CO 2 -Plume Geothermal (CPG) technology involves injecting CO 2 into natural, highly permeable geologic units to extract energy. The subsurface CO 2 absorbs heat from the reservoir, buoyantly rises to the surface, and drives a power generation system. The CO 2 is then cooled and reinjected underground. Here, we analyze the effects of multi-layered geologic reservoirs on CPG system performance by examining the CO 2 mass fraction in the produced fluid, pore-fluid pressure buildup during operation, and heat energy extraction rates. The produced CO 2 mass fraction depends on the stratigraphic positions of highly permeable layers which also affect the pore-fluid pressure drop across the reservoir.