The standard test conditions for photovoltaic modules are not capable of reproducing the environmental variations to which the modules are subjected under real operating conditions. The objective of this experimental work is to be an initial study on how the electric energy generation of photovoltaic cells varies according to the different wavelength ranges of the solar light spectrum under real operating conditions. Two modules were installed outdoors; color filters, which allow the passage of light at specific wavelengths, were installed on one of them. The amount of energy produced by the module with the filter was compared to the reference module, and the relative efficiency of each filter was defined. As a result, it was found that crystalline silicon modules do not respond uniformly to sunlight, being more sensitive to the red band (relative efficiency of 23.83%) and less sensitive to the green band (19.15%). The infrared contributes to a significant portion of energy production (relative efficiency of 13.56%), overcoming its negative effect of reducing energy generation capacity due to high photovoltaic cell temperature.

Partial shading conditions can cause low output power, hotspots, and a reduced lifespan in photovoltaic arrays. Interconnection (IC) and differential power processing (DPP) can be used to mitigate these effects. When individually applied to an array, these techniques can significantly increase the generated power. A few authors studied the combined use of these schemes under specific conditions such as large-scale arrays or a complex combination of several techniques, making it difficult to identify the individual contribution of each technique. Here, we aimed to determine whether the combined use of a switching-inductor DPP circuit and a total-cross-tied interconnection scheme presents better performance than each standalone technique, using a small-scale photovoltaic array. An array was tested using IC, DPP, and a combination of both techniques, and the array was subjected to 13 shading patterns and two irradiance levels. The performance in each case was assessed using maximum output power, performance ratio, mismatch power loss, and power enhancement indicators. The results showed that a standalone differential power processing circuit presents better performance than when it is combined with an interconnection. The DPP showed performance ratio values of up to 97%, mismatch power losses lower than 36.9%, and a power enhancement of up to 95.9%. The standalone interconnection shows the worst performance among the three techniques.

Partial shading in photovoltaic systems is one of the main causes of low power generation and hot spots, which may reduce the system’s lifespan. One solution to minimize its effects is the use of bypass diodes, installed in different configurations. In this work the performance of several bypass diode configurations is compared. Performance indicators (Efficiency, Mismatch Loss and Power Enhancement) are extracted from simulations using LTspice software. The results show that the configurations with one bypass diode per photovoltaic module present better performance and that diode configurations tend to present similar performance under high irradiance levels. However, the best-performance configuration depends on several combined factors, such as irradiance level, shading pattern and number of bypass diodes.