Abstract: In one respect, disclosed is an in-situ current-voltage (I-V) measurement device for photovoltaic modules in a photovoltaic array, comprising a variable load, wherein the variable load is configured to be connected in parallel with a module, wherein the module is connected in series with at least one other module in a string, such that the module supplies current simultaneously to the string and to the variable load, and wherein the variable load is controlled by a controller, and wherein the controller is configured to shift an I-V operating point of the module, based at least upon varying the variable load.

Abstract: In one respect, disclosed is a device comprising terminals or connections configured to connect to a first associated PV module, I-V measurement circuitry coupled to said terminals or connections and configured to measure I-V data of said first associated PV module, communication circuitry configured to communicate with at least one external device, and a processor coupled to said I-V measurement circuitry and to said communication circuitry, wherein said processor is configured to receive external data via said communication circuitry from said at least one external device, and wherein said processor is configured to determine a relative performance metric based at least upon said I-V data of said first associated PV module and said external data.

Abstract: In one respect, disclosed is a device or system for solar irradiance measurement comprising at least two irradiance sensors deployed outdoors at substantially different angles, such that, by analysis of readings from said irradiance sensors, direct irradiance, diffuse irradiance, and/or global irradiance are determined. In another respect, the disclosed device or system may additionally determine ground-reflected irradiance.

Abstract: In one respect, disclosed is an in-situ current-voltage (I-V) measurement device for photovoltaic modules in a photovoltaic array, comprising a variable load, wherein the variable load is configured to be connected in parallel with a module, wherein the module is connected in series with at least one other module in a string, such that the module supplies current simultaneously to the string and to the variable load, and wherein the variable load is controlled by a controller, and wherein the controller is configured to shift an I-V operating point of the module, based at least upon varying the variable load.

Abstract: In one respect, disclosed is a device or system for solar irradiance measurement comprising at least two irradiance sensors deployed outdoors at substantially different angles, such that, by analysis of readings from said irradiance sensors, a direct irradiance, a diffuse irradiance, a global irradiance, and/or a ground-reflected irradiance are determined. In some embodiments the disclosed device or system is stationary and has no moving parts.

Abstract: In one respect, disclosed is a device or system for solar irradiance measurement comprising at least two irradiance sensors deployed outdoors at substantially different angles, such that, by analysis of readings from said irradiance sensors, a direct irradiance, a diffuse irradiance, a global irradiance, and/or a ground-reflected irradiance are determined. In some embodiments the disclosed device or system is stationary and has no moving parts.

Abstract: In one respect, disclosed is a soiling measurement device for measuring the loss of light transmission to photovoltaic (PV) devices in a photovoltaic array arising from the accumulation of soiling particles, comprising a light source, a reference photodetector, a soiling collection window, a photodetector positioned underneath the soiling collection window, and a measurement and control system.

Abstract: A device comprising a transparent window, an imaging unit, and a computing element coupled to said imaging unit, wherein said device is configured to allow soiling particles to accumulate on a surface of said transparent window, said imaging unit is configured to capture an image of said surface, and said computing element is configured to perform analysis of said image to determine a soiling level of said transparent window, wherein a surface of said transparent window may include reference marks enabling calibration of said image during said analysis. Additionally, a method of performing said analysis.

Abstract: A device or system to measure a soiling level and/or soiling level non-uniformity, or power loss arising from soiling including soiling non-uniformity, representative of a PV module. In one respect, a device comprising at least a first transparent window and at least two sensors, wherein said sensors comprise a soiling sensor, an irradiance sensor, or a photovoltaic device, and wherein at least two of said sensors are configured to measure separate regions of said first transparent window and at least one of said sensors is a soiling sensor configured to measure a soiling level of said first transparent window or of a second transparent window substantially close to said first transparent window, and wherein from said measurements of said sensors said device determines a soiling level and/or a non-uniformity of said soiling level of said first transparent window.

Abstract: In one respect, disclosed is a device or system for solar irradiance measurement comprising at least two irradiance sensors deployed outdoors at substantially different angles, such that, by analysis of readings from said irradiance sensors, direct irradiance, diffuse irradiance, and/or global irradiance are determined. In another respect, the disclosed device or system may additionally determine ground-reflected irradiance.

Abstract: A device or system to measure a soiling level and/or soiling level non-uniformity, or power loss arising from soiling including soiling non-uniformity, representative of a PV module. In one respect, a device comprising at least a first transparent window and at least two sensors, wherein said sensors comprise a soiling sensor, an irradiance sensor, or a photovoltaic device, and wherein at least two of said sensors are configured to measure separate regions of said first transparent window and at least one of said sensors is a soiling sensor configured to measure a soiling level of said first transparent window or of a second transparent window substantially close to said first transparent window, and wherein from said measurements of said sensors said device determines a soiling level and/or a non-uniformity of said soiling level of said first transparent window.

Abstract: A device or system to measure a soiling level and/or soiling level non-uniformity, or power loss arising from soiling including soiling non-uniformity, representative of a PV module. In one respect, a device comprising at least a first transparent window and at least two sensors, wherein said sensors comprise a soiling sensor, an irradiance sensor, or a photovoltaic device, and wherein at least two of said sensors are configured to measure separate regions of said first transparent window and at least one of said sensors is a soiling sensor configured to measure a soiling level of said first transparent window or of a second transparent window substantially close to said first transparent window, and wherein from said measurements of said sensors said device determines a soiling level and/or a non-uniformity of said soiling level of said first transparent window.

Abstract: A soiling measurement device for PV arrays, comprising a clean PV device and a soiled PV device, wherein the soiled PV device is exposed to accumulate soiling, and wherein the clean PV device is maintained clean by a movable cover which normally shields it from accumulation of soiling, and wherein the movable cover opens automatically at periodic intervals for measurement, after which it closes again, and wherein soiling is determined by comparison of measurements from the soiled PV device and the clean PV device. In one embodiment, incident irradiance is measured from the clean device, with or without the presence of the soiled PV device.

Abstract: A device or system to measure a soiling level and/or soiling level non-uniformity, or power loss arising from soiling including soiling non-uniformity, representative of a PV module. In one respect, a device comprising at least a first transparent window and at least two sensors, wherein said sensors comprise a soiling sensor, an irradiance sensor, or a photovoltaic device, and wherein at least two of said sensors are configured to measure separate regions of said first transparent window and at least one of said sensors is a soiling sensor configured to measure a soiling level of said first transparent window or of a second transparent window substantially close to said first transparent window, and wherein from said measurements of said sensors said device determines a soiling level and/or a non-uniformity of said soiling level of said first transparent window.

Abstract: A device comprising a transparent window, a photoemitter, a photodetector, and a measurement unit, wherein said photoemitter is configured to illuminate soiling particles accumulating on a surface of said transparent window, said photodetector is configured to generate a signal based on detection of light that passes through said transparent window and reflects and/or scatters from said soiling particles, and said measurement unit determines a soiling level of said transparent window based upon a measurement of said signal.

Abstract: A device comprising a transparent window, a photoemitter, a photodetector, and a measurement unit, wherein said photoemitter is configured to illuminate soiling particles accumulating on a surface of said transparent window, said photodetector is configured to generate a signal based on detection of light that passes through said transparent window and reflects and/or scatters from said soiling particles, and said measurement unit determines a soiling level of said transparent window based upon a measurement of said signal.

Abstract: A system for measuring the power or energy loss in a photovoltaic array due to soiling, which is the accumulation of dust, dirt, and/or other contaminants on the surfaces of photovoltaic modules, comprising: a pair of photovoltaic reference devices placed within or near the photovoltaic array and co-planar to the modules comprising the array, wherein one reference device is a module or cell similar to those of the array and is allowed to accumulate soiling at the natural rate, and wherein the second reference device is a module or a cell and is maintained clean; and a measurement and control unit which measures and compares the electrical outputs of the soiled reference device and the clean reference device in order to determine the fraction of power lost by the soiled reference module due to soiling.

Abstract: A device comprising a transparent window, an imaging unit, and a computing element coupled to said imaging unit, wherein said device is configured to allow soiling particles to accumulate on a surface of said transparent window, said imaging unit is configured to capture an image of said surface, and said computing element is configured to perform analysis of said image to determine a soiling level of said transparent window, wherein a surface of said transparent window may include reference marks enabling calibration of said image during said analysis. Additionally, a method of performing said analysis.

Abstract: A device comprising a transparent window, an imaging unit, and a computing element coupled to said imaging unit, wherein said device is configured to allow soiling particles to accumulate on a surface of said transparent window, said imaging unit is configured to capture an image of said surface, and said computing element is configured to perform analysis of said image to determine a soiling level of said transparent window. Additionally, a method of performing said analysis.

Abstract: A device comprising a transparent window, a photoemitter, a photodetector, and a measurement unit, wherein said photoemitter is configured to illuminate soiling particles accumulating on a surface of said transparent window, said photodetector is configured to generate a signal based on detection of light that passes through said transparent window and reflects and/or scatters from said soiling particles, and said measurement unit determines a soiling level of said transparent window based upon a measurement of said signal.