Forecast solar variability and limit unbalancing costs with the most accurate photovoltaic production forecasts.
Since 2013, Steadysun has worked with producers, traders, and grid operators across six continents to turn atmospheric data into precise forecasts, from the next minute to 15 days ahead, at any scale, from a single rooftop to a national grid.
Solar power generation is highly variable; a single cloud can drop production by 80% in a matter of minutes. To efficiently integrate solar energy into electricity grids and markets, accurate advance knowledge of production is crucial.
That’s why Steadysun built a solar power forecasting solution grounded in weather inputs up to 2.6× more accurate than national models. That precision carries through to the power forecast itself: in one deployment, it cut Grid Code penalties by 50% and curtailment losses by 75%. Results depend on site and grid setup, but our solar energy forecasts empower you to:

Producers use our PV forecast to reduce balancing penalties, plan maintenance windows during low-production periods, and demonstrate forecast performance to offtakers and lenders. The probabilistic output (P10–P90) gives asset owners a quantified view of production risk, not just a single-line estimate.
Grid operators use our solar forecast to anticipate renewable injection volumes, reduce spinning reserve requirements, and manage the gap between day-ahead declarations and actual intraday production. Accurate forecasting directly reduces imbalance costs and supports higher penetration of solar without compromising grid stability.
For traders, the solar forecast is a direct input into market strategy. Day-ahead bids, intraday adjustments, and cross-border nominations all depend on knowing (with confidence intervals) what a portfolio will produce. Manage your photovoltaic portfolio with confidence using reliable short and medium-term forecasts.
In non-interconnected zones (islands, remote industrial sites, off-grid communities) solar variability is a direct threat to grid stability. Our intraday solar forecast enables operators to manage hybrid fossil-solar systems, reduce diesel consumption, and operate storage assets efficiently. Even a small improvement in forecast accuracy in these environments translates into significant fuel savings and reduced CO₂ emissions.
From a few minutes to 15 days ahead (depending on the processing chosen).
Every 5 minutes
Up to 1 minute
AC/DC Power, GHI, DNI, DHI, GTI, temperature, and more...
All types of technology (PV, with or without tracking, CSP)
For any size of installation and aggregation: from a few kW to forecasts for a whole country.
Measure uncertainty through 11 quantiles (P00, P10, P20, …, P80, P90, P100)
We deliver the most reliable solar production forecasts through two innovative approaches that seamlessly combine artificial intelligence (AI), expert meteorological analysis, and powerful multi-model processing.


We support:
If you already run an EMS, SCADA, or trading system, our API is the fastest way in, with a lightweight, well-documented integration that plugs the forecast straight into what you already use. Starting from scratch? Our team can help you get set up, whether that means integrating the API directly or using Steadyweb as a ready-to-use platform. And if your setup needs something more custom, our team can build that with you.
Put our forecasts to the test — easily integrate our solar data into your tools and see the impact firsthand. With our solar API, nothing could be simpler or faster.
Visualize, optimize, and secure your solar energy production with Steadyweb, the best solar power forecasting platform. Our all-in-one solution transforms complex weather data into forecasts of exceptional reliability, allowing you to:
Trusted by industry leaders, Steadyweb combines ease of use, accurate forecasts, and flexible API configuration to optimize every kilowatt-hour of your solar production. 🚀

View real-time photovoltaic production forecasts and weather data, updated continuously few minutes to 15 days.
Create an exact virtual model of your power plant by entering its technical specifications and integrating your historical or live data for solar energy forecasts perfectly calibrated to your installation.
Accurately assess the quality of our solar power forecasts using key statistical metrics (MAE, MBE, RMSE).
Integrate our soler forecasts directly into your tools using our powerful API, CSV files, or SMTP protocol for seamless and fully automated management.
Supervise your entire energy portfolio from an ergonomic interface, allowing for real-time monitoring and simple adjustment of your photovoltaic systems.
Optimize your budget with our forecast point billing system. Tailor your subscription to the actual scale of your needs.
Access live solar irradiance data, and much more for operational optimization.
Rebuild past weather and solar production to analyze performance, size your systems, and evaluate profitability.
Access high-precision wind energy forecasts to optimize turbine performance, reduce downtime, and maximize energy yield.
Q&A
A solar irradiance forecast predicts the amount of solar radiation reaching a surface (GHI, DNI, GTI). A solar power forecast goes one step further: it converts that irradiance prediction into an estimated AC or DC power output for a specific installation, accounting for panel technology, tilt, azimuth, temperature effects, inverter losses, and shading. Steadysun delivers both, but most operational clients need the power forecast directly.
Accuracy depends on your climate (cloud variability, aerosol load, seasonal patterns), your installation type, and the forecast horizon. We help you set up a site-specific benchmark so you can measure accuracy against your own data. Contact us to discuss what’s realistic for your location.
Via REST API (JSON), SFTP, CSV/XML, or direct SCADA connectors. Full API documentation is available at steadyweb.steady-sun.com/rapidoc/. Our team handles the integration setup and provides technical support throughout onboarding.
Yes! We offer a 30-day free trial as an EXPERT+ subscription with no credit card required. 🎁 You can experience the full capabilities of our API and SteadyWeb platform, calibrate forecasts to your site, and assess their accuracy using key performance metrics.
At minimum: site location (latitude/longitude), installed capacity (kWp), panel tilt and azimuth, and inverter type. For higher accuracy, we also use panel technology specs, shading analysis, and, if available, historical measured production data for model calibration. Our team is available to assist if needed.
Contact us, we will be happy to answer you!
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