Method and device for forecasting cloudiness by statistical processing of data selected by spatial analysis

The invention relates to a method and a device providing cloudiness forecasts by statistical processing of satellite data which can be combined with data measured on the ground. The method includes collecting (11) satellite data on cloudiness at n times {T1,...,Tn} (n>1), analysing (12 and 13) the movement (X) of the cloudiness values between two times, recovering (15) a history of data (DATA_SELEC) selected relative to (X), and then estimating (16) the cloudiness at a time (TH) later than the other times by applying a generalised linear model (MOD_G) to the data (DATA_SELEC). Data from sensors placed on the ground, communicating and self-contained, can advantageously be added to the input of (MOD_G). The device comprising said method in the form of a computer program product is specifically intended for forecasting the electricity generated by solar conversion systems.