A Salinity Gradient Solar Pond has saturated salt water in the bottom of the pond and nearly fresh water at the top, 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. This upward diffusion of salt has been found to range 60-80 gr/m.sup.2/day (Tabor, H.; Solar Ponds, Solar Energy, v. 27 (3), pp. 181-194, 1981 and v. 30 (1), pp. 85-86, 1983). Controlling the salinity gradient in SGSP systems is vital to their reliable operation. One proposed method for controlling the salinity gradient is the so called Falling Pond method, where water is extracted from the saturated bottom layer by some means and returned to the nearly fresh upper layer. This action creates a downward velocity in the pond's layers which can be matched to counter the upward diffusion of salt, thereby maintaining the pond's gradient stationary in space.

The present disclosure relates to a plate installed at the bottom of a salt lake to extract lithium, the plate being able to increase a lithium extraction amount by being installed on the bottom of a salt lake or an evaporation pond for lithium extraction and quickly evaporating salt water. The plate installed at the bottom of a salt lake to extract lithium of the present disclosure includes a base configured to be brought in close contact with a bottom of a salt lake for extraction of lithium and having a box shape with an open top, a low specific heat panel configured to cover the open top of the base and made of a material of which specific heat is lower than specific heat of the bottom of the salt lake, and a low-emissivity coating layer formed in a predetermined thickness on a top of the low specific heat panel.

The present disclosure relates to a plate installed at the bottom of a salt lake to extract lithium, the plate being able to increase a lithium extraction amount by being installed on the bottom of a salt lake or an evaporation pond for lithium extraction and quickly evaporating salt water. The plate installed at the bottom of a salt lake to extract lithium of the present disclosure includes a base configured to be brought in close contact with a bottom of a salt lake for extraction of lithium and having a box shape with an open top, a low specific heat panel configured to cover the open top of the base and made of a material of which specific heat is lower than specific heat of the bottom of the salt lake, and a low-emissivity coating layer formed in a predetermined thickness on a top of the low specific heat panel.

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.

Systems and methods for concentrating and storing solar energy are provided. A solar energy receiver for use with the systems and methods may include a container for holding a solar absorption material, such as a phase change material, and a cooled cover disposed above the container for condensing and collecting vaporized phase change material collected along an underside of the cover.

A carbonized manure photothermal evaporator derived from naturally abundant farm waste has high solar absorptance, effective water transportation, and rapid salt dissipation. It achieves high evaporation under 1-sun irradiance and is recyclable, durable, and cost-effective for use in energy-efficient solar-driven interfacial desalination.

A carbonized manure photothermal evaporator derived from naturally abundant farm waste has high solar absorptance, effective water transportation, and rapid salt dissipation. It achieves high evaporation under 1-sun irradiance and is recyclable, durable, and cost-effective for use in energy-efficient solar-driven interfacial desalination.