With the increasing scale of new energy, the ability to rationally utilize new energy power abandonment has become key to improving the operational efficiency of new power systems in the future. Existing new energy power abandonment consumption methods have problems such as limited consumption capacity and large-scale applications. Therefore, to consume the large-scale power abandonment of new energy and enable it to be stored for a long time, this study proposed a method in which electro-thermal conversion devices are used to convert electric energy into thermal energy, and the energy is stored in an underground aquifer. A finite element numerical analysis model was constructed to analyze and calculate this process. A multi-physical field coupling numerical analysis model, considering the seepage of groundwater and the heat transfer of the heat exchangers and porous media, was constructed by combining the distribution characteristics of power abandonment and a theoretical analysis of the heat transfer principle of an aquifer. A scaled test platform was constructed based on the similarity principle to verify the accuracy of the numerical analysis model. The results of the numerical analysis and simulated test showed that the energy storage system could store power abandonment in the form of thermal energy in the aquifer. At the same time, the annual energy loss of the system is only 14.89%, indicating that the system has long-term storage capabilities. In addition, a comparative analysis of the consumption effects of energy storage systems of different sizes showed that an aquifer energy storage system can be configured according to the capacity of power abandonment. Thus, a large-capacity new energy consumption space can be constructed to realize the complete consumption of power abandonment.