This article presents various detached eddy simulation (DES) results of a commercial wind turbine under multiple inflow conditions in complex and flat terrain. Challenges regarding the meshing process of wind turbines in complex terrain are described and an approach to overcome those is presented. The main focus of the evaluation is blade load and power response to inflow turbulence and terrain effects, e.g. the change of the inclination angle or the speed-up due to a hill. To separate the different influences, the complexity of the simulation setup is increased stepwise. Starting with a baseline simulation in flat terrain and uniform inflow over adding atmospheric turbulence to a complex terrain simulation of a fully meshed rotating 3D wind turbine under atmospheric inflow.