At the interface of renewable energies, this research takes a close look at the integration of geothermal energy, with a particular focus on the influence of the physical properties of unsaturated soils on geothermal energy transfer. Geothermal structures, which are essential for capturing energy from the soil, play a decisive role in heating and cooling buildings. By examining parameters such as soil composition, saturation level, water content, density, particle size, and arrangement, this study aims to derive differential equations to assess the energy balance at the soil surface, coupled with hydro-thermal transfer in unsaturated soils. A numerical model will be developed to simulate how climatic conditions influence geothermal energy transfer in these soils, taking into account their physical properties. The ultimate aim is to identify the most efficient soils for sustainable use of geothermal energy.