Molecular Solar Thermal (MOST) Energy Storage—Definitions and Requirements Revisited

Molecular solar thermal storage (MOST) systems have gained increasing attention in the past years after an intense initial exploration phase around five decades ago. Over time multiple terms have been circulating in the literature, such as solar thermal fuels or solar thermal batteries. Besides clarifying the nomenclature, we introduce the term “mostophore” as a molecular entity able to harvest and store light energy in the form of heat. Furthermore, we revisit the requirements for practical systems and put the concept in a historic perspective with a future outlook.