Design of a low cost irradiance meter using a photovoltaic panel

Solar Variability Datalogger

“…A handful of previous projects have attempted to design lowcost solar irradiance sensors, such as Mancilla-David et al [3], Cruz-Colon et al [4], and The Navy Research Lab [5], but they all focused on energy monitoring of PV system performance and not on solar variability analysis. Some groups have monitored solar variability with conventional pyranometers, including the National Renewable Energy Laboratory (NREL) [6], the Hawaii Electric Company (HECO) [7], the Sacramento Municipal Utility District (SMUD) [8], and the Electric Power Research Institute (EPRI) [9], but the geographic coverage of deployed sensors was limited to a few select areas, and the data were generally not available to other researchers (with the notable exception of the NREL Oahu data).…”

Final Technical Report: Low-Cost Solar Variability Sensors for Ubiquitous Deployment.

“…The cost of the sensor was approximately $40-50. Cruz-Colon, et al [5] monitored the open circuit voltage and short circuit current of a small solar cell to calculate the effective irradiance. This setup resulted in errors between 0-1% compared to a pyranometer for one instantaneous measurement.…”

“…Apogee Instruments: http://www.apogeeinstruments.com/pyranometer-sp-110/, accessed 8/28/2014 3 Campbell Scientific 2010 price list, accessed at http://tge2008-2.wikispaces.com/file/view/March_2010-macs-Price.pdf on 8/28/2014 4. Price Quote from LI-COR Biosciences 5. 1997 prices listed in Master's Thesis "An Improved Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation" accessed at http://esl.tamu.edu/docs/publications/thesis_dissertations/ESL-TH-97-12-02.pdf on 8/28/2014.…”

Low-Cost Solar Irradiance Sensing for PV Systems

“…Thus, the operator must place any sensor geometrically parallel to the panel itself. Direct sensing of irradiance on each PV module can be a rather unpractical solution, and for this reason, several authors propose alternative approaches in the literature [1][2][3][4][5][6][7][8]. In particular, some of these approaches focus on models representing the PV array.…”

“…In particular, some of these approaches focus on models representing the PV array. Some authors propose to estimate the irradiance by approximating the equations describing the PV device model [2][3][4], or by measuring either open circuit voltage or short circuit current [5][6][7]. In [8], the authors generalize the implicit unknown relationship between irradiance and operating point of a PV device by means of an artificial neural network (ANN) implemented on an embedded MCU (microcontroller unit).…”