Spectrally selective sensors for PV system performance monitoring

Abstract

The main purpose of PV system performance monitoring is to determine whether the system is operating as expected. This requires measuring the actual output of the system as well as the conditions under which it is operating. Solar radiation intensity in the plane of the array (POA) is by far the most important operating condition and is the basis for calculating performance ratios (PR). However, differences in spectral and directional response between pyranometers and PV modules lead to intraday as well as seasonal fluctuations in the performance ratio, even though the system may be operating without faults or degradation. For c-Si PV systems, a reference cell can be used instead of (or in addition to) a pyranometer to measure POA irradiance. Since reference cells have spectral and directional responses that are similar to PV modules, their output signals correlate better with system output. As a result, it is becomes easier to identify abnormal system operation. In this paper, we present a practical alternative to using a spectrally matched reference cell for measuring POA irradiance. The method uses dual sensors with different spectral responses whose outputs are combined to produce a composite signal. That composite signal can effectively match the spectral response of any PV module type over a wide range of irradiance conditions. As a result, this method makes possible the rapid and accurate detection of abnormal system operation for thin-film systems

Developing a Framework for Reference Cell Standards for PV Resource Applications

“…Historically, solar irradiance measurements for outdoor photovoltaic (PV) performance monitoring has been carried out using either pyranometers, reference cells, or sometimes both. The results obtained with these options are not directly comparable, resulting in frequent discussions about which option is preferred [1], [2]. The PV community is increasingly interested in using reference cells that accurately quantify the solar resource available to a PV system for outdoor solar resource measurement and characterizing PV performance.…”

“…PV reference cells can be used for prospecting. As stated in [1], [2], PV reference cells and the PV modules have close spectral matches that reduce the uncertainty in the available energy for conversion into electricity, which ultimately reduces the levelized cost of energy.…”

Solar irradiation estimator based on a self-calibrated reference solar cell

“…Pyranometers and calibrated PV reference devices (PVRDs) are the two most popular tools used by the PV industry for measuring irradiance [24,25]. According to [26][27][28] and the norm lEC 60904-3, to measure solar irradiance in PV applications, it would be beneficial to use the PV reference devices in terms of irradiance uncertainty estimation. The efficiency of photon-to-electron conversion is a wavelength-dependent function that is specific to various PV device technologies [26].…”

On the uncertainty of energetic impact on the yield of different PV technologies due to varying spectral irradiance

“…Spectral irradiance was measured and investigated all around the world -from Japan over tropic regions, south Africa, southern and middle continental Europe, the UK and the US (Japan: (Ishii et al, 2012(Ishii et al, , 2011a(Ishii et al, ,b, 2013bMinemoto et al, 2007aMinemoto et al, ,b, 2009Nagae et al, 2006Nagae et al, , 2009Nakada et al, 2010), tropic regions: (Eltbaakh et al, 2013;Sirisamphanwong and Ketjoy, 2012), South Africa: (Okullo et al, 2011), Continental Europe: (Alonso-Abella et al, 2014;Behrendt et al, 2013Behrendt et al, , 2010Cornaro and Andreotti, 2013;Dirnberger et al, 2015Dirnberger et al, , 2011bDriesse et al, 2012;Nofuentes et al, 2013;Perez-Lopez et al, 2007;Piliougine et al, 2013;Schweiger et al, 2012;Zinsser et al, 2011), UK: (Gottschalg et al, 2004(Gottschalg et al, , 2003, US: (King et al, 2002)). …”