The Weizmann Institute of Science in Rechovot has developed a process where zinc oxide is heated by solar energy until it splits into oxygen and gaseous zinc. The gas is condensed to powder. When reacted with water it produces hydrogen and zinc oxide which is recycled back to zinc.
The process generates no pollution, and the resultant zinc can be easily stored and transported, and converted to hydrogen on demand. In addition, the zinc can be used directly, for example, in zinc-air batteries, which serve as efficient converters of chemical to electrical energy. Thus, the method offers a way of storing solar energy in chemical form and releasing it as needed.
