Method of controlling a power plant associated with a temporally random source of energy

The invention concerns a method for controlling an electric power plant (2) associated with a power source (6) with random time-based availability, the unit comprising at least one battery (10) adapted to be supplied with electric current from the source. When the random power (6) is available, the battery (10) current supply is controlled. The supply is controlled until it comes as close as possible to the battery complete state of charge, and preferably until it reaches that state.