Much research aims to improve the efficiency of energy processes. However, it is often not clear where the biggest potential for improvement lies. Crucial for a namable improvement is a realistic chance for advancing the respective element as well as a significant influence of the respective element on the overall performance. A study on the potential for improving the efficiency of five exemplary chemical-energy systems is presented. It was found that replacing working substances by alternatives with better enthalpies of reactions or solubility behavior carries huge potential for improving energy processes. However, in most cases there is little potential, for example, in lower heat capacity, even though heat capacity highly influences the efficiency of the processes.