A thermal heat storage system is provided, including a storage tank, a heat injection system and a heat recovery system. The storage tank holds a material for thermal storage. The heat injection system is coupled to an intake on the storage tank. The heat recovery system is coupled to an output on the storage tank and also uses vapor under depressurized conditions for heat transfer.

Two sensible thermal energy storage (STES) systems in multiple chambers containing molten eutectic salts have been devised for use at temperatures above 565 C. For the first type, the thermal energy of low specific heat of an immiscible gaseous heat transfer fluid (HTF) at temperatures above 900 C. is readily converted to dispatchable heat of high specific heat in the molten eutectic salt liquid layers operating at high temperatures, which can again produce a gaseous HTF at a constant temperature of 700 C. or higher for the lower electricity generation capacities. For the second type, the molten eutectic salt liquids are used as a thermal energy storage (TES) medium and also a HTF at temperatures above 700 C. for the higher electricity generation capacities. These STES systems provide an effective cushion against the disturbances of heat supply from the sun.

A method for operating a solar thermal power plant comprising multiple solar radiation receivers operated using a molten salt as the heat transfer medium, wherein each solar radiation receiver comprises a reflector device and an absorber tube, includes: preheating of the absorber tubes, in the state in which said tubes are empty of the molten salt, to a temperature T by concentrating solar radiation on the absorber tubes by means of the reflector devices, wherein the temperature T is greater than or equal to the melting temperature of the salt; after reaching the temperature T: introduction of the molten salt into the absorber tubes and recirculated conduction of the molten salt through the absorber tubes while simultaneously repositioning the reflector devices depending on the position of the sun; on ending the operation: release of the molten salt out of the absorber tubes.

Steam can be generated using insolation by a solar collection system. A thermal storage system can store enthalpy in insolation-generated steam at times and can generate steam from stored enthalpy at other times. During some operating periods, a gas-fired superheater can further heat the generated steam to provide superheated steam to generate electricity. Steam at a substantially uniform electricity generating temperature may be produced selectively and at different operating periods from insolation only, from insolation and gas firing, from transfer of enthalpy from a thermal storage system and gas firing, or from a combination of insolation, stored enthalpy transfer, and gas firing. Operating periods can be characterized by at least one of an insolation level, a time of day, or a stage in the operation process. The generated steam can be used in the production of electricity.

The various embodiments described herein include devices and systems for thermal energy storage. A single-temperature-thermal-energy storage (SITTES) system for desalinating seawater and/or producing electrical power is described. The SITTES system includes insulated tanks, a molten eutectic salt media arranged within the insulated tanks, heat exchangers arranged within the insulated tanks, and an outlet. In the SITTES system the heat exchangers are coupled to one another and configured to transfer heat between the salt media and a seawater media, and the outlet is configured to output a steam portion of the seawater media, thereby providing desalination of the portion of the seawater media and steam for electrical power generation.