Desert sand could be used in thermal energy storage

SciDev.Net : Typical concentrated solar power facilities use materials such as synthetic oil or molten salts to collect excess thermal energy and save it for later use. Now researchers at the Masdar Institute of Science and Technology in Abu Dhabi, United Arab Emirates, propose replacing those materials with something cheaper and more readily available in that area: sand. Modeled on an hourglass, the new system comprises two reservoirs connected vertically by a narrow passage. As cold sand grains in the upper reservoir drain to the lower one, they are heated by solar energy. The hot sand in the lower reservoir can then be used to power various devices, such as electricity-generating turbines. Once the sand grows cold, it is then returned to the upper reservoir and the cycle is repeated. The researchers next plan to scale up their prototype and seek industrial collaboration.