The system was designed using specially-developed molecules of carbon, hydrogen, and nitrogen. When these are hit by sunlight, the atoms within the molecules are rearranged, turning them into an energy-rich isomer that's stored in liquid form. Impressively, the researchers say their system stores energy in this liquid form for up to 18 years. It is then released using a special catalyst that returns the molecules to their original shape, releasing the stored energy as heat.