WO1994028361A1

WO1994028361A1 - Method for changing solar energy distribution

Info

Publication number: WO1994028361A1
Application number: PCT/US1994/005864
Authority: WO
Inventors: Robert C. Stirbl; Peter J. Wilk
Original assignee: Stirbl Robert C; Wilk Peter J
Priority date: 1993-06-02
Filing date: 1994-05-24
Publication date: 1994-12-08
Also published as: AU7045094A; IL109815A0

Abstract

Waveform energy is directed to a predetermined region of the atmosphere. The directing of the energy is controlled so as to modulate an index of refraction of air in the predetermined region of the atmosphere to produce a predetermined refraction index pattern in the region. The distribution of solar radiation is modified as it passes through the atmospheric region to thereby concentrate the solar radiation at a predetermined location. An alternative solar concentrator utilizes a pool (210) of a homogenous fluidic substance disposed over a reflective surface (214). Mechanical energy is controllably imparted to the pool, to generate a standing wave of the fluidic substance in the pool (210) and the reflective surface (214) to concentrate the incoming solar radiation at a predetermined location space from the pool (210). Another solar energy concentrator assembly comprises a flexible polymeric sheet (314) which carries an integral optical element (316) for concentrating a substantial amount of incoming solar radiation on a desired location. Lofting elements (318) are attached to the sheet for providing aerodynamic lift thereto to maintain the optical element (316) at a predetermined distance above the surface of the earth.

Description

METHOD FOR CHANGING SOLAR ENERGY DISTRIBUTION

Background of the Invention

This invention relates to techniques for altering the distribution of solar energy falling on the earth's sur¬ face. More particularly, but not exclusively, this invention is related to methodology for concentrating solar energy.

It is well known that, with the exception of nuclear power, all of the energy on the earth originates with the sun. Extensive efforts in recent decades have been directed to harnassing solar radiation. Such efforts have resulted in huge mirrors erected on the earth's surface for concentrating incoming solar radiation on energy collectors. Another result of the continuing interest in solar energy is the development of solar cells and the arrangement of such cells in different configurations to convert the solar radiation into elec¬ tricity. Yet another area of development in the field of solar energy is solar panels for converting solar radiation into heat energy.

One well known natural phenomenon is the bending of light waves by heated air. Light refracting convection cur¬ rents are observable, for example, over road surfaces. The convection currents cause a shimmering or wavering effect in the perception of distant objects across roads or other heated surfaces.

The problem with such convection currents, as other natural phenomena, is that they are essentially uncontrol¬ lable. The variation in the index of refraction caused by localized heating of earth bound surfaces is random and unpre¬ dictable.

Problems with conventional solar energy concentrat¬ ing and collecting facilities are manifold. Some systems are too expensive. Others are fixed to the earth's surface and consequently subject to changing weather. In order to collect sufficient energy, most systems are large and occupy a large area on the earth's surface. Summary of the Invention

A method for concentrating solar energy comprises, in accordance with the present invention, the steps of (a) generating waveform energy, (b) directing the energy to a predetermined region of the atmosphere located a pre- established distance above a surface of the earth, (c) con¬ trolling the step of directing to modulate an index of refrac- tion of air in the predetermined region of the atmosphere to produce a predetermined refraction index pattern in the region, and (d) modifying the distribution of solar radiation passing through the region to thereby concentrate the solar radiation at a predetermined location.

According to another feature of the present inven¬ tion, the method further comprises the steps of absorbing, at the predetermined location, a substantial quantity of the con¬ centrated solar radiation and converting at least a sig¬ nificant portion of the absorbed concentrated solar radiation to a different form of energy. Where the second form of energy is heat energy, the method may further comprise the step of altering a climatic condition in a region proximate to the location in response to the steps of absorption of the concentrated solar radiation. For example, the concentrated solar energy may be directed to impinge upon ice in a blocked river, lake or other body of water. The solar energy melts the ice to open up a blocked waterway.

Another climatic condition alterable in accordance with the present invention is humidity. Concentrated solar energy falling upon a body of water, such as the sea or a lake, can rapidly increase the humidity in a region bounding the heated water. Such a marked increase in humidity can reduce the chances of fire in dried coastal areas. In addi¬ tion, under proper climatic conditions, it may be possible to generate rain over proximate land areas. Steps may be taken in accordance with the present invention to create the desired climatic conditions. For example, to ensure that water vapor in a rising column of air falls as rain over a desired area, a relatively cool region on or over the earth's surface may be created by modifying the atmospheric index of refraction to generate a diverging lens to reduce the amount of sunlight falling over a predetermined area.

Increasing the amount of sunlight falling over a selected area may be used to accelerate drying of wet surfaces in that selected area, for example, a playing field or race track. In addition, solar energy concentrated in accordance with the present invention may be used for controlling the spread of forest fires by causing fire breaks as in conven¬ tional fire fighting procedures. According to another, alternative, feature of the present invention, the concentrated solar energy may be con¬ verted into a chemically stored form. The concentrated solar energy is absorbed and converted into chemical bonds of energ laden molecules, for example, via photosynthetic reactions. In brief, the instant invention can be used to stimulate plan growth, for example, in farming areas. Where the farm land i coastal, the above-described method for increasing rainfall may also be used.

According to a further feature of the present inven tion, the concentrated solar energy may be converted directly into electrical energy via photovoltaic cells. Alternatively the concentrated solar energy may be converted indirectly int electrical energy, for example, by generating steam which is used to operate steam turbines.

According to yet another feature of the present invention, incoming solar radiation may be concentrated in or alongside an atmospheric whirlpool for purposes of causing th whirlpool to dissipate. More specifically, a plurality of atmospheric solar concentrators may be generated for heating air along the outer periphery of a hurricane, thereby produc¬ ing a plurality of ancillary whirlpools acting to oppose the circulation of air in the primary whirlpool, i.e., the hurri¬ cane.

According to an additional feature of the present invention, the concentrated solar radiation is directed to an absorbed in a body of salt water at the predetermined loca¬ tion. The consequently evaporated water is captured or col¬ lected to form an aqueous distillate. The salt water may be transported, e.g., by pumps and pipelines, over the desert to the predetermined location well inside the boundaries of a desert region. The separated salt may be collected and transported back to the sea.

According to another feature of the present inven¬ tion, the waveform energy^' is electromagnetic radiation which is generated by operating a laser. The modulation control is effectuated by concentrating the laser generated radiation differentially through the atmospheric region.

The refractive index modulation in accordance with the present invention is accomplished primarily by differen- tial heating of the air in the predetermined target region of the atmosphere. However, it is also possible that the modula tion is accomplished in whole or in part by ionizing the air within the atmospheric target region.

The refractive index profile of the air in the atmospheric target region may be modulated so as to produce a solar energy concentrator in the form of an atmospheric lens. More specifically, the index of refraction may be modulated s as to produce an atmospheric index profile approximating a Fresnel lens. It is to be noted that the lens may be or virtually any size, whereby the lens may be adapted to the particular application. Commercial solar energy collection b power companies or the production of rain, for example, may call for larger lenses. However, it is to be noted, that several interspaced atmospheric lenses may be generated, focusing the sun's energy onto the same collection or absorp¬ tion area.

According to one embodiment of the present inven¬ tion, laser radiation is transmitted from a plurality of dif¬ ferent sources to the atmospheric target region. Accordingly a plurality of lasers may generate different portions of the same concentrator or lens.

It is to be noted that an atmospheric solar con¬ centrator generated in accordance with the present invention will be effective even if the lens is partial or imperfect. It is only necessary that incoming solar radiation be con¬ centrated onto an absorption area. It is not necessary to produce an atmospheric lens capable of image formation. Accordingly, in this specification, the term "atmospheric lens" is used to mean an atmospheric index of refraction pro¬ file capable of concentrating incoming solar radiation onto a predetermined solar absorption location. Generally, the absorption area is located on the earth's surface, i.e., is a earth bound collector such as a steam generator which is con¬ nected to turbines, etc. In some minor applications, the col lector may be on a ship, submarine, balloon or other sea- or airborne device. The collector may even be a satellite in orbit around the earth.

Concomitantly, it is contemplated that the laser or lasers which generate the atmospheric lens are located on the earth's surface. However, it is also within the contemplatio of the invention that a lens generating laser is carried on a boat, submarine, balloon, airship or satellite.

Where there is a plurality of laser sources, the laser radiation may be simultaneously transmitted from those sources to the same point in the atmospheric target region. Thus, in this embodiment of the invention, each laser in itself generates insufficient energy to ionize or substan¬ tially heat the air, while the energy from a plurality of lasers, when converging or crossing at the same target point in the atmosphere, will be sufficient to heat or ionize the air to change the index of refraction at that point. The laser sources may be phase locked to enable and optimize energy absorption at the atmospheric target point.

It is to be noted that the energy density of the individual laser beams may be decreased to a tolerable level (a level insufficient to ionize) by so called beam expanders.

If a single beam of laser radiation of Gaussian waist radia w_a is sufficiently powerful to modulate the index of refraction of air, that beam waist radius w_a is preferably enlarged or expanded for transmission through the atmosphere. In addition, the expanded beam is acted upon by either active or passive focusing optics, e.g., lenses and/or mirrors, to cause a convergence of the beam so that it is focused at a preselected point in the atmospheric target region. Of course, if several beams are used, one or more of them may be subjected to expansion and focusing steps.

According to another feature of the present inven¬ tion, one or more lens generating laser beams are swept along a predetermined path through the atmospheric target region. This procedure is especially effective in the event that the atmospheric lens is a Fresnel lens. To generate each zone of the Fresnel lens, a laser beam distribution profile may be formed with a power gradient, the beam having a corresponding gradient at the region of the lens being generated.

Preferably, to optimize the concentration of solar radiation, adaptive optics is utilized to compensate for changes in atmospheric refractive index arising from atmospheric turbulence in the target region of the atmosphere. In general, adaptive optics is used in a predictive soalr point spread feedback loop to compensate for variations in the atmospheric refractive index profile in real time. More particularly, the modified spatio-temporal Fourier transform of an instantaneous atmospheric refractive index profile is iteratively measured for the atmospheric region at the predetermined absorption area, and in response to the measured profile, the intensity of laser radiation transmitted to the atmospheric region is varied. The turbulence compensation may be implemented by iteratively changing piston-and-tilt orientations of a plurality of adaptively deformable mirror segments disposed in a radiation transmission path between a laser and the target region in the atmosphere.

A method in accordance with the present invention may further comprise the steps of providing an internally reflecting tube having an inlet aperture larger than or matched with a collecting cone numerical aperture of the atmospheric lens at one end and an output aperture at an oppo¬ site end, effectively tapering the forward propagating rays of the concentrated solar radiation at the inlet aperture of the tube, guiding the concentrated solar radiation along the tube to the outlet aperture, and directing the concentrated solar radiation from the outlet aperture of the internally reflect¬ ing tube to a preselected point. In accordance with further specific features of the invention, the concentrated solar radiation may be focused by a lens at the outlet aperture of the tube. Also, the tube may be bent to extend through a curved bore in the earth or a large man-made structure. According, the concentrated solar radiation may be used for supplying energy to locations deep within the earth, under the sea, or within a building. The energy may be sufficiently intense to liquify heated coal and shale, carve or fracture rock during mining or tunneling operations.

As mentioned hereinabove, the present invention may be used for decreasing the amount of solar radiation which would naturally fall on a predetermined area. Accordingly, a method for shading a predetermined area from the effects of solar radiation comprises the steps of (i) generating waveform energy, (ii) directing the energy to a predetermined region of the atmosphere located a pre-established distance above a sur¬ face of the earth, (iii) controlling the step of directing to modulate an index of refraction of air in the predetermined region of the atmosphere to produce a predetermined refractio index pattern in the region, and (iv) modifying the distribu¬ tion of solar radiation passing through the region to thereby divert at least a portion of the incoming solar radiation fro falling within a predetermined area. The result of this method is to cool the predetermined area. Where the area is skiing resort, the cooling may be effective to maintain the ski slopes in a suitably snow-covered state.

In another embodiment, the present invention gener¬ ates a Fresnel lens in a sheet of moving liquid. This embodi ment of the invention includes the steps of (1) generating waveform energy, (2) guiding liquid to flow in a plane along pre-established path, (3) directing the energy to a predetermined region of the pre-established path, (4) con¬ trolling the step of directing to modulate an index of refrac tion of the liquid in the predetermined region of the pre- established flow path to produce a predetermined refraction index pattern of the liquid in the region, and (5) modifying the distribution of solar radiation passing through the regio to thereby concentrate the solar radiation at a predetermined location. The liquid used in the sheet may be a glycol or an oil.

As in other embodiments of the invention, the waveform energy is preferably electromagnetic radiation and the step of generating includes the step of generating the electromagnetic radiation via a laser. The step of controll¬ ing includes the step of concentrating the laser generated radiation differentially throughout the region, the step of controlling includes the step of differentially heating the liquid in the region. The step of differentially heating includes the step of controlling the heating to produce a Fresnel or surface gradient type lens.

Pursuant to another feature of the present inven¬ tion, the step of guiding includes the steps of providing a planar support and guiding the liquid to flow along the sup¬ port. Alternatively, the step of guiding includes the steps of providing a nozzle with an elongate mouth and dispensing the liquid through the mouth so that the liquid falls in a planar sheet. The lens generating radiation source, the directing components, the control algorithms and componentry, the sensors and the turbulence compensation circuitry and softwar are preferably on the earth's surface and fixed thereto. However, it is possible that one or more of these components are provided in an air vessel(s) or sea-going ship(s) and/or satellite(s) .

A method and an associated system in accordance wit the present invention as described above provide a relatively inexpensive source of power. Solar radiation which since the beginning of time has fallen on the sides of buildings or on useless ground (desert, semi-arid regions, bodies of water, etc.) can now be harnessed to fall on designated areas, spe¬ cifically a solar energy collector. Significant solar energy can be concentrated even if the atmospheric lens is only twenty or thirty feet in diameter and is located two or three hundred feet above the earth's surface. The amount of energy passing through the cross-section of such a lens and which is concentrated onto the designated spot can be readily calcu¬ lated. Of course, greater amounts of solar energy may be con centrated by increasing the size of the atmospheric lens and/or the distance of the lens from the surface of the earth Different spaced lenses or lens segments may be simultaneousl generated for concentrating solar energy on the same area. Lenses may be generated successively in different regions of the atmosphere, thereby allowing for atmospheric relaxation before further attempts at index modulation.

A method for concentrating solar radiation in accordance with the present invention as described above enables control of climactic conditions on a scale hitherto impossible. Solar energy is diverted to fall on preselected locations to increase humidity, cause rainfall, fight forest fires, accelerate plant growth, dissipate hurricanes, etc.

A method for concentrating solar radiation in accordance with the present invention also enables the gener¬ ation of electrical power from sunlight, e.g., directly through densely packed photoelectric transducer arrays or indirectly via steam generation and turbine driving or other well known thermoelectric transduction modalities.

A method for concentrating solar energy comprises, in accordance with another form of the present invention, the steps of forming a pool of a homogenous fluidic substance over an underlying surface, controllably imparting mechanical energy to the pool to generate a standing wave of the fluidic substance in the pool, and differentially reflecting incoming solar radiation from the pool, upon generation of the standing wave in the fluidic substance, to concentrate the incoming solar radiation at a predetermined location spaced from the pool.

The underlying surface of the pool may be a reflec¬ tive surface, whereby incoming solar radiation may be refracted through the pool and reflected from the reflective surface to be concentrated on a solar energy collector. In the event that the concentration and collection of solar energy is to take place over an extended period, the collector may be either constrained to move in tandem with the sun or may have an elongated solar collecting element which is dis¬ posed or disposable along the path of the concentrated energy beam from a concentrator in accordance with the present inven¬ tion.

According to another feature of the present inven¬ tion, the pool is formed by disposing the reflective surface in an essentially horizontal orientation, erecting a generally upstanding circular wall about the surface to define a pool volume, and filling the pool volume with the homogenous fluidic substance.

According to a further feature of the present inven¬ tion, the mechanical energy is imparted to the pool by provid¬ ing a plurality of electromechanical transducers in operative contact with the wall, the transducers being spaced from one another along the wall, and periodically energizing the trans¬ ducers to generate the standing wave in the pool of the fluidic substance.

According to an additional feature of the present invention, the differential reflection of the solar radiation is accomplished by transmitting incoming solar radiation through the fluidic substance to the reflective surface at the bottom of the pool, refracting the solar radiation during pas¬ sage thereof from the ambient air into the pool, reflecting the solar radiation from the reflective surface and out through the fluidic substance, and again refracting the reflected solar radiation during passage thereof from the poo into the ambient air.

According to a supplemental feature of the present invention, the method further comprises the step of substan¬ tially absorbing solar radiation concentrated at the predetermined location.

According to yet another feature of the present invention, the energizing of the transducers is implemented i part by controlling the intervals between successive activa¬ tions of the transducers to generate a standing wave with a surface characterized by a Bessel function, a Hankel function a modified Bessel function or a modified Hankel function.

A device for concentrating solar energy comprises, in accordance with the present invention, a homogenous fluidi substance, a container for holding the fluidic substance in a pool, the container having a substantially horizontal reflec¬ tive surface, and a mechanical wave generator connected to th container for generating a standing wave in the fluidic sub¬ stance of a predetermined characteristic shape able to con¬ centrate incoming solar radiation at a predetermined location spaced from the pool.

Pursuant to another feature of the present inven¬ tion, the container includes a substantially horizontal reflective surface and a circular wall surrounding the reflec tive surface, the wall and the reflective surface being con¬ tiguous with one another to define a pool.

Pursuant to a more specific embodiment of the pres¬ ent invention, the wave generator includes a plurality of electromechanical transducers in operative contact with the circular wall. The transducers are spaced from one another along the wall, while a control unit is operatively connected to the transducers for periodically energizing the transducer to generate the standing wave in the fluidic substance.

Pursuant to yet ^'another feature of the present invention, the fluidic substance has a high index of refrac¬ tion. The fluidic substance may be glycol, oil or a gel.

According to yet another feature of the present invention, the device further comprises a transparent sheet disposed above the pool for isolating the fluidic substance from wind and weather effects.

A solar concentrator as described above is inex¬ pensive to manufacture and install.

A device for concentrating solar energy comprises, in accordance with another embodiment of the present inven¬ tion, a reflective film, support elements in contact with the film for supporting the film in a substantially planar con¬ figuration, and a mechanical wave generator assembly connecte to the film for generating a standing wave in the film of a predetermined characteristic shape able to concentrate incom¬ ing solar radiation at a predetermined location spaced from the film.

In accordance with a further feature of the present invention, the wave generator assembly includes a plurality o electromechanical transducers in operative contact with the film, the transducers being spaced from one another along the film. A control unit is operatively connected to the trans¬ ducers for periodically energizing the transducers to generat the standing wave in the film.

A related method for concentrating solar energy com¬ prises, in accordance with the present invention, the steps of providing a reflective film, supporting the film in a substan¬ tially planar configuration, and generating a standing wave in the film of a predetermined characteristic shape able to con¬ centrate incoming solar radiation at a predetermined location spaced from the film.

A solar energy concentrator assembly comprises, in accordance with another embodiment of the present invention, a solar concentrator component including an optical element for concentrating a substantial amount of incoming solar radia¬ tion. Wing componentry is attached to the optical element for providing aerodynamic lift to the optical element, to thereby maintain the optical element a predetermined distance above the surface of the earth. A propulsion system is connected to the solar concentrator component for propelling the wing or wings through the atmosphere to generate aerodynamic lift due to differential air flow along wing surfaces. A power plant is operatively connected to the propulsion system for supply¬ ing power thereto. A solar collector component is mounted to the solar concentrator component and is operatively connected to the power plant for energizing the power plant in response to solar radiation received by the solar collector component.

According to another feature of the present inven¬ tion, the airborne solar concentrator component includes a sheet of flexible polymeric material. The optical element is mounted to or integral with the sheet, a plurality of dif¬ ferent wings being spaced from one^' another about a perimetric region of the sheet. Thus, the sheet or web functions as a carrier for the optical element. The sheet or web is in turn maintained aloft by the wings under the action of the propul¬ sion system. The propulsion system may include a plurality o different motors also spaced from one another about the perimetric region. Thus, in one embodiment of the invention a plurality of solar powered airplane components are spaced about the perpiphery of a plastic sheet for keeping the sheet and its integral or attached optical element at a predetermined altitude or within a range of altitudes.

According to another feature of the present inven¬ tion, the airborne solar concentrator assembly further com¬ prises a control unit operatively connected to the propulsion system for operating the propulsion system to change a dis¬ position of the solar concentrator component in the atmos¬ phere. A sensor may be operatively connected to the control unit for providing the control unit with feedback as to solar energy concentration by the optical element. Thus, the con¬ trol unit operates the propulsion system to change a disposi¬ tion of the solar concentrator component in the atmosphere to attain a predetermined level of solar concentration.

Preferably, the optical component of the airborne system is a lens and, more preferably, a Fresnel lens. Such lens is easily carried on a flexible polymeric sheet which in turn is easily maintained in a predetermined orientation and position in the atmosphere. It is to be noted that the sheet is advantageously provided with an array of air holes for min¬ imizing, if not eliminating, the rippling effects of high- altitude winds. The holes serve to reduce the wind forces on the lens-carrying sheet, thereby enhancing stability, reducin internal stresses, and augmenting predictability and control.

According to another feature of the present inven¬ tion, the propulsion system includes a multiplicity of propel- lers and cooperating electric motors,, while the power plant includes one or more electrical storage units conductively coupled to the electric motors.

A method for concentrating solar energy comprises, in accordance with the present invention, the steps of (a) providing an optical element capable of concentrating a sub¬ stantial amount of solar radiation, (b) attaching a plurality of air transport devices to the optical element at spaced positions, (c) operating the air transport devices to maintai the optical element at a predetermined position and orienta¬ tion above the earth's surface, and (d) modifying the distrib¬ ution of solar radiation passing through the optical element to thereby concentrate the solar radiation at a predetermined location.

According to another feature of the present inven¬ tion, the operation of the air transport devices includes the steps of sensing efficacy of solar energy concentration at a predetermined location by the optical element, generating con¬ trol signals for modifying operation of the air transport devices in response to the sensing input, and transmitting the control signals to the air transport devices.

Where the air transport devices include wings con¬ nected to the optical element for providing aerodynamic lift to the optical element and a propulsion unit is connected to the optical element, the operation of the air transport devices includes the step of propelling the wings through the atmosphere to generate aerodynamic lift due to differential air flow past wing surfaces.

Where the air transport devices include balloons, the operation of the air transport devices includes the step of changing effective amounts of a lighter-than-air gas inside the balloons.

According to another feature of the present inven¬ tion, solar energy is collected at the optical element and used to operate the air transport devices.

A method and associated airborne apparatus in accordance with the present invention for concentrating solar energy is cost effective. Since maintaining the energy con¬ centrating lens at a predetermined height or moving the lens is effectuated by solar powered equipment, the operating costs are virtually zero. A method and associated apparatus in accordance with the present invention for concentrating solar energy minimizes the extent to which the ground surface is monopolized by the solar concentrator. The concentrator diverts solar energy from some ground areas to others, but does not physically occupy the former areas. Brief Description of the Drawing

Fig. 1 is a block diagram of a system in accordance with the present invention for generating a predetermined refractive index pattern in a predetermined target region of the atmosphere for purposes of concentrating incoming solar radiation.

Fig. 2 is a diagram showing an atmospheric Fresnel lens generated by the system of Fig. 1 and further showing a solar energy collector and a photosensor array illustrated in Fig. 1.

Fig. 3 is a diagram showing a specific embodiment of components illustrated in Fig. 1 including a control unit, directional and focusing optics, and a servomechanism assembly for adjusting the optics.

Fig. 4 is a diagram similar to Fig. 3 depicting an alternative embodiment of components illustrated in Figs. 1 and 3.

Fig. 5 is a block diagram illustrating a modifica¬ tion of the system of Fig. 3 or 4.

Fig. 6 is a diagram of yet another embodiment of the system of Fig. 1.

Fig. 7 is a diagram a pair of atmosperic solar con¬ centrators in accordance with the present invention, generated for dissipating a hurricane type natural disturbance, indi¬ cated in side elevational view.

Fig. 8 is a diagram, in top view, of the hurricane type natural disturbance of Fig. 7, showing ancillary atmospheric whirlpools for counteracting and reducing the dis¬ turbance.

Fig. 9 is a schematic cross-sectional view of a water desalinization or distillation plant using an atmospheric solar concentrating lens as a power source, in accordance with the present invention.

Fig. 10 is a schematic side elevational view of an internally mirrored tube for transmitting, to an underground or underwater location, solar radiation which has been effec¬ tively focaused by an atmospheric concentrator.

Fig. 11 is a diagram illustrating operation of a solar concentrator where the index of refraction of a moving liquid sheet is modified by a laser beam.

Fig. 12 is a diagram similar to Fig. 11, showing an alternate embodiment of the invention.

Fig. 13 is partially a schematic vertical cross- sectional view and partially a block diagram of a device or system for concentrating and collecting solar energy, in accordance with the present invention.

Fig. 14 is partially a schematic top view of a solar energy concentrator shown in Fig. 13 and partially a block diagram.

Fig. 15 is a schematic vertical cross-sectional view, on a substantially enlarged scale, of a portion of the solar energy concentrator of Figs. 13 and 14, showing a wave perturbation in a surface of the concentrator, in accordance with the present invention.

Fig. 16 is partially a schematic vertical cross- sectional view and partially a block diagram of another device or system for concentrating solar energy, in accordance with the present invention.

Fig. 17 is a partial schematic perspective view of yet another device or system for concentrating solar energy, in accordance with the present invention.

Fig. 18 is a diagrammatic side elevational view of the solar energy concentrator of Fig. 17.

Fig. 19 is a schematic isometric view of another assembly or system for concentrating solar energy, in accord¬ ance with the present invention.

Fig. 20 is a block diagram of selected functional components of a propulsion system in the system of Fig. 19. Fig. 21 is a schematic isometric view of a flying lens assembly utilizable in the system of Fig. 19.

Fig. 22 is a schematic isometric view of another flying lens assembly utilizable in the system of Fig. 19.

Fig. 23 is a schematic isometric view of a floating lens assembly utilizable in the system of Fig. 19. Fig. 24 is a schematic plan view of a floating lens assembly utilizable in the system of Fig. 19.

Detailed Description

As illustrated in Fig. 1, a system for collecting solar radiation comprises a laser source 12 for emitting, along a schematically represented preselected path 14, laser radiation 16 having a wavelength absorbable by at least one type of atmospheric molecule. Because the power of laser bea or radiation 16, when emitted from a single source 12, must b sufficiently high to substantially heat or even ionize air, the beam must be expanded by a beam expander 18 prior to transmission through the atmosphere to a target region.

As further illustrated in Fig. 1, radiation direct¬ ing and focusing optics 20 such as lenses or mirrors (see Figs. 3 and 4) are disposed in the transmission path 14 for directing the radiation from source 12 to a predetermined atmospheric target 22 (Fig. 2) located a pre-established dis¬ tance dl above the earth. A servomechanism assembly 24 responsive to a control unit 26 is operatively connected to the radiation directing and focusing optics 20. Under the control of unit 26, servomechanism assembly 24 adjusts the operation of optics 20 to modulate an index of refraction of air in target region 22 to produce in that region a predetermined refractive index pattern or profile for con¬ centrating incoming solar radiation on a solar energy collec¬ tor 28.

In subsequent cycles of operation of the system of Fig. 1, when the index of refraction in target region 22 is again modulated to regenerate the desired refractive index pattern or profile, control unit 26 receives feedback from a photosensor array 30 and, in response to that feedback, adjusts the transmission of laser radiation 16 to compensate for atmospheric turbulence in target region 22, as well as in an underlying air volume.

Control unit 26 may be operatively connected to source 12 for timing the emission of radiation therefrom. Thus, source 12 may be energized only during operating cycles of the index modulation system of Fig. 1.

As illustrated schematically in Fig. 2, the index modulation system of Fig. 1 acts to generate in target region 22 an atmospheric Fresnel or alternate distribution con¬ centrating lens 32 having a plurality of sector or concentric \

scanned zones 34. Lens 32 is effective to concentrate incom¬ ing solar radiation 36 on solar energy collector 28. Collec¬ tor 28 may take any conventional form where heat energy is absorbed and conveyed away to perform a useful function. For example, collector 28 may comprise a boiler with a metallic plate 38 in thermal contact with a plurality of fluid guiding pipes or channels 40. Pipes 40 are- connected at an input end for example, to a water supply or source 42 and at an output end to a steam turbine 44. Water from supply 42 is turned into steam upon passing through a designated target area 46 onto which solar radiation is concentrated by atmospheric lens 32. It is to be understood that other working fluids or combination of thermal concentrating/storage media may be use in substitution for water.

Photosensor array 30 includes a multiplicity of photoelectric sensors 48 disposed in a planar array above col lector 28, as indicated in Fig. 2. Photosensors 48 serve essentially to detect the distribution of radiation concentra tion by lens 32. Feedback circuits 50 operatively connect sensors 48 to control unit 26 which functions via ser¬ vomechanism assembly 24 to modify the operation of optics 20 in response to signals from the sensors to compensate in real time for changes in atmospheric refractive index caused by turbulence or apparent sun motion with respect to the solar energy receiving area. This feedback loop serves therefore t optimize the concentration of solar radiation by lens 32 onto collector 28.

As shown in Fig. 3, optics 20 includes a plurality of deformable mirror segments 52 disposed in an aspheric con¬ cave array in the general surface form of a paraboloid. The deformable mirror array is formed with an aperture 54 through which laser beam 16 passes from laser source 12. Beam 16 is expanded by a convex mirror 56 disposed essentially at the focal point of mirror or mirror segments 52. Mirror 56 thus performs in part the function of beam expander 18 (Fig. 1). Mirror 56 also performs part of the directing function of optics 20.

As additionally shown in Fig. 2, servomechanism assembly 24 (Fig. 1) includes banks of servomechanism actuators 58 and 60 operatively linked to mirror or mirror segments 52 (or to mirror actuators). Generally, each mirror 52 will have one or more dedicated servo-actuators 58, 60 in the form, for example, of piezoelectric crystals. Actuators 58 and 60 function to control the instantaneous orientations of individual deformable mirror segments 52.

Control unit 26 includes a first module 62 for con¬ trolling the intensity of energy emitted from laser source 12. In particular, intensity control module 62 determines the times that laser source 12 is actively emitting laser radia¬ tion. Control unit 26 also includes a direction control module 64 for determining the orientations of mirror segments 52 necessary to sweep out zones 34 of Fresnel lens 32 (Fig. 2). In response to signals from control module 64, servo- actuators 58 and 60 tilt mirror segments 52 so that the expanded beam from mirror 56 converges to a predetermined point in the target region 22 (Fig. 2). That point shifts in time, for example., along an arc defining a zone 34 of lens 32.

Control unit 26 additionally includes a turbulence compensation module 66 which is operatively connected to servo-actuators 58 and 60 for controlling the operation thereof to adjust the orientation of mirror segments 52 (or mirror actuators) in response to signals from photosensors 48 (Fig. 2) to compensate in real time for changes in atmospheric refractive index induced by turbulence in target region 22. Turbulence compensation module includes circuitry or program¬ ming for controlling servo-actuators 58 and 60 to iteratively change the orientations of mirror segments 52.

Direction control module 64 and turbulence compensa¬ tion module 66 are coupled at their outputs to a further module 68 serving to adjust or fine tune the mirror wavefront operations determined by direction control module 64 in accordance with the compensation requirements determined by module 66. Module 68 is connected to servo-actuators 58 and 60 to modify the orientations and positions of mirror segments 52 (or mirror actuators) t^'o produce atmospheric Fresnel lens 32.

Intensity control module 62, direction control module 64 and composite orientation and position adjustment module 68, as well as turbulence compensation module, may be configured by hard wired circuits and/or specialized program- ming of a general purpose computer. In the event that the functions of modules 62, 64, 66 and 68 are programmed, the programming is a straightforward technical exercise for one of ordinary skill in the art of adaptive optics. Adaptive optics is used, for example, in astronomy, to adjust the orientations of the multiple individual deformable sections of segmented telescope mirrors to compensate in real time for atmospheric refractive index changes caused by turbulence and thereby obtain clear images of stellar bodies. The operation of tur¬ bulence compensation module 66 is essentially an operation in adaptive optics. Photosensor array 30 provides the feedback necessary to control instantaneous mirror orientation.

In Figs. 3 and 4, the same structures bear like reference designations. The embodiment illustrated in Fig. 4 separates, in optics 20, the turbulence compensation function from the overall directional function. Accordingly, a beam expanding mirror '70 is connected to a rotary carrier 72 which is operatively coupled to a two-axis rotary drive 74. Drive 74 is activated by a direction control module 76 which func¬ tions similarly to module 64 in the embodiment of Fig. 3. Via rotary carrier 72, control module 76 rotates mirror 70 in coordination with the emission of varying radiation intensities from laser source 12.

In the embodiment of Fig. 4, servo-actuators 78 and 80 are connected to respective deformable mirror segments 52 for adjusting the orientations thereof in response to signals from a turbulence compensation module 82 which functions similarly to corresponding module 66 in Fig. 3 to instantaneously compensate for the effects of atmospheric tur¬ bulence as detected by photosensor array 30.

Photosensors 48 cooperate with turbulence compensa¬ tion module 66 or 82 to determine the sharpness or degree of concentration of the incoming solar energy. To that end, sensor array 30 advantageously extends over an area larger than the designated area 46 of impingement of the incoming concentrated solar radiation. Turbulence compensation module 66 or 82 uses signals from photosensors 48 to determine whether solar radiation is falling only on the designated target area 46 or is falling outside the designated area. As in all Fresnel lenses, zones 34 of Fresnel or alternate distribution lens 32 have different refractive inde gradients depending on the distance of the respective zones from the center of the respective lens. In one mode of opera tion, laser beam 16 can be used to sweep out a single zone 34 in a single pass. To achieve that end, it is necessary to provide beam 16 with an energy gradient corresponding to the desired index gradient of the particular lens zone 34. As illustrated in Fig. 5, a plurality of passive or active amplitude and/or phase filters 84 having respective power gra dients are alternately disposable in the path of beam 16. Each complex filter 84 is an electronically constructed trans form filter or a holographic phase filter connected to a respective linear or angular drive 86 for translating or reciprocating the filter with respect to the beam path. In addition, to account for the curvature of lens zones 34 about the center of lens 32, filters 84 are coupled with respective rotary drives 88. Upon insertion of a selected filter 84 int the beam path by the respective drive 86, the respective rotary drive 88 rotates the filter at a respective predetermined angular velocity.

Drives 86 and 88 are controlled by a gradient modul 90 in control unit 26. In the event that the intensity of laser radiation 16 produced by source 12 is too great for ensuring the continued integrity of filters 84, beam 16 may b reimaged at a lower energy density by a beam expander 92 posi tioned upstream of filters 84. Filters 84 are in turn inter- disposed upstream (or upbeam) of mirror segments 52.

Fig. 6 depicts a modified system for generating an atmospheric Fresnel lens 93. A plurality of laser sources 94 and 96 are connected to one another via a phase-locking link 98. Each source 94 and 96 is provided with its own radiation directing and focusing optics 98 and 100.

As illustrated in Fig. 6, in one mode of operation, laser radiation is transmitted simultaneously from sources 94 and 96 to the same convergence point 102 in an atmospheric target region 104. Owing to the phase locking of laser sources 94 and 96, the intensities of beams 104 and 106 from those sources can be adjusted to coherently add (reconstruc- tively) at the convergence point 102 or incoherently add thei beam powers to generate sufficient energy to ionize or sub- 11-

stantially heat the air at that point.

Fig. 6 shows beams 104 and 106 as expanded beams being focused to convergence point 102 by the respective optics 98 and 100. However, it is possible to dispense with optics 98 and 100, provided that laser sources 94 and 96 pro¬ duce laser radiation which is insufficiently intense to sig¬ nificantly heat or ionize the atmosphere prior to convergence of beams 104 and 106 at point 102. Only when beams 104 and 106 cross or converge at point 102 do they have sufficient energy to significantly change the index of refraction of the air.

Fresnel or alternate distribution lens 93 con¬ centrates incoming solar radiation 108 on a boiler 110. If necessary, atmospheric turbulence is compensated by a control unit 112 receiving feedback signals from a photosensor array 114 at collector or boiler 110. Control unit 112 adapts the operation of optics 98 and 100 to real time atmospheric condi tions.

It is to be noted that the term "atmospheric lens" as used herein is intended to connote not an image forming lens but rather a refractive air volume of adequate structure to concentrate incoming solar rays upon a defined energy absorption or collection station. Such a refractive air volume is preferably in the form of a Fresnel or alternate distribution lens like structure. However, other shapes are also within the contemplation of the instant invention. For example, the heated or ionized air volume may have outwardly convex upper and lower boundaries.

Alternatively, the concentration of solar radiation on a collector may be accomplished by modulating the index of refraction in a predetermined region of the atmosphere to gen erate a diffraction pattern or volume serving to concentrate incoming radiation.

It is to be further noted that the radiation which is differentially focused^'in a predetermined pattern to pro¬ duce the atmospheric lens may be any wavelength or range of wavelengths capable of being absorbed by one or more major atmospheric constituent molecules (e.g., water, carbon dioxide, oxygen, nitrogen, etc.) in sufficient quantities to effectuate a change in the refractive index of the air. For instance, microwave energy may be used.

In addition, the source or sources of the modulating radiation need not be on the earth's surface but may instead be located in hot air balloons or on satellites.

It is to be noted that a lens generating laser beam may be provided with an intensity gradient by other techniques equivalent to the filtering technique described hereinabove with respect to Fig. 5. For example, a laser beam may be dif¬ ferentially expanded so that some portions of the beam have a higher intensity than other portions. Such differential expansion may be accomplished by forming expander 56 or 70 with an assymetric surface.

Modifying the index< of refraction in a predetermined region of the atmosphere with a laser as described in detail hereinabove can be used to either concentrate solar energy on an underlying area or to decrease the total amount of solar radiation falling on that area. In the former case, the atmospheric region acted upon by the laser becomes a solar energy concentrator, while in the latter case, the atmospheric region acted upon by the laser diverts the solar energy. In the former case, the target region of the atmosphere may take the form of a converging lens. In the latter case, the atmospheric target region becomes a diverging lens. In gen¬ eral, the result is to alter the otherwise natural distribu¬ tion of solar radiation falling on the preselected area.

Concentrated solar radiation can be collected or absorbed by systems other than a boiler with a metallic plate 38 in thermal contact with a plurality of fluid (or thermal storage and transport media) guiding pipes or channels 40, as described above with reference to Fig. 2. For example, col¬ lector 110 (Fig. 6) may take the form of an array of densely packed photoelectric transducers or photocells which convert the incoming concentrated solar radiation directly to electri¬ cal current. In contrast, in the systems described hereinabove with reference^' to Figs. 1-6, solar energy is con¬ verted into electrical energy indirectly by first being con¬ verted into heat energy which is used to drive turbines which then generate the electrical power output.

The collection or absorption of solar radiation con¬ centrated by one or more laser-generated atmospheric lenses or

diffraction gratings may be mediated by natural bodies instea of mad-made facilities. For example, a bed of ice in a river or lake may be the ultimate target of the concentrated solar radiation. Upon absorbing the concentrated solar radiation, the ice melts and opens up a waterway which had otherwise been blocked to desired human use.

Targeting natural bodies with solar energy con¬ centrated by a laser-generated atmospheric lens or diffraction grating as described herein is useful for controlling or altering a climatic condition in a region at or proximate to the targeted natural body. An ice block in a river or other natural body of water is one example of altering a climatic condition. Another climatic condition alterable in accordance with the present invention is humidity. Concentrated solar energy falling upon a body of water, such as the sea or a lake, can rapidly increase the humidity in a region bounding the heated water.' Such a marked increase in humidity can reduce the chances of fire in dried coastal areas. In addi¬ tion, under proper climatic conditions, rain can be produced over land areas near the targeting body of water.

Where rainfall is a desired climatic change and humidity is elevated in a column of air rising from a body of water heated by concentrated solar radiation, the water vapor may be induced to precipitate by cooling a selected area of the earth in the path of movement of the humid air column. As mentioned above, cooling is effectuated by generating one or more diverging atmospheric lens to decrease the amount of sun¬ light falling on the selected area, thereby cooling that area relative to surrounding areas and particularly relative to the column of moisture laden air produced by an atmopheric solar concentrator. Of course, the energy for undertaking such climatic modifications as described herein can come from solar energy collection as described hereinabove with reference to Figs. 1-6.

Another climactic use of the invention is to increase the amount of sunlight falling over a selected area, for example, to accelerate drying of wet surfaces in that selected area, for example, a playing field or race track. For such a use, the solar energy need not be intensely con¬ centrated. In other uses, for example, to control the spread US

of forest fires by causing fire breaks as in conventional fir fighting procedures, the amount of energy must be larger.

Solar energy concentrated by an atmospheric lens ma be converted into a chemically stored form. The concentrated solar energy is absorbed and converted into chemical bonds of energy laden molecules, for example, via photosynthetic reac¬ tions or some other photoreactive process. Specifically, the instant invention can be used to stimulate plant growth in dense farming areas by providing concentrated sunlight.

It is to be noted that in many applications, it wil not be convenient to position photosensors 48 or 114 directly over the targeted solar absorption area. However, it is not necessary that the sensors be juxtaposed to the target area. Instead, photosensors 48 or 114 may be positioned to detect the distribution of light concentrated by lens 32 or 93 onto the photosensors from a distant calibration object other than the sun. This calibration object can be a planet, the moon, satellite, a balloon, an airplane or other high-flying known source distribution. Accordingly, photosensors 48 or 114 may be spaced from the target region by a distance approximating the distance of the laser beam source 12, 94, or 96 from the targeted natural body or other energy absorption target.

Once again, it is to be noted that an atmospheric solar concentrator generated in accordance with the present invention will be effective even if the lens is partial or imperfect. It is only necessary that incoming solar radiatio be concentrated onto an absorption area. It is not necessary to produce an atmospheric lens capable of image formation. Accordingly, in this specification, the term "atmospheric lens" is used to mean an atmospheric index of refraction pro¬ file capable of concentrating incoming solar radiation onto a predetermined solar absorption location.

Yet another climactic change which may be induced b an atmospheric solar energy concentrator as described herein is the dissipation of whirlpool type storms, e.g., hurricanes. As illustrated in Fig. 7, incoming solar radiation 116 is con centrated by a plurality of atmospheric Fresnel type lenses 118 and 120 onto atmospheric regions 122 and 124 and/or at underlying surfaces of a body of water 126. The targeted atmospheric regions 122 and 124 and/or underlying water sur¬ faces lie proximate to an outer periphery of a hurricane type natural disturbance 128. In response to incoming concentrate solar radiation, quickly rising columns 130 and 132 of air an water vapor are produced at the periphery of hurricane type natural disturbance 128. As illustrated in Fig. 8, the risin columns 130 and 132 of air and water vapor result in ancillar atmospheric whirlpools 134 and 136 which work against the air flow at the periphery of disturbance 128, thereby serving to counteract and dissipate the force of the hurricane. Fresnel type lenses 118 and 120 are generated by laser sources 138 an 140 and associated focusing elements 142 and 144.

Solar radiation concentrated by an atmospheric lens as described above may be directed to and absorbed in a body of salt water at the predetermined location. The body of sal water may be naturally occurring, e.g., a salt water lake or sea, or it may be man-made. In the latter event, the salt water may have been transported from a distant sea via pipes or an aqueduct to a desert area. Water is evaporated from th body of salt water and captured or collected to form an aqueous distillate, which may be used for drinking, irrigat¬ ing, etc. The separated salt may be collected and transporte back to the sea.

As illustrated in Fig. 9, a water desalinization or distillation plant using an atmospheric solar concentrating lens as a power source comprises a plurality of flat tanks or evaporation pans 146 each flanked by a pair of slotted pipes 148. A roof 150 of transparent plastic webbing is supported over the pans 146 for providing a condensation surface for water evaporated from pans 146 as a consequence of con¬ centrated solar radiation falling on the installation owing t an atmospheric lens. The aqueous condensate flows down panels 152 of roof 150 and is deposited into slotted pipes 148 for guidance thereby to a water collection station or storage facility (not shown). Roof panels 152 may be cooled to facil¬ itate condensation. Power for cooling may be provided by solar energy collected as described hereinabove with reference to Figs. 1-6.

As illustrated in Fig. 10, incoming solar radiation 154 may be focused or concentrated by an atmospheric con-

to heat air along the outer periphery of a hurricane, thereby producing one or more ancillary whirlpools acting to oppose the circulation of air in the primary whirlpool, i.e., the hurricane.

Concentrated solar radiation may be used for desalinization purposes. The radiation is directed to and absorbed in a body of salt water. The consequently evaporate water is captured or collected to form an aqueous distillate. The salt water may be pumped or transported over the desert t the predetermined location well inside the boundaries of a desert region. The separated salt may be collected and transported back to the sea.

Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the draw ings and descriptions herein are profferred by way of example to facilitate comprehension of the invention and should not b construed to limit the scope thereof.

Claims

3BWHAT IS CLAIMED IS:

1. A method for concentrating solar energy, compris¬ ing the steps of: generating waveform energy; directing said energy to a predetermined region of the atmosphere located a pre-established distance above a sur¬ face of the earth; controlling said step of directing to modulate an index of refraction of air in said predetermined region of the atmosphere to produce a predetermined refraction index pattern in said region; and modifying the distribution of solar radiation pass¬ ing through said region to thereby concentrate the solar radiation at a predetermined location.

2. The method defined in claim 1, further comprising the steps of absorbing, at said location, a substantial quantity of the concentrated solar radiation and converting at least a significant portion of the absorbed concentrated solar radiation to a different form of energy.

3. The method defined in claim 2 wherein said dif¬ ferent form of energy is heat energy, further comprising the step of altering a climatic condition in a region proximate to said location in response to said steps of absorbing and con¬ verting.

4. The method defined in claim 3 wherein a body of water is disposed at said location, said step of altering including the step of converting water from said body of water into water vapor to alter humidity conditions in said region.

5. The method defined in claim 3 wherein a body of ice is disposed at said location, said step of altering including the step of converting ice in said body of ice into water to remove or open up said body of ice.

6. The method defined in claim 3 wherein said step of altering includes the steps drying a surface at said loca- tion .

7. The method defined in claim 2 wherein said dif¬ ferent form of energy is chemical, said step of converting including the step of producing energy laden molecules via photosynthetic reactions.

8. The method defined in claim 7 wherein said step of producing is executed inside plant cells, thereby stimulat¬ ing plant growth.

9. The method defined in claim 2 wherein said dif¬ ferent form of energy is electrical, said step of converting including the steps .of generating heat energy and using the generated heat energy to produce the electrical energy.

10. The method defined in claim 2 wherein said dif¬ ferent form of energy is electrical, said step of converting including the step of operating a photoelectric transducer device to convert the absorbed concentrated solar radiation to electrical energy.

11. The method defined in claim 1 wherein said loca¬ tion is in or prpoximate to an atmospheric whirlpool, whereby energy fed to said location induces said whirlpool to dis¬ sipate.

12. The method defined in claim 1, further compris¬ ing the steps of: absorbing, in a body of salt water at said location, a substantial quantity of the concentrated solar radiation; evaporating water from said body of salt water in response to said step of absorbing; and collecting the evaporated water to form an aqueous distillate.

13. The method defined in claim 1 wherein said waveform energy is electromagnetic radiation and said step of generating includes the step of generating said electromag¬ netic radiation via a laser, said step of controlling includ- *+0

ing the step of concentrating the laser generated radiation differentially through said region.

14. The device defined in claim 13 wherein said step of directing includes the step of transmitting laser radiation from a plurality of different sources to said region.

15. The method defined in claim 14 wherein said step of transmitting includes the step of transmitting the laser radiation simultaneously to the same point in said region, further comprising the step of phase locking said sources.

16. The method defined in claim 14 wherein said step of transmitting includes the step of transmitting laser beams from said sources to different points in said region at any one time.

17. The method defined in claim 13, further compris¬ ing the step of expanding a beam of laser radiation produced during said step of generating, said step of directing includ¬ ing the step of transmitting the expanded beam through the atmosphere to said region, said step of controlling including the step of focusing the expanded beam to a point in said region.

18. The method defined in claim 17 wherein said step of controlling includes the step of sweeping the focused beam along a predetermined path through said region.

19. The method defined in claim 18 wherein said step of controlling further includes the step of generating a power gradient within said beam, the focused beam having a cor¬ responding gradient.

20. The method defined in claim 13 wherein said step of controlling includes the step of utilizing adaptive optics to compensate for refractive index changes induced by atmospheric turbulence in said region.

21. The method defined in claim 20 wherein said step of utilizing adaptive optics includes the steps of: detecting an effect of an instantaneous atmospheric refractive index profile for said region on a power distibu- tion over an energy collecting area; and in response to said step of detecting, varying an intensity of laser radiation transmitted to said region to compensate for variations in said atmospheric refractive inde profile in real time.

22. The method defined in claim 21 wherein said ste of varying includes the step of iteratively changing orienta¬ tions of a plurality of mirror segments disposed in a radia¬ tion transmission path between said laser and said region.

23. The device defined in claim 1 wherein said predetermined refraction index pattern is essentially an atmospheric lens in said region, said step of modifying including the step of refracting the incoming solar radiation through said lens.

24. The method defined in claim 23 wherein said step of controlling includes the step of controlling the index of refraction to produce a Fresnel type atmospheric lens.

25. The method defined in claim 1 wherein said step of controlling includes the step of differentially heating the air in said region.

26. The method defined in claim 25 wherein said step of differentially heating includes the step of controlling the heating to produce a Fresnel type atmospheric lens.

27. The method defined in claim 1 wherein said step of modulating includes the step of ionizing air in said region.

28. The method defined in claim 1, further compris¬ ing the steps of: providing an internally reflecting tube having an inlet aperture at one end and an output aperture at an oppo- site end; effectively tapering forward propagating rays of the concentrated solar radiation at said inlet aperture of said tube; guiding the concentrated solar radiation along said tube to said outlet aperture; and directing the concentrated solar radiation from said outlet aperture to a preselected point.

29. The method defined in claim 28, further compris¬ ing the step of focusing the concentrated solar radiation leaving said tube at said outlet aperture.

30. The method defined in claim 28, further compris¬ ing the step of extending said tube through a bore in the earth.

31. The method defined in claim 28 wherein said step of directing includes the step of bending the tube.

32. A method for shading a predetermined area from the effects of solar radiation, comprising the steps of: generating waveform energy; directing said energy to a predetermined region of the atmosphere located a pre-established distance above a sur¬ face of the earth; controlling said step of directing to modulate an index of refraction of air in said predetermined region of the atmosphere to produce a predetermined refraction index pattern in said region; and modifying the distribution of solar radiation pass¬ ing through said region to thereby divert at least a portion of the incoming solar radiation from falling within a predetermined area.

33. The method defined in claim 32, further compris¬ ing the step of cooling said area as a result of said step of modifying.

34. A method for concentrating solar energy, com- prising the steps of: generating waveform energy; guiding liquid to flow in a plane along a pre- established path; directing said energy to a predetermined region of said pre-established path; controlling said step of directing to modulate an index of refraction of said liquid in said predetermined region of said pre-established flow path to produce a predetermined refraction index pattern of said liquid in said region; and modifying the distribution of solar radiation pass¬ ing through said region to thereby concentrate the solar radiation at a predetermined location.

35. The method defined in claim 34 wherein said waveform energy is electromagnetic radiation and said step of generating includes the step of generating said electromag¬ netic radiation via a laser, said step of controlling includ¬ ing the step of concentrating the laser generated radiation differentially throughout said region.

36. The method defined in claim 34 wherein said ste of controlling includes the step of differentially heating th liquid in said region.

37. The method defined in claim 36 wherein said step of differentially heating includes the step of controlling the heating to produce a Fresnel type lens.

38. The method defined in claim 34 wherein said liq¬ uid is a glycol.

39. The method defined in claim 34 wherein said liq¬ uid is an oil.

40. The method defined in claim 34 wherein said step of guiding includes the steps of providing a planar support and guiding said liquid to flow along said support.

41. The method defined in claim 34 wherein said ste of guiding includes the steps of providing a nozzle with an elongate mouth and dispensing said liquid through said mouth so that said liquid falls in a planar sheet.

42. A system for collecting solar radiation, com¬ prising: source means for emitting, along a preselected path radiation having a wavelength absorbable by at least one type of atmospheric molecule; directing means in said path for directing said radiation from said source to a predetermined region of the atmosphere located a pre-established distance above a surface of the earth; control means operatively connected to said direct¬ ing means for controlling the operation thereof to modulate a index of refraction of air in said region of the atmosphere t produce in said region a predetermined refraction index pat¬ tern for concentrating incoming solar radiation on a solar energy collector, said control means being operatively con¬ nected to said source means for timing the emission of radia¬ tion therefrom; sensor means for detecting effectiveness of con¬ centration of incoming solar radiation by said atmospheric lens; and compensation means operatively connected to said sensor means and to said directing means for modifying the operation of said directing means in response to signals from said sensor means to compensate in real time for changes in atmospheric refractive index induced by atmospheric tur¬ bulence, thereby optimizing concentration of solar radiation by said region on said collector.

43. The system defined in claim 42 wherein said directing means includes a^' plurality of plane mirror segments arranged in a concave array, further comprising orientation means operatively connected to said mirror segments for inde¬ pendently tilting said mirror segments.

44. The system defined in claim 43 wherein said com- pensation means is operatively connected to said orientation means for controlling the operation thereof in response to signals from said sensor means to compensate in real time fo changes in atmospheric refractive index arising from tur¬ bulence in said region.

45. The system defined in claim 44 wherein said co pensation means includes means for controlling said orienta¬ tion means to iteratively change orientations of said mirror segments.

46. The system defined in claim 42 wherein said source means includes at least one radiation source, said directing means including means for expanding radiation from said radiation source to prevent heating of air other than i said region, said directing means also including focusing means for focusing said radiation in different amounts at a plurality of points within said region.

47. The system defined in claim 46 wherein said radiation source is a laser source.

48. The system defined in claim 42 wherein said source means, said directing means, said control means, said sensor means and said compensation means are fixed to a sur¬ face of the earth.

49. The system defined in claim 42 wherein said source means includes a plurality of laser sources spaced fro one another, further comprising means operatively connected t said laser sources for ensuring that said laser sources operate in phase with one another.

50. The system defined in claim 42 wherein said directing means includes means for sweeping a beam of radia¬ tion from said source means along a predetermined path throug said region.

51. The system defined in claim 42 wherein said directing means includes means for generating a power gradien within a beam of radiation from said source means, whereby ai in said region is differentially heated or ionized.

52. A method for collecting solar energy, comprisin the steps of: modulating an index of refraction of air in a predetermined region of the atmosphere located a pre- established distance above a surface of the earth, thereby generating an atmospheric lens in said region; refracting incoming solar radiation through said lens to concentrate the solar radiation at a predetermined location on said surface; and absorbing, at said location, a substantial quantity of the concentrated solar radiation to produce heat energy.

53. The method defined in claim 52 wherein said ste of modulating includes the steps of: generating at least one beam of laser radiation; expanding said beam; transmitting the expanded beam through the atmos¬ phere to said region; and focusing the expanded beam to a point in said region.

54. The method defined in claim 53, further compris ing the step of sweeping the focused beam along a predetermined path through said region.

55. The method defined in claim 54, further compris¬ ing the step of generating a power gradient within said beam, the focused beam having a corresponding gradient.

56. The method defined in claim 53 wherein said step of modulating includes the step of utilizing adaptive optics to compensate for atmospheric turbulence in a volume of air between a laser source and said region.

57. A method for concentrating solar energy, com¬ prising the steps of: forming a pool of a homogenous fluidic substance; controllably imparting mechanical energy to said pool to generate a standing wave of said fluidic substance in said pool; and upon generation of said standing wave in said fluidic substance, differentially reflecting incoming solar radiation from said pool to concentrate the incoming solar radiation at a predetermined location spaced from said pool.

58. The method defined in claim 57 wherein said pool is defined in part by a reflective surface underlying said fluidic substance, said step of reflecting including the step of reflecting the incoming solar radiation from said reflec¬ tive surface.

59. The method defined in claim 58 wherein said step of forming said pool includes the steps of: disposing said reflective surface in an essentially horizontal orientation; erecting a generally upstanding circular wall about said surface to define a pool volume; and filling said pool volume with said homogenous fluidic substance.

60. The method defined in claim 59 wherein said step of controllably imparting includes the steps of: providing a plurality of electromechanical trans¬ ducers in operative contact with said wall, said transducers being spaced from one another along said wall; and periodically energizing said transducers to generate said standing wave of said fluidic substance in said pool.

61. The method defined in claim 60 wherein said step of differentially reflecting includes the steps of: refracting incoming solar radiation upon passage thereof from ambient air into said pool; transmitting the refracted solar radiation through said fluidic substance to said surface; reflecting the solar radiation from said surface and out through said fluidic substance; and again refracting the solar radiation upon passage thereof from said pool into the ambient air.

62. The method defined in claim 61, further compris¬ ing the step of substantially absorbing solar radiation con¬ centrated at said location. .

63. The method defined in claim 58 wherein said ste of differentially reflecting includes the steps of: refracting incoming solar radiation upon passage thereof from ambient air into said pool; transmitting the refracted solar radiation through said fluidic substance to said surface; reflecting the solar radiation from said surface and out through said fluidic substance; and again refracting the solar radiation upon passage thereof from said pool into the ambient air.

64. The method defined in claim 57 wherein said step of controllably imparting includes the steps of: providing a plurality of electromechanical trans¬ ducers in operative contact with said pool, said transducers being spaced from one another; and periodically energizing said transducers to generate said standing wave in said pool.

65. The method defined in claim 64 wherein said step of energizing includes the step of controlling the intervals between successive activations of said transducers to generate a standing wave with a surface characterized by a Bessel type function.

66. The method defined in claim 64 wherein said step of energizing includes the step of controlling the intervals between successive activations of said transducers to generate a standing wave with a surface characterized by a Hankel type function.

67. The method defined in claim 57, further compris¬ ing the step of substantially absorbing solar radiation con¬ centrated at said location. W

68. A method for collecting solar energy, comprisin the steps of: providing a pool of a homogenous fluidic substance ^• disposed over an underlying reflective surface and surrounded by a circular wall; also providing a plurality of electromechanical transducers in operative contact with said wall, said trans¬ ducers being spaced from one another along said wall; further providing a solar energy collector; periodically energizing said transducers to generate a standing wave of said fluidic substance in said pool; refracting incoming solar radiation upon a passage thereof from ambient air into said pool; transmitting the refracted solar radiation through said fluidic substance to said surface; reflecting the solar radiation from said surface and out through said fluidic substance; again refracting the solar radiation upon passage thereof from said pool into the ambient air; concentrating the incoming solar radiation, by virtue of said steps of refracting and reflecting, on said collector; and substantially absorbing solar radiation concentrated onto said collector by said steps of refracting and reflect¬ ing.

69. The method defined in claim 68 wherein said step of energizing includes the step of controlling the intervals between successive activations of said transducers to generate a standing wave with a surface characterized by a Bessel type function.

70. The method defined in claim 68 wherein said step of energizing includes the^' step of controlling the intervals between successive activations of said transducers to generate a standing wave with a surface characterized by a Hankel type function.

71. A device for concentrating solar energy, com- prising: a homogenous fluidic substance; container means for holding said fluidic substance in a pool; and mechanical wave generating means connected to said container means for generating a standing wave in said fluidi substance of a predetermined characteristic shape able to con centrate incoming solar radiation at a predetermined location spaced from said pool.

72. The device defined in claim 71 wherein said con tainer means includes: a substantially horizontal reflective surface; and a circular wall surrounding said reflective surface said wall and said reflective surface being contiguous with one another to define a shallow pool.

73. The device defined in claim 72 wherein said wav generating means includes: a plurality of electromechanical transducers in operative contact with said wall, said transducers being spaced from one another along said wall; and control means operatively connected to said trans¬ ducers for periodically energizing said transducers to gener¬ ate said standing wave in said fluidic substance.

74. A device for concentrating solar energy, com¬ prising: a substantially horizontal surface; a circular wall surrounding said surface, said wall and said surface being contiguous with one another to define shallow pool; a homogenous fluidic substance disposed in said pool; a plurality of electromechanical transducers in operative contact with said wall, said transducers being spaced from one another along said wall; and control means operatively connected to said trans¬ ducers for periodically energizing said transducers to gener¬ ate a standing wave in said fluidic substance of a predetermined characteristic shape, whereby incoming solar radiation is concentrated by said pool and said fluidic sub¬ stance at a predetermined location spaced from said pool.

75. The device defined in claim 74 wherein said fluidic substance has a high index of refraction.

76. The device defined in claim 75 wherein said fluidic substance is taken from the group consisting of glycol, oil and a gel.

77. The device defined in claim 74 wherein said transducers include piezoelectric crystals.

78. The device defined in claim 74, further compris ing means disposed above said pool for isolating said fluidic substance from wind and weather effects.

79. The device defined in claim 74 wherein said standing wave is characterized by a function taken from the group consisting of a Bessel function, a modified Bessel func tion, a Hankel function, and a modified Hankel function.

80. The device defined in claim 74 wherein said sur face is a reflective surface.

81. A device for concentrating solar energy, com¬ prising: a reflective film; means for supporting said film in a substantially planar configuration; and mechanical wave generating means connected to said film for generating a standing wave in said film of a predetermined characteristic shape able to concentrate incom¬ ing solar radiation at a predetermined location spaced from said film.

82. The device defined in claim 81 wherein said wave generating means includes: a plurality of electromechanical transducers in operative contact with said film, said transducers being spaced from one another along said film; and control means operatively connected to said trans¬ ducers for periodically energizing said transducers to gener¬ ate said standing wave in said film.

83. A method for concentrating solar energy, com¬ prising the steps of: providing a reflective film; supporting said film in a substantially planar con¬ figuration; and generating a standing wave in said film of a predetermined characteristic shape able to concentrate incom¬ ing solar radiation at a predetermined location spaced from said film.

84. The method defined in claim 83 wherein said ste of generating includes the steps of: providing a plurality of electromechanical trans¬ ducers in operative contact with said film, said transducers being spaced from one another along said film; and periodically energizing said transducers to generate said standing wave in said film.

85. A solar energy concentrator assembly comprising: solar concentrator means including an optical ele¬ ment for concentrating a substantial amount of incoming solar radiation; wing means connected to said solar concentrator means for providing aerodynamic lift to said solar con¬ centrator means, to thereby maintain said solar concentrator means a predetermined distance above the surface of the earth; propulsion means connected to said solar con¬ centrator means for propelling said wing means through the atmosphere to generate aerodynamic lift due to differential air along past surfaces of said wing means; power plant means operatively connected to said propulsion means for supplying power to said propulsion means; and solar collection means mounted to said solar con- centrator means and operatively connected to said power plant means for energizing same in response to solar radiation received by said solar collection means.

86. The assembly defined in claim 85 wherein said concentrator means includes a sheet of flexible polymeric material with a perimetric region, said optical element being mounted to or integral with said sheet, said wing means including a plurality of different wings spaced from one another about said perimetric region.

87. The assembly defined in claim 86 wherein said propulsion means includes a plurality of different motors also spaced from one another about said perimetric region.

88. The assembly defined in claim 85, further com¬ prising control means operatively connected to said propulsion means for operating said propulsion means to change a disposi¬ tion of said solar concentrator means in the atmosphere.

89. The assembly defined in claim 88, further com¬ prising sensor means operatively connected to said control means for providing said control means with feedback as to solar energy concentration by said solar concentrator means, whereby said control means operates said propulsion means to change a disposition of said solar concentrator means in the atmosphere to attain a predetermined level of solar concentra¬ tion by said concentrator means.

90. The assembly defined in claim 85 wherein said optical element is a lens.

91. The assembly defined in claim 85 wherein said optical element is a Fresnel lens.

92. The assembly defined in claim 85 wherein said optical element is carried on a flexible polymeric sheet.

93. The assembly defined in claim 85 wherein said propulsion means includes a propeller and an electric motor, and wherein said power plant means includes an electrical storage unit.

94. A method for concentrating solar energy, com¬ prising the steps of: providing an optical element capable of concentrat¬ ing a substantial amount of solar radiation; attaching a plurality of air transport devices to said optical element at spaced positions; operating said air transport devices to maintain said optical element at a predetermined position and orienta¬ tion above the earth's surface; and modifying the distribution of solar radiation pass¬ ing through said optical element to thereby concentrate the solar radiation at a predetermined location.

95. The method defined in claim 94 wherein said ste of operating includes the steps of: sensing efficacy of solar energy concentration at a predetermined location by said optical element; in response to said step of sensing, generating con trol signals for modifying operation of said air transport devices; and transmitting said control signals to said air transport devices.

96. The method defined in claim 94 wherein said air transport devices include wing means connected to said optica element for providing aerodynamic lift to said optical ele¬ ment, propulsion means connected to said optical element, sai step of operating including the step of propelling said wing means through the atmosphere to generate aerodynamic lift due to differential air flow past surfaces of said wing means.

97. The method defined in claim 94 wherein said air transport devices include balloons, said step of operating including the step of changing effective amounts of a lighter than-air gas inside said balloons.

98. The method defined in claim 94, further compris ing the steps of collecting solar energy at said optical ele¬ ment and using the collected solar energy to operate said air transport devices.