Transcutaneous Energy Transmitters (TETs) transfer wireless energy through an inductive link established between two pancake coils placed, respectively, outside and inside the body of a patient. The simulation of the misalignment between the coils must be performed in three dimensions (3D), e.g., with a Finite Element (FE) method. This paper introduces a homogenization method to minimize the cost of the expensive 3D FE computation in the frequency domain. Its originality lies in the non-homogeneous TET geometry during the meshing process. The results of this technique are compared with those obtained by considering regular stranded TET coils. They showed improvements mainly at kilohertz frequencies, the typical TET operating frequency range