Abstract: In a startup period for a solar thermal electricity generating system, a non-solar source of steam heats a downstream receiver (for example, a superheating receiver) prior to insolation being available. Insolation, once available, heats an upstream receiver (for example, an evaporator). The upstream receiver can be arranged in a recirculation loop with a steam separation drum, which may be bypassed during the initial heating of the upstream receiver by insolation. Once sufficient temperature and pressure have been reached, steam from the upstream receiver is directed to the downstream receiver by way of the steam separation drum to replace the non-solar source of steam. Heating of the downstream receiver using steam from the upstream receiver continues until a threshold temperature and pressure are reached. Insolation is then directed at both the upstream and downstream receivers to generate steam for electricity production by a turbine.

Abstract: A solar energy system can be controlled during periods of reduced insolation. For example, one or more environmental condition sensors can detect environmental properties indicating current or expected insolation levels and can generate at least one signal indicating a current or impending transient reduced-insolation event. The at least one signal can be received (for example, by a controller) from the sensors that indicates changes in insolation. Responsively to the at least one signal, characteristics of a current reduced insolation event or of an impending transient reduced-insolation event can be calculated. In response to the calculated characteristics, a quantity of available insolation can be calculated. An attemperation flow rate in the solar steam system can be controlled responsively to the calculated quantity of available insolation such that the temperature of steam entering the steam turbines is maintained within a predefined range.

Abstract: A solar energy collection system can include a plurality of heliostats configured to reflect sunlight to a target mounted on a tower. Each of the heliostats can have a heliostat controller configured to control a respective heliostat so that the sunlight reflected therefrom is directed to at least one of a plurality of cameras. The cameras can be oriented to image the heliostat. A second controller can be configured to compute geometry data that defines a geometry of the surface of the heliostat from captured images thereof. The geometry data can designate a plurality of subsections of the surface. The computing by the second controller can include storing data indicating sections of the captured images corresponding to the plurality of subsections of the heliostat. The second controller can also calculate data indicating respective surface normals of each of said subsections of each of said heliostat.

Abstract: Images representative of cloud shadows with respect to a field of heliostats can be used to adjust operation of a solar energy system. For example, images of a field of heliostats and shadows produced by the clouds can be obtained. Additionally or alternatively, images of the sky and clouds can be obtained. The images can be analyzed to determine a shading parameter. Based on the shading parameter, an operating parameter of the solar energy system can be changed or maintained. For example, the operating parameter may include aiming directions for one or more of the heliostats. Cloud characteristics in addition to the location of the cloud shadow can be used in determining the shading parameter. Such characteristics can be used in determining if and/or how to change the operating parameter of the solar energy system.

Abstract: Embodiments relate to methods and systems of controlling and operating a wirelessly controlled solar field. By placing a higher density of access points in regions close to the solar field border, communication interference may be mitigated. A method of mitigating interference between an access point and a heliostat in a wireless communication system located in a solar field, may include in a first section of the solar field, deploying a first plurality of access points such that each of the access points is a first distance from its neighbor; and in a second section of the solar field, deploying a second plurality of access points such that each of the access points is a second distance from its neighbor. The first distance is greater than the second distance and the second section of the solar field may be closer to a perimeter of the solar field.

Abstract: A solar energy thermal storage system can include a receiver in which a first storage medium is heated by insolation. First and second thermal storage reservoirs for a second storage medium can be provided. A first heat exchanger can be configured to transfer heat in the first storage medium to the second storage medium. A buffer tank can be located at a height above the receiver and can be fluidically connected to the first heat exchanger at its inlet and the receiver at its outlet. A second heat exchanger can be configured to transfer heat between the second storage medium and pressurized water and/or steam. The use of a buffer tank in conjunction with the first storage medium increases the overall efficiency of the system and results in a higher temperature for the thermal storage system, which can be used to generate superheated steam.

Abstract: Thermal energy can be stored in a fluid-based thermal storage system for later use. The stored thermal energy may be derived from steam generated using insolation in a steam-based solar power system. The thermal storage system can store energy when insolation is generally available. Alternatively or additionally, the thermal energy may be derived from electricity from the electrical grid. For example, the thermal energy can store energy when the electrical grid has excess electricity available for storage. At a later time, the energy stored in the thermal storage system can be released to heat pressurized water or steam in addition to or in place of steam generated by the insolation. For example, the stored thermal energy may be used in preheating the solar power system during startup, in supplementing steam output of the solar power system, or to replace steam generation during low insolation periods.

Abstract: A paint formulation can include an inorganic oxide-based pigment and an organic binder. The organic binder can be irreversibly converted to an inorganic binder upon curing of the paint formulation at a temperature greater than 200° C. The oxide-based pigment and/or the paint formulation itself can have an absorptivity of at least 80% with respect to the AM 1.5 spectrum. The paint formulation can also include at least one organic solvent, an inorganic filler, and/or at least one additive. Such paint formulations may be stable at high temperatures (e.g., 750° C.) and can be used as solar-radiation-absorbing heat-resistant coatings for components of a solar tower system.

Abstract: 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.

Abstract: Embodiments relate to methods and systems of controlling and operating a wirelessly controlled solar field. By placing a higher density of access points in regions close to the solar field border, communication interference may be mitigated. A method of mitigating interference between an access point and a heliostat in a wireless communication system located in a solar field, may include in a first section of the solar field, deploying a first plurality of access points such that each of the access points is a first distance from its neighbor; and in a second section of the solar field, deploying a second plurality of access points such that each of the access points is a second distance from its neighbor. The first distance is greater than the second distance and the second section of the solar field may be closer to a perimeter of the solar field.

Abstract: Paint formulations having a high absorptivity with respect to solar radiation are disclosed herein. The disclosed paint formulations are also thermally and mechanically durable, thereby enabling the paint formulations to be used on components in solar thermal applications where exposure to high temperatures and environmental conditions may be an issue. The paint formulation can include an oxide-based pigment, an organic binder, one or more additives, an inorganic filler, and/or an organic solvent. The pigment can have a relatively high absorptivity with respect to light having a wavelength in the range from 250 nm to 3000 nm. Curing of the paint formulation can irreversibly convert the organic binder into an inorganic binder.

Abstract: Support members for heliostats (or other components installed in a field) can be hollow and thin-walled, for example, to reduce construction and/or material costs. However, such support members may be relatively fragile and susceptible to buckling or other damage when driven into relatively rocky and/or hard-packed soil using pile-driving. To avoid damaging the support members, the soil may be pre-conditioned to loosen the soil prior to insertion of the support member therein. An auger can drill a hole in the soil and then be reversed such that soil remains in and/or is subsequently re-introduced into the hole after removal of the auger, thereby leaving a substantially loosened column of soil in the hole. Vibration hammering can cause temporary liquefaction of the soil around the support member to insert the support member into the column of soil while reducing the potential for damage to the support member.

Abstract: A first period may be characterized by relatively high insolation, while a second period may be characterized by relatively low insolation. At the first period, steam is generated using insolation. A portion of the steam produces electricity, while a second portion of the steam is directed to a heat exchanger in thermal communication with thermal reservoirs. A storage fluid is flowed through the heat exchanger from a first reservoir to a second reservoir and/or from the second reservoir to a third reservoir such that enthalpy in the steam second portion is transferred to the storage fluid. At a second period, the storage fluid is reverse-flowed through the heat exchanger from the third to the second reservoir and/or from the second to the first reservoir such that enthalpy in the storage fluid generates steam to produce electricity. Enthalpy during high insolation periods can thus be stored for use during low insolation periods.

Abstract: A solar energy thermal storage system can include a receiver in which a first storage medium is heated by insolation. First and second thermal storage reservoirs for a second storage medium can be provided. A first heat exchanger can be configured to transfer heat in the first storage medium to the second storage medium. A buffer tank can be located at a height above the receiver and can be fluidically connected to the first heat exchanger at its inlet and the receiver at its outlet. A second heat exchanger can be configured to transfer heat between the second storage medium and pressurized water and/or steam. The use of a buffer tank in conjunction with the first storage medium increases the overall efficiency of the system and results in a higher temperature for the thermal storage system, which can be used to generate superheated steam.

Abstract: Insolation can be used to heat a solar fluid for use in generating electricity. During periods of relatively higher insolation, excess enthalpy in a superheated solar fluid can be stored in a thermal storage system for subsequent use during periods of relatively lower insolation or at times when supplemental electricity generation is necessary. Enthalpy from superheated solar fluid can be transferred to the thermal storage system so as to heat a storage medium therein, but the enthalpy transfer can be limited such that the superheated solar fluid does not condense or only partially condenses. The remaining enthalpy in the de-superheated solar fluid can be used for other applications, such as, but not limited to, preheating the solar fluid for an evaporating solar receiver, supplementing the input to a superheating solar receiver, industrial applications, resource extraction, and/or fuel production.

Abstract: A solar energy system can be controlled and operated responsively to detected and/or predicted changes in insolation conditions. By placing an imaging aperture of an imaging device as part of an external surface of a solar receiver, an orientation of each heliostat in a heliostat field can be determined. The imaging device can be used to image at least a portion of the heliostat field based on light passing through the imaging aperture, which is proximate to, adjacent to, or at least partially within the capture area of the solar receiver so as to acquire at least one image indicating a change in a distribution of insolation levels falling on the portion of the field. Characteristics of heliostats within the portion of the field can be calculated based on the at least one image. Aiming directions of one or more can be changed based on the calculated characteristics.

Abstract: A solar energy system can be controlled during periods of reduced insolation. For example, one or more environmental condition sensors can detect environmental properties indicating current or expected insolation levels and can generate at least one signal indicating a current or impending transient reduced-insolation event. The at least one signal can be received (for example, by a controller) from the sensors that indicates changes in insolation. Responsively to the at least one signal, characteristics of a current reduced insolation event or of an impending transient reduced-insolation event can be calculated. In response to the calculated characteristics, a quantity of available insolation can be calculated. An attemperation flow rate in the solar steam system can be controlled responsively to the calculated quantity of available insolation such that the temperature of steam entering the steam turbines is maintained within a predefined range.

Abstract: A solar energy collection system can include a plurality of heliostats configured to reflect sunlight to a target mounted on a tower. Each of the heliostats can have a heliostat controller configured to control a respective heliostat so that the sunlight reflected therefrom is directed to at least one of a plurality of cameras. The cameras can be oriented to image the heliostat. A second controller can be configured to compute geometry data that defines a geometry of the surface of the heliostat from captured images thereof. The geometry data can designate a plurality of subsections of the surface. The computing by the second controller can include storing data indicating sections of the captured images corresponding to the plurality of subsections of the heliostat. The second controller can also calculate data indicating respective surface normals of each of said subsections of each of said heliostat.

Abstract: The present disclosure relates to operating sun-tracking assemblies in response to one or more wind parameters or conditions. By judiciously reorienting one or more sun-tracking assemblies in response to detected or predicted wind conditions, the potential for wind- damage may be reduced. Some of the sun-tracking assemblies may act as a wind buffer for more fragile or sensitive components, thereby protecting them from damage. Such wind- sensitive components may be other sun-tracking assemblies arranged downwind from the reoriented assemblies. The downwind sun-tracking assemblies may continue to operate normally or substantially normally (i.e., to track the sun) despite the presence of the wind. During times of reduced or no wind, the sun-tracking assemblies may continue to track the sun until wind conditions require reorientation.

Abstract: In a startup period for a solar thermal electricity generating system, a non-solar source of steam heats a downstream receiver (for example, a superheating receiver) prior to insolation being available. Insolation, once available, heats an upstream receiver (for example, an evaporator). The upstream receiver can be arranged in a recirculation loop with a steam separation drum, which may be bypassed during the initial heating of the upstream receiver by insolation. Once sufficient temperature and pressure have been reached, steam from the upstream receiver is directed to the downstream receiver by way of the steam separation drum to replace the non-solar source of steam. Heating of the downstream receiver using steam from the upstream receiver continues until a threshold temperature and pressure are reached. Insolation is then directed at both the upstream and downstream receivers to generate steam for electricity production by a turbine.