Control and switch boxes, in the battery room, for each of the five turbines.  The turbine output is a sinusoidal three-phase AC (alternating current) that varies in voltage and frequency with wind speed.   Electricity is stored in the batteries as DC (direct current). So, in the control box the  AC from the turbines is converted to DC, and variations in voltage and frequency are “smoothed”, before being used to charge the battery bank.  When the batteries are fully charged, the controller 'disconnects' the turbine from the grid.