Patent Publication Number: US-2010116266-A1

Title: Solar Energy Collecting Apparatus

Description:
TECHNICAL FIELD 
     The presently disclosed invention relates most generally to solar energy collecting devices and apparatus. More particularly, the present invention relates to a solar energy collecting arrangement, which employs a plurality of focusing elements that are paired up with properly spaced and aligned concave collectors. Each focusing element and concave collector is fixed within a stationary support structure, for enabling a focusing of solar energy upon each concave collector for a temporal interval lasting at least a number of hours. 
     BACKGROUND 
     As the concerns of global climate change and global warming continue to mount, a clear necessity has arisen to develop and deploy renewable, affordable, and clean alternate energy sources including those based on hydro, geothermal, wind, solar energy, etc. This background section provides a concise general introduction to selected and relevant prior art, and introduces motivations for a plurality of the features of the presently taught and claimed invention. The art discussed herein is not to be considered admitted prior art, and is presented as a starting point to attempt to more clearly discuss and describe important features and structures of the solar energy collecting apparatus of the present invention. 
     There are a number of prior art teachings wherein solar energy is collected using a variety of structures. A first and well known approach employs what are termed solar collectors, which convert the solar-light energy into electricity or alternately to heat a fluid that is passed through the collectors. Although each type is popular, there are clear limitations to these collectors. First the collectors are far more efficient when facing substantially directly at the Sun. However, the position of the Sun varies with a number of known parameters, such as with the time of day and the time of year. When these types of collectors are mounted using fixed structures, the efficiency and associated duty cycle are clearly not at a maximum for large intervals of daylight hours. 
     Due to the limitations of fixed mounted collectors, the prior art contains many examples of “tracking structures”. Tracking structures are generally electro-mechanical approaches employed to keep the solar collectors of an apparatus substantially directly facing the Sun for as many hours a day, and as many days of the year, as possible. These systems are quite expensive, requiring hinged and pivoting structures along with motors and suitable control systems for sensing and tracking activities. Their cost of ownership is quite high. 
     Yet another group of prior art teachings attempts to simplify these tracking structures, and in some cases additionally centralize the collecting member(s) of these systems, by employing designs that provide for a tracking of many many mirrors to direct light to one or more centralized ‘solar receivers’. However, these latter teachings still suffer from a number of issues and limitations. For example, they still require complex and costly sensing and or tracking mechanisms, and additionally require considerable acreage for large scale deployment. Mirrored approaches also require a nearly constant cleaning and upkeep. 
     Another approach that is known in the art for collecting solar energy is to employ optical lenses to focus a light source to create a concentrated ‘hot spot’. The well known magnifying glass, with its simple convex lens, has been long used for this purpose—on a clearly very small scale. However, larger versions of such lenses are quite heavy and expensive when scaled up for use in power generation. In addition, such arrangements again require sensing/tracking means for realistic operation over a reasonable number of daylight hours. 
     Accordingly, what is most desirable in a solar collecting means is a structure and approach that uses fixed or non-tracking structures that are able to be utilized so as to provide reasonable energy collection over a large number of hours a day, and for a large number of days a year. The most preferable approaches would use affordable and scalable methods and structures, requiring minimal maintenance and upkeep. It would further be desirable to provide such a system and approach wherein large acreage is also not required. A number of other characteristics, advantages, and or associated novel features of the present invention, will become clear from the description and figures provided herein. Attention is called to the fact, however, that the drawings are illustrative only. In particular, the embodiments included and described, have been chosen in order to best explain the principles, features, and characteristics of the invention, and its practical application, to thereby enable skilled persons to best utilize the invention and a wide variety of embodiments providable that are based on these principles, features, and characteristics. Accordingly, all equivalent variations possible are contemplated as being part of the invention, limited only by the scope of the appended claims. 
     SUMMARY OF PREFERRED EMBODIMENTS 
     In accordance with the present invention, a solar energy collecting structure includes a focusing element supported and fixed in spaced relationship to, and axially aligned with an (associated) solar energy concave collector. This solar energy collecting structure, which may also be termed a ‘focusing-collecting pair’ or ‘focusing and collecting pair’, functions to enable solar energy incident upon the focusing element to be efficiently focused and collected (upon a collecting black or transparent surface of the concave collector). Importantly, the focusing-collecting pair is specifically structured to enable solar energy to be collected over a temporal interval. Accordingly, each focusing-collecting pair represents a fixed, low cost, and low maintenance structure enabling solar energy to be collected over a temporal interval (e.g., hours) without the need for moving and tracking mechanisms. The collected (solar) heat energy may be stored for later use as a heat source, and or the heat energy may be used immediately as a heat input to any suitable heat powered mechanism. This fixed position solar energy collecting structure, preferably including at least one focusing element and one concave collector, will enable solar energy to be collected over a temporal interval of approximately 3 to 6 hours, at minimum. In addition, based on the structure of the included concave collector, the concave surface of the collector may be provided as a concave black surface for directly receiving and collecting solar light energy. Alternately the concave surface or the collector may be provided by a transparent receiving surface, for receiving and transmitting focused solar energy for subsequent collecting and storage/use. 
     Further, in order to support a collecting of an increased amount of solar energy, over longer duration temporal intervals (e.g., most of the daylight hours of a typical sunny day), a plurality of the solar energy collecting structures may be provided in tightly packed configurations wherein a plurality of focusing-collecting pairs are placed side-by-side, with an exterior/outer surface of each of the focusing elements closely spaced and collectively forming a significant portion of the area of a curved (outer) surface of a solar energy collecting apparatus. One contemplated preferred embodiment of the solar energy collecting apparatus of the invention may provide a transparent curved surface formed substantially of focusing elements, most preferably fixed in a spherical or dome shaped configuration, wherein 80 to 90% of the curved surface is provided by an outer surface of the focusing elements. It may be noted that the focusing elements may be planar and substantially flattened (as illustrated), or may be more sphere-like in shape (not explicitly shown). When the focusing elements are planar the curved (outer) surface will be relatively flat. When the focusing elements are provided as spheres or balls, the curved surface may be much more textured and possibly described as ‘bumpy’ or nodulous in nature. 
     To properly support and fix the plurality of focusing elements, the apparatus may include a support structure having a framework establishing the curved surface. Preferably the curved surface includes a plurality of tightly packed openings, into which the focusing elements are supported and fixed. For example, an exemplary focusing element may be provided by, or include, a simple monolithic Fresnel lens. Alternately, other suitable focusing elements may be employed. Importantly, each focusing element, or cluster of focusing elements, would preferably be supported and fixed so as to substantially fill a respective opening of the support structure, and thereby provide a significant portion of the outer surface area of the curved surface of the solar energy collecting apparatus. Specifically, a most preferred solar energy collecting apparatus would provide a curved outer surface wherein at least 80 to 90 percent of the area of the curved surface is provided by a surface of the focusing element material or a clear transparent surface of a cover installed over the focusing elements. 
     Returning to the focusing elements, each included focusing element is capable of focusing useful incident solar energy at a pre-selected fixed focal length for a determinable temporal interval during daylight hours. Importantly, preferred focusing elements, such as Fresnel lenses, will enable focused light to be captured along a curved arc or surface, over a number of hours. This aspect of the invention, which will be discussed in greater detail when referring to  FIGS. 4A through 4C , results in a need for a concave collector to be provided having a curved concave receiving surface, with this surface positioned in spaced relationship to, and axially aligned with, the focusing element. The possibly most preferred concave collectors will be configured having a surface with a concave curvature that is determined by (or matched to) the focusing element employed. Further, when a plurality of solar energy concave collectors are employed and positioned in one-to-one aligned and spaced relationship to a corresponding plurality of focusing elements—at a distance equal to the focal length—then the solar energy receiving surface of each concave collector enables focused solar energy to be received over a determinable temporal interval. 
     Accordingly, when considering the dome or spherical shaped solar energy collecting apparatus of the invention, a group of tightly packed and adjacent solar energy collecting structures (e.g., focusing-collecting pairs) will actively enable the collecting of energy over an interval of hours each day, while other groups located upon other portions of the curved surface of the collecting apparatus, will be actively collecting solar energy over another group of hours. As such, a properly curved surface which includes a plurality of closely spaced focusing elements that will be facing the Sun during differing hours of the day, will provide an extended temporal interval during which solar energy may be received and collected. 
     Yet another aspect of the preferred embodiments of the invention calls for the inclusion of one or more thermal coupling structures. Included thermal coupling structures enable a thermal coupling of each concave collector in order to transfer received and collected solar energy to a heat producing output of the invention. Heat energy delivered to the output of the solar energy collecting apparatus may be employed for at least one of: 
     a) a storing of the collected solar (heat) energy; and 
     b) a using of the collected energy as a heat source for powering a variety heat-powered items and mechanisms. 
     Several preferred thermal coupling structures will be discussed hereinafter. However, the present invention may be employed with many suitable and varied thermal coupling structures, which may be utilized with a variety of energy storage arrangements and or heat powered mechanisms. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like elements are assigned like reference numerals. The drawings are not necessarily to scale, with the emphasis instead placed upon the principles and features of the present invention. Additionally, each of the embodiments depicted are but one of a number of possible arrangements utilizing the fundamental components and concepts of the present invention. The drawings are briefly described as follows: 
         FIGS. 1A and 1B  provide illustrations of well known prior art Fresnel lens constructions, which function by taking a point source light source (e.g. an oil lamp or incandescent lamp) and directed light therefrom for forming a parallel beam of much more concentrated light. 
         FIGS. 2A ,  2 B, and  2 C depict how the curvature of a basic single convex lens ( FIG. 2A ) can be reduced ( FIG. 2B ) to discrete lens portions, to yield an equivalent Fresnel lens ( FIG. 2C ), which clearly has a significantly reduced mass and weight. 
         FIG. 3A  illustrates a traditional light ray diagram for a Fresnel lens showing how the light rays of a point source are redirected in order to produce a powerful and concentrated beam of light. 
         FIG. 3B  illustrates the use of a focusing element of the invention, depicted as a conventional multi-prism Fresnel lens, wherein substantially parallel light rays of incident (incoming) solar light energy are focused at a pre-determined and focal point for providing concentrated and collectable solar energy. 
         FIGS. 4A ,  4 B, and  4 C depict a representative solar energy collecting structure of the invention, which as shown enables focused solar energy to be efficiently collected over a temporal interval that may be as long as a number of hours, by employing a concave collector having a concave solar energy receiving and or collecting surface. 
         FIG. 5A  is a simplified and somewhat conceptual depiction of a first embodiment of a solar energy collecting structure including a concave collector structure that is thermally coupled to a heat energy conduction mechanism, for coupling the collected heat energy to a selected device, apparatus, or sub-system. 
         FIG. 5B  is a simplified and somewhat conceptual depiction of a second embodiment of a solar energy collecting structure including an alternate concave collector structure wherein an optical material receives and accepts focused solar energy and optically transmits and thermally couples the energy into a heat energy conduction mechanism. 
         FIG. 6A  provides a conceptual and simplified embodiment of a portion of a fixed solar energy collecting apparatus in accordance with the invention that will collect solar energy over a pre-determined and extended temporal interval. 
         FIG. 6B  provides a conceptual and simplified depiction of another embodiment of a portion of a fixed solar energy collecting apparatus, which employs an optical concave collector structure. 
         FIGS. 7 and 8  provide high level block-type diagrams of several possible embodiments of fixed structure solar energy collecting apparatus of the invention. 
         FIG. 9  depicts a partial solar energy collecting dome wherein a fixed curved surface includes a plurality of solar energy collecting structures, enabling solar energy to be collected over a larger or expanded temporal interval (e.g., 12 hours) when compared to a single solar energy collecting structure (e.g., a focusing-collecting pair). 
         FIGS. 10A , and  10 B provide detailed examples of several curved outer surfaces formed of a preferably minimal framework of coupled elongated members, establishing a plurality of openings having selected geometric shapes configured for (as illustrated) supporting and fixing a focusing element therein. 
         FIG. 11  illustrates a more detailed first embodiment of a dome shaped surface including a plurality of focusing elements, with a sub-structure supporting a corresponding plurality of concave collectors. 
         FIGS. 12 and 13  depict solar energy collecting dome arrangements, which are consistent with the embodiment of  FIG. 11 , but further adding a vent that may function as an exhaust vent in such embodiments. 
         FIG. 14  depicts an alternate solar energy collecting dome apparatus wherein a fixed curved outer surface includes a plurality of solar energy focusing elements supported by a support structure, with a plurality of corresponding concave collectors each individually supported by a thermal conduction stem, which both supports the concave collector at the appropriate distance below the corresponding focusing element while also transferring collected solar energy to another structure coupled to a second end of each respective stem (not explicitly shown). 
     
    
    
     PARTIAL LIST OF REFERENCE NUMERALS 
       20 , 20 - 1 , . . . —solar energy collecting apparatus 
       24 —solar energy collecting structure 
       30 —focusing element 
       30   a —bulls-eye lens (of  30 ) 
       30   b —(prism) ring lens (of  30 ) 
       40 —(solar energy) concave collector 
       40   a —solar energy receiving surface (of  40 ) 
       40 - 1 —optical concave collector 
       40 - 1   a —(optical) solar energy receiving surface 
       44 —stem 
       48 —thermal coupler 
       52 —fluid conduit 
       54 —heat transfer fluid 
       60 —support structure 
       60   a —elongated member (of  60 ) 
       62 —solar energy collecting dome 
       64 —curved surface (of  62 ) 
       66 —opening 
       70 —heat energy conductor 
       70   a —steel portion 
       70   b —copper portion 
       72 —thermal coupling 
       78 —heat accepting (utilizing) portion 
       80 —vent 
       80   a —top opening (of  80 ) 
       86 —building 
       90 —roof 
       100 —light source 
       102   a —reflected and refracted light ray 
       102   b —refracted light ray 
       104 —directed light beam 
       108 —focal plane 
       110 —focal length 
       112 —reference plane 
       120 —Fresnel lens assembly (prior art) 
       130 —Fresnel lens (prior art) 
       130   a —bulls-eye lens (of  130 ) 
       130   b —prism ring lens (partial or full) 
       140 —convex lens 
       140   a —bulls-eye lens portion (of  140 ) 
       140   b —prism ring portion (or  140 ) 
       142 —curved surface (of  140 ) 
       200 —concentrated solar energy 
       204 —directed incident solar light rays 
       204   a —reflected and refracted solar rays 
       204   b —refracted solar rays 
     F 1 ,F 2 ,F 3 —(respective) focusing elements 
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     It is important to establish the definition of a number of descriptive terms and expressions that will be used throughout this disclosure. The term ‘temporal interval’ will be employed to indicate a period of the daylight hours. For example, a common temporal interval will be approximately in the range of 3 to 6 hours for each focusing-collecting pair. As will be discussed, the actual temporal interval over which useful amounts of solar energy may be focused and collected can vary with the specific structure and configuration of the respective embodiment, as well as items such as the latitude and or the general location of the embodiment, the season of the year, prevailing weather cycles, etc. The terms ‘significant portion’, ‘significant area’, and the like, when employed for discussing the area of solar energy focusing surfaces, formed substantially of a plurality of focusing elements, relative to the total area of the curved surface. It may be assumed that a significant area of a curved (outer) surface may certainly be provided by, or associated with, the plurality of focusing elements. For example, typically at least 80 to 90 percent of the total area of a such a curved surface will be associated with the focusing elements (or included clear or possibly tinted optical covers). The terms ‘curved surface’, ‘curved outer surface’, and equivalents, may be assumed to indicate that the overall outer surface of the solar energy collecting apparatus is curved, and most preferably configured having a dome or spherical shape. It should be understood that an invention providing a curved surface having the shape of a dome or sphere may certainly include only a portion, section, and or slice, of the dome or sphere. 
     Continuing, the term ‘substantially’ will be employed as a modifier to indicate either exactly or quite close to the given feature, structure, or characteristic. For example, the phrase ‘substantially dome shaped’ may indicate that the portion of a curved surface of the invention is exactly spherically shaped or close to spherically shaped, with say one dimension (e.g., width) greater than a second dimension (e.g., the depth) by up to ±5 to 10 percent. In like fashion, the terms ‘substantially orthogonal’, ‘substantially orthogonally oriented’, etc., can be assumed to mean that the members may be exactly fixed or rigidly coupled to each other at a true 90 degree angle, or alternately somewhat close to 90 degrees. As such, substantially orthogonal members may actually be up to ±5 to 10 degrees or so from a truly orthogonal arrangement, and still be correctly termed substantially orthogonal. Importantly, the terms ‘coupler’, ‘coupled to’, ‘coupling’, etc., are to be understood to mean that two or more described items are either directly connected together, or alternately, connected to each other via one or more additional, possibly implied or inherent structures or components. When considering the thermal coupling structures compatible with the invention, a heat providing output of each concave collector may be provided that is ‘thermally coupled’ to other heat transferring elements, where various thermally conductive components may be needed, such as elongated heat conductive conduits, heat transfer fluid, thermal junction conducting grease or pads, and any required fasteners and or mechanical holding means. Further, these thermal conductive means may not be explicitly illustrated and discussed in any significant detail—as these items are well understood by skilled persons. Other important terms and definitions will be provided, as they are needed, to properly define the present invention and its associated novel characteristics and features. In addition, the terms and expressions employed herein have been selected in an attempt to provide a full and complete description of the invention. These terms may very well have equivalents known to skilled individuals, which may be long established in the art. As such, the terminology employed has been carefully chosen and is intended for illustration and completeness of description, and may very well have equivalents that are known in the art, but not employed here. 
     Referring now to the drawings,  FIGS. 1A and 1B  provide depictions of well known prior art Fresnel lens assemblies  120 . The specific Fresnel lens assemblies  120  illustrated are typical of complex lens constructions used for many decades in maritime lighthouses. These assemblies actually included a number of Fresnel lenses  130  in each assembly  120 . These types of Fresnel lenses functioned by taking a point source light source (e.g. a candle or an oil lamp in the very early years) and directing the light from the light source for forming a powerful, directed, and greatly concentrated beam of light. 
     One important aspect of each Fresnel lens  130  of the assembly  120 , as clearly shown in  FIGS. 1A and 1B , calls for each included Fresnel lens to be formed of a number of discrete portions. For example, if one considers the convex lens of  FIG. 2A , say having a diameter of 1 meter, the lens will have a very significant weight. However, as discovered by the French scientist Augustin Fresnel, it is actually the curved portions  140   a,    140   b,  . . . , that provide for the focusing and needed light ray re-direction. As such, the hashed area  138  of  FIG. 2B , may be omitted and the remaining portions, including  140   a,    140   b,  etc., can be provided as a substantially planar or flattened (Fresnel) lens  130 —while still mimicking the function of the original convex  140 . That is, by design a Fresnel lens reduces the amount of material required (and associated weight) when compared to a conventional spherical lens by breaking the lens into a set of concentric annular sections known as Fresnel zones. In the early (and largest) variations of these lenses, each of these zones was a different prism. Though a lens might look like a single piece of glass, a closer examination typically reveals that the lens is actually many smaller separate pieces. As technology advanced, it became possible to turn out large and complex Fresnel lenses that were formed essentially of a single monolithic piece of glass, plastic, quartz, etc. It must be noted that a reduced material/weight Fresnel lens is an ideal low cost lens that is usable for focusing light for non-imaging purposes. 
     As shown in  FIG. 3A , a typical Fresnel lens  130  may actually be constructed of a plurality of separate sections, or alternately formed of a single monolithic material and or construction (as depicted in  FIGS. 4A through 7 ). Importantly, a portion of the divergent light rays of  FIG. 3A , including light rays  102   a,    102   b,  ect., that are emitted from the light source  100 , are re-directed (via reflection and or refraction) to yield a directed light beam  104 , which is now concentrated and directed to travel substantially parallel to the focal plane  108 . In contrast, and as clearly illustrated in FIG.  3 B, this arrangement may be reversed. That is, the use of a focusing element of the invention, preferably in the form of a Fresnel lens  130 , enables substantially parallel incoming solar light rays of incident solar energy to be focused to converge at a known and or pre-determined focal length  110 —providing notable concentrated solar energy at the focal point. It may be noted that the terms focal length and focal point are often considered equivalents. Importantly, in the case of the present invention, a known fixed focal length of a focusing element (such as Fresnel lens  130 ) will determine the location to position an associated concave collector that must be positioned in an appropriate spaced relationship to, and with a suitable (in-line) axial alignment with, at least one focusing element. 
     Turning now to  FIGS. 4A ,  4 B, and  4 C, a helpful depiction of how the solar energy collecting structure  24  of the invention, which is somewhat conceptually illustrated, enables focused incident solar energy to be efficiently collected over a temporal interval that may be as long as several hours or more. As shown in  FIG. 4A , if a focusing element  30 , here depicted as a Fresnel lens, focuses a light source (e.g., the Sun) that is below the normal focal plane  108 , then the focused solar energy will be rotated upwardly and will not be focused upon the reference plane  112 . Accordingly, a curved and concave receiving surface will be required if solar energy is to be continually focused upon a collecting surface, such as the solar energy receiving surface  40   a  of a concave collector  40 . 
     As illustrated in  FIGS. 4A through 4C , each concave collector  40  may be supported and fixed in spaced relationship to, and axially aligned with, a focusing element  30 , at a distance equal to the pre-selected or known focal length of the focusing element  30 . The axial alignment is most preferably as depicted, with the focal plane  108  of the focusing element aligned with an orthogonal projection from the bottom of (e.g., deepest point within) the concave receiving surface of the concave collector  40 . When axially aligned at a distance equal to the focal length, it is then possible to focus incident solar energy upon the solar energy receiving surface  40   a  of a concave collector  40  over an entire temporal interval of typically at least 3 to 6 hours. For the example depicted in  FIGS. 4A ,  4 B, and  4 C, the temporal interval would be approximately 2 hours, starting at 8 AM ( FIG. 4A ) and continuing until about 10 AM ( FIG. 4C ). However, it must be noted that the actual temporal interval can and will vary with many factors. These factors include the type of focusing element employed, the depth/size of the concave receiving surface  40   a,  the latitude of a location at which the solar energy collecting structure  24  is located, the season of the year, and or other considerations such as man-made and or natural obstacles. 
     Returning briefly to  FIGS. 4A through 4C , it must be understood that the focusing elements  30  depicted as substantially flattened Fresnel lenses may be provided by other possibly more complicated and or 3-dimensional structures. For example, the focusing elements  30  may include a lens element that is much more spherical in shape (not explicitly illustrated). As appreciated by skilled individuals, such non-planar focusing element embodiments would certainly be much heavier and would most likely need to be constructed using advanced light weight materials. In addition, the focusing elements  30  may include structures to control the intensity of the solar energy reaching each concave collector  40 . For example, one simple approach may be to employ tinted filters over a plurality of the focusing elements. Alternately, a more complex solution may include a distance controlling mechanism for varying the distance between a focusing lens of the focusing element  30  and the collecting surface  40   a  of a concave collector  40 . That is, if a concave collector begins to reach a maximum desired temperature, the focusing element may be de-focused by adjusting the distance between an included focusing member and the concave collector, as required, to reduce the solar energy being collected. This mechanical arrangement would not, in any way, provide for tracking and following the position of the sun in the sky—which is not required with the present invention. 
     To better understand the range and variety of the structural embodiments of the concave collectors  40  that may be employed, attention will now be turned to  FIGS. 5A through 6B . As illustrated in  FIG. 5A , a first basic embodiment of a basic concave collector  40  is depicted in a simplified and high level cross sectional diagram. As shown, this first embodiment is provided as a portion of a solar energy collecting structure  24  including a focusing element  30  and the concave collector  40 . The embodiment of the concave collector  40  as depicted has a first portion  42   a,  which may preferably be provided by a high melting point material such as steel, and a second portion  42   b,  which is preferably provided by a low melting point material such as copper. The first portion  42   a  and the second portion  42   b  may be thermally joined by employing a thermal coupler  48 , such as thermal grease or thermal pads. Accordingly, this preferred concave collector  40  may be provided by a steel-over-copper construction. 
     As shown in  FIGS. 5A and 5B , an important feature of the concave collector  40  is the inclusion of the required concave solar energy receiving surface  40   a.  As discussed when referring to  FIGS. 4A through 4C , this concave receiving surface is a necessity so that the concave collector  40  may receive focused solar light energy over an entire temporal interval. Also, the positioning of the concave collector  40  in proper axial alignment, with a proper spacing relationship that is directly related to the fixed focal length of the employed focusing element  30 . Specifically, as shown in the figures including  FIGS. 5A and 5B , the focal plane  108  of the focusing element  30  may be preferably arranged to be axially aligned (along the focal plane  108 ) and substantially orthogonal to the deepest portion of the concave receiving surface  40   a —and clearly fixed at a distance therefrom that is equivalent to the focal length of the focusing element  30 . As discussed hereinabove, this arrangement enables incident solar energy to be focused, received, and or collected for a temporal interval of at least 6 hours or so. 
     Returning to  FIGS. 5A and 5B , one simple approach for transferring heat energy that is collected by a solar energy collecting structure  24  of the invention is depicted. As shown, this exemplary approach involves transferring heat energy from a receiving location proximate to the solar energy receiving surface  40   a  using fluid conduits  52 , and a flow of heat transfer fluid therethrough. As understood by skilled individuals, the inclusion of one or more cooling conduits  52  enables a preferably closed heat transfer system to be employed wherein a volume of a heat transfer fluid  54  is employed for causing a transferring of collected (solar) heat energy away from the concave collector  40 . An included thermal coupling structure, such as a fluid based closed system, will enable a thermal coupling to, and transferring of, collected heat energy to a heat input of a heat powered device to be energized (using collected heat). For example, the collected heat energy may be immediately coupled to a turbine, a heat difference fuel cell, a Rankine Cycle engine, a sterling engine, a steam engine, etc. 
     Alternately the transferred heat energy may be stored for later use. For example, to store collected heat energy at least one of the following may be employed: 
     a) a high mass insulated storage tank filled with a suitable fluid, may be heated during daylight hours, and used later for heating purposes; 
     b) a plurality of dense heat retention thermal bricks; or 
     c) a molten phase change based system. 
     Returning now to  FIG. 5B , a simplified and somewhat conceptual depiction of a second embodiment of a solar energy collecting structure  24 - 1  includes an alternate optical concave collector  40 - 1  wherein an optical receiving of the focused solar energy causes an optical transmitting of the solar energy from a solar energy receiving surface  40 - 1   a  to a second location for collection. For example, as shown the second location may be a second surface  40 - 1   b  of the optical concave collector  40 - 1 , which may include a collection junction for thermally collecting the received solar (light) energy. That is solar light energy is focused upon the solar energy receiving surface  40 - 1   a  by a focusing element  30 , causing the solar energy to enter an optically transmissive material (glass, sapphire, etc.), causing optical solar energy to be transmitted (or transferred) to a second end  40 - 1   b,  where the solar (light) energy is collected and converted into heat energy. It may be noted that the concave collectors  40  and  40 - 1  may be provided having proportions and scaling that is quite different then the conceptual exemplary representations of  FIGS. 5A through 6B . 
     Turning now to  FIG. 6A , a conceptual representation of a first embodiment of a portion of a fixed structure solar energy collecting apparatus  20 - 1  is depicted. This simple embodiment employs a support structure  60 , along with elongated members  60   a,  for forming a plurality of openings into which focusing elements  30  are supported and fixed. As shown, the focusing elements  30 , along with corresponding concave collectors  40 , provide three focusing-collecting pairs, which are angled in 45 degree steps from one to the next. That is, there is a 45 degree rotation from focusing element F 1  to focusing element F 2 , and another 45 degree rotation from focusing element F 2  to focusing element F 3  This arrangement will enable solar energy to be received and collected over an extended temporal interval, say in the range of 6 to 8 hours. 
     The embodiment of the solar energy collecting apparatus  20 - 1  of  FIG. 6A  depicts an arrangement wherein concave collectors  40  are formed (having a spherical curvature) within a structure that may be termed a heat energy conductor  70 , which may be considered to include a thermal coupling structure for aiding in transferring and delivering collected solar heat energy. As shown, the heat energy conductor  70  depicted in  FIG. 6A  includes a first steel (layer) portion  70   a,  into which the concave collectors  40  and a solar energy receiving surfaces  40   a  thereof are formed. As such, the steel portion  70   a  is provided by what may be termed a ‘high melting point material’ (HMPM), while a copper portion  70   b  is provided as a ‘low melting point material’ (LMPM). It may also be helpful to provide concave surface  40   a  as a black colored surface. This structure enables the solar energy focused by the focusing elements  30  to be received and collected, which may involve handling localized temperatures (at the focal point) in the range of substantially 100 degrees to 1600 degrees centigrade, or so. 
     Returning to  FIG. 6A , a concise description of the operation of the solar energy collecting apparatus  20 - 1  will be provided. The same basic principles of operation will also be consistent with the operation of the embodiments of  FIGS. 6B through 14 . For the depiction of  FIG. 6A  it may be noted that North is up, East is to the right, etc. Accordingly, early in the day, the Sun will rise in the East (on the right side of  FIG. 6A ), and move in a counter clockwise (CCW) direction. Initially, as at 6 AM, the first focusing-collecting pair including focusing element F 1  and the axially aligned and spaced concave collector  40 , will be actively focusing, receiving, and collecting solar energy. In addition, a second focusing-collecting pair (with F 2 ) will also be focusing, receiving, and collecting solar energy. However, at 6 AM in the morning the third focusing-collecting pair (with F 3 ) is not actively receiving solar energy. As the day progresses, the Sun will rise. At 9 AM all three focusing-collecting pairs depicted in  FIG. 6A  will be actively focusing, receiving, and collecting solar energy. 
     An alternate manner in which to analyze the solar energy collecting capabilities of the embodiment of  FIGS. 6A and 6B , and equivalent arrangements that employ a plurality of focusing-collecting pairs, is to consider the temporal intervals over which each focusing-collecting pair will be actively collecting solar energy. When considering the F 1  focusing-collecting pair, as depicted, solar energy would be actively collected during an interval starting from approximately sunrise and continue until about 9 AM—at which point the angle of the Sun will soon no longer permit the focusing element F 1  to focus solar energy upon the concave receiving surface  40   a  of concave collector  40 . For the F 2  focusing-collecting pair, an active interval (as depicted) would be from about 6 AM until about Noon. And for the F 3  focusing-collecting pair the active temporal interval would be from about 9 AM until about 3 PM. 
     As a skilled individual would appreciate, the more focusing-collecting pairs that are included, especially when preferably tightly spaced so as to substantially form a (convex) curved spherical surface, the more solar energy the apparatus of the invention can collect per unit time. A further discussion of this practical implementation aspect of the present invention will be provided when discussing  FIGS. 9 ,  10 A, and  10 B. 
     Turning now to  FIG. 6B , another embodiment of a solar energy collecting apparatus  20 - 2  provides the same arrangement of support structure  60 / 60   a  and spaced focusing elements  30  as was found in the embodiment of  FIG. 6A . However, in  FIG. 6B  a modified heat energy conductor  70 - 1  now employs a optical concave collector  40 - 1  which is arranged with a transparent concave surface  40 - 1   a  for receiving solar energy focused upon the surface  40 - 1   a.  The received solar (light) energy will be optically received causing an optical transmitting of the received solar energy to a second end  40 - 1   b  of the concave collector  40 - 1 . As depicted, at the second end  40 - 1   b  the solar (light) energy may be converted to heat energy effecting a heating of portion  70   a,  which may best be provided as a high melting point material (HMPM) for aiding in collecting and transferring the heat energy for storage and or immediate use. It may be noted that the body of the optical concave collector  40 - 1  may be constructed using any suitable optical transmission material including at least one of sapphire, quartz, ruby, high temperature glass, etc. Importantly, the actual material employed for an optical concave collector  40 - 1  may actually depend on the respective embodiment in which the concave collector  40 - 1  is employed and factors such as the latitude of the installation, the rate at which solar (heat) energy is transferred and or utilized, the size and quality of the focusing elements employed, etc. 
     Turning now to  FIGS. 7 and 8 , two high level block-type diagrams of several other embodiments of fixed structure solar energy collecting apparatus of the invention will be discussed. As can be seen in  FIG. 7 , a plurality of tightly packed/spaced focusing-collecting pairs are provided. Each focusing-collecting pair includes a focusing element  30  which is axially aligned and supported/fixed in spaced relationship to a concave collector  40 . As discussed when referring to  FIG. 6A , the concave collectors  40  may be formed (e.g., cast) within a high melting point material (HMPM), which may be realized as a first steel portion  70   a.  The steel portion  70   a  is again a first HMPM layer that covers a second LMPM layer, depicted as a copper portion  70   b.  A thermal coupling  72  may be provided between the steel portion  70   a  and the copper portion  70   b,  as required. 
     Importantly, as indicated in  FIG. 7 , the simplified focusing-collecting pairs, with a focusing element  30  axially aligned and paired with a concave collector  40 , may be considered a ‘heat collection’ front end. As further illustrated, the heat collection front end may be coupled to additional heat transporting layers, such as the first (HTMP) steel portion  70   a  and or the second (LTMP) copper portion  70   b,  which may be considered at least a portion of a ‘heat delivery’ portion. As shown, a suitable thermal coupling arrangement, including thermal coupling  72  and heat energy conductor  70 , may be employed for coupling and delivering the collected solar energy to a heat accepting portion  78 . For example, if the collected solar energy is to be stored, the collected solar energy may be employed to increase the temperature of a heat storage mass, such as provided by a mass of high density thermal bricks. Alternately, the collected heat may be, at least in part, used immediately to power a heat-to-torque converting mechanism, such as a sterling engine. 
     Referring now to  FIG. 8 , a high level block diagram representation of a possibly most generalized solar energy collecting apparatus  20  includes a plurality of focusing-collecting pairs, with each including a focusing element  30 , a concave collector  40 , along with the required support structure  60 . The functions of the focusing element  30  and concave collector  40  are as discussed hereinabove. The support structure  60  may be employed for multiple purposes, including a supporting of the focusing elements within voids or openings of the support structure, while also possibly supporting each of the concave collectors—possibly with separate or discrete supporting structure portions. 
     It should be understood that the embodiment of  FIG. 8  may provide for the focusing-collecting pairs to be tightly packed, with juxtaposed (adjacent) focusing-collecting pairs oriented slightly off axis (say by 2 to 5 degrees) with other proximate focusing-collecting pairs. A depiction of one preferred embodiment of a solar energy collecting apparatus having a plurality of tightly packed focusing-collecting pairs, which is consistent with the high level representations of  FIGS. 7 and 8 , is provided in  FIG. 9 . As clearly shown in  FIG. 9 , an outer or exterior planar surface of the focusing elements  30  provides a substantial portion of a curved (outer) surface  64  of a solar energy collecting dome  62 . The dome  62  is shown installed upon a roof  90  of a building  86 , wherein the building may further include other items, which are not explicitly illustrated, such as energy transfer, energy storage, and or energy conversion means. It may be noted that the openings of  FIGS. 9 ,  10 A, and  10 B, may actually be spaced somewhat further apart, possibly with a heavier framework structure and thicker elongated members. The actual spacing of one focusing element from another, along the curved surface  64  may best be determined by the underlying structure and spacing of the plurality of concave collectors  40 , and the associated concave collector and thermal coupling structures employed therewith. 
     Returning briefly to  FIG. 8 , the solar energy collecting apparatus  20  may include a solar energy heat collection function or portion, as well as a heat energy transfer function or portion. In practice, such means will certainly be required, and have been depicted in  FIG. 8  as the heat energy conductor  70  and the heat accepting portion  78 . Contemplated ‘heat accepting portions’ will enable collected heat energy that is received from a heat energy conductor  70  via a thermal coupling  72  to be stored (for later use when needed) and or employed as a heat input source (for immediate use) to a variety of devices and systems that immediately use the available heat energy. 
     When considering the most efficient and practical embodiments of the present invention, a variety of preferred curved surfaces  64 , as depicted in  FIGS. 9 through 14  will now be discussed. When considering such embodiments of the solar energy collecting apparatus  20 , an included support structure  60  may include a plurality of coupled elongated members  60   a,  and or other pre-formed components (not illustrated) for forming a plurality of closely or tightly packed and non-overlapping voids or openings  66 . As depicted in  FIG. 9 , each of the openings  66  may be substantially filled by a focusing element  30 . For the depictions of  FIGS. 10A and 10B , the focusing elements  30  are provided as Fresnel lenses, which are substantially planar and form at least 80 to 90 percent of an exterior surface of the curved surface  64 . As discussed hereinabove, alternate lens structures of the focusing elements may be more ball or sphere-like in shape (not shown), causing the curved (outer) surface of the apparatus to have a much less flattened appearance. 
     Turning again to  FIGS. 10A and 10B , it should be noted that the openings  66  may be provided having any useful and efficient shape. For example, as shown the openings  66  of  FIG. 10A  are hexagonal in shape, while the openings  66  of  FIG. 10B  are substantially quadrilateral in shape. However, other shapes may be employed when forming the openings, including one or more of triangular, octagonal, honey-comb shaped, circular, etc. 
     Similarly, when considering preferred outer or overall exterior shapes employable with the embodiments of the solar energy collecting apparatus  20  of the invention, generally spherical, ball, dome, or other curved shapes and the associated curved outer surfaces, may be most preferred. These and other possible shapes are specifically employed to place and orient a plurality of proximate, preferably tightly packed focusing-collecting pairs to be able to actively receive and collect solar energy during most of the hours of a typical sunny day. However for one or more reasons, a full sphere or dome may not be needed, required, or practical. As such, other curved shapes such as a partial dome, a partial hemispherical shape, or a section/slice of a sphere or hemisphere may be most preferable. In addition, although preferred smooth curved surfaces are depicted in the figures, other less smooth surfaces possibly having discontinuities and other protruding structures are certainly contemplated. 
     Turning now to  FIG. 11 , a portion of a dome shaped solar energy collecting apparatus  20 - 4  is shown with an inner possibly dome shaped heat energy conductor  70 . As shown, a (solar) heat energy conductor  70  may be formed with a plurality of concave collectors  40  formed within the conductor  70 . It may be noted that as depicted, a first support structure  60  including a plurality of elongated members  60   a  may be employed for supporting and fixing the focusing elements for forming the curved surface  64  of the solar energy collecting apparatus. In addition, a very different and inner second support structure may be employed in the form of the heat energy conductor  70  for supporting inner concave collectors  40  in aligned and spaced relationship to the focusing elements  30  of the outer curved surface  64 . 
     A number of possible additions and or alterations to the basic solar energy collecting apparatus  20 - 4  of the invention is certainly contemplated. For example, as shown in  FIGS. 12 and 13 , the basic dome or sphere shaped curved surface of a solar energy collecting apparatus  20 - 5  may be modified to include an air exhaust vent  80  providing an opening  80   a  to an interior within the curved surface  64 . The vent  80 , and opening  80   a  may be employed for a number of uses ranging from passive cooling to solar-to-wind powered generation mechanisms. 
     As shown in  FIG. 14 , yet another possibly embodiment of a solar energy collecting apparatus  20 - 6  includes an alternate internal structure for supporting and thermally coupling to the concave collectors  40 . As shown, each concave collector  40  may be supported by at least one stem  44 . Each stem  44  must be strong enough to support the weight of a concave collector  40 , as well as provide an efficient thermal coupling of the concave collector  40  to an included heat energy conductor, or an equivalent structure, for enabling the received and collected solar energy to be output as a heat source. Accordingly, the stems  42  may be provided having complex internal structures for enabling collected heat energy to be readily delivered for storage or energizing an included heat powered mechanism. 
     While there have been described herein a plurality of the currently preferred embodiments of the means and methods of the present invention, those skilled in the art will recognize that other and further modifications may be made without departing from the invention. For example, other support structures may be employed for supporting the focusing element and or concave collectors of the invention. As such, the foregoing descriptions of the specific embodiments of the present invention have been provided for the purposes of illustration, description, and enablement. They are not intended to be exhaustive or to limit the invention to the specific forms disclosed and or illustrated. Obviously numerous modifications and alterations are possible in light of the above teachings, and it is fully intended to claim all modifications and variations that fall within the scope of the appended claims provided hereinafter.