Molecular solar thermal energy storage systems (MOST) offer emission-free energy storage where solar power is stored via valence isomerization in molecular photoswitches. These photoswitchable molecules can later release the stored energy as heat on-demand. Such systems are emerging in recent years as a vibr
These systems have been expanded significantly in the last decades , even though the first idea dates a while back . The MOST approach is based on the storage of solar energy as chemical energy using a photoactive molecule, which, after being exposed to sunlight, isomerizes into a metastable high-energy photoisomer .
This is especially relevant for solar energy use and storage , which has been envisioned as an abundant, clean, and promising energy source. Using natural photosynthesis as a working model for solar energy use, scientists are designing and preparing chemical systems capable of capturing and storing solar energy.
The calculated energy densities of the dimer and trimer systems of up to 927 kJ kg −1 (257 Wh kg −1) and measured densities up to 559 kJ kg −1 (155 Wh kg −1) greatly exceed the original targets of 300 kJ kg -1 15 highlighting the potential of applying molecular photoswitches in future solar thermal energy storage technologies.
While it is not strictly a photochemical property, another crucial concern in MOST systems is the energy storage. MOST technology is designed for generating the greatest possible increase in temperature after releasing the stored chemical energy in the photoisomer as heat.
Consequently, different methodologies have been developed to exploit solar power such as underground solar energy storage (USES) and molecular solar thermal (MOST) systems. The USES system mechanism consists of the storage of sun energy underground during summer months using a pile [8,9].