The article presents a case study on soil-structure interaction modelling for Wind turbines. After a brief presentation on the history of wind turbines and their potential in Romania, the authors take on the task of modelling the soil-structure interaction for the raft and piles. Three models are chosen: in the first model the piles are fixed at foundation depth; in the second, elastic supports are modelled on the raft and the piles and in the third model both elastic supports and fixed supports are modelled. Several comparisons are made between the three cases referring to displacements, efforts and necessary reinforcement. Based on these comparisons, the most important conclusion drawn is that the modelling of the soil-structure interaction has an important effect on the final reinforcement of the raft and the piles, considering that the difference between the models reaches almost 18%, which in the case of really large foundations can draw the line between economic and non-economic design.