Modern PV inverters are the “brains” of PV systems, playing a key role in efficient energy conversion and protecting system components.
In addition to their primary function of converting DC (direct current) to AC (alternating current), inverters have evolved to incorporate advanced technologies that monitor, optimize and ensure the longevity of solar modules.
With the increasing scale and complexity of PV projects, especially in large power plants and commercial systems, new solutions have been integrated into inverters to address specific challenges such as potential induced degradation (PID).
Technologies such as Anti-PID and PID Recovery exemplify this technological evolution, showing how modern inverters not only optimize energy performance but also help extend the lifespan of modules.
Potential-induced degradation is one of the main challenges that can compromise the efficiency and durability of photovoltaic modules.
This phenomenon occurs due to the combination of three main factors: the difference in electrical potential between the solar modules and the grounded structure, adverse environmental conditions such as high humidity and temperature, and the quality of the materials used in the manufacture of the modules.
When these factors combine, electrical current leakage can occur between the photovoltaic cells and the grounded structure, resulting in degradation of the module's electrical properties.
This degradation has direct impacts on system performance, such as reduced energy conversion efficiency, losses in output power and, in severe cases, a significant compromise in the useful life of the photovoltaic system.
In systems affected by PID, efficiency losses can reach up to 30%, which represents a substantial impact on the return on investment. Therefore, technologies such as Anti-PID, which prevent degradation, and PID Recovery, which repairs already affected modules, are essential to maintain the reliability and performance of photovoltaic systems throughout their useful life.
Technological advances in photovoltaic modules have also played a crucial role in reducing susceptibility to potential-induced degradation.
State-of-the-art modules, such as those using TOPCon (Tunnel Oxide ivated ) technology, offer significant improvements in efficiency and durability.
Leading manufacturers such as Canadian Solar already offer modules with significantly lower degradation rates compared to previous generations.
This evolution is due to the application of more resistant materials and the improvement of manufacturing processes, which minimize ion migration and reduce vulnerability to adverse environmental conditions.
As a result, TOPCon modules not only deliver higher conversion efficiency, but also ensure greater performance stability throughout their lifetime. This combination of high efficiency and low degradation strengthens the long-term return on investment in PV systems.
Although modern PV modules are more resistant to PID effects, the implementation of Anti-PID and PID Recovery technologies in inverters remains highly beneficial.
These state-of-the-art modules, with lower degradation rates, are less susceptible to the effects of PID, as mentioned previously; however, even with these improvements, environmental factors such as high humidity, elevated temperatures, and the system configuration itself can still contribute to the occurrence of PID over time.
In this context, the integration of Anti-PID and PID Recovery functionalities in inverters plays an essential complementary role. The Anti-PID system acts preventively, protecting the modules against degradation from the start of operation, while PID Recovery allows the loss of efficiency to be reversed if the effect has already occurred.
This synergy between advanced modules and inverters with mitigation technologies ensures greater stability and performance of photovoltaic systems throughout their useful life, maximizing return on investment and contributing to energy sustainability.
The operating dynamics of the Anti-PID system are based on neutralizing the electrical potential difference between the photovoltaic modules and the grounded structure, which is primarily responsible for degradation due to induced potential.
This technological solution acts preventively, ensuring the electrical integrity of the modules and mitigating the degradation of their properties over time.
The Anti-PID device, integrated into the inverter, Canadian Solar, continuously measures the voltages present between the module strings and the grounding potential, identifying conditions that are favorable for the development of the PID.
During periods when the photovoltaic system is in active operation, the Anti-PID module of Canadian Solar inverters raises the electrical potential between the negative pole of the photovoltaic string and ground to a controlled positive value.
This potential adjustment creates an electric field opposite to the driving force of the PID effect that one wishes to avoid, neutralizing the migration of ions in the photovoltaic modules and thus effectively suppressing the occurrence of the phenomenon during system operation.
During periods when the equipment is not operating, especially at night, to reverse the damage already caused by the PID in the photovoltaic modules, the device applies a voltage with the opposite polarity to that which caused the degradation, in the order of 500Vdc.
This voltage is carefully controlled so as not to damage the modules, but sufficient to induce the reverse migration of the ions, restoring the original electrical properties of the photovoltaic cells.
The compensating voltage applied during this activation period of the Anti-PID module prevents the displacement of ions in the constituent materials of the solar cells, such as the encapsulants or the dielectric layers.
This action preserves the ivation of the cells and prevents the degradation of electrical parameters, such as series resistance and conversion efficiency.
The Anti-PID system operates autonomously and adaptively, adjusting voltage levels according to the electrical characteristics of the system. that to have these functions enabled, it is necessary to understand the type of connection of the installation.
The longevity and efficiency of photovoltaic systems are crucial factors for maximizing return on investment and the sustainability of solar energy generation.
Modern technologies, such as high-efficiency photovoltaic modules based on TOPCon cells, and advanced control systems integrated into inverters, play complementary roles in mitigating and recovering from degrading effects such as PID.
While the most advanced modules offer greater intrinsic resistance to degradation, solutions such as Anti-PID and PID Recovery ensure the prevention and recovery of performance losses, even in adverse environmental conditions and challenging configurations. This technological synergy not only preserves the nominal performance of the systems, but also significantly contributes to increasing their operational lifespan.
By implementing these technologies, photovoltaic systems can operate with greater reliability and efficiency for longer periods, reducing maintenance and replacement costs, and promoting a sustainable energy transition.
Therefore, continuous advances in this field are essential to drive the development of more resilient and long-lasting energy solutions, aligned with the needs of the future.
The opinions and information expressed are the sole responsibility of the author and do not necessarily represent the official position of the author. Canal Solar.
