Researchers in South Korea have highlighted the importance of precisely adjusting the angle of solar louvers to maximize electricity production. They found that there is a trade-off between high power and self-shading effects in this BIPV technology.
“What stands out in this study is the emphasis on its shading effects with PV blinds, a factor that is often overlooked,” said study lead author Jongho Joon. pv magazine. “Despite the general acclaim for the ability of PV blinds to produce more power than fixed PV modules due to their adjustable angles, the study points to significant operational performance degradation that can be caused by shading effects between, above and below the blind slats. .”
The researchers compared the performance of the PV blind in fixed angle vertical and inclined conditions with the performance of a fixed angle reference BIPV module in vertical and inclined conditions. They used both experimental field equipment and a simulation model to represent real scenarios.
“To measure the radiation delivered to the installed module, three pyranometers were installed at an angle of 30 degrees, 90 degrees and 0 degrees on the inclined, vertical and horizontal planes,” elaborated the researchers.
The researchers found that except for the 90-degree angle setting, the PV blinds consistently produced less power than the reference module at alternate angles. Normally, the optimum angle for solar power systems in Korea is 30 degrees.
“Interestingly, the PV blinds produced peak power at this 30-degree angle, but a significant difference compared to the reference module was also observed,” explained Joon. “This shows that increased power output produces more pronounced self-shading effects in PV blinds.”
The scientists compared the power output of the PV blinds at their monthly optimal angles with a fixed reference module set at 30 degrees or 90 degrees. The PV blinds performed better than the reference module mounted at a 90-degree angle, but their power output was 13-21% lower than at a 30-degree angle.
“These findings suggest that adjusting the angle of the PV blinds could improve power generation efficiency, although there were limitations due to self-shading effects caused by the upper slat module,” the researchers highlighted.
The research team also looked at scenarios where users might set the angle of the PV blinds incorrectly. On a monthly basis, they compared the performance of PV blinds placed at the least optimal angles with a reference slat module mounted at either a 30-degree or 90-degree angle. It found considerable differences in power generation performance. The reference module at 30 degrees produced 83-86% more power than the misaligned PV blinds, while it produced 14-28% less power than the reference module mounted at a 90-degree angle.
“This highlighted the importance of precisely adjusting the angle of PV blinds to maximize electricity production,” the researchers noted.
They introduced the new concept in a study published in 2010 entitled “Evaluation of electric light curtain performance considering self-shading effects”. Solar energy.
“It is important to note that the results did not consider the effects of series-parallel connections between the slat modules and the bypass diodes,” Yoon said, pointing to future directions for the research. “Therefore, including these factors in real-world conditions can potentially reduce the effectiveness of PV blinds.”