Large-Scale Daylight Photoluminescence: Automated Photovoltaic Module Operating Point Detection and Performance Loss Assessment by Quantitative Signal Analysis

Article Physics, Applied

Photoluminescence imaging of field-installed photovoltaic modules in diffuse irradiance

M. Vukovic et al.

Summary: Photoluminescence imaging under different irradiance conditions has been studied in the inspection of field-installed photovoltaic modules. The potential of photoluminescence images in defect analysis has been shown at low irradiance levels. A new method without the use of the lock-in technique has been proposed for photoluminescence imaging to filter sunlight. This study demonstrates the valuable information that can be obtained from photoluminescence imaging under diffuse irradiance conditions.

JOURNAL OF APPLIED PHYSICS (2023)

Add to Collection

Article Physics, Applied

Evaluating the effects of photovoltaic module heating during electroluminescence inspection

Lukas Koester et al.

Summary: The application of electroluminescence imaging of photovoltaic modules has increased in recent years due to its reliable and detailed identification of degradation and failures. In the future, the use of inverters with bi-directional functionality could eliminate the time-consuming connection of power supplies, allowing backpowering of module strings directly. This study investigates the heating effect caused by backpowering of different types of photovoltaic modules during electroluminescence inspection, estimating a temperature increase of around 20 degrees C and resulting voltage drops of up to 3 V.

EPJ PHOTOVOLTAICS (2023)

Add to Collection

Article Energy & Fuels

Photoluminescence imaging of silicon modules in a string

Marija Vukovic et al.

Summary: Spectral imaging techniques are useful for monitoring degradation mechanisms in solar panels, and recent studies have explored the detection of luminescence during daylight. This research presents a proof of concept for detecting photoluminescence using sunlight excitation, allowing for imaging of multiple modules simultaneously. The method shows promise in identifying degradation mechanisms with lower resolution, such as large area damage and inactive areas.

PROGRESS IN PHOTOVOLTAICS (2022)

Add to Collection

Article Physics, Applied

Noninvasive photoluminescence imaging of silicon PV modules in daylight

M. Vukovic et al.

Summary: Outdoor photoluminescence imaging on field-deployed solar cell modules has been increasingly conducted in recent years. This imaging technique provides more detailed information about defects compared to thermal infrared imaging, and it has the potential to be faster than electroluminescence imaging as it does not require electrical connection to the modules. However, when conducted with sunlight excitation, it usually relies on lock-in technique, which involves switching between the modules' two operating points. This often requires additional electrical equipment and causes production disruption for the modules. This study demonstrates a noninvasive image acquisition method based on the string inverter's ability to sweep the IV curve. The advantage of this approach is that it only requires imaging apparatus and allows for flexible imaging procedures without additional equipment. Photoluminescence images spanning the whole IV curve can be obtained during one sweep, offering insights into the state of the cells and modules.

APPLIED PHYSICS LETTERS (2022)

Add to Collection

Article Energy & Fuels

Outdoor Implied Current-Voltage Measurements of an Individual Encapsulated Cell in a Module

Raghavi Bhoopathy et al.

Summary: This study introduces a novel contactless and nondestructive method based on Suns-photoluminescence measurements to extract the current-voltage characteristics of individual solar cells under operating conditions in the field. The method is demonstrated to be effective in identifying various degradation mechanisms and has the advantages of low cost, fast applicability, and ease of use.

IEEE JOURNAL OF PHOTOVOLTAICS (2021)

Add to Collection

Article Energy & Fuels