The Sun is a huge source of energy. In just one hour, planet Earth is hit by so much sunshine that humankind could cover its energy needs for an entire year if only we knew how to harvest and save it. A student at the University of Copenhagen has researched his way to a breakthrough that may prove pivotal for technologies trying to capture the energy of the Sun, and saving it for a rainy day.
Researchers are developing molecules capable of harvesting and holding substantial amounts of solar energy, storing it for significant amounts of time, and releasing it on demand. The group is working with molecules known as the Dihydroazulene-Vinylheptafulvene system. This stores energy by changing shape. By doubling the energy density in a molecule, it can hold its shape for 100 years.
In theory, a kilogram of the right molecules could store a megajoule of energy if they were perfectly designed. With that amount of energy, you can heat three liters of water from room temperature to boiling. A kilo of the new molecules can boil only 75 centiliters, but it does that in just three minutes. This means that the molecules could bring 15 liters of water to boil per hour.