.

How to evaluate live and forecast data accuracy?

Forecast accuracy is evaluated using metrics that compare predicted values with actual outcomes, typically including bias and RMSE. When looking for forecast data that meets your needs, an evaluation requires extensive data analysis and review. Check the assessment guide compiled from Solcast’s numerous commercial data evaluations, or assess the accuracy of Solcast data in your region using the interactive Live and Forecast accuracy map.