A zero-emission, closed-loop and hybrid solar-produced syngas power cycle is introduced utilizing an oxygen transport reactor (OTR). The fuel is syngas produced within the cycle. The separated oxygen inside the OTR through the ion transport membrane (ITM) is used in the syngas-oxygen combustion process in the permeate side of the OTR. The combustion products in the permeate side of the OTR are CO.sub.2 and H.sub.2O. The combustion gases are used in a turbine for power production and energy utilization then a condenser is used to separate H.sub.2O from CO.sub.2. CO.sub.2 is compressed to the feed side of the OTR. H.sub.2O is evaporated after separation from CO.sub.2 and fed to the feed side of the OTR.

A back-up boiler system for a solar thermal power plant (201) for transferring solar energy into electricity, said back-up boiler system comprising a combustion chamber (70) and a convection section (80) in fluid connection with said combustion chamber (70), wherein in the convection section (80) at least a first heat exchanger (92) is provided for heating a molten salts mixture of the solar thermal power plant and a second heat exchanger (90) for pre-heating boiler feed water of the solar thermal power plant, wherein the back-up boiler system (25) is configured to allow selection between only providing heat to the first heat exchanger (92), only providing heat to the second heat exchanger (90) and providing heat to both heat exchangers (90, 92), preferably dependent on availability of solar radiation and/or dependent on demand of power generation. The invention also relates to a solar thermal power plant (201) for transferring solar energy into electricity and a method for operating a solar thermal power plant.

A method of operating a solar energy plant and a solar plant are disclosed. Thermal energy produced in the plant is used to heat a first volume of water and charge a hot store in the plant. Electricity produced in the plant operates a heat engine or other device, such as a refrigeration unit, to extract heat and consequently cool a second volume of water and charge a cold store. As desired, energy is transferred from the hot store to a heat engine and energy is transferred from the heat engine to the cold store to operate the heat engine to produce power in the plant.

Heat transfer fluid in vapour only state is cycled through solar collector(s) (12) and a sensible heat storage medium (14) to transfer heat from the solar collector(s) (12) to the sensible heat storage medium (14). The heat transfer fluid is a liquid at ambient temperature, but substantially in the vapour state throughout the entire cycle when in operation.

Systems and methods for generating electrical power using a solar power system comprising pressurized pipes for transporting liquid water. The pressurized pipes flow through solar collectors which concentrate sunlight on the water flowing through the pipes. The pressurization in the pipes allows the water flowing through the pipes to absorb large quantities of energy. The pressurized and heated water is then pumped to a heat exchanger coil where the thermal energy is released to produce steam for powering a steam turbine electrical generator. Thereafter, the water is returned to the solar collectors in a closed loop to repeat the process.

The invention relates to a pipeline system for a linearly concentrating solar power plant (1) with at least one receiver line (13), in which a heat transfer medium is heated by radiating solar energy, or with a central receiver and at least one emptying tank (21) and/or one store for the heat transfer medium, the heat transfer medium having a vapor pressure of less than 0.5 bar at the maximum operating temperature. Furthermore, a gas displacement system (31) is comprised, which connects gas spaces in the at least one emptying tank (21) and/or in the store for the heat transfer medium to one another and which has a central gas store (35) and/or a central gas connection (37) and a central exhaust gas outlet (39), through which gas can be discharged into the surroundings.

Systems and methods for generating electrical power using a solar power system that comprises a pressurized closed loop pipe containing a transfer liquid extending between a solar collector and a heat exchanger. The transfer liquid is heated by the solar collector and gives up its thermal energy at the heat exchange to produce steam. The system also includes a source of geothermal energy and a source of natural gas. The geothermal energy in the form of heat separates the natural gas from the ground water in a separation tank. At the resulting heated ground water from the separation tank is connected to the heat exchanger to supplement thermal energy from the solar collector.

A method of operating a solar energy plant and a solar plant are disclosed. Thermal energy produced in the plant is used to heat a first volume of water and charge a hot store in the plant. Electricity produced in the plant operates a heat engine or other device, such as a refrigeration unit, to extract heat and consequently cool a second volume of water and charge a cold store. As desired, energy is transferred from the hot store to a heat engine and energy is transferred from the heat engine to the cold store to operate the heat engine to produce power in the plant.