This chapter reviews key Molecular Solar Thermal (MOST) parameters using azobenzenes as a model. The ease of modifying azobenzene structures allows for tuning properties such as absorption wavelength, energy storage capacity, and release. Effective strategies include adding substituents, incorporating heterocycles, combining multiple MOST-active structures, or integrating into macrocycles. While many modifications influence multiple parameters, optimizing them simultaneously remains challenging. The ideal azobenzene MOST candidate is yet to be found, underscoring the need for further research and exploration of alternative structures.