The shortest-term forecast CloudMove is based on a novel forecast concept. With the help of wind fields from weather models the currently measured cloudiness is propagated to the future to forecast the radiation.
CloudMove is updated every 15 minutes and delivers 15-minute values for the next 6 hours. The precision (rel. RMSE) averages to about 20% (RMSE of satellite data) for the first forecast steps and goes towards the precision of a standard forecast within the forecast time domain of 6 hours.
Illustration for the shortest-term forecast CloudMove. The Clouds (clear sky index) retrieved from satellite images is moved with wind vectors from weather models.
By taking the exact position of the clouds into account for the forecast, CloudMove reaches for the first few hours a precision that cannot be achieved by standard weather models.
The CloudMove Standard delivers the following parameters:
- Global radiation [W/m2]
- Air temperature [°C]
With the CloudMove Advanced you receive in addition the following parameters:
- Direct and diffuse radiation [W/m2]
- Direct normal radiation [W/m2]
- Global radiation on the inclined plane [W/m2]
- Reference yield (for standard module and standard inverter) [Wh/kWp]
The product CloudMove Kalman uses real-time on-site measurements of radiation and/or yield to improve the forecast with a post processing using a Kalman filter.
A Kalman filter is a statistical algorithm which improves the forecast by eliminating systematic deviations between forecast and measurement data.
In order for CloudMove Kalman to function properly, the measurement data also needs to have 15-minute resolution and be updated every 15 minutes. The measured data needs to be submitted to the webservice using the HTTP Post protocol. Accepted data formats are JSON and CSV (comma separated values). Meteotest does not check the submitted data for completeness and consistency.