Abstract: A system for providing a thermal transformer to provide heating and cooling to enclosed structures, most generally a building using solar power combined with geothermal storage and a heat powered heat pump to raise or lower the temperature of the stored energy to a useful temperature as needed. The system also has an electrical generation embodiment to provide electricity in addition to the heating and cooling. The system will collect and store solar energy and supply heated or cooled water to the building's existing HVAC system while consuming no fossil fuels and emitting no greenhouse gases. The system may also be used in one embodiment to supply power for the pumps/fans used to circulate the heated or cooled air or water throughout the building.

Abstract: Methods, systems, and apparatus, including computer programs encoded on one or more computer storage devices, for collecting solar energy using heliostats arranged about a collection of solar energy receivers. For each heliostat, estimated efficiencies of the heliostat in directing solar rays to two or more receivers at various times of day are determined. Each heliostat is assigned to direct solar rays to two or more different receivers at two or more different times of day, wherein each heliostat directs solar rays to one receiver at a time and the assigning is based on the determined estimated efficiencies for the heliostat at the various of times of day. In some implementations, the receivers are repositionable.

Abstract: The present invention includes a solar water heating system including: a water tank to hold water to be heated, an heat transfer fluid circuit including an heat exchanger associated with said water tank to heat water therein, a solar collection means in communication with said heat exchanger, an inlet connection to carry heat transfer fluid from said solar collection means to said heat exchanger where said water will be heated; and an outlet connection to carry heat transfer fluid from said heat exchanger to said solar collection means where said heat transfer fluid will be heated, said heat transfer fluid circuit including a reversibly evaporable heat transfer fluid which will absorb heat from said solar collection means and which will transfer said heat to said water in said water tank by means of said heat exchanger; and an diversion path being provided in said heat transfer circuit, whereby when a portion of heat transfer fluid changes to a gaseous state in said solar collection means, heat transfer fluid

Abstract: A heliostat control system includes a heliostat having a reflective surface and at least one reflective element, the reflective surface having a different radius of curvature than the at least one reflective element, a receiver configured to receive sunlight reflected from the reflective surface, and a camera configured to receive sunlight reflected from the at least one reflective element and to generate an image including pixels having a brightness dependent on an orientation of the reflective surface.

Abstract: A working fluid heating system that utilizes solar energy and fuel-fired heaters to heat the working fluid is provided. The system may have a fuel heating plant that has a first fuel-fired heater to heat a first portion of working fluid, a solar heating plant that has both a solar thermal-energy heater and a second fuel-fired heater to heat a second portion of working fluid. The first and second portions may join in a pipeline to supply heated working fluid to a facility such as an electrical generation facility, desalination facility, petrochemical facility, enhanced oil recovery facility, or air conditioning facility.

Abstract: A solar hot water and recovery system includes a water loop, a refrigerant loop and a solar loop. Cross-heat exchange occurs in a first heat exchanger between the heat transfer mediums of the refrigerant loop and the solar loop to produce a super-heated fluid stream which is returned to the air conditioning or heat pump unit. Cross-heat exchange also takes place in a second heat exchanger between the now-lower temperature heat transfer medium of the solar loop and the water loop to produce a heated water stream. The main objective of the system is to superheat refrigerant and use all excess heat for heating the water. The heat exchangers are preferably housed in the same heat recovery unit and arranged so that the refrigerant heat exchange area is before the water heat exchange area, thereby maximizing solar potential.

Abstract: A system and method for energy-efficient and environmentally-friendly recovery of bitumen aims at recovering unconventional oil in an environmentally friendly and sustainable way that has the potential of eliminating the need of natural gas currently employed for steam production and power generation. The system and method aims at providing low temperature steam for the stimulation of the formation by means of solar radiation. In addition, the system and method provides a novel solution for hydrogen production that does not employ reforming of natural gas. Furthermore, the use of thermoelectric devices in combination with low temperature steam can be employed to power an electrolysis plant to generate the hydrogen necessary to produce synthetic oil.

Abstract: A solar tracking device that uses thermal actuation to rotate a solar energy device to track movement of the sun for improved solar energy output of the solar energy device. Thermal actuation is generated by concentrating solar radiation using a solar collector and solar receiver. A medium that expands when heated is in thermal communication with the solar receiver and drives an actuator for rotating the solar tracking device to follow the movement of the sun. The medium may be a phase change material such as Paraffin wax. Rotational actuation may be performed using helical slots in a main housing and cam followers coupled to a shaft extended out of the main housing. At the end of the day, a combination of gravity and/or mechanical return forces may assist in returning the system to an initial position such that it is ready to receive solar radiation the next day.

Abstract: A method of collecting and redistributing energy, including receiving energy from an energy vendor at a transaction station, measuring the received energy, identifying and crediting the energy vendor, storing the received energy in an energy storage medium, identifying an energy user, dispensing energy to the energy user at a transaction station, measuring the dispensed energy, and debiting the energy user for the dispensed energy. The transaction station includes a housing, a microprocessor portion in the housing operationally connected to a computer network, an energy metering portion operationally connected to the microprocessor, an energy inlet operationally connected to the energy metering portion, an energy outlet operationally connected to the energy inlet and the energy metering portion, an energy storage operationally connected to the energy inlet and to the energy outlet, and an energy source operationally connected to the energy inlet.

Abstract: In one aspect of the present invention, a structure comprises a plurality of reflective panels secured to the structure. Each reflective panel has an axis of rotation. A processing element controls an orientation of each reflective panel about its axis of rotation to direct solar energy within the structure.

Abstract: A solar energy conversion system includes a solar collector having a protective cover having a closed position and an open position, wherein a surface of the protective cover adjacent to the solar collector includes a reflective surface configured to reflect solar radiation at the solar collector when the protective cover is in the open position. The solar collector further includes a plane angle modifier configured to allow adjustment of the solar collector relative to the sun.

Abstract: A tankless water heating auxiliary system for a solar water heating system, includes a solar collector; a tankless water heater auxiliary system; an insulated water storage tank storing the potable water; a heat exchange system for heating stored water; and piping for connecting the collector, the storage tank and the heat exchanger in fluid communication. A first sensor is connected to and located adjacent the storage tank for sensing the temperature of the stored water at an outlet of the tank.

Abstract: An energy generation apparatus is disclosed. The apparatus includes a base, a sidewall enclosing a perimeter of the base to define a first volume, and a tube having a first end and a second end. The base includes a solar energy collection surface. The first end of the tube is disposed in the first volume adjacent the base, and the second end of the tube is disposed in a second volume outside of the first volume. The apparatus also includes a fluid flow initiator to initiate a flow of a fluid from the first volume to the second volume through the tube when the fluid in the first volume has been heated by the solar energy collection surface to generate a super-adiabatic lapse rate.

Abstract: The present invention is a method for storing solar collected heat and using the stored heat to produce power, comprising the steps of diverting solar heated fluid at a temperature greater than a predetermined power plant block (PPB) nominal temperature from a heat transfer circuit; transferring heat from the diverted solar heated fluid to a portion of a liquid water storage medium maintained at a temperature significantly less than the predetermined PPB nominal temperature and thermally storing the heated portion; and transferring heat from the heated liquid water storage medium to a fluid during periods of decreased solar radiation levels, whereby to produce power by means of said heated heat transfer fluid.

Abstract: An aerospace platform includes a structure having a cavity and a light-transmissive portion that exposes the cavity to sunlight. The aerospace platform further includes a fluid heating system. The fluid heating system includes a fluid-carrying, thermally absorptive structure within the cavity, and a solar collector for collecting light transmitted through the light-transmissive portion and focusing the collected light onto the absorptive structure. The thermally absorptive structure has a high surface absorptivity that retains thermal energy when exposed to solar irradiance and heats fluid contained therein.

Abstract: The invention in the preferred embodiment features a solar concentrator that can align and/or track based on images from a video camera, for example. The concentrator preferably includes one or more optical elements for directing light to a receiver, a camera for capturing an image of the optical elements, and a controller configured to: detect the orientation of the one or more optical elements from the one or more images, determine an orientation error based on the detected orientation, and automatically orient the one or more optical elements to minimize the orientation error. The optical elements generally comprise a plurality of mirrors or lenses arranged in a one or two dimensional array.

Abstract: One or more cables are attached to the ring-shaped heliostat tracker assembly to control a position of the heliostat mirror on the ring shaped heliostat tracker assembly by winding the one or more cables with a cable winder spool and a cable unwinder spool. The ring-shaped rail track couples to two or more wheels joined to a structure housing a heliostat mirror. One or more position encoders track the heliostat mirror to indicate a position of the heliostat mirror on the ring-shaped rail track.

Abstract: A suction-recirculation device for stabilizing the flow of a curtain of blackened heat absorption particles falling inside of a solar receiver with an open aperture. The curtain of particles absorbs the concentrated heat from a solar mirror array reflected up to the receiver on a solar power tower. External winds entering the receiver at an oblique angle can destabilize the particle curtain and eject particles. A fan and ductwork is located behind the back wall of the receiver and sucks air out through an array of small holes in the back wall. Any entrained particles are separated out by a conventional cyclone device. Then, the air is recirculated back to the top of the receiver by injecting the recycled air through an array of small holes in the receiver's ceiling and upper aperture front wall. Since internal air is recirculated, heat losses are minimized and high receiver efficiency is maintained.

Abstract: Methods of operating solar tracking apparatuses are described. For example, a method includes determining a minimum amount of energy required to move the solar tracking apparatus from a first position to a second position. An available radiance is estimated for a solar resource coupled to the solar tracking apparatus. The solar tracking apparatus is moved from the first position to the second position prior to a point in time when the energy derivable from the available radiance is less than the minimum amount of energy required to move the solar tracking apparatus from the first position to the second position.

Abstract: A method and system is provided for controlling efficiency of a heating system which is a combination hot water and space heating system that can modulate energy transfer. The heating system includes a heat exchanger for transferring and modulating heat between a primary fluid system having a hot water supply and a secondary fluid system for space heating. The primary fluid system includes a storage container, temperature sensors, a heating element connected to the heating assembly within the storage container for increasing the temperature of the storage fluid therein, a heating assembly, and a storage pump for delivering storage fluid from the storage container to the heat exchanger. The secondary fluid system includes a heating supply structure for containing a heating supply fluid, temperature sensors, and a heating supply pump in connection with the heating supply structure for circulating the heating supply fluid.

Abstract: Various embodiments for an improved solar collector are disclosed. For example, a heat absorber can be positioned inside an evacuated chamber formed by a frame and a transparent cover. Heat absorbed by the heat absorber within the evacuated chamber can be delivered to a heat transfer fluid inside a chamber of a heat exchanger. The heat exchanger chamber can also reside in the evacuated chamber. In a preferred embodiment, the heat absorber comprises a planar heat pipe. Also in a preferred embodiment, a reflector can be positioned to reflect energy radiated by the heat absorber back to the heat absorber.

Abstract: The invention relates to a mirror comprising a glass sheet and a silver layer applied to the glass and provided on its back with a protective coating comprising a layer of dried and crosslinked paint of the alkyd type and a layer of dried and crosslinked paint of the polyurethane type, the alkyd layer being located between the silver layer and the polyurethane layer. The invention also relates to its use for deflecting solar light onto a heat collector. The invention also relates to a process for manufacturing a mirror comprising: a silver layer is deposited on a glass sheet using a silverplating solution; then a layer of alkyd paint having a viscosity of between 25 and 110 seconds measured using a Ford No. 4 cup is applied on the side with the silver layer; then the alkyd paint layer is dried and crosslinked; then a layer of polyurethane paint having a viscosity of between 25 and 110 seconds measured using a Ford No.

Abstract: A simple solar heating system incorporates a heat dissipater into a heat exchange circuit for bypassing solar collectors when either the temperature or the pressure in the heat exchange circuit exceeds preset limits. In the absence of electric controllers, fluid in the heat exchange circuit is caused to bypass the solar collectors using a valve which is controlled by either the temperature or pressure of the fluid. A solar photovoltaic panel energizes a circulating pump for increasing the rate of pumping as more solar energy is available at the PV panel and decreasing the rate as solar energy decreases.

Abstract: An improved solar oven with the ability to overcome recognized prior art limitations, such as temperature variation during prolonged cloudy periods is described. The solar oven according to the invention utilizes an enclosure similar to a box type oven and a thermosiphon (alt. thermosyphon) device to generate and maintain heat sufficient to cook food. The invention also encompasses a method of solar cooking utilizing an enclosure similar to a box type oven and a thermosiphon device.

Abstract: A movable solar array and method for capturing solar energy which includes a V-shaped longitudinal support forming a corner of an elongated truss located at each angle of a polygonal axial cross-section where an open web is fixedly attached between each V-shaped longitudinal support extending the length of the elongated truss. An end member is fixedly attached at each end of the support truss and includes a shaft extending longitudinally outwardly from the end member adapted to engage a drive to longitudinally rotate the elongated truss. Solar panels are attached along one face of the elongated truss, and at least one rotatable drive is capable of driving the shafts at the end of the elongated truss to move the solar panels in relation to a change of direction of incoming solar energy.

Abstract: Embodiments of the present invention disclose systems and methods for the efficient conversion of solar energy into a useable form of energy using a solar collector subsystem and a heat conversion subsystem. The systems and methods transfer solar energy directly to an intermediate solution and a working solution and indirectly to and between a basic rich solution, a condensing solution, a lean solution and a rich vapor solution. The systems and methods also include condensing the basic rich solution using an external coolant. The systems and methods support a closed thermodynamic cycle.

Abstract: Solar trough apparatuses are disclosed, where a heat transfer fluid conduit remains fixed in a focal of a solar trough as the solar trough tracks the sun. The support structures can be ring or arcuate structures, where rotation is about their central axis and the trough is support in them so that the focal zone is coincident with the axis of rotation and the conduit is situated in the focal zone eliminating the need for articulated or flexible conduit.

Abstract: The system facilitates dynamically allocating a variable amount of solar radiation to or between multiple solar applications based on optimizing a time-dependent cost function using multiple parameters as inputs to the cost function. Also described is an optical architecture that enables dynamically channeling incident solar radiation to or between multiple solar applications based on the optimization of a cost function. A solar allocation and distribution system includes an allocation sub-system; a distribution sub-system; and a controller configured for controlling the allocation sub-system and the distribution sub-system based on optimizing a cost function, wherein the cost function is time-dependent and based on energy utilization of a facility.

Abstract: A novel method of concentrating solar energy using wave generators is disclosed. The systems and methods enable the collection of energy over large area at high efficiencies and the concentrating of energy at a target for use and transfer.

Abstract: A system (100) for directing incident sun light to a receiver (150) based on an integral imager (116) is disclosed. The system includes an imager (116) mounted to a reflector (112); a tracking controller (226) coupled to the imager; and one or more actuators (114) connected to the reflector and tracking controller. The tracking controller (226) is configured to receive and process image data from the imager (116); determine angular positions of a radiation source and target relative to the mirror normal vector (N) based on the image data; and orient the reflector with the axis bisecting the angular positions of the sun and receiver (150). When the optical axis of the imager is precisely aligned with the vector normal to the reflector, the source and target will be detected as antipodal spots (320, 330) with respect to the center of the imager's field of view, which may be used to effectively track the sun or like object.

Abstract: Provided are a method for controlling a heliostat used for collecting of sunlight and a device of the method that achieve: a high sunlight collecting efficiency with a high light collecting rate by allowing no deviation of a light collecting point (a focal point) of sunlight; and a high area arrangement efficiency by having such a configuration in which no rotation by means of a rotation mechanism is carried out. The method is a method for controlling a heliostat being used for collecting of sunlight and having multiple reflecting mirrors in a way that the heliostat tracks the sun in motion, reflects sunlight, and collects the sunlight at a predetermined focal point.

Abstract: An embodiment of the present invention may take the form of a system and method that may use at least at least one solar heating system to heat the feedwater consumed by a boiler. An embodiment of the present invention may incorporate concentrated solar power (CSP). Generally, CSP systems incorporate a plurality of lenses, mirrors, or combinations thereof and a tracking system to focus a large area of sunlight forming a small concentrated beam of light. The concentrated light may then be used as a heat source. In an embodiment of the present invention, the heat source may be used to partially or completely heat the feedwater consumed by a boiler. CSP systems may take the form of a solar trough system, a parabolic dish system, a solar power tower system, or the like.

Abstract: A novel concentrator system is described, which increases the efficiency of collecting and concentrating sunlight energy onto a target. This method uses an array of small movable reflective or refractive concentrator components that can move via a feedback mechanism which tracks the sun and concentrates the suns energy on to a second array of energy converting elements. In order to improve the effective collected energy, the array of concentrator elements is placed on a moving or tiltable flat slab (or dish, substrate, plane, plate, holder, tablet, or similar flat or non-flat surface) that tracks the sun. An alternative method uses an array of target elements or linear elements and a second array of concentrator elements in harmony such that the suns energy is efficiently redistributed by the reflective or refractive array on to the energy converting array as the sun's position in the sky (elevation and azimuth) changes.

Abstract: A tracking system is provided for a roof-mounted solar array. The system includes a sensor mechanism for sensing an orientation of the sun relative to the solar array, and a controller connected to the sensor mechanism that generates a signal that represents an optimal tilt angle of the solar array relative to the orientation of the sun. An actuator connected to the controller receives the signal from the controller and adjusts the tilt angle of the solar array in response to the received signal.

Abstract: A solar collector is provided, in one embodiment. The solar collector comprises a heat core to convert incident radiation into heat; a wicking layer spaced from the heat core to absorb infrared radiation emitted by the heat core due to the conversion of incident radiation into heat; an inlet to introduce a heat transfer fluid into the wicking layer; wherein the absorption of the infrared radiation is by the heat transfer fluid in the wicking layer and causes a portion of the heat transfer fluid to enter into a vapor phase thereof which propagates into the heat core where it undergoes heating; and an outlet to transport the heated vapor phase of the heat transfer fluid out of the collector.

Abstract: A method for tracking the movement of the sun from East to West across the sky during daylight hours to enable solar photovoltaic (PV) panels or arrays of such panels to capture significantly more solar energy than fixed solar panels. Readily-available sun position data (taken from ephemeris or celestial navigation tables) can be programmed into read-only memory (ROM) chips. Date and time of day information can also be programmed into ROM chips powered by long-life, rechargeable batteries, such as lithium-ion batteries. Using such ROM chip data, a solar panel or an array of solar panels can track the sun position provided that during installation (with the panels aimed longitudinally towards the South), the solar panels are positioned upwards towards the noontime sun position to establish a starting point. This enables the sun tracking system of the present invention to track the sun without requiring a solar sensing device.

Abstract: Provided are an adjusting method and an adjusting apparatus for adjusting a heliostat on site while actually measuring that a mirror surface of the heliostat and a mirror surface of a center reflector are exactly facing each other. The adjusting apparatus is provided with an irradiation device 3 which irradiates an upper focal point p of a center reflector 30 and a heliostat 20 with laser beams L1 and L2, respectively. The elevation angle and/or the turning angle of the heliostat 20 are adjusted so that the reflected light L4 of the laser beam applied on the heliostat 20 forms the same axial line as the laser beam L1 applied on the upper focal point p of the center reflector 30.

Abstract: A solar energy collector panel intended for invisible incorporation behind and in thermal contact with a climate shield (94) of bituminous roofing felt or tar board on a building, said panel being made of a heat-conducting material and having at least one through- going fluid-impervious duct (91) embedded in said panel for passing a thermal energy carrying-capable fluid through it and having or being attached to a flat member (93) of heat-conducting material and substantial surface area intended to be mounted in direct physical contact with said climate shield. The solar panel provides excellent exploitation and transmission efficiency of sun radiation to an energy carrying-capable fluid in the fluid-impervious duct.

Abstract: Solar energy is concentrated on a target by at least one group of Fresnel light-shifting devices.

Abstract: A system and method of collecting solar energy from sunlight, employing a thermal generation apparatus having a solar collector module including a receiver in optical communication with an array of mirrors. The method comprises reflecting energy impinging upon the reflector assembly with a plurality of reflective elements. The plurality of reflective elements is configured to direct energy reflected therefrom onto the receiver. The solar collector module is configured to rotate about an axis; and an angular position of the plurality of reflective elements is changed in relation to relative movement of the sun with respect to earth.

Abstract: The present invention relates to a thermal solar installation with draining by gravity, wherein: the return circuit of the primary circuit (2) is subdivided into two conduits (25;26,27), a first conduit (26,27) that brings the heat-transfer liquid back to a low point of the buffer tank (31) when the pump (19) is operating and a second conduit (25) opening at a high point of said tank (31), and provided with an anti-return valve (20), which allows air to be returned to the collector (1) and hence the primary circuit (2) to be drained by gravity when the pump (19) no longer operates; the first conduit (26,27) is separated into a conduit (27) opening into the buffer tank (31) and a bypass conduit (28) opening into said supply circuit (30) downstream from the pump (19), and provided with a normally open valve (21) that closes as soon as the pump (19) operates; the buffer tank (31) is connected to the exchanger (4) through a connection conduit to the exchanger (14), the return conduit (29) connecting the exchan

Abstract: A system for heating water and cooling a house has a power cell including a first tube to contain the water so that the water cools the power cell, a power unit that produces the electricity from light, a mirror that reflects the light onto the power unit, and a lens that helps focus the light onto the power unit; a water heater including a second, generally transparent tube to contain the water that is warmed by the light, a third tube inside the second tube to contain the water that is further warmed by the light, and a reflective material on the second tube that helps reflect the light onto the third tube; and a thermal barrier including a base made of material that provides thermal isolation and shade for cooling.

Abstract: 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.

Abstract: The present invention relates to primary and secondary concentrators of solar radiation. New primary concentrators of adjusted etendue combined with secondary concentrators are presented, for single of multiple receivers, capable of attaining the maximum possible concentration. The present invention also refers to devices which reduce the thermal losses by convection of the receivers.

Abstract: A solar energy collection system comprises a frame for mounting the system on a suitable substrate and a plurality of solar panels disposed adjacent to one another on the frame. A first set of the solar panels are movable relative to a second set of the solar panels, for tracking movement of the sun during the day. Solar panels of the first set are arranged in alternating fashion with solar panels of the second set. In some embodiments of the invention, the panels in the second set of solar panels are stationary. The second set of solar panels, in some embodiments, are disposed substantially flat, relative to the frame and the substrate on which the frame is mounted. In some embodiments, differing from those in which the second set of solar panels are stationary, the second set of solar panels may be arranged to be movable relative to the first set of solar panels.

Abstract: A control system includes a control module and one or more input sources. The control module is coupled to an output of the solar module in order to operate the solar panel so that an output of the solar panel is at a maximum power level. The control module is able to selectively decrease a current level of the solar panel's output in response to a condition that is indicative of a temperature of the solar panel while maintaining the power output of the solar panel at or within a designated percentage of the maximum level. The input source is coupled to the control module to provide an input that is indicative of the temperature.

Abstract: Adherence to flux or resultant measurable parameter limits, ranges, or patterns can be achieved by directing heliostat mounted mirrors to focus on aiming points designated on the surface of a solar receiver. Different heliostats can be directed to different aiming points, and a heliostat can be directed to different aiming points at different times. The cumulative flux distribution resulting from directing a plurality of heliostats to any aiming point on a receiver surface can be predicted by using statistical methods to calculate the expected beam projection for each individual heliostat or alternatively for a group of heliostats. Control of the heliostats in a solar power system can include designating aiming points on a receiver from time to time and assigning heliostats to aiming points from time to time in accordance with an optimization goal.

Abstract: Systems, methods, and apparatus by which solar energy may be collected to provide heat, electricity, or a combination of heat and electricity are disclosed herein.

Abstract: In a hot water supply system having a solar heater that heats a heating medium with absorbed solar heat, a cogeneration unit that heats the medium by heat exhausted from an engine, a hot water supply unit with a heat exchanger for heat-exchanging between the medium and water supplied from a water supply source to generate the hot water, a medium circulator that circulates the medium among the solar heater, cogeneration unit and heat exchanger, an electric heater that heats the hot water with the power generated by the generator, a heat absorption amount to be adsorbed by the solar heater is estimated and operations of the cogeneration unit and the electric heater are controlled based on the estimated heat absorption amount, thereby enabling to improve energy efficiency of the entire system.

Abstract: Deployable wings supporting solar collector arrays for mobile structures and associated methods of use are disclosed that provide significant power generation capacity, easy deployment, shaded work areas, and protection for solar collector arrays during transport. Some embodiments include a support surface configured to be hingedly coupled to a vehicle, a plurality of support rails extending away from the support surface to form at least one cavity, a solar collector array coupled to the support surface and within the at least one cavity, and at least one retractable cover configured to selectively cover the at least one cavity.