This thesis is based on the thermodynamic aspect of thermoelectricity, a physical phenomenon that describes the conversion of heat into electricity and vice versa through two related mechanisms, the Seebeck effect and the Peltier effect. By combining the diffusion and drift contribution to charge and heat transport and through simple mathematical manipulations, we derive expressions that elucidate the causes of electric and heat flow, defining fundamental transport coefficients. The electric flow is related to the gradient of the electrochemical potential by the electric conductivity coefficient, and to the temperature gradient by the Seebeck coefficient. The heat flow is associated to the temperature gradient by the thermal conductivity coefficient (conduction), while the Peltier coefficient connects it to the charge flow (convection). We emphasize the importance of the thermodynamic approach, which provides a theoretical basis for understanding the transport processes and interactions between electrical and thermal transport, thus contributing to the development of efficient and sustainable thermoelectric systems and finding new energy solutions.