## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Ref/Year** & **EL/PL** & **Day/Night** & **Excitation Source** & \
\begin{tabular}{c} **Equignment for** \\ **Modulation** \\ \end{tabular} &
\begin{tabular}{c} **PV Module** \\ **Disconnection** \\ \end{tabular} & **Camera Sensor** & **Filter** \\ \hline
[18; 19] & EL/PL & Day/night & \begin{tabular}{c} Power supply (EL) or \\ electronic board (PL) \\ \end{tabular} & \begin{tabular}{c} Power supply (EL) or \\ electronic board (PL) \\ \end{tabular} & Required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ bandpass \\ filter \\ \end{tabular} \\ \hline
[20] & EL & Day & PV module current & Electronic board & Required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ bandpass \\ filter \\ \end{tabular} \\ \hline
[21; 22; 23] & PL & Day & Sunlight & \begin{tabular}{c} Optical solar cell \\ controllers \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ bandpass \\ filter \\ \end{tabular} \\ \hline
[24] & EL & Night & \begin{tabular}{c} Bidirectional \\ inverter \\ \end{tabular} & \
\begin{tabular}{c} No modulation \\ needed \\ \end{tabular} & Not required &
\begin{tabular}{c} InGaAs \\ \end{tabular} & - \\ \hline
[25] & PL & Day & Sunlight & \begin{tabular}{c} Two optical filters \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filters \\ \end{tabular} &
\begin{tabular}{c} Two bandpass \\ optical filters \\ \end{tabular} \\ \hline
[26; 27] & PL & Night & LED lighting & \begin{tabular}{c} No modulation \\ needed \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs or \\ Silicon \\ \end{tabular} &
\begin{tabular}{c} Optical lowpass \\ filter \\ \end{tabular} \\ \hline
[28; 29] & PL & Day & Sunlight & \begin{tabular}{c} PV Inverter \\ (MPPT functionality) \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ filter \\ \end{tabular} \\ \hline
[30; 31; 32] & PL & Day & Sunlight & \begin{tabular}{c} PV Inverter (J-V curve \\ sweep functionality) \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ bandpass \\ filter \\ \end{tabular} \\ \hline
[33] & PL & Day & Sunlight & \begin{tabular}{c} No modulation \\ needed \\ \end{tabular} & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ \end{tabular} &
\begin{tabular}{c} Ultranarrow \\ optical bandpass \\ filter \\ \end{tabular} \\ \hline
[34] & EL/PL & Day & Sunlight (PL) or \\ PV string current (EL) & Electronic board & Not required & \
\begin{tabular}{c} InGaAs sensor \\ Optical \\ bandpass filter \\ \end{tabular} &
\begin{tabular}{c} Optical \\ bandpass \\ filter \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of studies proposing alternative luminescence imaging methods for PV power plant inspection. work [34]. The self-powered approach is also compared with a conventional method based on a programmable power supply. The second section of the manuscript describes the equipment used, the tested PV configuration, and the electronic board topology, as well as the FFT-based processing. The third section presents the results obtained for both the conventional and self-powered approaches, while the final section includes a detailed discussion and conclusions regarding the proposed method.