Joint research between UPE and CLAMPER presented in Japan proves that the use of an external SPD is essential to ensure the durability and safety of photovoltaic inverters.
The solar energy market in Brazil has grown at an accelerated pace, surpassing significant milestones in distributed generation. However, the high incidence of lightning strikes across the country requires heightened attention to the electrical safety of these systems. In this scenario, new scientific research conducted in a partnership between UPE (University of Pernambuco) and CLAMPER has brought to light important revelations regarding the vulnerability of these systems and the actual effectiveness of equipment defense mechanisms.
The in-depth study was officially presented at ICLP 2026, held in Japan. Entitled “Photovoltaic Inverter Surge Resilience: Internal Protection vs. External SPDs Analysis,” the work continued investigations initiated in 2024 in Germany, consolidating fundamental technical data for the clean and sustainable energy sector.
The Danger of Vulnerability in Solar Inverters
During practical tests, researchers analyzed three popular 5 kW photovoltaic inverter models widely commercialized in Brazil. The equipment was subjected to intense currents to simulate lightning impacts. Without an external surge protective device, the results were alarming: the devices failed rapidly, withstanding an average of only a few electrical pulses on both the direct current and alternating current sides.
These findings reinforce that relying solely on built-in factory protection can compromise an entire project. The tests demonstrated that the robustness claimed by some manufacturers is not always sufficient to withstand the severity of Brazilian weather conditions, putting consumer assets and the continuity of renewable energy generation at risk.
The Proven Effectiveness of the External SPD
A turning point in the tests occurred when the same devices were fitted with a proper external SPD. With the component integrated into the system, the scenario changed completely, and all inverters withstood the maximum limit of 100 impulses applied in the laboratory, blocking the vast majority of the destructive energy from electrical surges.
“Internal protection does not replace the external SPD. This second study reinforces what was already demonstrated by the first and shows, in a practical and measurable way, how exposed inverters become when an installation relies solely on built-in protection,” assessed Douglas Lara, Application Engineering Coordinator at CLAMPER.
The research emphasizes strict compliance with Brazilian technical standards for electrical installations. The external SPD acts by diverting most of the unwanted energy before it reaches sensitive inverter components, drastically optimizing the resilience of the photovoltaic system.
The Future of Protection in Photovoltaic Systems
Ensuring that a solar plant operates at maximum efficiency for decades requires long-term planning. Because projects typically last twenty years or more, outlasting the lifespan of inverters without costly corrective maintenance depends directly on good engineering practices right from the design phase.
“It is important to remember that a photovoltaic installation is designed to operate for 10, 15, 20 years or even longer, a period that may even exceed the warranty period of some inverters. Therefore, surge protection must be considered throughout the entire lifespan of the installation. The external SPD is an application mandated by Brazilian standards and is indispensable to protect investments in solar energy and ensure continuous generation, even for inverters that claim Class II internal protection,” concluded Douglas Lara.
With the continuous expansion of the energy transition, studies like the one by UPE and CLAMPER serve as an essential guide for integrators, designers, and consumers. Adopting the external SPD is not only a regulatory recommendation, but a fundamental pillar for the consolidation of an increasingly safe, reliable, and durable solar energy market in Brazil.
