Transcutaneous energy transmission systems (TETS), which use electromagnetic induction to wirelessly transfer energy, have been widely used as energy transmission systems for artificial hearts. TETS help to improve the patient’s quality of life and reduce the risk of infection caused by percutaneous connections. However, to provide protection against the established adverse health effects caused by electromagnetic induction, it is necessary to quantify the amount of energy absorbed by biological tissues. In this study, we sought to analyze the specific absorption rate (SAR) and the internal electric field E of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. We used four types of human biological tissue models with different genders, ages, weights, heights, and body sizes, at a frequency of 0.9 MHz. Each tissue model consisted of dry skin, wet skin, fat, muscle, and cortical bone tissue. A primary coil was placed on the surface of the dry skin tissue, while the secondary coil was embedded between the wet skin and fat tissues. The transmission power was 15 W, and the load resistance was 38.4 Ω. The simulation data was obtained using the FEKO electromagnetic simulator. The results showed that the SAR and E for adult models (male and female) were well below the limits specified by ICNIRP for both general public and occupational exposure. For children, the SAR and E exceeded the ICNIRP general public exposure limits but remained below the limits prescribed by ICNIRP for occupational exposure. These results show that it is safe to transmit 15 W of energy in an adult.