Abstract:
A system for integrating and co-generating renewable energies which achieves a combined powerful AC/DC electricity output, includes an enclosed volume chamber having an inner surface including a plurality of thermophotovoltaic cells located thereon and an opening for admitting a condensed high-temperature solar energy beam. A heat absorbing member located within the chamber for receiving a portion of the solar energy beam and acts as a thermal storage as well as a thermal emitter to supply thermal energy to the thermophotovoltaic cells to create DC electricity. Air is fed into the chamber to capture thermal energy from the emitter and any waste thermal energy, which is then converted into AC electricity. The system relies on the power of simplicity using a new twist in solar physics to allow for the highest conversion of sunlight energy to electricity at zero carbon emission while occupying significantly less space than typical solar energy systems.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from U.S. Provisional Patent Application No. 61/998,754, filed Jul. 8, 2014, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates generally to an apparatus for converting solar energy into a usable energy product and, more particularly, to an economical system for converting a high percentage of sunlight radiant energy to electricity with negligible optical losses utilizing thermophotovoltaic cells. The system simultaneously produces both AC and DC electricity on a sustainable cycle with zero carbon emission. 
         [0004]    2. Description of Related Art 
         [0005]    Solar energy has been available as a source of power for more than 4.5 billion years. For centuries, inventors have been devising various means to harness this energy. As far back as the third century B.C., records indicate that the Greek and Roman armies used “burning mirrors” to focus sunlight as weapons of war to ignite fires and to burn sails of enemy warships. 
         [0006]    Solar energy provides the world either directly or indirectly with the majority of its energy. Solar energy is a renewable energy source having vast potential. Although solar energy is abundant, a major drawback is that it is diffuse and not available at all hours. Solar energy can be affected by the time of the day, the seasons, and the changing sun path in the sky as the earth&#39;s axis is not at a right angle to the sun but it is tilted away at an angle of 23.5°. 
         [0007]    For decades, inventors have tried various systems for harnessing this incredible energy source. For example, U.S. Pat. Nos. 3,988,166; 4,286,581; 5,275,149 and 4,038,971 have sought to control and convert this energy into a cost-effective usable form. Unfortunately, these systems are cumbersome, expensive to manufacture and maintain, expensive to operate, and yield little in terms of usable, convertible energy. 
         [0008]    The article entitled “Principles of Solar Thermal Conversion” by R. H. B. Exell, 2000. King Mongkut&#39;s University of Technology Thonburi also discusses, in terms of academic interest only, of trapping solar radiation in an enclosed volume with perfectly reflecting walls at the temperature of the sun, i.e., approximately 5800 K and the need for a parabolic concentrator that focuses direct solar radiation into the enclosed volume. The article further discusses that if solar energy were to be used on a large scale, since solar energy is theoretically a very high temperature resource, one should try to harness it at this very high temperature for efficient conversion and then use the waste heat for low temperature purposes instead of downgrading the solar energy with low temperature collectors at the start. This article recites a theory for what is desired in this technology, but provides no direction as to how it can be achieved. 
         [0009]    U.S. Pat. No. 7,640,931 to Tarabishi (hereinafter, “the &#39;931 patent”), the entirety thereof being incorporated by reference thereto, is directed to a solar collecting system which can concentrate or condense solar energy at a fixed, stationary focal point to economically harness the sun&#39;s energy into a manageable and convertible form as desired in the Exell article. In particular, the &#39;931 patent teaches a system for tracking the sun and maintaining a constant fixed focal point or sub-focal point to at least partially condense the sun&#39;s rays into a high-energy beam that can be redirected to a predetermined location for generating electrical power, heat energy, steam, and the like. 
         [0010]    U.S. Pat. No. 8,413,442, also to Tarabishi (hereinafter, the &#39;442 patent”), the entirety thereof being incorporated by reference thereto, is directed to an economical system for harnessing the sun&#39;s energy collected from the system described in the &#39;931 patent, storing this energy, and/or converting this energy into a mechanical and/or electrical energy product on a sustainable cycle. The system utilizes one or more enclosed volume chambers having a mirrored inner surface connected in series for trapping the heat therein, a source for feeding a first fluid into the chamber to convert this fluid into a high pressure source, an outlet for allowing the high pressure source to exit the chamber, and at least one turbine for converting the high pressure source into mechanical and electrical energy product. The enclosed volume chambers may or may not include a heat absorbing member located therein for trapping and storing the energy for use during sunless hours. The heat trapped within the chamber can reach a temperature as high as plasma level. The system is highly efficient in that it achieves almost 100% conversion of the solar energy into a usable format and has increased efficiency through the use of multiple integrated units which are compact in size and space compared to previously used systems. 
         [0011]    Photovoltaic cells are used to convert light into electricity. Thermophotovoltaic cells use different technology to produce electricity. “Thermo” means heat and therefore these cells convert heat into electricity. Thermophotovoltaic cells use semiconductors, which are designed for specific wavelength, invisible light, like infrared rays, released by hot objects. This way of generating electricity is very neat and clean. Another advantage to the use of thermophotovoltaic cells is that they do not require much maintenance to work and do not produce any by-product that can harm the environment. For this reason, thermophotovoltaic cells are “clean” sources of energy. 
         [0012]    The article entitled “Utilization of the Wider Solar Spectrum Using Thermophotovoltaic Cells” by Dr. Dino Ponnampalam recognizes that thermophotovoltaic cell technology may be a way to harness solar energy without actually utilizing direct sunlight to meet the ever-increasing demand for energy without depleting the earth&#39;s natural resources. Since thermophotovoltaic cell systems match the band gap in the near infrared (0.078-3 micrometers), whereas the sun emits radiation that spans the entire electromagnetic (EM) spectrum, an interesting point to note is that the majority of the sun&#39;s irradiance is in the infrared region, making exploitation of this region, and this technology extremely worthwhile. As noted by Dr. Ponnampalam, the drawback of efficiency conversion of thermophotovoltaic cell technology has prevented a roll out of this technology. Dr. Ponnampalam further notes that currently there is no single piece of solar energy technology that could fully harness the power of the sun in providing and sustaining the power demands of society; however, through the intelligent utilization of the technology available, it is indeed feasible that solar energy could meet the energy demands of the world. 
         [0013]    The present invention is directed to a system that utilizes thermophotovoltaic cell technology in an efficient and cost-effective manner. The system is capable of converting up to 95% of sunlight radiant energy to electricity simultaneously producing AC and DC energy using the proper level of condensed solar energy temperature. The system uses the power of simplicity to exploit the broad spectrum of the harnessed solar energy resulting from the design of the &#39;931 patent and uses it in a creative way. The system of the present invention is self-sustaining, achieving a powerful AC and DC electricity combined output with the highest energy intensity per space unit, allowing the highest conversion of sunlight energy across the entire spectrum to electricity at zero carbon emission. Additionally, the present invention utilizes a creative way that relies upon a combination of diverse frequencies of thermophotovoltaic cells to generate DC electricity and, from waste heat to generate AC electricity, as well as from direct condensed solar beams to also generate AC electricity all from the same source of solar energy, and is capable of storing energy for several weeks, all in a single system. A full implementation of all of the system stages would result in a cost of kwh of less than one cent, making carbon capture and storage affordable. 
       SUMMARY OF THE INVENTION 
       [0014]    The above two systems disclosed by U.S. Pat. Nos. 7,640,931 and 8,413,442 to Tarabishi, the inventor of the present invention, represent a breakthrough regarding the Bose-Einstein condensate hypothesis “BEC” 1924 which scientists considered impossible to create. The above two inventions highly condense solar light, trap accumulated photons in an enclosed chamber, and keep photons from escaping under realistic conditions. 
         [0015]    The system of the present invention represents several breakthroughs in the solar industry as it combines the power of simplicity and a new twist in solar physics and applies it to the complex issue of solar energy to allow for the highest conversion of sunlight energy to electricity at zero carbon emission while occupying a fraction of the space required to operate typical photovoltaic solar energy systems. The system of the present invention has minimal optical losses and is able to use thermophotovoltaic cell technology in an efficient and cost-effective manner to convert the sun&#39;s energy into electricity. In theory, it is possible to convert 95% of sunlight radiant energy to electricity (Helmholtz ratio). Creative integration involves the above two renewable energies using the same source of concentrated broad spectrum of solar energy beams simultaneously, to directly and indirectly excite massive solar cells covering the inside wall of an enclosed chamber to generate DC electricity, with or without photon filters, while at the same time inject ambient air into the chamber, which would produce a mild expansion pressure sufficient to drive the thermal energy inside the enclosed chamber and pass it into a turbine to generate AC electricity. The system of the present invention would generate the highest energy per space unit and even has potential for use in space, such as on the moon, to extract Helium  3  and for building shelters. The system occupies a small space in comparison to traditional photovoltaic systems. 
         [0016]    According to a first aspect, the invention is directed to an apparatus for storing and/or converting solar energy into a mechanical and/or electrical energy product. The apparatus includes an enclosed volume chamber having an inner surface including a plurality of thermophotovoltaic cells located thereon, at least one opening, which may be a one-way opening, extending through a wall of the chamber for admitting a condensed high-temperature solar energy beam into the chamber, a heat absorbing member located within the chamber for receiving at least a portion of the solar energy beams and emitting or radiating heat energy to the thermophotovoltaic cells. A first conversion device is associated with the thermophotovoltaic cells for converting the heat energy into electrical energy. The heat absorbing member can be a black body that is placed in the center of the enclosed chamber and acts as both a thermal storage and a thermal emitter. The apparatus also includes at least one inlet extending through the wall of the chamber for feeding air into the chamber and/or into the black body wherein the air becomes heated, at least one outlet for allowing the heated air to exit the chamber, and a second conversion device configured for cooperating with the outlet for receiving the heated air and for converting the heated air to mechanical and/or electrical energy. 
         [0017]    The heat energy applied to the thermophotovoltaic cells causes the cells to become excited and the first conversion device comprises a wiring system associated with the thermophotovoltaic cells for carrying the DC energy away from the cells. The second conversion device, which is separate from the first conversion device, can be a turbine connected to a generator for converting the heated air into AC electricity. Also, the DC electricity produced from the first conversion device can be converted to AC electricity which is then joined with the AC electricity generated from the turbine. 
         [0018]    The heat absorbing member is capable of storing at least a portion of the heat energy for heating the air fed into the chamber. The heat absorbing member can have various sizes depending upon the desired electrical output. The chamber can include an open space containing air located between the inner surface of the chamber wall and the heat absorbing member. In addition to the absorbed heat of the heat absorbing member, a portion of the condensed high energy solar beam that enters into the chamber can heat the air contained within the open space as well as the air fed into the chamber. 
         [0019]    A cooling tunnel is provided, which extends about an outer surface of the chamber for cooling the back surface of the thermophotovoltaic cells. The cooling tunnel includes at least one inlet and one outlet opening for cycling cooling air or a cooling material, such as liquid nitrogen, through the cooling tunnel. 
         [0020]    According to one embodiment, the thermophotovoltaic cells can be formed from gallium antimonide or germanium; however, any known material can be used to form the thermophotovoltaic cells. The plurality of thermophotovoltaic cells can comprise an array formed from multiple frequency cells to capture rays emitting along the entire spectrum. The array can produce at least 5-6 watts per square centimeter. The thermophotovoltaic cells can have an operating temperature within the range of 900-1200° C. 
         [0021]    The air fed into the chamber can be a low pressure air source at ambient temperature as long as the air has sufficient force to drive the thermal energy out of the chamber to the turbine. Also, the thermophotovoltaic cell array can be formed from a net comprising a series of thermophotovoltaic cells having side edges which are interlocked within a plurality of frames covering the entire inside surface of the enclosed chamber shell facing the heat absorbing member. According to one embodiment, this net can form the outer surface of the chamber. 
         [0022]    According to one embodiment, the heat absorbing member can be formed from a combination of heat absorbing materials having differing heat capacity levels, and the chamber is capable of storing heat energy for up to several weeks, or even several months, depending upon the rate of depletion and/or the amount of usage of the heat energy as well as the size of the heat absorbing member (black body/emitter). 
         [0023]    The condensed solar energy beam can be supplied from a solar collecting system comprising a parabolic solar collector panel configured for reflecting solar rays to one of a focal point and a sub-focal point to at least partially condense the rays and at least one deflecting mirror mounted at one of the focal point and sub-focal point for receiving the condensed rays and redirecting the rays as a condensed solar energy beam to the enclosed chamber. 
         [0024]    A heat sensor can be provided for monitoring the temperature level of the enclosed volume chamber. The heat sensor can be in communication with a power source for moving the at least one deflecting mirror from the focal point to interrupt the feed of the solar energy beam into the chamber at a given time and to control the amount of heat absorbed by the chamber and/or for increasing the airflow entering into the chamber. The amount of heat fed to the chamber can be depleted as needed such that the amount of heat absorbed by the chamber is maintained at a temperature that is below the melting point of the material forming the heat absorbing member. 
         [0025]    According to one embodiment, the enclosed chamber can include at least two openings for receiving a solar energy beam into the chamber and wherein the openings include a one-way mirror and/or a divergent mirrored edge. 
         [0026]    A plurality of enclosed volume chambers can be provided in series and the stored thermal energy can be fed to a second of the series of enclosed volume chambers to enable the subsequent enclosed volume chamber to increase and/or maintain a predetermined level of heat energy in the second chamber. 
         [0027]    According to another aspect of the invention, an apparatus for converting solar energy simultaneously into AC and DC electricity includes a chamber having an inner surface including a plurality of thermophotovoltaic cells located thereon. At least one opening extends through a wall of the chamber for admitting a condensed high-temperature solar energy beam into the chamber. A heat absorbing member is located within the chamber for absorbing at least a portion of the solar energy beam and emitting heat to the thermophotovoltaic cells. The apparatus further includes a first conversion device in the form of a wiring system associated with the thermophotovoltaic cells for carrying DC electricity away from the cells and a second conversion device for converting the heat absorbed by the heat absorbing member and the waste heat into AC electricity. 
         [0028]    This system is self-sustaining and would achieve a combined powerful AC/DC electricity output, allowing the highest conversion of sunlight energy to electricity at a zero carbon emission. Efficiency becomes of no concern. Full implementation of all of the system stages, results in the cost of kwh to be less than one cent, which would make carbon capture and storage affordable, as well as water distillation and hydrogen production. Widespread use of the system will significantly contribute to the fight against global warming and the greenhouse effect, provide cheap carbon free chemical fuel, and solve the clean water shortage. A third industrial revolution is possible using solar energy. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0029]      FIG. 1  shows a schematic top open view of an apparatus for converting solar energy into a mechanical and/or electrical energy product including an enclosed chamber in combination with a sustainable energy supply system according to an embodiment of the present invention; 
           [0030]      FIG. 2  shows an expanded top view of the enclosed chamber of  FIG. 1  for converting solar energy into a mechanical and/or electrical energy product; 
           [0031]      FIG. 3  shows a schematic representation of a thermophotovoltaic cell which can be used in the solar energy converting apparatuses of  FIGS. 1 and 2 ; 
           [0032]      FIG. 4  shows a solar collector panel according to one design, having a fixed, stationary focal point, which can be used to supply solar energy to the apparatus/system of the present invention; 
           [0033]      FIG. 5  shows a solar collector panel according to another design, having a fixed, stationary focal point, which can be used to supply solar energy to the apparatus/system of the present invention and including a retractable protective shelter for guarding against bad weather; 
           [0034]      FIGS. 6A and 6B  show a top view and a front view of the tracking cones of  FIG. 5 ; and 
           [0035]      FIG. 7  shows a perspective view of a solar collector panel according to yet another design wherein the deflecting mirror is mounted onto a retractable scope. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0036]    For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”, “longitudinal”, and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations, except where expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting. 
         [0037]    Reference is now made to  FIGS. 1 and 2  which show schematic side elevation views of an apparatus, generally indicated as  10 ,  110 , according to a first embodiment and a second embodiment, for converting solar energy into a mechanical and/or electrical energy product. The apparatus  10 ,  110  comprises an enclosed volume chamber  12  formed from a shell which can have a spherical or oval shape. A portion of the shell or chamber  12 , such as a top portion, can be removed to allow for access to the interior portion of the chamber  12  for maintenance and/or modification of the components contained therein. The chamber  12  has an inner surface  14  which is lined with a plurality of thermophotovoltaic cells  15 . According to one embodiment, the thermophotovoltaic cells  15  can have edge portions that abut one another in a “frame” arrangement wherein the thermophotovoltaic cells  15  are held in an interlocking arrangement within a series of frames  27  which at least partially lines the inner surface  14  of the chamber  12 . This interlocking “frame” arrangement can form a net extending about the heat absorbing member, leaving at least one window or opening  16  to allow rays  18  to enter therethrough. According to a further embodiment, the thermophotovoltaic cells  15  line the entire inner surface  14  of the chamber  12 . An example of a thermophotovoltaic cell is shown in  FIG. 3  and is described in more detail below. The chamber  12  can include at least one first opening, generally indicated as  16 , which extends through a wall  17  of the chamber  12  for admitting condensed high-temperature solar energy beams  18  fed from a parabolic solar collector panel  19  into the chamber  12 . Examples of parabolic solar collector panels are shown in  FIGS. 4 ,  5 , and  7  and are described in more detail below. 
         [0038]    With continuing reference to  FIGS. 1 and 2 , a heat absorbing member  20 ,  120  is located within the chamber  12  for receiving at least a portion of the solar energy beams  18  and emitting heat energy, shown by  23 , to the thermophotovoltaic cells  15 . The embodiment shown in  FIG. 2  differs from that shown in  FIG. 1  in that the heat absorbing member  120  of  FIG. 2  is smaller in size than the heat absorbing member  20  shown in  FIG. 1 , increasing the distance from the thermophotovoltaic cells  15 . It can be appreciated that various sizes of heat absorbing members  20 ,  120  may be used in the apparatus  10 ,  110  of the invention depending upon the amount of electricity production required. It can also be appreciated that the size of the heat absorbing member  20 ,  120  affects the amount of thermal energy held therein and, depending upon the material used to form the thermophotovoltaic cells  15 , will determine the size of heat absorbing member  15  needed for heat absorption. The apparatus  10  also includes a first conversion device, generally indicated as  24 , associated with the thermophotovoltaic cells  15  for converting the heat energy into electrical energy. The heat absorbing member  20  can be a black body that is placed in the center of the enclosed chamber  12  and acts as both a thermal storage and a thermal emitter. The apparatus  10  also includes at least one inlet  26  extending through the wall  17  of the chamber  12  for feeding air  28  into the chamber  12  wherein the air becomes heated. At least one outlet  30  is provided for allowing heated air  32  to exit the chamber  12 . A second conversion device, generally indicated as  34  can be provided which is configured for cooperating with the outlet  30  for converting the heated air  32  to mechanical and/or electrical energy. 
         [0039]    Reference is now made to  FIG. 3  which shows a schematic representation of one example of a thermophotovoltaic cell which can be used in the solar energy converting apparatuses  10 ,  110  of the invention. Thermophotovoltaic systems convert heat energy into electricity via photons and consist of, at a minimum, an emitter and a photovoltaic cell power converter. However, most thermophotovoltaic systems include additional components, such as concentrators, filters, and reflectors. Thermophotovoltaic systems generate electricity by electromagnetic frequency at high temperatures and high frequencies. The basic principle of operation is similar to that of traditional photovoltaics where a p-n junction is used to absorb optical energy, generate and separate electron hold pairs, and in doing so, convert that energy into electrical power. As shown in  FIG. 3 , the thermophotovoltaic cell requires a heat source  50 , which can be sunlight, fossil fuels, radioactive decay, waste heat, and the like. In the present invention, this heat source  50  is provided from the condensed high-temperature solar energy beams  18  fed from the parabolic solar collector panel  19  into the chamber  12 . An absorber/emitter  52  is provided which absorbs the heat and emits or radiates the heat to a photovoltaic cell  56 . 
         [0040]    In the present invention, the absorber/emitter  52  corresponds to the heat absorbing member  20 ,  120  and the heat energy emitted to the photovoltaic cell corresponds to  23  as shown in  FIGS. 1 and 2 . For the emitter, deviations from perfect absorbing and perfect blackbody behavior lead to photon losses. For the case of selective emitters, any light emitted at wavelengths not matched to the band gap energy of the photovoltaic cells may not be efficiently converted and leads to reduced efficiency. To minimize these losses, it is important to select an emitter formed from a material that has a narrow wavelength range, i.e., band gap, so as to minimize the heat loss. One way to optimize the performance of the emitter is to form the blackbody or heat absorbing member  20 ,  120  from a variety of materials having a series of wavelengths. Examples for forming the heat absorbing member  20 ,  120  or emitter include, but are not limited to, polycrystalline silicon carbide, tungsten, rare-earth oxides, such as ytterbium oxide and erbium oxide, and photonic crystals. A spectral filter  54  can be provided to reflect non-ideal wavelengths back to the emitter. Since these filters  54  are rarely perfect, any light that is absorbed or scattered and not redirected to the emitter or the converter is lost. However, because the present invention utilizes an enclosed chamber  12  along with the feeding of ambient air  28  into the enclosed chamber  12 , any lost energy from the scattered or non-redirected light is recovered and converted into electricity via the second conversion device  34 . Additionally, the present invention can include a photon filter  21  within the chamber  12 , as shown in  FIG. 2 , and located around the heat absorbing member  20 ,  120  to further optimize the performance of the thermophotovoltaic cells  15 . In this embodiment, the temperature within the chamber  12  must be maintained below the melting point of the photon filter  21 . Photon filters are typically made of glass and can have varying melting point temperature depending upon the particular material used to form the glass. According to a further embodiment, the photon filter  21  can be comprise a series of retractable/extendable panels, similar to the retractable/extendable panels forming the protective shelter  95  shown in  FIG. 5 . 
         [0041]    The thermophotovoltaic system of the present invention consists of both thermal and photovoltaic energy and offers improvements of both, as a whole, since the thermal radiation, which occurs mostly in the infrared region, and the photovoltaic energy are both trapped in the enclosed chamber at the same time. In photovoltaic cells, the photons are in the range of 0.4-0.8 μm mostly, while in thermophotovoltaic cells the wavelengths can be extended up to approximately 1.9 μm. The thermophotovoltaic system of the present invention has the potential to generate current densities close to 300 times that of traditional photovoltaic systems alone. Utilizing advanced arrays having multi-frequency cells can potentially produce well over 6 watts of electric power per square centimeter of the photovoltaic cell surface area in addition to the AC electricity generated by the waste heat that has been continuously trapped in the enclosed chamber  12 . 
         [0042]    As the emitter  20 ,  120  temperature increases and the radiation temperature increases, the radiation shifts to a shorter wavelength allowing for more efficient absorption by the thermophotovoltaic cells  15 . Optimum emitter temperature is 1600-1800° C. For example, polycrystalline silicon (CID) is extremely cheap; however, much of its energy is in the long wavelength. In the system of the present invention, this material can still be used among other materials since any waste heat resulting from the long waves can be used with no loss of photons because these lost photons are trapped in the enclosed chamber. 
         [0043]    According to one embodiment, the thermophotovoltaic cells  15  can be formed from gallium antimonide or germanium; however, any known material can be used to form the thermophotovoltaic cells. These other materials include silicon, indium gallium arsenide antimonide, indium gallium arsenide, and indium phosphide arsenide antmonide. The cut off wavelength and corresponding band gap for different materials are provided in the following table. Silica (Si) with a cut off at 1.1 μm is good for visible light but not for longer wavelengths. GaSb and InGaAs are better flying cut offs suitable for thermophotovoltaic cells. 
         [0000]                                                TABLE                   Cut off and threshold energy for different materials                Cut off wavelength    Band Gap                    Si:   1.1 μm   1.12 eV       GaSb:   1.7 μm   0.72 eV       InGaAs:   2.3 μm   0.55 eV       InGaAsSb   2.4 μm   0.53 eV                    
The cut-off means that photons with a wavelength higher than the cut-off are filtered off, while those with short wavelengths are passing through to the photovoltaic cell. Accordingly, the same amount of electricity can be produced with a surface area of around 100 times smaller than used for conventional photovoltaic cells. To optimize the potential of the system, the thermophotovoltaic cells can comprise an array formed from multiple frequency cells to optimize efficiency while considering the price of the materials to form the thermophotovoltaic cells. The thermophotovoltaic cells can have an operating temperature within the range of 900-1200° C.
 
         [0044]    The heat energy  23  applied to the thermophotovoltaic cells  15  causes the cells to become excited and the first conversion device  24  can include a wiring system, generally indicated as  58  in  FIG. 3 , associated with the photovoltaic cell  56  of the thermophotovoltaic cell  15  for converting the excited cells into DC electricity. 
         [0045]    Referring back to  FIGS. 1 and 2 , the second conversion device  34  can be a turbine  60  connected to a generator  62  for converting the heated air  32  into AC electricity. The air  28  fed into the chamber can be a low pressure air source at ambient temperature as long as the air has sufficient force to drive the thermal energy out of the chamber  12  to the turbine  60 . The outer surface  17  of the chamber can be formed from a poorly conductive, insulated material. 
         [0046]    According to one embodiment, the heat absorbing member  20 ,  120  can be formed from a combination of heat absorbing materials having differing heat capacity levels, and the chamber  12  is capable of storing heat energy for up to several months, depending upon the rate of depletion and the continuous recharging and/or the amount of usage of the heat energy. In addition to the materials discussed above, the heat absorbing member or emitter  20 ,  120  can be formed from a combination of heat absorbing materials, such as cast iron, magnesium, mixed ceramic material, concrete, and the like, having differing heat capacity levels and differing heat conductive properties. According to one design, the heat absorbing member  20 ,  120  can be formed as a series or block of bricks  77  which are positioned with spacing  78  therebetween to increase the exposed surface area of the bricks  77 . The air  28  fed into the chamber  12  can be ambient air, which is injected into the spacing between the bricks  77  within the block and moves through the spaces  78  between the bricks  77  so that the air  28  quickly contacts the surface areas of the solar heated bricks  77  and quickly heats up. The chamber  12  and its contents are capable of storing heat energy for up to several months depending upon the rate of depletion and/or the amount of usage of the heat energy and the size of the storage/chamber  12 . This would be desirable in areas of the world where there are prolonged periods where sunlight is absent or there is very low sun intensity. 
         [0047]    The heat absorbing member  20 ,  120  is capable of storing at least a portion of the heat energy supplied by the solar beams  18  for heating the air  28  fed into the chamber. As stated above, the heat absorbing member  20 ,  120  can have various sizes depending upon the desired electrical output. The chamber  12  can include an open space  65  containing air located between the inner surface  14  of the chamber wall  17  and the heat absorbing member  20 ,  120 . In addition to the absorbed heat of the heat absorbing member transmitting heat energy  23 , a portion of the condensed high energy solar beams  18  that enter into the chamber  12  can be used to transmit heat energy  25  to heat the air contained within the open space  65  and to heat the air  28  fed into the chamber  12 . 
         [0048]    A cooling tunnel  68  can be provided which extends about an outer surface of the inner wall  14  of the chamber  12  for cooling a back surface  15   a  of the thermophotovoltaic cells  15 . The cooling tunnel  68  includes at least one inlet  72  and one outlet opening  74  for cycling cooling air or a cooling material  76 , such as liquid nitrogen, through the cooling tunnel  68 . It can be appreciated that multiple outlet openings  74  can be provided and that the outer wall  68   a  forming the cooling tunnel  68  does not have to be air tight. 
         [0049]    The opening  16  into the enclosed volume chamber can comprise a one-way mirror  38  on the north or the south side of the chamber to allow one-way entrance of the solar beam. Also, the heat trapped within the chamber should not exceed 2000° C., which is below the melting point of the material forming the head absorbing member  20 ,  120 , and can be controlled by controlling the size of a solar collector deflecting mirror  40 , as shown in  FIGS. 4 ,  5 , and  7 , how long the solar energy is trapped in the chamber  12 , and the continuation of solar energy inputted into the chamber  12  and/or into the heat absorbing member  20 ,  120 . 
         [0050]    Reference is now made to  FIGS. 4 ,  5 , and  7 , which show different parabolic solar collector devices, generally indicated as  44 ,  46 , and  48  including a solar collecting panel  19 , which can be used to supply the condensed high-temperature solar energy beam  18  into the enclosed volume chamber  12 . The solar collector devices  44  and  46  of  FIGS. 4 and 5  are described in detail in U.S. Pat. No. 7,640,931 to Tarabishi. The solar collector device  46  of  FIG. 5  includes a retractable/extendable protective shelter  95  which can be used to partially or fully shield the solar collector device  46 . The parabolic solar collector panel  19  is configured for reflecting solar rays  42  to either a stationary fixed focal point F or a stationary fixed sub-focal point. At least one deflecting mirror  40  is mounted via mounting arm  130 ,  131  at one of the focal point and sub-focal point for receiving the rays  42  and redirecting the rays  42  as the condensed high-temperature solar energy beam  18  moves along an imaginary axis  45  to the enclosed volume chamber  12 . The solar energy beam  18  can be deflected directly into the enclosed volume chamber  12  from the deflecting mirror  40  or it can be delivered by a cable (not shown), such as a fiber-optic cable having a lumen having an inside wall which is lined with highly reflective material. It can be appreciated that any other well-known device can be used for delivering the condensed high-temperature solar energy beam  18  to the enclosed volume chamber  12 . 
         [0051]    It can be appreciated that the stored thermal energy is capable of being fed to a second enclosed volume chamber, such as the enclosed volume chamber  12  as shown in  FIG. 1 , to enable this second enclosed volume chamber  12  to increase and/or maintain a predetermined level of heat energy therein. 
         [0052]    With continuing reference to  FIGS. 1 and 2 , one or more heat sensors  80  can be provided in the chamber  12  for monitoring the temperature level of the enclosed volume chamber  12 . This heat sensor  80  can be in communication with a power source (not shown) for moving the at least one deflecting mirror  40  from the focal point to interrupt the feed of the solar energy beam  18  into the chamber  12  at a given time and to control the amount of heat absorbed by the heat absorbing member  20 ,  120 . Reference is made to  FIG. 7 , which shows the deflecting mirror  40  mounted onto a retractable scope  82 , which can be retracted depending upon a sensed level of heat within the chamber  12  to move the deflecting mirror away from the focal point to reduce or interrupt delivery of solar energy into the chamber  12 . The amount of heat fed to the chamber  12  can be depleted as needed and/or the amount of energy fed therein can be controlled by movement of the retractable scope  82  to interrupt the feed of solar energy into the chamber such that the amount of heat fed and/or absorbed by the heat absorbing member  20 ,  120  within the chamber  12  is maintained at a temperature which is below the melting point of the material forming the heat absorbing member  20 ,  120 . The retractable scope  82  is configured to retract or remove the deflecting mirror  40  from the focal point or sub-focal point. This movement can be achieved manually or electronically in response to the heat sensors  80 . The scope  82  can return the deflecting mirror  40  to its proper position once the chamber  12  has cooled to a predetermined temperature. 
         [0053]    Reference is now made to  FIGS. 6A-6B  which show a daily east-to-west tracking system that can be used to control the rotation of the solar collecting panel  19 . The daily tracking system includes at least two cones  92  mounted on a flat surface of the solar collecting system  46 . The cones  92  are positioned at slight diverging angles with respect to each other such that the collective panel axis of rotation at a perpendicular line in relation to the east-west axis at all times as the collecting panel  19  rotates. The purpose of the tracking system is to track the sun during the sunny hours as the sun cruises from east to west and maintain the sun rays perpendicular on the collective panel at all times. Seasonal manual adjustment of the collector panel (the whole system) for seasonal inclination along the north-south axis can be provided to further adjust the system due to seasonal inclination of the sun. Each of the cones includes a photocell located at the bottom of the cone. The cones  92  can be placed, for example, on the upper surface of the arm  131  of the solar collecting system extending in an east-west direction with respect to each other. The cones  92  are placed in an upright position at a slightly tilted angle extending away from each other to ensure that none of the rays of the sun enter the cones at the same time. The east cone can be wired to an electric circuit such that it would be interrupted once the sunlight hits the photocell at the bottom of the east cone. The collecting panel  19  will then stop rotation and then resume rotating once the sunlight is no longer shining into the cones  92  as the sun moves to the west. The west cone can be wired to an electric circuit that would accelerate rotation of the collecting panel  19  once the sunlight hits the photocell in the bottom of the cone. The cones are placed in an upright position such that no shadow appears in the north or south at the cone base. Any shadow to the south of the cone base would indicate an inclination to the north and vice versa, and thus adjustment would be necessary. During the daily east-west tracking, the cones  92  are placed on the arm  131  of the solar collecting system  46  along the east-west axis. These cones  92  are diverted from each other at a narrow angle. The collector panel includes a gear system that is set to rotate at a predetermined speed to approximately follow the speed of the sun as it cruises from east to west. The cones  92  act as a control system to maintain the sunlight perpendicular on the collector panel  19 . Once the sun shines inside the east cone, such indicates that the collector panel  19  is rotating too fast and the electric circuit is cut off to briefly stop the rotation of the collector panel until the rays no longer shine inside the cone. The collector panel  19  then resumes rotation at the predetermined speed. Once the sun shines inside the west cone, indicating that the collector panel is rotating slower than it should be, and thus, the speed of the collector panel is accelerated to make up this lag. When the sunlight is no longer shining inside the west cone, the predetermined speed of rotation is resumed. Since the sun tracking is set to work automatically and self-adjusts, any cloud interruption will not stop the collector panel rotation and once the clouds clear, readjustment is carried out automatically using the same principals set forth above. The seasonal tracking system includes providing a plurality of adjustable mounting legs  96 , i.e., five legs, for supporting the solar collecting system  46 . These legs are equipped with screws that can be manually twisted up and down on the north-south axis, i.e., lowering or elevating the entire system until the north or south shadow relative to the cones disappears, indicating no more inclination. Seasonal inclination is very slow and readjustment should take place every few weeks. 
         [0054]    Accordingly, the present invention is a clean energy, economically feasible, system that is simple in design and operation, is self-sustainable, and features a central mechanism that is capable of a steadily high percentage of collection of available solar energy. Furthermore, the present invention exploits the broad spectrum of the harnessed solar energy and uses it in a creative way to include energy storage and the use of a thermal emitter to obtain the most powerful and cheapest electricity possible by diversifying the electricity energy mix, i.e., both AC and DC electricity on a sustainable basis, using the power of simplicity and by applying a new twist in solar physics. One such creative way is a system that includes both photovoltaic and thermophotovoltaic cell technology which generates electricity from waste heat, as well as from direct condensed solar beams at zero carbon emissions, which is capable of storing thermal energy and being continuously recharged for several weeks, all in a single system. Additionally, the invention is easy to maintain, capable of condensing solar energy onto a focal point that is continuously fixed as a stationary location, i.e., perfect focal point, which can be deflected to a receiver that can convert thermal energy to provide energy for numerous applications. Further still, the invention provides a sun-tracking system that maintains the sun&#39;s rays perpendicular on the collecting surface throughout the sunny hours; provides an efficient and effective thermal energy storage system that is capable of providing a steady energy source to meet basic energy demand during the sunless hours for many days; has the capability to integrate and co-generate with other sources of green energy in multi-hybrid arrangements having expandable features; and has a desirable level of efficiency which is obtainable through the used smaller space requirements. 
         [0055]    Although the invention has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred embodiments, it is to be understood that such detail is solely for that purpose and that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the invention. For example, it is to be understood that the present invention contemplates that, to the extent possible, one or more features of any embodiment can be combined with one or more features of any other embodiment.