Within the scope of this project the electrical losses for the Schwennenz wind farm were calculated. It consists of three wind turbines with a total of 13 MW connected capacity. The basis are the power curves and calculated frequency distributions of the wind speeds. The calculation was done with the software DIgSILENT PowerFactory. Both the electrical energy loss per year and the electrical power loss for cos(φ) = 1 at nominal voltage for two cable cross sections of the wind farm connection were shown.