Regional Solar Energy Forecast

As solar capacity grows so does its impact on the grid system and energy prices. Our forecast is designed to give energy traders, schedulers, and asset managers the information they need to reduce risk and make day-to-day financial and operational decisions with confidence. This day-ahead forecast enables you to bid into forward markets and proactively manage your assets based on scientifically supported predictions rather than reacting to real time constraints.

See also - Solar Energy Forecasting

Vaisala's 3TIER Services forecast team applies cutting edge weather modeling and robust super-computing capabilities to solve the problem of solar variability. Our forecast is consistently more accurate than the day-ahead public forecast, particularly on cloudy days where anticipating solar availability is especially critical. Extensive validation shows that Vaisala's forecast successfully predicts reduced production days 60% more often than the public forecast.

Day-Ahead Forecast

  • Updates multiple times per day
  • 0-6 day projection
  • 1 hour granularity

Additional Forecast Information

  • P10 and P90 exceedance probabilities
  • Six months of historical forecasts and actual production
  • Flexible display for side-by-side comparison of Vaisala and Public forecasts with actuals


  • Consistently beats public forecast in CAISO SP-15 zone
  • Mean Average Error: Public 6.5% vs. Vaisala 5%
  • Mostly Clear Day Detection: Public 77% vs. Vaisala 83%
  • Mostly Cloudy Day Detection: Public 14% vs. Vaisala 83%

Available Zones

  • CAISO SP-15
  • CAISO ZP-26
  • CAISO NP-15

Delivery Method

Forecasting tools are available via a client-specific, dashboard interface and downloadable data files are delivered in multiple formats (CSV, XLS, and XML) to allow easy integration with your own analysis tools and programming software. In addition, we offer an API option for faster integration of downloadable forecast data, which can also be provided through data aggregation service partners.


Aligned with Vaisala's commitment to using state-of-the-art, proven, and transparent methods, our regional solar forecast system is a combination of publicly available global and regional weather forecasts, high resolution surface data, and highly customized mesoscale numerical weather prediction (NWP) models. The result is an aggregate solar forecast converted into real world values of hourly power generation in megawatts. Where aggregate power data is publicly available, Vaisala will incorporate observations to deliver statistically corrected power forecasts.

See Also

Solar Energy Forecasting

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Key Benefits

Accurate day-ahead regional forecasts
Using proven science and powerful modeling approaches we consistently outperform publicly-available solar forecasts
Convenient and security
Guaranteed 24/7 availability and a customizable dashboard interface. Easily set up your own permissions system with usernames and passwords for access to information. A secure password protected web host server is also provided for all data transfers.
Our model and data hardware will continually adapt as new solar projects come online and new data becomes available to ensure the highest forecasting accuracy.​