A wind turbine for generating electricity is configured as a drum with a housing that has adjustable shutters to control the amount of wind reaching the turbine blades. Each pixel region is provided with a first thin film transistor for selectively supplying a signal corresponding to a display information to the pixel region, and a storage capacitor connected to the first thin film transistor for retaining the signal corresponding to the display information. Said heating element is fixed to the heat exchanger by means of a holding element is mounted in front of the corresponding flat pipe and parallel thereto by means of the holding element which also runs parallel to the flat pipe. The slots may be provided at regular vertical intervals so that the unit packages may be stacked in the vertical direction.