InstaCast provides ultra high resolution intra-hour solar forecasts. In order to anticipate local events in the forthcoming minutes, on-site images of the sky are the most valuable source of information. InstaCast processes those images to precisely and reliably forecast solar production, and deliver it in a convenient way.


Slide thumbnail


1-minute updates of the forecasts

1-minute forecast updates

With rapid forecast updates down to 1 minute, InstaCast offers unmatched short-term prediction of cloud events and solar production drops.

Easy interfacing with plant control sytems

Easy interfacing with plant control sytems

InstaCast has a proven compatibility with major energy management & power control solutions from the market.

100% offline mode for remote sites

100% offline mode for remote sites

An embedded version of InstaCast integrated within Reuniwatt’s sky imagers enables it to be used for microgrid projects in off-grid sites.



Intra-hour solar forecasts process

Sky image acquisition

Local images of the sky are acquired at a high frequency (1 min or less), as well as local weather measurements. Since the quality of this input data influences the accuracy of the intra-hour solar forecasts, Reuniwatt decided to design and build its own imagers, including the Sky InSight, after testing various sky-imaging systems available on the market since 2011.

Irradiance & production forecast

Image processing methods are applied to distinguish the clouds from the sky and sun glares. A geometric calibration of the image permits a projection of the clouds and their cast shadows within the solar plant’s environment. Irradiance and production forecasts are derived from it. Besides, machine learning post-processing enables the forecasts to adapt to each site.

Formatting & transmission

Once computed, forecasts are formatted in a convenient way to be integrated in the plant’s management system, for an improved control of the plant. Reuniwatt’s InstaCast solution has a proven compatibility with major energy management & power control system providers. Last but not least, the intra-hour solar forecasts can be delivered locally in an embedded mode, or through the Internet.


Several variables available: solar irradiance (GHI/DNI/GTI…), output power, drops

1-minute updates

30-minute horizon at 1-minute granularity

10 m² spatial resolution

180° field of view / 2 km radius

Tailored distant (http, sftp…) or local (MODBUS) data transfer



You might also be interested in

Sky InSight, our infrared sky imager

Intraday solar forecasts with HourCast

Solar forecasting for microgrids and off-grid projects

Publication: forecasting for improved management of hybrid systems