Devices measuring diffuse and global irradiances using an internal automated shadowband

Abstract

Solar irradiance incident on the surface of the earth is typically classified into three components: global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI) and direct normal irradiance (DNI). Accurate measurements of these irradiance components are vital for many applications but for an ever-increasing number of PV sites, in addition to measuring the GHI, the measurement of DHI is mandated or required. Many instruments from several manufacturers exist to perform these tasks, such as a pyranometer and a pyrheliometer requiring a suite of at least these two expensive instruments and a solar tracker to perform the required measurements. Accordingly, the invention provides users with a single instrument with no moving external parts capable of measuring all three irradiance components, thereby simplifying the data acquisition and minimizing equipment cost whilst providing measurements with low uncertainty.

Description

01 X 1 C I S MEASURING DIFI LSI AND GLOBAL IRRADIANCES USING AN INTERNAL AUTOMATED SHADOWBANDCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of priority to U.S. Provisional Patent Application 63 / 640,494 filed April 30, 2024; the entire contents of which are incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates to solar irradiance and more particularly to compact self- contained field deployable devices and methods of measuring and resolving global, direct and diffuse irradiance.BACKGROUND OF THE INVENTION

[0003] Large arrays of PV devices are referred to as PV power stations but are more commonly referred to as a solar farm. A solar farm differs from most building-mounted and other decentralized solar power generation as it supplies power at the utility level, rather than to a local user or users. However, whether it is a solar farm or any other solar installation the operator in establishing a PV power plant performance assessment requires accurate information of the solar irradiance. Further, solar irradiance measurements are important for other applications such as weather forecasting and climate studies.

[0004] Solar irradiance incident on the surface of the earth is typically classified into three components: global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI) and direct normal irradiance (DNI). The DNI is defined as a direct beam of sunlight within a narrow field of view (+ / - 2.5 degrees), while DHI is the irradiance that has been scattered by the sky dome and / or the clouds. The combination of the DNI and DHI received by the horizontal plane is termed the GHI. As noted accurate measurements of these irradiance components are vital for many applications but for an ever- increasing number of PV sites, in addition to measuring the GHI, the measurement of DHI is mandated or required. Many instruments from several manufacturers exist to perform these tasks, such as a pyranometer and a pyrheliometer. However, one would require a suite of at least these two expensive instruments and a solar tracker to perform the required measurements. Accordingly, it wouldbe beneficial to provide users with a single instrument with no moving external parts capable of measuring all three irradiance components, thereby simplifying the data acquisition and minimizing equipment cost. Further, the instrument should measure all three components of sunlight with low uncertainty.

[0005] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to mitigate limitations within the prior art relating to solar irradiance and more particularly to compact self-contained field deployable devices and methods of measuring and resolving global, direct and diffuse irradiances.

[0007] In accordance with an embodiment of the invention there is provided a device comprising a controller for controlling a motor having a rotatable shaft; the motor; a shadow band (shadowband) mechanically coupled to an assembly mounted to the rotatable shaft a first detector responsive to optical signals over a predetermined wavelength range mechanically coupled to the assembly disposed in a first position with respect to the shadowband such that the first detector is exposed to both diffuse horizontal irradiance (DHI) of an ambient environment the device is deployed within and direct normal irradiance (DNI) of the ambient environment; and a second detector responsive to optical signals over the predetermined wavelength range mechanically coupled to the assembly disposed in a second position with respect to the shadowband such that the second detector is exposed to only the DHI of the ambient environment as the DNI of the ambient environment is blocked by the shadowband; wherein the controller executes a measurement algorithm which drives the motor to rotate the rotatable shaft to azimuthally track the sun and process measurements from the first detector and the second detector.

[0008] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:

[0010] Figure 1 depicts a front elevation view of a solar irradiance measurement device with a shadow band (ShadowBand), the device being referred to hereinafter as a SolarBand device, according to an embodiment of the invention;

[0011] Figure 2 depicts a side elevation view of the SolarBand device according to the embodiment of the invention depicted in Figure 1 ;

[0012] Figure 3 and 4 depict front and rear perspective views of the SolarBand device according to the embodiment of the invention depicted in Figure 1;

[0013] Figure 5 depicts a plan view of the SolarBand device according to the embodiment of the invention depicted in Figure 1;

[0014] Figure 6 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 1 with the outer casing and cover dome removed;

[0015] Figure 7 depicts a rear view of the SolarBand device according to the embodiment of the invention depicted in Figure 1 with the outer casing and cover dome removed;

[0016] Figure 8 depicts a rear perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 1 with the outer casing and cover dome removed;

[0017] Figure 9A depicts a rear perspective view of the optical sub-assembly for the SolarBand device according to the embodiment of the invention depicted in Figure 1;

[0018] Figure 9B depicts the diffuser plate of the SolarBand device with a cover removed to show the navigation sensor disposed within the diffuser plate depicted in Figure 1;

[0019] Figure 10A depicts a cross-section of a sensor assembly for the SolarBand device according to the embodiment of the invention depicted in Figure 1;

[0020] Figure 10B depicts a cross-section of a sensor assembly according to an embodiment of the invention for the SolarBand device depicted in Figure 1;

[0021] Figure 10C depicts a cross-section of a sensor assembly according to an embodiment of the invention for the SolarBand device depicted in Figure 1; and

[0022] Figure 10D depicts transmission spectra of silica glasses for use as diffuser elements within the sensor assemblies of SolarBand devices according to the embodiment of the invention and other embodiments of the invention.

[0023] Figure 11 depicts a front elevation view of a solar irradiance measurement device with ShadowBand (hereinafter referred to as a SolarBand device) according to an embodiment of the invention;

[0024] Figure 12 depicts a side elevation view of the SolarBand device according to the embodiment of the invention depicted in Figure 11 ;

[0025] Figure 13 and 14 depict front and rear perspective views of the SolarBand device according to the embodiment of the invention depicted in Figure 11 ;

[0026] Figure 15 depicts a plan view of the SolarBand device according to the embodiment of the invention depicted in Figure 11 ;

[0027] Figure 16 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 11 with the outer casing and cover dome removed;

[0028] Figure 17 depicts a rear view of the SolarBand device according to the embodiment of the invention depicted in Figure 11 with the outer casing and cover dome removed;

[0029] Figure 18 depicts a rear perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 11 with the outer casing and cover dome removed; and

[0030] Figure 19 depicts a rear perspective view of the upper optical assembly and ShadowBand for the SolarBand device according to other embodiment of the invention depicted in Figure 11 ;

[0031] Figures 20 and 21 depict front and rear perspective views of a SolarBand device according to an embodiment of the invention;

[0032] Figure 22 depicts a plan view of the SolarBand device according to the embodiment of the invention depicted in Figure 20;

[0033] Figure 23 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 20 with the outer casing and cover dome removed;

[0034] Figure 24 depicts a front perspective view of the upper optical assembly and ShadowBand for the SolarBand device according to other embodiment of the invention depicted in Figure 20;

[0035] Figure 25 depicts a front perspective view of the upper optical assembly and ShadowBand for the SolarBand device according to other embodiment of the invention depicted in Figure 20 with a diffuser mounting plate removed;

[0036] Figure 26 depicts a plan view of a SolarBand device according to an embodiment of the invention;

[0037] Figure 27 depicts a perspective view of a SolarBand device according to an embodiment of the invention with fixed photodetectors and rotating shadow band;

[0038] Figure 28 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the dome and outer casing removed;

[0039] Figure 29 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the external protective portions removed together with a diffuser assembly cover removed;

[0040] Figure 30 depicts a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the external protective portions removed together with a diffuser assembly removed;

[0041] Figure 31 depicts a cross-sectional perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the dome and outer casing removed;

[0042] Figure 32 depicts a cross-sectional view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the dome, outer casing and elements of the diffuser assembly removed; and

[0043] Figure 33 depicts a perspective view of the diffuser assembly of the SolarBand device according to the embodiment of the invention depicted in Figure 27.

[0044] DETAILED DESCRIPTION

[0045] The present invention is directed to solar irradiance and more particularly to compact self-contained field deployable devices and methods of measuring and resolving global, direct and diffuse irradiances.

[0046] The ensuing description provides representative embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the disclosure. Rather, theensuing description of the embodiment(s) will provide those skilled in the art with an enabling description for implementing an embodiment or embodiments of the invention. It being understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope as set forth in the appended claims. Accordingly, an embodiment is an example or implementation of the inventions and not the sole implementation. Various appearances of “one embodiment,” “an embodiment” or “some embodiments” do not necessarily all refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention can also be implemented in a single embodiment or any combination of embodiments.

[0047] Reference in the specification to “one embodiment”, “an embodiment”, “some embodiments” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment, but not necessarily all embodiments, of the inventions. The phraseology and terminology employed herein is not to be construed as limiting but is for descriptive purpose only. It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not to be construed as there being only one of that element. It is to be understood that where the specification states that a component feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included.

[0048] Reference to terms such as “left”, “right”, “top”, “bottom”, “front” and “back” are intended for use in respect to the orientation of the particular feature, structure, or element within the figures depicting embodiments of the invention. It would be evident that such directional terminology with respect to the actual use of a device has no specific meaning as the device can be employed in a multiplicity of orientations by the user or users. Reference to terms “including”, “comprising”, “consisting” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, integers or groups thereof and that the terms are not to be construed as specifying components, features, steps or integers. Likewise, the phrase “consisting essentially of’, and grammatical variants thereof, when used herein is not to be construed as excluding additional components, steps, features integers or groups thereof but rather that the additional features, integers, steps, components or groups thereof do not materially alter the basic and novel characteristics of the claimedcomposition, device or method. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.

[0049] A “portable electronic device” (PED) as used herein and throughout this disclosure, refers to a wireless device used for communications and other applications that requires a battery or other independent form of energy for power. This includes devices, but is not limited to, such as a cellular telephone, smartphone, personal digital assistant (PDA), portable computer, pager, portable multimedia player, portable gaming console, laptop computer, tablet computer, a wearable device and an electronic reader.

[0050] A “fixed electronic device” (FED) as used herein and throughout this disclosure, refers to a wireless and / or wired device used for communications and other applications that requires connection to a fixed interface to obtain power. This includes, but is not limited to, a laptop computer, a personal computer, a computer server, a kiosk, a gaming console, a digital set-top box, an analog set-top box, an Internet enabled appliance, an Internet enabled television, and a multimedia player.

[0051] A “server” as used herein, and throughout this disclosure, refers to one or more physical computers co-located and / or geographically distributed running one or more services as a host to users of other computers, PEDs, FEDs, etc. to serve the client needs of these other users. This includes, but is not limited to, a database server, file server, mail server, print server, web server, gaming server, or virtual environment server.

[0052] An “application” (commonly referred to as an “app”) as used herein may refer to, but is not limited to, a “software application”, an element of a “software suite”, a computer program designed to allow an individual to perform an activity, a computer program designed to allow an electronic device to perform an activity, and a computer program designed to communicate with local and / or remote electronic devices. An application thus differs from an operating system (which runs a computer), a utility (which performs maintenance or general-purpose chores), and programming tool (with which computer programs are created). Generally, within the following description with respect to embodiments of the invention an application is generally presented in respect of software permanently and / or temporarily installed upon a PED and / or FED.

[0053] “Electronic content” (also referred to as “content” or “digital content”) as used herein may refer to, but is not limited to, any type of content that exists in the form of digital data as stored, transmitted, received and / or converted wherein one or more of these steps may be analog although generally these steps will be digital. Forms of digital content include, but are not limited to, information that is digitally broadcast, streamed or contained in discrete files.Viewed narrowly, types of digital content include popular media types such as MP3, JPG, AVI, TIFF, AAC, TXT, RTF, HTML, XHTML, PDF, XLS, SVG, WMA, MP4, FLV, and PPT, for example, as well as others, see for example http: / / en.wikipedia.org / wiki / List_of_fde_formats. Within a broader approach digital content mat include any type of digital information, e.g. digitally updated weather forecast, a GPS map, an eBook, a photograph, a video, a Vine™, a blog posting, a Facebook™ posting, a Twitter™ tweet, online TV, etc. The digital content may be any digital data that is at least one of generated, selected, created, modified, and transmitted in response to a user request, said request may be a query, a search, a trigger, an alarm, and a message for example.

[0054] A “plug” as used herein and throughout this disclosure, refer to, but is not limited to, one half of an electrical connector with the other half being the socket. The plug is usually considered the male portion of an electrical connector and comprises one or more pins or jacks that are designed to mate with their corresponding socket.

[0055] A “socket” as used herein and throughout this disclosure, refer to, but is not limited to, one half of an electrical connector with the other half being the plug. The socket is usually considered the female portion of an electrical connector and comprises one or more openings that are designed to mate with their corresponding plug pins or jack.

[0056] An “electrical connector” is an electro -mechanical device used to join electrical terminations and create an electrical circuit. Electrical connectors typically consist of plugs (male-ended) and jacks (female-ended). The connection may be made / unmade manually or may require a tool for assembly and removal.

[0057] An “electrical supply” as used herein and throughout this disclosure, refer to, but is not limited to, an electrical power supply to which an electrical receptacle or switch receptacle is connected in order to provide electrical power for the receptacle, its user accessible features such as a socket, switch, etc. and provides power to the demountable insert(s) supported by the electrical receptacle. In most instances the electrical supply is the general-purpose alternating-current (AC) electric power supply received at the residence, retail building, office, commercial building etc. However, in other instances it may be a different AC electrical power supply derived from the general-purpose AC or another power supply such as a generator. In other instances, the electrical supply may be a direct-current (DC) electrical supply. General-purpose AC is typically 110V / 120V or 220V / 230V / 240V at either 50Hz or 60Hz. However, in other instances it may be at other frequencies such as 400Hz for example in avionics applications.

[0058] A “wireless standard” as used herein and throughout this disclosure, refer to, but is not limited to, a standard for transmitting signals and / or data through electromagnetic radiation which may be optical, radio-frequency (RF) or microwave although typically RF wireless systems and techniques dominate. A wireless standard may be defined globally, nationally, or specific to an equipment manufacturer or set of equipment manufacturers. Dominant wireless standards at present include, but are not limited to IEEE 802.11, IEEE 802.15, IEEE 802.16, IEEE 802.20, UMTS, GSM 850, GSM 900, GSM 1800, GSM 1900, GPRS, ITU-R 5.138, ITU-R 5.150, ITU-R 5.280, IMT-1000, Bluetooth, Wi-Fi, Ultra- Wideband and WiMAX. Some standards may be a conglomeration of sub-standards such as IEEE 802.11 which may refer to, but is not limited to, IEEE 802.1a, IEEE 802.11b, IEEE 802.11g, or IEEE 802.1 In as well as others under the IEEE 802.11 umbrella.

[0059] A “wired standard” as used herein and throughout this disclosure, generally refer to, but is not limited to, a standard for transmitting signals and / or data through an electrical cable discretely or in combination with another signal. Such wired standards may include, but are not limited to, digital subscriber loop (DSL), Dial-Up (exploiting the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP)), Data Over Cable Service Interface Specification (DOCSIS), Ethernet, Gigabit home networking (G.hn), Integrated Services Digital Network (ISDN), Multimedia over Coax Alliance (MoCA), and Power Line Communication (PLC, wherein data is overlaid to AC / DC power supply). In some embodiments a “wired standard” may refer to, but is not limited to, exploiting an optical cable and optical interfaces such as within Passive Optical Networks (PONs) for example.

[0060] Solar irradiance incident on the surface of the earth is typically classified into three components, these being global horizontal irradiance (GHI), diffuse horizontal irradiance (DHI) and direct normal irradiance (DNI). DNI is defined as a direct beam of sunlight within a narrow field of view (+ / - 2.5 degrees), whilst DHI is the irradiance that has been scattered by the sky dome and / or the clouds. The combination of the DNI and DHI received by the horizontal plane is termed the GHI. Accurate measurements of these irradiance components are vital for many applications from photovoltaic (PV) power plant performance assessment to weather forecasting and climate studies. Further, at an ever-increasing number of PV sites, in addition to the GHI, the measurement of the DHI is mandated or required.

[0061] Several manufacturers offer instruments for irradiance measurements, such as pyranometers and pyrheliometers. However, the measurement of all three irradiance components requires a suite of at least two of these instruments and a solar tracker.Accordingly, it would be beneficial to provide plant operators and others requiring these irradiance measurements with a single instrument capable of measuring all three irradiance components thereby simplifying the data acquisition and minimizing equipment costs, maintenance costs etc.

[0062] Within the prior art there are two instruments capable of measuring and / or resolving all three irradiance components within a single device, these being a rotating shadow band (or shadowband) radiometer and shadow mask (or shadowmask) pyranometer. The rotating shadowband radiometer employs a single silicon-based detector positioned in the center of the rotating shadowband. The rotating shadowband radiometer makes measurements of the GHI whilst the shadowband is down, then rotates the shadowband to scan the sky and identify when the shadow from the band falls onto the detector wherein the rotating shadowband radiometer makes a DHI measurement. Accordingly, the DNI can be calculated from these two measurements.

[0063] A shadowmask pyranometer, in contrast, employs a computer generated shadowmask and an array of seven sensors, for example thermopile sensors, with the intent that, at any time, one sensor is completely exposed to the sun and one thermopile sensor is completely shaded at any location around the world. Accordingly, the sun illuminated sensor measures the GHI, while the shaded sensor measures the DHI, from which the DNI can again be calculated.

[0064] However, in each a significant limitation is their relatively high uncertainty. Accordingly, the inventors in addition to establishing a single instrument capable of measuring all three irradiance components have established an instrument with no moving external parts that measures all three irradiance components with reduced uncertainty relative to these prior art alternatives.

[0065] Within the following description the single instrument capable of measuring all three irradiance components, established by the inventors according to embodiments of the invention, is a solar irradiance measurement device with a shadow band (shadowband) referred to hereinafter as a SolarBand device.

[0066] Referring to Figure 1 there is depicted a front elevation view of the SolarBand device, according to an embodiment of the invention. As depicted the SolarBand device comprises a Housing 130, a Base Plate 140, a Dome 110 and a Shadow Band (ShadowBand) 120. The Dome 110 being transparent over the range of wavelength range(s) of interest for the device’s operation, for example, 200 nm - 1,000 nm (1 pm) or to 250 nm - 3,000 nm (3 pm).

[0067] For improved performance the ShadowBand 120 has a surface finish that minimizes the reflection(s) of incident light, e.g. sunlight. Accordingly, the ShadowBand 120 may be optically black over the wavelength range(s) of interest for the device’s operation, for example, 200 nm - 1,000 nm (1 pm) or to 250 nm - 3,000 nm (3 pm).

[0068] In Figure 2 there is depicted a side elevation view of the SolarBand device according to the embodiment of the invention wherein a Connector 210 is depicted on the rear of the Housing 130. The Connector 210 providing, for example, an external power interface discretely or an external power interface and a communications interface. Connector 210 may be a plug or socket. The external power interface being coupled to an external electrical supply and / or battery. The communications interface being according to a wired standard.

[0069] Figures 3 and 4 depict front and rear perspective views of the SolarBand device according to the embodiment of the invention. As depicted within the SolarBand device under the Dome 110 are the ShadowBand 120, a Bubble Level 310, Shadow Diffuser and Detector Set 320, Exposed Diffuser and Detector Set 330, Diffuser Mounting Plate 340 and Navigation Receiver Cover 350. Also depicted is Blanking Plate 360 as within the embodiment of the invention depicted in Figures 1 to 9B a single Exposed Diffuser and Detector Set 330 is depicted. Within another embodiment of the invention the Blanking Plate 360 may be replaced with another Exposed Diffuser and Detector Set 330 such that a pair of Exposed Diffuser and Detector Sets 330 are employed.

[0070] The Bubble Level 310 being a bull's eye (or circular) bubble level for levelling the SolarBand upon a base, mounting or other element the SolarBand is deployed upon permanently, periodically, or temporarily. As evident from Figures 7 and 8 the Diffuser Mounting Plate 340 and therein ShadowBand 120 are mounted upon a rotary motor, e.g. Stepper Motor 750 as depicted in Figure 7, which provides for rotation of the Diffuser Mounting Plate 340 and ShadowBand 120 within the Dome 110 and Housing 130.

[0071] Within embodiments of the invention the Diffuser Mounting Plate 340 may have a surface finish that is reflective, diffusing, optically absorbent or a combination of these in order to both optimize the angular responses of each the diffuse and global sensors. Within other embodiments of the invention various insets, inserts or other mechanical modifications to the surface of the Diffuser Mounting Plate 340 may be made in order to improve the cosine response of the sensors.

[0072] The Navigation Receiver Cover 350 being transparent to wireless signals within a frequency band or frequency bands of a global navigation satellite system (GNSS) depending upon whether the GNSS Antenna, such as GNSS Antenna 950 in Figure 9B which ismounted with a cavity within the Diffuser Mounting Plate 340. Exemplary GNSS systems including, for example, Beidou, Galileo, GLONASS, GPS, and NAVIC. Beidou, Galileo, GLONASS and GPS provide for dual-band operation in the frequency range 1150MHz- 1610MHz.

[0073] The junction of the ShadowBand 120 is evident in Figure 5 which depicts a pian view of the SolarBand device according to the embodiment of the invention. Accordingly, depicted are the Bubble Level 310, Exposed Diffuser and Detector Set 330 and Navigation Receiver Cover 350 within the Diffuser Mounting Plate 340. The Shadow Diffuser and Detector Set 320 within the Diffuser Mounting Plate 340 is covered by the ShadowBand 120 such that the ShadowBand 120 blocks the Shadow Diffuser and Detector Set 320 from solar illumination. The angle blocked by the ShadowBand 120 is defined by the width of the ShadowBand 120 and its distance from the Shadow Diffuser and Detector Set 320.

[0074] Now referring to Figure 6 there is depicted a perspective view of the SolarBand device according to the embodiment of the invention with the outer casing, Housing 130, and cover, Dome 110, removed. Accordingly, the Bubble Level 310, Exposed Diffuser and Detector Set 330 and Navigation Receiver Cover 350 within the Diffuser Mounting Plate 340 are depicted with the ShadowBand 120 attached to the Diffuser Mounting Plate 340. Disposed below the Diffuser Mounting Plate 340 is Main Printed Circuit Board (PCB) 610.

[0075] Figures 7 and 8 depict rear and rear perspective views of the SolarBand device according to the embodiment of the invention with the outer casing, Housing 130, and cover, Dome 110, removed. Accordingly, there is depicted the Base Plate 140 upon which is mounted Stepper Motor 750 and atop the body of the Stepper Motor 750 the Main PCB 610. Disposed between the Main PCB 610 and Base Plate 140 are Stepper Motor Driver 740 and Microcontroller 760. Disposed atop the Stepper Motor 750 is Collar 730 which forms part of or is joined with Mounting Flange 720 atop of which is Diffuser Mounting Plate 340 and ShadowBand 120. Disposed on the bottom of the Diffuser Mounting Plate 340 is Auxiliary PCB 710 and disposed on the bottom of the Mounting Flange 720 is GNSS Receiver Circuit 770 which is coupled to the GNSS Antenna, such as GNSS Antenna 950 in Figure 9B. The Auxiliary PCB 710 may be mounted to the Mounting Flange 720 or to the Diffuser Mounting Plate 340.

[0076] Within embodiments of the invention the Stepper Motor 750 is mounted to the Base Plate 140 such that there is good thermal conductions from the Stepper Motor 750 to the Base Plate 140 and therein heat sinking to the structure upon which the SolarBand device is mounted. Within Figures 7 and 8 a Stop 790 is depicted forming part of the Mounting Flange720 wherein within some embodiments of the invention the Stop 790 engages a Limiter or a pair of Limiters (not depicted for clarity singly or as pair). The single Limiter limiting rotation of the Mounting Flange 720 and all elements connected to it in a single direction whereas a pair of Limiters limit rotation of the Mounting Flange 720 and all elements connected to it in both directions. Within other embodiments of the invention the Stop 790 and / or Limiter(s) are omitted.

[0077] Accordingly, the shaft of the Stepper Motor 750 is coupled to the Collar 730 as depicted in the insert of Figure 7 such that operation of the Stepper Motor 750 results in rotation of the shaft of the Stepper Motor 750 and therein rotation of the Collar 730, Mounting Flange 720 and Diffuser Mounting Plate 340 with its attached ShadowBand 120. Collar 730 and Mounting Flange 720 may be a single piece-part or different piece-parts.

[0078] Within embodiments of the invention the electrical power for the circuits and elements which rotate relative to the Base Plate 140 via action of the Stepper Motor 750 would be provided by one of several means including, for example, slip-ring electrical connections upon the shaft of the Stepper Motor 750 and Collar 730, wireless power transfer, or direct electrical connections from the lower stationary portion of the SolarBand device to the upper rotating portion of the SolarBand device which can accommodate the rotation without tangling etc. These electrical connection methodology is not depicted for clarity.

[0079] Figure 9 A depicts a rear perspective view of the Auxiliary PCB 710 supporting the optical sub-assembly for the SolarBand device according to the embodiment of the invention together with the Bubble Level 310 and ShadowBand 120. Mounted upon the Auxiliary PCB 710 are first and second Shadow Sensors 920(A) and 920(B) together with first and second Diffuser Elements 910(A) and 910(B) respectively which form part of the Shadow Diffuser and Detector Set 320. Also mounted upon the Auxiliary PCB 710 are first and second Exposed Sensors 940(A) and 940(B) together with third and fourth Diffuser Elements 930(A) and 930(B) respectively which form part of the Exposed Diffuser and Detector Set 330.

[0080] As depicted each of the Shadow Diffuser and Detector Set 320 and Exposed Diffuser and Detector Set 330 comprises a pair of sensor elements, for example, first and second Shadow Sensors 920(A) and 920(B) in the Shadow Diffuser and Detector Set 320 and first and second Exposed Sensors 940(A) and 940(B) within the Exposed Diffuser and Detector Set 330. In each pair of sensor elements one sensor element is defined as “active” and the other is defined as a “reference.”

[0081] Within other embodiments of the invention the Bubble Level 310 may be attached to another part of the SolarBand device rather than the Diffuser Element Plate 340, for example Base Plate 140.

[0082] Figure 9B depicts the Diffuser Mounting Plate 340 of the SolarBand device with the Navigation Receiver Cover 350 removed to show the navigation antenna, GNSS Antenna 950, disposed within the Diffuser Mounting Plate 340. The GNSS Antenna 950 being coupled to the GNSS Receiver Circuit 770 depicted in Figure 7.

[0083] Referring to Figure 10A there is depicted a cross-section of a Sensor Assembly 1000A for the SolarBand device according to the other embodiment of the invention which provides an “active” sensor element as described above. The Sensor 1030 is depicted attached to the Auxiliary PCB 710 with the Diffuser Mounting Plate 340 mounted above wherein a Diffuser Element 1010 is mounted within a recess within the other distal side of the Diffuser Mounting Plate 340 wherein an Opening 1020 within the Diffuser Mounting Plate 340 provides an optical path between the Diffuser Element 1010 and Sensor 1030. The Diffuser Element 1010 being formed from a material transparent over the range of wavelength range(s) of interest for the device’s operation, for example, 200 nm - 1,000 nm (1 pm) or to 250 nm - 3,000 nm (3 pm) but providing diffusion of impinging optical signals, e.g. the surfaces of the Diffuser Element 1010 are fine ground or etched or the Diffuser Element 1010 may comprise a sheet of holographic diffuser elements etc. Optionally, the Opening 1020 may be filed with a material other than air provided that is similarly formed from a material transparent over the range of wavelength range(s) of interest for the device’s operation, for example, 200 nm - 1,000 nm (1 pm) or to 250 nm - 3,000 nm (3 pm).

[0084] Referring to Figure 10B depicts a cross-section of a Sensor 1000B assembly according to an embodiment of the invention for a SolarBand device which provides a “reference” sensor element as described above. The design being similar to that of the Sensor 1000A except a Blanking Element 1040 is disposed between the Diffuser Element 1010 and Opening 1020. The Blanking Element 1040 preventing optical signals within the range of interest propagating to the Sensor 1030, i.e. the material is opaque, highly absorptive, reflective etc. Now referring to Figure 10C there is depicted a cross-section of a Sensor 1000C assembly according to another embodiment of the invention for the SolarBand device according to the other embodiment of the invention which provides a “reference” sensor element as described above. Within Sensor 1000C the Diffuser Element 1010 has been omitted and the Opening 1020 is now a Blanked Hole 1050. In each of Sensor 1000B and 1000C respectively the intent being to provide a reference sensor for providing a correctionsignal for use in conjunction with the output of Sensor Assembly 1000A, e.g. noise correction, and accordingly whilst the same Sensor 1030 is employed optical signals are blocked from it.

[0085] Now referring to Figure 10D there are depicted transmission spectra of silica glasses for use as diffuser elements, such as Diffuser Element 1010, within the sensor assemblies of SolarBand devices according to the embodiment of the invention and the other embodiment of the invention. First Spectrum 1000D being for an ultraviolet grade fiised silica, referred to as JGS1, which provides approximately 90% transmission from -205 nm to -1,250 nm. Second Spectrum 1000E being for an infrared grade fiised silica, referred to as JGS3, which provides approximately 90% transmission from -300 nmto -2,500 nm.

[0086] Within other embodiments of the invention the Diffuser Element 1010 may be formed from other glasses, Teflon™ or other suitable polymers that provide the required transparency over the wavelength range of interest for the SolarBand device.

[0087] It would be evident that the material for the diffuser is selected according to the target wavelength range of the SolarBand device as would the material for the Dome 110. As most plastics have significant absorption below -400 nm and above -1,500 nm with absorption peaks between 1,000 nm - 1,500 nm then a glass material offers improved transmission over the wavelength range(s) of interest.

[0088] Within other embodiments of the invention the optical Diffuser Element 1010 may be replaced with a black body receiver / emitter assembly. Optionally, within other embodiments of the invention an optical filter or optical filters may be disposed between the Diffuser Element 1010 and the Sensor 1030 in order to remove some wavelengths or ranges of wavelengths, provide repeatable upper and / or lower limits to the bandwidth, or attenuate some wavelengths or ranges of wavelengths to adjust responses to common responsivity with varying diffuser - sensor materials etc. Optionally, the Diffuser Element 1010 may be formed from a material having defined filtering or attenuation for specific wavelengths or ranges of wavelengths.

[0089] Optionally, referring to Figure 10C the Blanked Hole 1050 may be eliminated. Optionally, referring to Figures 10A to 10C the Diffuser Mounting Plate 340 may physically be in contact with or thermally in contact with the Package 1060 of the Sensor 340, e.g. using thermal paste or thermally conductive rubber, etc.

[0090] As depicted in Figures 10A and 10B the Diffuser Mounting Plate 340 may have a profile such that there is an Indented Ring 1070 around the Diffuser Element 1010. Theradius and depth of the Indented Ring 1070 relative to the Diffuser Element 1010 may provide an improved optical performance of the Sensor 1030 but may be omitted within other embodiments of the invention.

[0091] Referring to Figure 11 there is depicted a front elevation view of the SolarBand device, according to another embodiment of the invention. As depicted the SolarBand device comprises a Housing 1130, a Base Plate 1140, a Dome 1110 and a Shadow Band (ShadowBand) 1120. The Dome 1110 being transparent over the range of wavelength range(s) of interest for the device’s operation, for example, 200 nm - 1,000 nm (1 pm) or to 250 nm - 3,000 nm (3 pm).

[0092] In Figure 12 there is depicted a side elevation view of the SolarBand device according to the other embodiment of the invention wherein a Connector 1210 is depicted on the rear of the Housing 1130. The Connector 1210 providing, for example, an external power interface discretely or an external power interface and a communications interface. The external power interface being coupled to an external electrical supply and / or battery. The communications interface being according to a wired standard.

[0093] Figures 13 and 14 depict front and rear perspective views of the SolarBand device according to the other embodiment of the invention. As depicted within the SolarBand device under the Dome 1110 are the ShadowBand 1120, a Bubble 1310, Shadow Diffuser and Detector 1320, Exposed Diffuser and Detectors 1330(A) and 1330(B), Diffuser Mounting Plate 1340 and Navigation Receiver Cover 1350.

[0094] The Bubble Level 1310 being a bull's eye (or circular) bubble level for levelling the SolarBand upon a base, mounting or other element the SolarBand is deployed upon permanently, periodically, or temporarily. As evident from Figures 17 and 18 the Diffuser Mounting Plate 1340 and therein ShadowBand 1120 are mounted upon a rotary motor, e.g. Stepper Motor 1750 as depicted in Figure 17, which provides for rotation of the Diffuser Mounting Plate 1340 and ShadowBand 1120 within the Dome 1110 and Housing 1130.

[0095] The Navigation Receiver Cover 1350 being transparent to wireless signals within a frequency band or frequency bands of a global navigation satellite system (GNSS) depending upon whether the GNSS Antenna, such as GNSS Antenna 950 in Figure 9B which is mounted with a cavity within the Diffuser Mounting Plate 1340. Exemplary GNSS systems including, for example, Beidou, Galileo, GLONASS, GPS, and NAVIC. Beidou, Galileo, GLONASS and GPS provide for dual-band operation in the frequency range 1150MHz- 1610MHz.

[0096] The function of the ShadowBand 1120 is evident in Figure 15 which depicts a plan view of the SolarBand device according to the other embodiment of the invention. Accordingly, depicted are the Bubble Level 1310, Exposed Diffuser and Detectors 1330(A) and 1330(B) respectively and Navigation Receiver Cover 1350 within the Diffuser Mounting Plate 1340. The Shadow Diffuser and Detector 1320 within the Diffuser Mounting Plate 1340 is covered by the ShadowBand 1120 such that the ShadowBand 1120 blocks the Shadow Diffuser and Detector 1320 from solar illumination. The angle blocked by the ShadowBand 1120 is defined by the width of the ShadowBand 1120 and its distance from the Shadow Diffuser and Detector 1320.

[0097] Now referring to Figure 16 there is depicted a perspective view of the SolarBand device according to the other embodiment of the invention with the outer casing, Housing 1130, and cover, Dome 1110, removed. Accordingly, the Bubble Level 1310, Exposed Diffuser and Detectors 1330(A) and 1330(B) respectively and Navigation Receiver Cover 1350 within the Diffuser Mounting Plate 1340 are depicted with the ShadowBand 1120 attached to the Diffuser Mounting Plate 1340. Disposed below the Diffuser Mounting Plate 1340 is Main Printed Circuit Board (PCB) 1610.

[0098] Figures 17 and 18 depict rear and rear perspective views of the SolarBand device according to the other embodiment of the invention with the outer casing, Housing 1130, and cover, Dome 1110, removed. Accordingly, there is depicted the Base Plate 1140 upon which is mounted Stepper Motor 1750 and atop the body of the Stepper Motor 1750 the Main PCB 1610. Disposed between the Main PCB 1610 and Base Plate 1140 are Stepper Motor Driver 1740 and Microcontroller 1760. Disposed atop the Stepper Motor 1750 is Collar 1730 which forms part of or is joined with Mounting Flange 1720 atop of which is Diffuser Mounting Plate 1340 and ShadowBand 1120.

[0099] An Auxiliary PCB, such as Auxiliary PCB 1910 in Figure 19, which is not depicted for clarity would be disposed on the bottom of the Diffuser Mounting Plate 1340 and mounted to it. Disposed on the bottom of the Mounting Flange 720 is GNSS Receiver Circuit 770 which is coupled to the GNSS Antenna, such as GNSS Antenna 950 in Figure 9B. Accordingly, the shaft of the Stepper Motor 1750 is coupled to the Collar 1730, in a manner similar to that depicted in the insert of Figure 7, such that operation of the Stepper Motor 1750 results in rotation of the shaft of the Stepper Motor 1750 and therein rotation of the Collar 1730, Mounting Flange 1720 and Diffuser Mounting Plate 1340 with its attached ShadowBand 1120.

[0100] Figure 19 depicts a rear perspective view of the Auxiliary PCB 1910 supporting the optical sub-assembly for the SolarBand device according to the other embodiment of the invention together with the Bubble Level 1310 and ShadowBand 1120. Mounted upon the Auxiliary PCB 1910 is Shadow Diffuser and Sensor 1320(2) together with first Diffuser Element 1320(1) respectively which form part of the Shadow Diffuser and Detector 1320. Also mounted upon the Auxiliary PCB 1910 are first and second Exposed Sensors 1330(A)(2) and 1330(B)(2) together with second and third Diffuser Elements 1330(A)(1) and 1330(B)(1) respectively which form the Exposed Diffuser and Detectors 1330(A) and 1330(B) respectively. Within an embodiment of the invention each of the Exposed Diffuser and Detectors 1330(A) and 1330(B) respectively and Shadow Diffuser and Detector 1320 may have a design such as that depicted in Figure 10A. Within an alternate embodiment of the invention one of the Exposed Diffuser and Detectors 1330(A) and 1330(B) is “active” according to the design in Figure 10A and the other is a “reference” sensor according to a design such as those depicted in Figures 10B and 10C respectively.

[0101] Referring to Figures 20 to 25 there are depicted views of a SolarBand device according to an embodiment of the invention. Referring initially to Figures 20 and 21 there are depicted front and rear perspective views of a SolarBand device according to an embodiment of the invention. As depicted within the SolarBand device under a Dome 2010 are a ShadowBand 2020, a Bubble Level 2110, Shadow Diffuser and Detector 2040, Exposed Diffuser and Detectors 2030(A) and 2030(B) and Diffuser Mounting Plate 2050. In common with the SolarBand device depicted in Figures 11 to 19 the Diffuser Mounting Plate 2050 is attached to a Stepper Motor for example such as Stepper Motor 1750, wherein activation of the Stepper Motor results in rotation of the shaft of the Stepper Motor and therein rotation of the assembly mounted to the shaft of the Stepper Motor which includes the Diffuser Mounting Plate 2050 with its attached ShadowBand 2020.

[0102] Now referring to Figure 22 there is depicted a plan view of the SolarBand device according to the embodiment of the invention depicted in Figure 20 where the ShadowBand 2020, the Bubble Level 2110, Exposed Diffuser and Detectors 2030(A) and 2030(B) and Diffuser Mounting Plate 2050 are visible. In contrast to the design depicted in Figures 11 to 19 the Bubble Level 2110 is now part of the Outer Casing 2210 of the SolarBand device rather than the Diffuser Mounting Plate 2050. The Shadow Diffuser and Detector, e.g. Shadow Diffuser and Detector 2040 in Figure 20, is below the ShadowBand 2020 and accordingly hidden from view. Also depicted is Navigation Receiver Cover 2220 whichfunctions in a similar manner to Navigation Receiver Cover 350 in Figure 3 which provides a cover to a GNSS Antenna, such as GNSS Antenna 950 in Figure 9.

[0103] Referring to Figure 23 there is depicted a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 20 with the outer casing and cover dome removed. Accordingly, there are depicted the ShadowBand 2020, the Bubble Level 2110, Exposed Diffuser and Detectors 2030(A) and 2030(B) and Diffuser Mounting Plate 2050. Also depicted are Mounting Plate 2320, a Main PCB 2310 and Stepper Motor 2330. The Stepper Motor 2330 being controlled by a microprocessor disposed upon the Main PCB 2310 such that the Diffuser Mounting Plate 2050 rotates under the direction of software in execution upon the microprocessor.

[0104] Now referring to Figure 24 there is depicted a front perspective view of the upper optical assembly and ShadowBand for the SolarBand device according to other embodiment of the invention depicted in Figure 20 where an Auxiliary PCB 2410 which forms part of the Diffuser Mounting Plate 2050 is depicted upon which the Exposed Diffuser and Detectors 2030(A) and 2030(B) are assembled together with the Shadow Diffuser and Detector 2040 and a Diffuser Mounting Plate 2420. In Figure 25 the same front perspective view of the upper optical assembly and ShadowBand for the SolarBand device according to other embodiment of the invention depicted in Figure 20 with the Diffuser Mounting Plate 2420 is removed. Accordingly, there are depicted first and second Exposed Diffusers 2510(A) and 2510(B) and their associated first and second Exposed Detectors 2520(A) and 2520(B). Also depicted is Shadow Diffuser 2530 with its associated first and second Shadow Detectors 2540(A) and 2540(B) respectively. Accordingly, three diffusers are provided in associated with four photodetectors. Alternatively, each of the first and second Shadow Detectors 2540(A) and 2540(B) respectively may be associated with different diffuser elements.

[0105] The first and second Shadow Detectors 2540(A) and 2540(B) by virtue of being under the ShadowBand 2020 provide for the diffuse solar measurement rather than direct solar measurement as described above. Within an embodiment of the invention the spectral responses of the first and second Shadow Detectors 2540(A) and 2540(B) are spectrally different in order to improve the overall diffuse irradiance measurement accuracy.

[0106] Within the embodiment described and depicted in Figures 20 to 24 the Exposed Diffuser and Detectors 2030(A) and 2030(B) each comprise a single detector, as depicted in Figure 25 with first and second Exposed Detectors 2520(A) and 2520(B). In contrast, the Shadow Diffuser and Detector 2040 as depicted in Figures 20 to 24 comprises a pair of detectors, as depicted in Figure 25 by first and second Shadow Detectors 2540(A) and2540(B) respectively. However, it would be evident that within other embodiments of the invention one or both of the Exposed Diffuser and Detectors 2030(A) and 2030(B) may, rather than comprising a single detector, comprise a pair of detectors or three or more detectors. Where two or more detectors are provided for one or both of the Exposed Diffuser and Detectors 2030(A) and 2030(B) then each detector may have a different spectral response.

[0107] Similarly, within other embodiments of the invention, the Shadow Diffuser and Detector 2040 may employ three or more detectors rather than the two detectors shown.

[0108] Further, within embodiments of the invention each detector as depicted may comprise a single junction detector or a stacked multi-junction detector such as a stacked tandem junction detector or a stacked triple junction detector for example. Stacked tandem or triple junction detectors etc. may provide for broader spectral coverage or provide higher efficiency relative to a single cell detector.

[0109] Referring to Figure 26 there is depicted a plan view of a SolarBand device according to an embodiment of the invention. In addition to the exposed and shadow diffuser and detector elements in the same configuration with the shadow band as the SolarBand device depicted in Figure 22 a Sky Imaging Sensor 2610 is disposed within the Diffuser Mounting Plate 2050. The Sky Imaging Sensor 2610 providing a system with the SolarBand device with a future irradiance forecasting capability. The Sky Imaging Sensor 2610 as depicted is shadowed by the ShadowBand 2020 such that the Sky Imaging Sensor 2610 is not directly exposed.

[0110] Within another embodiment of the invention the Sky Imaging Sensor 2610 may replace the Shaded Diffuser and Detector 2040. The Sky Imaging Sensor 2610 may be an electronic image sensor such as a charge-coupled device (CCD) or active-pixel sensor (e.g. a CMOS sensor). The Sky Imaging Sensor 2610 may or may not incorporate one or more lenses.

[0111] Now referring to Figure 27 there is depicted a perspective view of a SolarBand device according to an embodiment of the invention with fixed photodetectors and rotating shadow band. As depicted the SolarBand device includes under a Dome 2710 a ShadowBand 2720, a Shadow Diffuser and Detector 2740, Exposed Diffuser and Detectors 2730(A) and 2730(B) together with a Diffuser Mounting Plate 2750. These elements being within or upon a Casing 2760. Accordingly, referring to Figure 28 there is depicted a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the Dome 2710 and Casing 2760 removed. Visible are the ShadowBand 2720, the ShadowDiffuser and Detector 2740, the Exposed Diffuser and Detectors 2730(A) and 2730(B) together with the Diffuser Mounting Plate 2750 as well as Diffuser Baseplate 2830, PCB 2810, Stepper Motor 2820 and Baseplate 2840.

[0112] As will be evident from the description the ShadowBand 2720 is mechanically joined to the shaft of the Stepper Motor 2820 such that it rotates under action of the Stepper Motor 2820. Also it will be evident from the description that whilst the Diffuser Baseplate 2830 and Diffuser Mounting Plate 2750 are mounted upon the shaft of the Stepper Motor 2820 they are not mechanically joined to it such that they do not rotate under rotation of the shaft of the Stepper Motor 2820. The Stepper Motor 2820 being controlled by a microprocessor disposed upon the PCB 2810.

[0113] Within Figure 29 there is depicted a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 as per Figure 28 but now with upper cover of the Diffuser Mounting Plate 2750 removed. Similarly, referring to Figure 30 there is depicted a perspective view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 as per Figure 28 but now with the diffuser assembly removed which comprises the Diffuser Baseplate 2830 and the Diffuser Mounting Plate 2750. Accordingly, it is now evident that the ShadowBand 2720 is mounted to an Arm 3010 which is itself joined to a Collar 3020 which is mechanically joined to a shaft of the Stepper Motor 2820.

[0114] Referring to Figures 31 and 32 there are depicted a cross-sectional perspective view and cross-section view of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the Dome 2710 and Casing 2760 removed. Accordingly, the ShadowBand 2720 is evident mounted to the Arm 3010 which is itself joined to the Collar 3020 which is mechanically joined to the shaft of the Stepper Motor 2820. The Diffuser Mounting Plate 2750 and Diffuser Baseplate 2830 are depicted as being mounted to the upper portion of the Arm 3010 via a Collar Insert 3210. A Ball Bearing 3220 is disposed between the Collar Insert 3210 and the Arm 3010 such that rotation of the Arm 3010 is not coupled to the Collar Insert 3210.

[0115] The Diffuser Baseplate 2830 being coupled via a Threaded Assembly 3230 which is coupled to the PCB 2810 such that the rotational alignment of the Diffuser Baseplate 2830 is defined with respect to the PCB 2810. This mechanical configuration being such that the Diffuser Baseplate 2830 and Diffuser Mounting Plate 2750 are restrained from rotating whilst the Stepper Motor 2820 rotates the shaft but are centrally mounted such that the Arm 3010 and ShadowBand 2720 can rotate around the periphery of the Diffuser Baseplate 2830 andDiffuser Mounting Plate 2750. Whilst a single Threaded Assembly 3230 is depicted it would be evident that multiple Threaded Assemblies 3230 may be employed.

[0116] Now referring to Figure 33 there is depicted a perspective view of the diffuser assembly of the SolarBand device according to the embodiment of the invention depicted in Figure 27 with the majority of elements omitted for clarity. Accordingly, there are depicted the ShadowBand 2720 and Arm 3010 together with a Sub-PCB 3340 which is counted to the Diffuser Baseplate 2830 and upon which are disposed first and second Exposed Detectors 3315(A) and 3315(B) respectively and Shadow Detector 3325. Also depicted are first and second Exposed Diffusers 3310(A) and 3310(B) respectively and Shadow Diffuser 3320 which form part of the Diffuser Mounting Plate 2750 disposed above the Diffuser Baseplate 2830. In common with the other SolarBand devices the first and second Exposed Detectors 3315(A) and 3315(B) respectively provide global illumination measurements and the Shadow Detector 3325 provides a diffuse illumination measurement.

[0117] Within the embodiment of the invention depicted in Figures 27 to 33 with fixed photodetectors and rotating shadow band the Diffuser Baseplate 2830 and Diffuser Mounting Plate 2750 are fixed in position whilst mounted above the Arm 3010 which via Collar 3020 is attached to the shaft of the Stepper Motor 2820. However, it would be evident that within other embodiments of the invention the Diffuser Baseplate 2830 and Diffuser Mounting Plate 2750 may be fixed directly or indirectly to one or more of the Baseplate 2840, Casing 2760, and PCB 2810.

[0118] Within the embodiments of the invention described above each detector of the detectors may be a silicon photodetector, a thermopile, an organic photodetector, gallium arsenide (GaAs) photodetector, a visible / near-infrared phototransistor, or other optoelectronic device generating a current, or voltage, in dependence upon incident optical radiation. Further, a detector may be a single junction photodetector or a stacked multi-junction detector such as a stacked tandem junction detector or a stacked triple junction detector for example. Where a detector is a thermopile it may employ a film of gold-black, carbon-black or platinum-black.

[0119] Within the embodiments of the invention described above the shadowband, e.g. ShadowBand 120 or ShadowBand 1120, is attached to a plate, e.g. the Diffuser Mounting Plate 340, Diffuser Mounting Plate 1340 or Diffuser Mounting Plate 2750, which is mounted upon a motor, e.g. Stepper Motor 730, Stepper Motor 1730 or Stepper Motor 2820. Within other embodiments of the invention the motor may be a brushed DC motor, brushless DCmotor, servo motor or other device providing controllable rotation of its shaft and therein the shadowband via its intermediate supports.

[0120] Within the embodiments of the invention a first photodetector is always illuminated directly by the ambient environment, including directly by the sun, and accordingly measures the global horizontal irradiance (GHI) which comprises the diffuse horizontal irradiance (DHI) and direct normal irradiance (DNI). A second photodetector is always shaded by the shadowband and hence measures the DHI allowing the DNI to be calculated from these two measurements. In order to achieve this the microcontroller, e.g. Microcontroller 760 in Figure 7 or Microcontroller 1760 in Figure 17, establishes or calculates the local solar azimuth angle in dependence upon the position of the SolarBand device as established by the integrated global positioning, using GNSS Receiver Circuit 770 or GNSS Receiver Circuit 170 which is coupled to the GNSS Antenna, such as GNSS Antenna 950. The microcontroller then maneuvers the shadowband, e.g. ShadowBand 120 or ShadowBand 1120, to azimuthally track the sun throughout the day.

[0121] Within an embodiment of the invention the shadowband, e.g. ShadowBand 120 or ShadowBand 1120, blocks the sky from 0 degrees (horizontal) to 95 degrees in the elevation orientation with ±7-degree half angle from the perspective of the shaded sensor. Within other embodiments of the invention the shadowband, e.g. ShadowBand 120 or ShadowBand 1120, may cover a larger elevation range up to and including 1800 degrees.

[0122] Where employed, the “reference” sensors, compensation sensors, are in the dark (i.e. they never see the sunlight) and can be used to correct for aspects of the detector performance such as noise with optical photodetectors or to correct for temperature fluctuations inside the device where the detectors are thermopiles.

[0123] Within an embodiment of the invention the Main PCB, e.g. Main PCB 610 or Main PCB 1610, mounts on the motor, e.g. Stepper Motor 750 or Stepper Motor 1750, contains the power and communication electronics as well as the microcontroller (MCU). The motor mounting flange, e.g. Collar 730 or Collar 1730, is fastened to the shaft of the motor, for example via several set screws. A flange, for example Mounting Flange 720 or Mounting Flange 1720, acts as a mechanical support for the Auxiliary PCB, e.g. Auxiliary PCB 710 or Auxiliary PCB 1910, and the diffuser mounting plate, e.g. Diffuser Mounting Plate 340 or Diffuser Mounting Plate 1340. The AUX PCB houses the detectors, e.g. silicon photodetector or thermopiles, and associated electronics for signal processing. Additionally, the diffuser mounting plate houses the bubble level, the shadowband, diffusers, and the GPS antenna. The diffuser shape and height being selected to optimize the cosine response of the device.Finally, the base plate and the dome seal the overall enclosure of the device in order to prevent moisture ingress, dirt ingress, condensation etc.

[0124] Whilst within the embodiments of the invention the global positioning is established based upon an integrated GNSS Receiver and processing circuit it would be evident that within other embodiments of the invention that the microcontroller may be provided with the global position based upon an external GNSS Receiver / processing circuit or from another device which provides the global positioning to the SolarBand device. Azimuthally tracking the sun being based upon the global position of the SolarBand device and the time of day established by the microcontroller.

[0125] Within embodiments of the invention the SolarBand device is mounted in a defined orientation with respect to a reference direction, e.g. by using a marker or markers upon the casing or baseplate of the SolarBand device such that the SolarBand device is aligned to a geographic pole, e.g. north or south, for example. The SolarBand device being installed level as aided by the integral bubble for example or by other means relating to ensuring the mounting surface to which the baseplate is to be attached is level.

[0126] Whilst the embodiments of the invention described and depicted have employed a GNSS receiver to determine the location of the SolarBand device and therein the azimuth of the sun it would be evident that other embodiments of the invention may operate solely without a GNSS receiver, provide an alternative for poor GNSS signal reception or provide an adjunct to the GNSS receiver to provide correction for alignment errors in the installation of the SolarBand device with respect to the target alignment along a north-south axis. Such a positional establishment algorithm or initial self-correction algorithm may be executed by the SolarBand device at start-up discreetly with or without subsequent periodic verification. Accordingly, the positional establishment algorithm or self-correction algorithm scans the ShadowBand of the SolarBand device in azimuth to reveal a signal minimum and therefore the azimuth of the sun at that location at that time. This position is then stored and employed to either define the subsequent rotational operation of the SolarBand device or correct for the installation error in the SolarBand device.

[0127] Optionally, the alignment error may be established from a compass integrated within the SolarBand device which communicates with the controller, e.g. Microcontroller 760 in Figure 7 or Microcontroller 1760 in Figure 17. Accordingly, the controller employs the compass output to establish the correction factor for the alignment error. Within other embodiments of the invention a tilt / orientation sensor may be incorporated into the SolarBand device which can be employed to compensate and adjust the ShadowBandposition such as in applications where the device is deployed in a tilted or variable tilt scenario, for example upon a single-axis solar tracker.

[0128] Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details. For example, circuits may be shown in block diagrams in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments.

[0129] Implementation of the techniques, blocks, steps and means described above may be done in various ways. For example, these techniques, blocks, steps and means may be implemented in hardware, software, or a combination thereof. For a hardware implementation, the processing units may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro -controllers, microprocessors, other electronic units designed to perform the functions described above and / or a combination thereof.

[0130] Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function.

[0131] Furthermore, embodiments may be implemented by hardware, software, scripting languages, firmware, middleware, microcode, hardware description languages and / or any combination thereof. When implemented in software, firmware, middleware, scripting language and / or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium, such as a storage medium A code segment or machine-executable instruction may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a script, a class, or any combination of instructions, data structures and / or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / orreceiving information, data, arguments, parameters and / or memory content. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0132] For a firmware and / or software implementation, the methodologies may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software codes may be stored in a memory. Memory may be implemented within the processor or external to the processor and may vary in implementation where the memory is employed in storing software codes for subsequent execution to that when the memory is employed in executing the software codes. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other storage medium and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

[0133] Moreover, as disclosed herein, the term “storage medium” may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and / or other machine readable mediums for storing information. The term “machine-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, wireless channels and / or various other mediums capable of storing, containing or carrying instruction(s) and / or data.

[0134] The methodologies described herein are, in one or more embodiments, performable by a machine which includes one or more processors that accept code segments containing instructions. For any of the methods described herein, when the instructions are executed by the machine, the machine performs the method. Any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine are included. Thus, a typical machine may be exemplified by a typical processing system that includes one or more processors. Each processor may include one or more of a CPU, a graphics-processing unit, and a programmable DSP unit. The processing system further may include a memory subsystem including main RAM and / or a static RAM, and / or ROM. A bus subsystem may be included for communicating between the components. If the processing system requires a display, such a display may be included, e.g., a liquid crystal display (LCD). If manual data entry is required, the processing system also includes an input device such as one or more of an alphanumeric input unit such as a keyboard, a pointing control device such as a mouse, and so forth.

[0135] The memory includes machine-readable code segments (e.g. software or software code) including instructions for performing, when executed by the processing system, one of more of the methods described herein. The software may reside entirely in the memory, or may also reside, completely or at least partially, within the RAM and / or within the processor during execution thereof by the computer system. Thus, the memory and the processor also constitute a system comprising machine-readable code.

[0136] In alternative embodiments, the machine operates as a standalone device or may be connected, e.g., networked to other machines, in a networked deployment, the machine may operate in the capacity of a server or a client machine in server-client network environment, or as a peer machine in a peer-to-peer or distributed network environment. The machine may be, for example, a computer, a server, a cluster of servers, a cluster of computers, a web appliance, a distributed computing environment, a cloud computing environment, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. The term “machine” may also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.

[0137] The foregoing disclosure of the exemplary embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be apparent to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.

[0138] Further, in describing representative embodiments of the present invention, the specification may have presented the method and / or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and / or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.

Claims

CLAIMSWhat is claimed is:

1. A device comprising: a controller for controlling a motor having a rotatable shaft; the motor; a shadow band (shadowband) mechanically coupled to an assembly mounted to the rotatable shaft; a first detector responsive to optical signals over a predetermined wavelength range mechanically coupled to the assembly disposed in a first position with respect to the shadowband such that the first detector is exposed to both diffuse horizontal irradiance (DHI) of an ambient environment the device is deployed within and direct normal irradiance (DNI) of the ambient environment; and a second detector responsive to optical signals over the predetermined wavelength range mechanically coupled to the assembly disposed in a second position with respect to the shadowband such that the second detector is exposed to only the DHI of the ambient environment as the DNI of the ambient environment is blocked by the shadowband; wherein the controller executes a measurement algorithm which drives the motor to rotate the rotatable shaft to azimuthally track the sun and process measurements from the first detector and the second detector.

2. The device according to claim 1, further comprising: a third detector responsive to optical signals over the predetermined wavelength range mechanically coupled to the assembly disposed in a third position with respect to the shadowband such that the third detector is exposed to both the diffuse horizontal irradiance (DHI) of the ambient environment the device is deployed within and direct normal irradiance (DNI) of the ambient environment; wherein the controller processes measurements from the third detector in conjunction with those from the first detector and the second detector3. The device according to claim 1, wherein the controller executes an alignment algorithm comprising:driving the motor to rotate the rotatable shaft and process measurements from the first detector and the second detector; establishing the azimuthal position at the time the alignment sequence is executed; and establishing an azimuthal alignment error for use by the measurement algorithm to correct for an installation error of the alignment of the device with respect to a defined orientation to a geographic pole.

4. The device according to claim 1, wherein the controller: establishes a global position of the device either directly based upon an integrated global positioning receiver or indirectly from another global position receiver associated with an external device with a defined positional relationship to the device; and azimuthally tracks the sun in dependence upon at least the global position of the device.

5. The device according to claim 1, further comprising at least one of: a compass electronically coupled to the controller and at least a marker upon a casing of the device wherein the at least the marker is employed to align the device at installation in a defined orientation to a geographic pole and the controller employs at least a reading from the compass to establish a correction factor to correct for an alignment error of the device with respect to the defined orientation to the geographic pole arising from installation of the device; and a tilt / orientation sensor which can be employed to either compensate for or adjust a position of the shadowband where the device deployed upon with a fixed tilt or variable tilt.

6. The device according to claim 1, wherein each of the first detector and the second detector has a diffuser element disposed in front of it.

7. The device according to claim 1, whereineach of the first detector and the second detector has a diffuser element disposed in front of it between the external ambient environment; and the device further comprises: a third detector mechanically coupled to the assembly disposed in a third position with respect to the shadowband and the first detector; and a fourth detector mechanically coupled to the assembly disposed in a fourth position with respect to the shadowband and the second detector; each of the third detector and the fourth detector is a thermopile which is blocked from optical signals within the ambient environment; an output of the first detector is compensated in dependence upon an output of the third detector; and an output of the second detector is compensated in dependence upon an output of the fourth detector.

8. The device according to claim 7, wherein each of the first detector, the second detector, the third detector and fourth detector has a diffuser element disposed in front of it; and each of the third detector and fourth detector has an element disposed between it and its associated diffuser element that blocks optical signals.

9. The device according to claim 7, wherein each of the first detector and the second detector has a diffuser element disposed in front of it; and each of the third detector and fourth detector is disposed behind an element that blocks optical signals.

10. The device according to claim 1, further comprising a casing housing the controller, the motor, the shadowband, the assembly, the first detector and second detector; wherein the casing includes a dome formed from a material transmissive to optical signals over the predetermined wavelength range; and the shadowband rotates within the dome and the first detector and second detector receive optical signals within the predetermined wavelength range that impinge upon the dome.

11. The device according to claim 1, wherein the first detector and the second detector are mounted to a platform which is attached to the assembly mounted to the rotatable shaft; and the platform and shadowband rotate together upon rotation of the rotatable shaft of the motor.

12. The device according to claim 1, wherein the first detector and the second detector are mounted to a platform which is mounted upon the assembly which is mounted to the rotatable shaft; the platform does not rotate upon rotation of the rotatable shaft of the motor; and the shadowband rotates upon rotation of the rotatable shaft of the motor.

13. The device according to claim 1, wherein the first detector and the second detector are mounted to a platform which is fixed in position with respect to the device such that the platform does not rotate upon rotation of the rotatable shaft of the motor; and the shadowband rotates upon rotation of the rotatable shaft of the motor.

14. The device according to claim 1, further comprising a third detector responsive to optical signals over the predetermined wavelength range mechanically coupled to the assembly disposed in a third position with respect to the shadowband such that the third detector is exposed to only the DHI of the ambient environment as the DNI of the ambient environment is blocked by the shadowband; wherein the second detector and the third detector have different spectral responses.

15. The device according to claim 14, wherein the second detector and the third detector each receive the DHI of the ambient environment via a common optical diffuser element.

16. The device according to claim 1, further comprising a third detector disposed proximate the first detector where the first detector and the third detector are disposed below a cover plate and a first diffuser such that they bothreceive the DHI of the ambient environment and the DNI of the ambient environment; and a fourth detector disposed proximate the second detector wherein the second detector and the fourth detector are disposed below the cover plate and a second diffuser such that both receive only the DHI of the ambient environment.

17. The device according to claim 16, wherein at least one of: the first detector and the third detector have different spectral responses; and the second detector and the fourth detector have different spectral responses.

18. The device according to claim 1, further comprising an imaging sensor disposed in a third position with respect to the shadowband.

19. The device according to claim 1, further comprising an imaging sensor disposed in a third position with respect to the shadowband; wherein the imaging sensor is a charge-coupled device or active-pixel sensor.

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