Live and Forecast Data

Overview

Irradiance and weather data for operating and analysing solar assets, grids and markets

Real clouds, real data. Designed specifically for solar energy applications.

Real time and forecast irradiance data and PV power data based on 3 dimensional cloud modelling. Powered by live satellite irradiance data, updating every 5 to 15 minutes. Ready to integrate via API.

Observed estimated actual cloud opacity and ensemble forecast
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 and forecast solar data tracks and forecasts 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.

Solcast's live and forecast data spans from 7 days ago to +14 days ahead, at 5 to 60 minute granularity, globally. Check the data parameters to learn more.

DATA SPECIFICATIONS

Data that actually meets your requirements

Data spanning from 7 days ago to +14 days ahead, at 5 to 60 minute granularity, anywhere on Earth, providing solar irradiance data by location. Includes probabilistic forecast estimates of PV power and all types of irradiance. Actuals available in real-time. Historical data also available.

ACCURACY

Proven, replicable accuracy levels

Our forecast accuracy beats global weather models by 25% (day-ahead) to 50% (hour-ahead). Hundreds of data scientists and engineers have confirmed our accuracy, and we're willing to guarantee it. Review our accuracy verification, or contact our team to access real past forecasts for your actual sites.

Data Accuracy

PV POWER DATA

Simulate and forecast your production directly in our system

Create your own live and forecast simulated PV power data in minutes, by specifying details of your sites in a UI or programmatically. Or, have our team configure your sites using your historical production data. Separate models are used for roof VS ground mounted systems. All simulations and forecasts are powered by our industry-leading irradiance and weather data.

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.

Commonly Asked Questions about Live and Forecast 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.

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.

Solcast’s live solar irradiance data is updated every 5 minutes. 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.

Solcast’s live irradiance data primarily relies on real-time satellite observations to provide real-time actuals from 7 days ago 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.

Solcast solar irradiance data have been found to have a mean bias of +0.33%, ±2.47% Std Dev. and RMSE 15.99%! And similar results globally and across climate zones. The level of accuracy is achieved through the usage of high quality input data, processes using advanced algorithm models, to produce data that’s built for solar.

Solcast’s solar forecast irradiance data predicts future solar irradiance at a specific location, from +5 minutes to 14 days ahead. The data is generated using recent satellite imagery to predict the movement of clouds to produce a “nowcast” and global numerical weather prediction models. Check our irradiance methodology .

A solar nowcast is a short-term solar irradiance forecast, up to 4 hours ahead, using real-time data. Solcast uses satellite cloud tracking models, using near real-time imagery from geostationary satellites, to track cloud movement and deliver high-resolution solar data every 5 to 15 minutes. Accurate solar nowcasts are essential for quick operational adjustments to optimize energy production and respond to changing weather conditions.

Day-ahead forecasting predicts solar irradiance for the upcoming day, usually 0 to 24 hours in advance. Solcast provides probabilistic forecasting, including P10, P50 and P90, for day-ahead forecasts. These help gauge uncertainties and provide a range of possible outcomes for better decision-making, preventing inefficient power management, regulatory violations, unnecessary storage system cycles and more. 

Several factors affect the accuracy of forecasts, such as cloud impacts, aerosols, snow soiling, terrain shading and more. Unlike generic weather models, the Solcast API takes these factors into account. Another factor that affects accuracy is the quality of input data. Solcast takes advantage of the rise of meso-scale weather models and integrates them into the model, which has helped enhance forecast accuracy in Europe and North America.

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.