Abstract: A halocline is maintained in open body of salt water at a depth to which a significant amount of solar radiation penetrates by inducing an upward vertical flow in the body of water sufficient to counter wind-mixing and molecular diffusion thereby establishing an ascending or rising solar lake. The upward flow is induced by injecting into the body of water a concentrate with a density greater than the density of liquid at the lower end of the halocline, the concentrate being formed by evaporating liquid drawn from the surface of the body of water. The halocline suppresses convention currents and allows solar radiation to heat the halocline as well as a layer of liquid therebelow to temperatures significantly higher than the surface temperature. Heat for useful work can be extracted from the heat storage layer beneath the halocline.

Abstract: A solar pond serving the dual purposes of concentrating an aqueous brine by evaporation and simultaneously producing power by storage of incident solar radiation. The so-stored solar energy is used by a heat machine. The solar pond has a concentrated aqueous brine which serves as the heat storage layer, and a halocline overlying the heat storage layer. An evaporation layer, whose density does not exceed that of the upper stratum of the halocline, overlies the halocline. A heat exchanger forms a part of a heat machine, and includes an organic, water-emiscible operating fluid as heat carrier, means for withdrawing hot brine from the heat storage layer to the heat exchanger, means for returning brine from the heat exchanger to the heat storage layer, a condenser for the operating fluid adapted for the throughflow of an aqueous coolant as heat sink, and means for feeding a warmed coolant emerging from the condenser to the evaporation layer.

Abstract: A segregated solar pond includes an upper level of water overlying a lower level of water, and an impermeable barrier interposed between the two levels for preventing intermixing. The average density of the upper level exceeds the average density of the upper level. Floats on the periphery of the upper level buoyantly support it on the surface of a larger body of water connected to the lower level. The upper level contains dissolved salts establishing a halocline that renders the upper level non-convective such that it is heated by absorption of solar radiation, the heat being transferred to the lower level by conduction across the barrier. Vertical curtains attached to the periphery of the barrier inhibit mixing of the water in the lower level with the water in the larger body of water such that the lower level constitutes a heat storage layer.The barrier between the two layers includes a sheet of flexible material and a frame supporting the same rigidly connected to the floats.

Abstract: A heat storage pond, of the type having a lower heat storage layer of water covered by an insulating layer, has a partition that extends from a location on the periphery of the pond toward an opposite peripheral location, but terminates short thereof, for dividing at least the heat storage layer into two interconnecting portions. Water from the heat storage layer in one of the portions is drawn off and passed through a heat exchanger for extracting heat from the water. The water passed through the heat exchanger is then returned to the heat storage layer in the other of the two portions thereof, the partition effecting a physical separation between the intake and discharge. This arrangement sets up a circulation pattern in the lower region of the heat storage layer, while water in the other portion flows away from the point at which the cooler water is discharged into the heat storage layer, the only interconnection between the portions being in the region at the free end of the partition.

Abstract: A method for treating a body of water forming a solar pond includes applying oil to the surface of the pond from at least one predetermined area of the surface, collecting oil from the surface, purifying the collected oil, and then recirculating the purified oil to said at least one predetermined area. Apparatus is provided for performing the method and includes wind-activated nozzles for applying the oil at an upwind peripheral location, a trough for collecting the oil at a downwind peripheral location, a filter for purifying the collected oil, color and spreadability sensors for examining the collected oil, and a quality improvement device for controlling the quality of the collected oil in accordance with the sensor output. A pump and pipe recirculate the treated oil from the trough to the nozzles.

Abstract: A solar pond power plant has a solar pond with a heat storage layer for storing heat absorbed from solar radiation incident on the pond, and a low-temperature, closed Rankine-cycle turbogenerator operating on heat extracted from the heat storage layer. The turbogenerator has a generating capacity of Q.sub.I watts/m.sup.2 of pond area, this capacity being in excess of Q.sub.e watts/m.sup.2 of pond area where Q.sub.e is the net electrical energy that can be generated by the turbogenerator when heat is extracted from the heat storage layer at substantially the same average rate at which heat is absorbed by the layer. According to the invention, the generating capacity Q.sub.I of the turbogenerator is in the range 2-10 times Q.sub.e, whereby the solar pond power plant can be utilized for peak power requirements of a regional electrical generating system.

Abstract: Make-up water contaminated with nutrients is pretreated by establishing a stagnant pond of brackish water having an upper wind-mixed layer exposed to solar radiation and of relatively low, uniform salinity, an intermediate halocline whose salinity increases monotonically with depth, and a lower collection layer of relatively high, uniform salinity. Make-up water contaminated with nutrients is added to the wind-mixed layer wherein the nutrients support the growth of photosynthetic microbes. The wind-mixed layer is provided with Artemia salina (brine shrimp) that feed on the photosynthetic microbes growing in the wind-mixed layer and extrude fecal pellets of a density in excess of the density of at least the upper layer of the pond, whereby the pellets sink below the wind-mixed layer, and preferably to the collection layer. Upward diffusion from the collection layer into the wind-mixed layer of the disintegrated constituents of the fecal pellets is suppressed by reason of the stratified nature of the halocline.

Abstract: A halocline is maintained in open body of salt water at a depth to which a significant amount of solar radiation penetrates by inducing an upward vertical flow in the body of water sufficient to counter wind-mixing and molecular diffusion thereby establishing an ascending or rising solar lake. The upward flow is induced by injecting into the body of water a concentrate with a density greater than the density of liquid at the lower end of the halocline, the concentrate being formed by evaporating liquid drawn from the surface of the body of water. The halocline suppresses convention currents and allows solar radiation to heat the halocline as well as a layer of liquid therebelow to temperatures signficantly higher than the surface temperature. Heat for useful work can be extracted from the heat storage layer beneath the halocline.

Abstract: Apparatus for measuring the density profile of a layer of liquid includes a plurality of individual tubes arranged in side-by-side fashion, each of the tubes having an inlet opening in its lower end. A vacuum manifold is connected to the apertured upper ends of the tubes. The apertures in the lower ends of the tubes are vertically staggered and the tubes are vertically oriented with the lower ends of the tubes immersed in the liquid, so that the inlet openings are differentially spaced from the surface of the liquid. The application of a vacuum to the tubes causes liquid from the different levels to be drawn into the tubes, the height of the liquid in the tubes above the surface being proportional to the density of the liquid drawn into the tubes through the inlets.

Abstract: A solar power station has a heat source in the form of the heat storage layer of a solar pond, a heat sink in the form of the wind-mixed layer of the pond covering the halocline interposed between the heat storage layer and the wind-mixed layer, and a power plant associated therewith. The power plant includes a boiler responsive to water from the heat storage layer for vaporizing a working fluid, a prime mover for producing work by extracting heat from vaporized working fluid, and a condenser cooled by water from a cooling pond connected to the solar pond such that only water in the wind-mixed layer is exchanged with the cooling pond. The wind-mixed layer serves to dissipate heat from the condenser and the volume of water in the cooling pond increase the heat absorption capacity of the heat sink.

Abstract: A pond construction, especially useful for non-convective solar ponds, having a multi-layer bottom in order to minimize seepage of liquid through the pond bottom. Liquid which permeates the multi-layer construction is pumped back into the pond.

Abstract: The density profile of a halocline, which increases monotonically with depth, is modified by drawing water from different levels of the halocline (and therefore of different densities) into a mixing chamber, mixing the water in the mixing chamber and discharging the water in the mixing chamber into the halocline intermediate the levels from which the water is drawn. In one technique, a closed chamber is inserted into the halocline, the chamber having a vertically oriented slot defining a preselected layer of the halocline. The contents of the chamber are mixed to establish a uniform density equal to the average density of the water in the preselected layer. As a consequence, the vertical variation in density across the slot between the water inside and outside the chamber establishes a static pressure differential which causes water in the layer to flow into and out of the chamber until the density of the layer is uniform.

Abstract: A method of changing the salt content of a solution is described by including the salt in a nonconvective solar pond heated by solar radiation and having stable salt-concentration and temperature gradients increasing from the top to the bottom of the pond, the bottom layer of the pond being a substantially saturated solution at a predetermined temperature. A feed solution containing the salt is introduced directly into the bottom layer and is circulated through the bottom layer. The predetermined temperature of the bottom layer is different from the initial temperature of the feed solution when introduced into the pond bottom layer and is selected to effect a change in solubility, and thereby a change in the salt content, of the feed solution by causing salt in the feed solution to be precipitated therefrom, or additional salt to be dissolved therein.