SolarWX service provides forecasts of Global Horizontal Irradiance (GHI) and
    estimated power output SolarWX service provides forecasts of Global Horizontal Irradiance (GHI) and
    estimated power output


Solar Forecasting
Data Services

Global Weather Corporation’s SolarWX® service provides forecasts of Global Horizontal Irradiance (GHI) and estimated power output (when system characteristics are available), for any solar installation at any location in the world. SolarWX’s accurate estimates of GHI enable applications such as solar energy generation, home and industrial energy use, and agriculture. Typical users include utilities, energy traders, smart home applications, photovoltaic monitoring systems, and agricultural information services. Forecasts can be displayed in our simple, intuitive, web-based display, shown here. Alternatively, our forecast data feed can be integrated into any customer system.

GWC’s web-based time-series graphical user

SolarWX combines two critical modeling steps.

  1. The first is GWC’s best-in-the-world atmospheric forecast, 1 used in this case to generate GHI information.
  2. The second is our power conversion model that converts GHI to forecasted output power. Some customers need only GHI; others need the conversion to power as well. When observational data are available, the system can provide an improved forecast based on statistical analysis of the observations.

Accuracy of both the GHI and power conversion steps has been verified by comparison to observations. The line graph shows forecast error statistics for a 72-hour period, illustrating GWC’s reduction in forecast error (light blue line) as compared to U.S. and Canada weather service models.


SolarWX is generated at hourly intervals, with forecasts available to 168 hours. Observations of GHI and power, when available, are input to the system. These data are used to optimize the forecast generation and power conversion steps in the processing chain. Output is available through GWC’s web-based time-series graphical user interface and as a data feed for integration into automated processes. The table below summarizes the standard output variables when power output data are provided in addition to GHI.

Data for SolarWX Services


  • Output Power at Node
  • Average GHI at Site
  • Rolling 7-day Power %MAE
  • Rolling 30-day Power %MAE
  • Rolling 365 day Power %MAE
  • Minimum Node Power
  • Maximum Node Power
  • Power as % of Capacity
  • Available Power at Node
  • Min Available Power at Node
  • Max Available Power at Node
  • Available Power 7-day %MAE
  • Available Power 30-day %MAE

Delivery Method

  • Standard web services as bulk CSV files

1. ForecastWatch is an independent provider of forecast accuracy and skill information. Read the report at

Contact US



Office Address

3005 Sterling Circle, Suite 201
Boulder, CO 80301