Abstract:
An energy conversion system includes a heat to power conversion unit to convert thermal energy of a high temperature fluid into electricity. A space heating element is connected to a heated fluid storage unit to provide heating. A heat driven cooling element is connected to the heated fluid storage unit to provide refrigerated fluid to provide cooling. An array of sensors is distributed to measure system parameters and collect data. A central processing unit is coupled to the array of sensors to process data from the array of sensors, electrical grid data from a utilities operator and data history on water, heat, and power used to calculate operation parameters for components of the energy conversion system. A memory unit coupled to the central processing unit to store processing instructions to be executed by the central processing unit and to store the data history on water, heat, and power used.

Description:
REFERENCE TO PRIOR APPLICATION(S) 
       [0001]    This application is a divisional of U.S. patent application Ser. No. 13/232,842, filed Sep. 14, 2011, now pending, which claims the benefit of U.S. Provisional Application No. 61/383,226, filed Sep. 15, 2010, entitled “METHOD AND APPARATUS FOR COLLECTING SOLAR THERMAL ENERGY.” U.S. patent application Ser. Nos. 13/232,842 and 61/383,226 are hereby incorporated by reference. 
     
    
     BACKGROUND INFORMATION 
       [0002]    1. Field of the Disclosure 
         [0003]    The present invention relates generally to solar energy, and more specifically, the invention relates to collecting solar thermal energy. 
         [0004]    2. Background 
         [0005]    Solar thermal collectors are devices that collect solar energy by converting sunlight into heat through the use of a radiation absorber. There are a variety of types of solar thermal collectors. In general, the different types of solar thermal collectors can be categorized based on their design and the temperature of the working fluid. 
         [0006]    One type of solar thermal collector is a flat panel collector. A flat panel collector is a collector with a flat shape/topology that is placed in the sun to absorb solar radiation and a fluid that is transported through the flat panel collector is heated as a result of the absorption of the sunlight. In general, as the losses of the flat panel collectors are relatively high, the fluid that is transported through a flat panel collector is heated to temperatures up to approximately 100° C. 
         [0007]    Another type of solar thermal collector is an evacuated tube collector. An evacuated tube collector is similar to a flat panel collector in that it is placed in the sun to absorb sunlight and a fluid that is transported through the collector is heated as a result of the absorption of the sunlight. However, in evacuated tube collectors, the tube through which the fluid is transported is surrounded by vacuum and the collector has a cylindrical shape. As a result, the loss of heat to the outside from the tube due to convection or conduction is greatly reduced. In general, the fluid that is transported through an evacuated tube collector can be heated to temperatures of up to approximately 150° C. 
         [0008]    Other types of solar thermal collectors include parabolic trough collectors and Fresnel collectors. These types of solar thermal collectors include structures that concentrate or focus the solar radiation onto an element that is utilized to heat the fluid that is transported through the solar thermal collector. By concentrating solar radiation, the fluid that is transported through the solar thermal collector can be heated to temperatures in excess of 150° C. However, in order for these concentrating structures to be effective, the parabolic trough collectors and Fresnel collectors require one or two axis tracking structures to track the sun as it travels across the sky and adjust the focus of the concentrating structures accordingly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. 
           [0010]      FIG. 1  shows a cross section illustration of an example low loss flat evacuated solar thermal panel in accordance with the teachings of the present invention. 
           [0011]      FIG. 2  shows a cross section illustration of another example low loss flat evacuated solar thermal panel in accordance with the teachings of the present invention. 
           [0012]      FIG. 3  shows cross section illustrations of an example low loss flat evacuated solar thermal panel including an example manifold structure in accordance with the teachings of the present invention. 
           [0013]      FIG. 4  shows an example arrangement of a plurality of example low loss flat evacuated solar thermal panels connected to one another in accordance with the teachings of the present invention. 
           [0014]      FIG. 5  shows a block diagram of an example system that includes one or more example low loss flat evacuated solar thermal panels in accordance with the teachings of the present invention. 
           [0015]      FIG. 6  shows a block diagram of example processing included in an example system that includes one or more example low loss flat evacuated solar thermal panels in accordance with the teachings of the present invention. 
           [0016]      FIG. 7  shows an example chart illustrating example curves of calculated collector loss profiles as a function of temperature of operation in accordance with the teachings of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Examples related to low thermal loss, high temperature, monolithic flat evacuated solar thermal panels in accordance with the present invention are disclosed. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one having ordinary skill in the art that the specific detail need not be employed to practice the present invention. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present invention. 
         [0018]    Reference throughout this specification to “one embodiment,” “an embodiment,” “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment or example of the present invention. Thus, the appearances of the phrases “in one embodiment,” “in an embodiment,” “in one example” or “in an example” in various places throughout this specification are not necessarily all referring to the same embodiment. The particular features, structures or characteristics may be combined for example into any suitable combinations and/or sub-combinations in one or more embodiments or examples. Furthermore, it is appreciated that the figures provided herewith are for explanation purposes to persons ordinarily skilled in the art and that the drawings are not necessarily drawn to scale. 
         [0019]    As will be discussed, examples according to the teachings of the present invention include methods and apparatuses for a monolithic, evacuated flat panel collector that does not require a tracking mechanism and is able to operate/heat the working fluid at temperatures in excess of 150° C. under average incident solar radiation conditions. As will be discussed, examples of the disclosed collector have the ability to provide heated steam at temperatures of at least 150-250° C. and can be integrated into a building to provide the building with a combined heating, power generation and cooling solution. 
         [0020]    To illustrate,  FIG. 1  shows a cross section of one example of low loss flat evacuated solar thermal panel  100  in accordance with the teachings of the present invention. As shown in the illustrated example, the solar thermal panel  100  includes five layers, which include first layer  101 , second layer  103 , third layer  108 , fourth layer  112  and an optional fifth layer  115 . In one example, the first, second, third, fourth and optional fifth layers  101 ,  103 ,  108 ,  112  and  115  are made of a material such as glass or other suitable materials including for example tailored glass compositions, such as boron doped glass or a polymer able to operate at temperatures in excess of 100 degrees Celsius such as PTFE (i.e. polytetrafluoroethylene) or ETFE (i.e. ethylene/tetrafluoroethylene copolymer) or a transparent to light polymer able to operate at temperatures in excess of 100 degrees Celsius. In another example, first, fourth and fifth layers  101 ,  112  and  115  are made of glass, while second and third layers  103  and  108  are made of copper or other suitable material. In one example, a first evacuated cavity  104  is enclosed between the first layer  101  and second layer  103 . A second evacuated cavity  110  is enclosed between the third layer  108  and fourth layer  112 . As shown in the example, the second layer  103  and third layer  108  enclose a high temperature working fluid cavity  107  through which a working fluid is to flow. In one example, an optional climate control cavity  114  may be included between the fourth layer  112  and optional fifth layer  115 . In one example, pillars  105  are disposed between first and second layers  101  and  103 , and pillars  111  are disposed between third and fourth layers  108  and  112  as shown. 
         [0021]    In operation, solar radiation is incident on a top surface of the solar thermal panel  100  and passes through the first layer  101 , through the first evacuated cavity  104  and then gets absorbed by a coated second layer  103 . In one example, second layer  103  is coated with a coating  106 , which in one example is a high absorption, low emissivity coating. As mentioned above, the second and third layers  103  and  108  enclose the high temperature working fluid cavity  107  that contains the working fluid. In operation, heat is transferred to the working fluid that is circulated through the high temperature working fluid cavity  107 . 
         [0022]    In one example, the working fluid is pumped out of the high temperature working fluid cavity  107  to a heat to power conversion unit and heated fluid storage units. The first and second evacuated cavities  104  and  110  defined on the opposing sides of the high temperature working fluid cavity  107  minimize the conduction and convection thermal losses of heat in the working fluid to the environment. 
         [0023]    In one example, a coating  106  having high absorption in the visible spectrum and low infrared emissivity is applied to second layer  103  to reduce the thermal losses to the environment due to radiative transfer. In one example, a coating  113  is applied to layer  112  to reflect back infrared radiation emitted by the high temperature working fluid cavity  107  to further reduce losses though the back side of solar thermal panel  100 . As shown in the depicted example, layer  101  is coated with a coating  102  that in one example is a dichroic coating, which has high transmission in the visible and high reflectivity in the mid to far infra red spectrum. In addition, coating  102  further reduces radiative losses from the high temperature working fluid cavity  107  and surrounding structure as well by partially reflecting back the infrared radiation emitted by the high temperature working fluid cavity  107 . 
         [0024]    In one example, the chemical composition of layers  103  and  108 , which enclose the high temperature working fluid cavity  107  and the high temperature working fluid is optimized to maximize absorption of infrared radiation in excess of 2 microns. In one example, pillars  105  and  111  are silica aerogel pillars. In an evacuated atmosphere in the first and second evacuated cavities  104  and  110 , pillars  105  and  111  provide mechanical structural integrity to the solar thermal panel  100  while minimizing conduction and convection losses. 
         [0025]    In one example, first layer  101  is an outdoor facing layer and is transparent to solar radiation and has the required mechanical integrity to support large pressure gradients. In one example, the material used for creating the structure of first layer  101  could be SiO2 silica glass, although other materials and glass compositions can be used. 
         [0026]    As mentioned above, coating  102  in one example is a dichroic coating, which has high transmission in the visible part of the spectrum, high reflectivity in the mid and far infrared part of the solar spectrum for wavelengths in excess of 2 microns. 
         [0027]    In one example, second layer  103  is made of transparent or opaque material with the required mechanical integrity to support large pressure gradients, high temperatures and has high absorption for radiation with wavelength in excess of 2 microns. In one example, the material used for creating the structure of second layer  103  could be SiO2 silica glass, although other materials or tailored glass compositions, such as boron doped glass or a polymer able to operate at temperatures in excess of 100 degrees Celsius such as PTFE (i.e. polytetrafluoroethylene) or ETFE (i.e. ethylene/tetrafluoroethylene copolymer) can be used. 
         [0028]    In one example, the first evacuated cavity  104  defined between first and second layers  101  and  103  reduces heat transfer between cold first layer  101  and hot second layer  103 . 
         [0029]    In one example, pillars  105  are made of high strength, very low thermal conductivity material. In one example, pillars  105  are silica aerogel pillars having a density designed to achieve a combination of optimal strength and thermal conductivity. In one example, the silica aerogel is reinforced with additional compounds and other materials with similar properties can be used. Pillars  105  can be transparent, opaque, have spatial transparency gradients or dichroic properties. In one example, the geometric shape of pillars  105  can be designed to achieve optimal structural, thermal, and optical properties. In one example, the pillars  105  can be rectangular running for the width of the solar thermal panel  100  as shown in  FIG. 1 . In another example, the pillars  105  may be hemispheres with a cut top as will be shown below in  FIG. 2 . It is appreciated of course that these geometries are provided for explanation purposes and that pillars  105  may be other shapes or configurations in accordance with the teachings of the present invention. 
         [0030]    In one example, coating  106  is a high temperature, high absorption for the solar spectrum and very low infrared emissivity coating. In one example, coating  106  may be a cermet, ceramic metal coating. In another example, coating  106  may be a silver based ceramic metal coating with high absorption coefficient for solar radiation wavelengths of less than 2-3 microns, and with a low emissivity coefficient for infrared radiation wavelengths of greater than 2-3 microns. 
         [0031]    As discussed above, high temperature working fluid cavity  107  contains heat transfer/working fluid. In one example, the working fluid used can be water vapor. In other examples, it is appreciated of course that other fluids can be used for working fluid in the high temperature working fluid cavity  107 . 
         [0032]    In one example, third layer  108  is made of transparent or opaque material with the required mechanical integrity to support large pressure gradients, high temperatures and has high absorption for radiation with wavelength in excess of 2 microns. In one example, the material used for creating the structure of third layer  108  could be SiO2 silica glass, although other materials or tailored glass compositions can be used. 
         [0033]    In one example, an optional coating  109  may be included on third layer  108  as shown. In one example, coating  109  is a high temperature, high absorption coating for the solar spectrum and a very low infrared emissivity coating. In one embodiment coating  109  may be a cermet, ceramic metal coating. In another example, coating  109  may be silver based ceramic metal coating with high absorption coefficient for solar radiation wavelengths of less than 2-3 microns, and with a low emissivity coefficient for infrared radiation wavelengths of greater than 2-3 microns. 
         [0034]    In one example, evacuated cavity  110  defined between third and fourth layers  108  and  112  reduces heat transfer between hot third layer  108  and cold fourth layer  112 . 
         [0035]    In one example, pillars  111  are made of high strength, very low thermal conductivity material. In one example, pillars  111  are silica aerogel pillars having a density designed to achieve a combination of optimal strength and thermal conductivity. In one example, the silica aerogel is reinforced with additional compounds and other materials with similar properties can be used. Pillars  111  can be transparent, opaque, have spatial transparency gradients or dichroic properties. In one example, the geometric shape of pillars  111  can be designed to achieve optimal structural, thermal, and optical properties. In one example, the pillars  111  can be rectangular running for the width of the panel as shown in  FIG. 1 . In another example, the pillars  111  can be hemispheres with a cut top as will be shown below in  FIG. 2 . It is appreciated of course that these geometries are provided for explanation purposes and that pillars  105  may be other shapes or configurations in accordance with the teachings of the present invention. 
         [0036]    In one example, fourth layer  112  is made of a transparent or opaque material with the required mechanical integrity to support large pressure gradients, high temperatures and has high absorption for radiation with wavelength in excess of 2 microns. In one example, the material used for creating the structure of fourth layer  112  could be SiO2 silica glass, although other materials or glass compositions can be used. 
         [0037]    In one example, coating  113  is a broadband high reflectivity coating covering the visible and infrared parts of the electromagnetic radiation spectrum. In one example, coating  113  is designed to have peak reflectivity in the mid to far infrared sections of the spectrum. 
         [0038]    In one example, an optional climate control cavity  114  is included between fourth layer  112  and optional fifth layer  115  as discussed above. In one example, climate control cavity  114  contains circulating heating or cooling fluid intended to provide thermal control of the housing unit for which the solar thermal collector  100  serves as a roof/wall. 
         [0039]    In one example, an optional fifth layer  115  is made of opaque or transparent material exhibiting high thermal conductivity. In different examples, fifth layer  115  and climate control  114  may or may not be present in solar thermal collector  100 . 
         [0040]      FIG. 2  shows a cross section of another example of low loss evacuated solar thermal panel  200  in accordance with the teachings of the present invention. It is appreciated that the example solar thermal panel  200  illustrated in  FIG. 2  shares many similarities with example solar thermal panel  100  illustrated in  FIG. 1 . As mentioned previously, one difference between example solar thermal panel  200  of  FIG. 2  and example solar thermal panel  100  of  FIG. 1  is that example solar thermal panel  200  includes pillars  205  instead of pillars  105  and  111 . In one example, pillars  205  are hemispheres with a cut top as shown in  FIG. 2  instead of rectangular pillars  105  and  111  running for the width of the panel as shown in  FIG. 1 . 
         [0041]    In one example, pillars  205  are hemispherical silica aerogel structures that reduce the material cross section through which conductive heat transfer can occur between first and second layers  101  and  103  and between third and fourth layers  108  and  112 . Pillars  205  can also eliminate any non-compressive forces on the support structure. In one example, pillars  205  can be positioned every 5 cm in both horizontal directions and have a hemisphere radius of 5 mm and a radius at contact to the hot second and third layers  103  and  108  of 3 mm. 
         [0042]      FIG. 3  shows two cross-section illustrations of example solar thermal panel  100  with a working fluid cavity  107  having an example manifold structure. As can be observed, the cross-section illustration of solar thermal panel  100  on the left hand side of  FIG. 3  is similar to the cross-section illustration of solar thermal panel  100  shown in  FIG. 1 . The cross-section illustration of solar thermal panel  100  on the right hand side of  FIG. 3  is a cross-section of solar thermal panel  100  through the high temperature working fluid cavity  107 . As shown in the cross-section of solar thermal panel  100  on the right hand side of  FIG. 3 , working fluid  316  in one example enters the manifold structure of high temperature working fluid cavity  107  of solar thermal panel  100  on the left hand side. In operation, the working fluid  316  is heated as it is transported through high temperature working fluid cavity  107  as a result of the absorbed solar radiation and heat transfer from contact to the hot walls of the high temperature working fluid  107 . When working fluid  316  exits the high temperature working fluid cavity  107  on the right hand side, the working fluid  316  is hot. In another example, the cavity  107  can be designed so that the working fluid  316  has a meandering path (instead of the path through the example manifold structure shown in  FIG. 3 ) from entry to exit of the high temperature working fluid cavity  107 . 
         [0043]      FIG. 4  shows an illustration which shows an example in which a plurality of individual solar thermal panels  100  are connected to one another to form an assembly  400  of solar thermal panels  100 . As can be observed in the illustrated example, solar thermal panels  100  may be constructed as modules, which can be interconnected to work together to build assembly  400  having a variety of shapes, sizes and configurations. As such, a large assembly  400  can be constructed for integration into a roof of a building or a smaller assembly  400  can be constructed for integration into a portion of a wall. 
         [0044]    As shown in the illustrated example, the plurality of solar thermal panels  100  may be directly connected to one another, or may be connected to one another by tubing  417 . In operation, cold working fluid  316  can be pumped into assembly  400  through tubing  417  as shown on the left hand side of  FIG. 4 . As working fluid  316  is transported through each of the individual solar thermal panels  100 , working fluid  316  is heated until hot working fluid  316  exits assembly  400  from tubing  417  on the right hand side of  FIG. 4 . 
         [0045]    As mentioned above, with solar thermal panel  100  constructed as modules that can be configured as assemblies  400  as shown in  FIG. 4 , it is appreciated that solar thermal panel  100  can be integrated roofs and walls of buildings to provide integrated systems for power generation, heating, cooling and hot water for the building. In one example, the working fluid  316  heated by solar radiation in solar thermal panels  100  is transported and used as a high temperature source for a heat to electrical power conversion unit situated adjacent to or nearby the solar thermal panel  100 . In one example, the power conversion unit used to convert heat into electricity can be a Stirling engine or a steam turbine. In one example, the heat to electrical power conversion unit generates electricity to be used in the residential unit. 
         [0046]    In one example, residual high temperature working fluid  316  may be stored and (a) used to provide heat for the home; (b) used for air conditioning through a heat driven cooling unit; and (c) used for hot water appliances. In one example, a single or double effect steam powered absorption chiller can be used for air conditioning. In one example, the hot water appliance can utilize the cooling water used to maintain the constant temperature of the cold side of a Stirling engine in the range of 290 to 330° K used for residential hot water. The excess heat from the working fluid  316  used to heat the hot side of the Stirling engine is transferred to a heat reservoir. 
         [0047]    In one example, optimal distribution between the different types of uses of electricity, space heating, cooling, and/or hot water, is dynamically adjusted based on the specific demand conditions at the location and time of conversion. For example, a system in a warmer southern location in the summer will allocate more energy use for cooling, hot water and electricity with little or no energy use for space heating. In contrast, a system in winter in a northern area will use more energy in the space heating and hot water component while no cooling will be needed and electricity conversion would be on a best effort basis. Once the optimal distribution of collected energy is established, the system operating parameters are adjusted to maximize conversion efficiency for the specific mix required by the demand conditions. 
         [0048]      FIG. 5  is an illustration of a block diagram of one example of such a system  500  that includes evacuated solar thermal panels  100  in accordance with the teachings of the present invention. In the depicted example, one or more evacuated solar thermal panels are shown collectively in  FIG. 5  as collector array  501 . As shown, a flow control unit  503  coupled to collector array  501  adjusts the flow of working fluid through collector array  501  to control the collector temperature. The working fluid flows from collector array  501  to fluid routing unit  515 . In one example, the fluid routing unit routes the working fluid to loads  519 , which may include one or more of a spaced heating element  521 , a cooling element  523  (e.g. air conditioning), hot water storage  525  and/or a heat to power conversion unit  527 . As shown in the depicted example, fluid control unit  503  and fluid routing unit  515  are both coupled to be controlled by a central processing unit  517 . In one example, central processing unit  517  receives input information from an array of sensors  505 . In one example, the array of sensors  505  may include one or more of indoor temperature sensors  507 , outdoor photodetectors  509 , motion sensors  511  and/or usage sensors  513 . In one example, usages sensors  513  may include any combination of water usage sensors, heat usage sensors, air conditioning usage sensors, or the like. 
         [0049]    In one example, system  500  is an integrated system that is fully configurable to maximize the conversion efficiency of the system, defined as a percentage of total energy demand of the unit supplied by system  500 , by continuously adjusting certain operating parameters. As shown in the example depicted in  FIG. 5 , operation of system  500  is based on central processing unit  517 . In one example, central processing unit  517  may include a microcontroller or a digital signal processor with a suitable amount of memory. In the illustrated example, the array of sensors  505  provides central processing unit  517  with real time information regarding indoor and outdoor parameters. In one example, the indoor parameters provided by the array of sensors  505  include temperature, humidity, and/or the number of occupants of the unit at any given moment. In one example, the outdoor parameters provided by the array of sensors  505  include the solar radiation incident on collector array  501  and/or the outside temperature. 
         [0050]    In one example, central processing unit  517  is coupled to control the flow and temperature of the working fluid through collector array  501  based on input solar radiation conditions and demand patterns as provided from the array of sensors  505  to maximize conversion efficiency of the system  500  and useable energy. For example, a system  500  operating in winter with low ambient temperatures in overcast conditions would have a low level of incident solar radiation, such as for example on the order of approximately 100-200 W/m2. In this situation, example system  500  maximizes its overall conversion efficiency by using most of the heat output of collector array  501  as energy supply for space heating element  521 . As space heating does not require elevated temperatures, efficiency can be maximized by reducing the operating temperature from 200° C. to 100° C. of the working fluid through collector array  501  to reduce radiative loss, even if electricity generation by heat to power conversion unit  527  would be impaired. In addition, the array of sensors  505  throughout the home coupled with electronic control would further optimize parameters range for optimum efficiency. Examples of parameters to be taken into account include preset comfort levels, electricity pricing, storage efficiency, and the like. Excess heat stored in the heat reservoir can be used for heating needs or transformed in electricity during the times when no direct solar radiation is available, such as for example during night time or during periods of cloudy weather. 
         [0051]      FIG. 6  shows a block diagram of example processing included in an example system that includes one or more example low loss evacuated solar thermal panels in accordance with the teachings of the present invention. As shown in the depicted illustration, example system  600  includes a central processing unit  617 , receives sensor data  603  and electrical grid data  613 , and utilizes processing and library  619 , which includes historical data, to optimize for maximum system efficiency, defined as percentage of total energy demand of the unit supplied by system  500 , when calculating desired operation parameters for collector flow rate  601  of the energy from the collector array, and when calculating the flow rate distribution to loads  615 . 
         [0052]    As will be discussed in greater detail below, the processing and library  619  utilized by central processing unit  617  includes one or more of energy maximization processing  621 , weather forecast data  623 , calculated solar intensity  625 , collector loss vs. operation temperature data  627 , data history on water, heat, air conditioning power used  629  and user settings  631 . In addition, the sensor data  603  received by central processing unit  617  includes one or more of indoor temperature  605 , solar radiation intensity  607 , number of household members  609  and data acquisition on water, heat and air conditioning power used  611 . 
         [0053]    In particular, one example of the efficiency maximization processing  621  utilized by the central processing unit  617  calculates collector array temperature of operation and flow rates and distribution of collected heat to the loads to maximize system efficiency, defined as percentage of total energy demand of the unit supplied by system  500 . In one example, the weather forecast data  623  includes short/medium term weather data provided by local weather services. The calculated solar intensity  625  includes theoretical solar flux data for the location and time of the year without taking into account weather. In one example, weather information may also be added based on the weather forecast data and real time data. Collector loss vs. operation temperature data  627  may include specified loss curves for the collector, such as for example the loss curves illustrated and described in greater detail below with respect to  FIG. 7 . Data history on water, heat, air conditioning power used  629  data may include data collected over time by the array of sensors that is used to establish time based usage patterns specific to the household. 
         [0054]    In one example, indoor temperature sensors  605  measure real time indoor temperatures. Solar radiation intensity sensors  607  include photodetectors that measure real time flux of incident radiation incident on the collector array. In one example, number of household members sensors  609  include motion sensors to detect the number of members of the household present and location to determine hot water and/or heating needs. 
         [0055]    In operation, in order to achieve maximum overall efficiency of system  600 , one example of central processing unit  617  utilizes several categories of data including real time input sensor data  603  from an array of sensors measuring the indoor and outdoor related parameters. Examples of indoor related parameters include indoor temperature data  605  such as air temperature data that is compared to the set/desired temperature, humidity, number of household members  609  or the number of occupants present in the unit at any time. Outdoors related parameters received by the central processing unit  617  include supply data such as solar radiation intensity  607  or solar energy flux on the collector, outdoor temperature, etc. 
         [0056]    In one example, central processing unit  617  also receives historical data from processing and library  619  on energy usage and type of energy, such as thermal and/or electrical, and time and location dependent weather patterns. In one example, usage data collected by the sensors is stored to be used by central processing unit  617  to determine usage patterns and optimize the operation of the system  600 . In one example, medium term weather forecast data  623  may be provided to central processing unit  617  from external sources, such as for example public weather services. In one example, central processing unit  617  also utilizes electrical grid data  613 , such as for example grid loading at particular times that can be used to decide on the priority for conversion of the collected energy into electricity. 
         [0057]    As mentioned above, in order to maximize efficiency, one example of central processing unit  617  also considers calculated collector loss profiles as a function of temperature of operation, examples of which are illustrated in the example curves shown in the graph  FIG. 7 . In particular, curve  701  of  FIG. 7  shows an example of normalized loss for the collector (W/m2) versus temperature of operation of the working fluid (° C.) for aggregate loss (including radiative, conductive/convective and junction loss). Curve  703  shows an example of normalized loss for the versus temperature of operation of the working fluid for conductive/convective loss, while curve  705  shows an example of normalized loss for the versus temperature of operation of the working fluid for junction loss. By comparing the input normalized energy flux on the collector array with the normalized loss at set operation temperature, optimal parameters of operation for the collector array can be determined. For example if the incident radiation is in the range of 180 W/m2, a collector operating at 250° C. will have an efficiency of less than 30% (180−130)/180 while operating at 100° C. the efficiency will be over 80% (180−30)/180). 
         [0058]    In summary, referring back to  FIG. 5 , based on the input data discussed above, one example of the central processing unit  517  calculates the optimal temperature of operation for the collector array  501 /working fluid and the fluid flow required to achieve the desired temperature. The central processing unit  517  output is provided to a flow control unit  503  to adjust the flow of the working fluid to adjust the collector temperature. In addition, a second parameter that is calculated by the central processing unit  517  is provided to a fluid routing unit  515  to control the distribution of the collected energy to the different loads in loads  519 , including for example, space heating element  521 , cooling element  523 , hot water storage  525  and heat to power conversion unit  527 . 
         [0059]    The above description of illustrated examples of the present invention, including what is described in the Abstract, are not intended to be exhaustive or to be limitation to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible without departing from the broader spirit and scope of the present invention. Indeed, it is appreciated that the specific temperatures, mechanical parameters, voltages, currents, frequencies, power range values, times, etc., are provided for explanation purposes and that other values may also be employed in other embodiments and examples in accordance with the teachings of the present invention. 
         [0060]    These modifications can be made to examples of the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims. Rather, the scope is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation. The present specification and figures are accordingly to be regarded as illustrative rather than restrictive.