System and method to refurbish the non-convective zone in a salinity gradient solar pond

A Salinity Gradient Solar Pond (SGSP) has saturated salt water in the bottom zone of the pond and nearly fresh water at the top zone, with a gradient zone between the top and bottom. Due to this salinity stratification the upward diffusion of salt is a natural consequence in SGSP's. Controlling the salinity gradient in SGSP systems is vital to their reliable operation. The method for controlling the salinity gradient disclosed in this application, coined the "Pond Rolling Method" by the authors, rapidly drains the pond's non-gradient zones, refurbishes the gradient, and restores the non-gradient zones of the SGSP system, in a manner that minimizes land use, water and heat loss. The salt in the pond is allowed to diffuse upward over time and, on condition as needed to restore the gradient, the Pond Rolling Method is used to completely rebuild the gradient and the SGSP zones.