Topics in gradient maintenance and salt recycling in an operational solar pond

Since 1986, the 3355 m² salt gradient solar pond facility in El Paso, Texas, has operated with a temperature difference between the upper and lower zones of 55 to 75°C while delivering industrial process heat, grid-connected electrical power, and thermal energy for the experimental production of desalted water. Because the El Paso solar pond is an inland facility, it is necessary to recycle the salt in a sustainable salt management system. A method that uses the main pond surface for initial brine concentration and short-term storage was developed after it became evident that the original evaporation pond system was undersized. This paper examines the method for brine concentration and storage, the effects of a brine storage zone on pond operation, and the installation of an enhanced evaporation net system and an automatic scanning injection system. A short description of the performance history and current status of the project is also included.