The Sun is the most abundant source of energy, but periods of supply do not always match periods of demand. Therefore finding solutions for storing solar energy is one of the major challenges for a sustainable society. One approach is to employ light-induced isomerization of photoactive molecules as exemplified by the DHA/VHF thermocouple in Figure . Upon irradiation, a molecule is converted to a high-energy photo-isomer and upon a certain stimulus, the high-energy isomer returns to the original molecule, and the excess energy is released as heat. This corresponds to a closed energy cycle of light-harvesting, energy storage and release, with no emission of CO 2 or other chemical products. Such systems are termed molecular solar-heat batteries. A suitable molecule 1) must absorb sunlight by converting to a higher energy form, 2) must absorb as much energy as possible (where ca 1 kJ/g is considered the practical maximum limit , but 0.3 kJ/g has been considered a reasonable target for some applications ), and 3) must be stable in the high-energy form for days or weeks. Dihydroazulenes (DHAs) are one class of promising candidates for solar heat batteries. The parent system (shown in Figure ) absorbs at the right wavelength with good quantum yield. However, the energy density is only 0.14 kJ/g and the half-life of VHF is only 3-39 hours (depending on solvent). Removal of one cyano group increases the storage density to 0.25 kJ/g and the half-life to years. Unfortunately, the back reaction could not be triggered without causing degradation. With both cyano groups present the storage density can be increased by up to 0.38 kJ/g but not without decreasing the half-life significantly. The goal of this study is to identify substituted DHAs with both higher energy density and longer half life through high throughput virtually screening.