Scientists Unveil Rechargeable Molecule That Stores Sunlight as Heat

A UC Santa Barbara team has designed a pyrimidone molecule for molecular solar thermal (MOST) storage that traps sunlight and stores it as heat in a rechargeable, recyclable system. With an energy density above 1.6 MJ/kg—higher than typical Li-ion batteries—the molecule can absorb energy, hold it, and release heat on demand, potentially circulating in solar collectors to store daytime energy for later use without a separate battery.