Why Should Rooftop Solar Power Plants Be Protected from Lightning and Sudden Overvoltage?

Rooftop solar power plants have gained great popularity in recent years as a sustainable and renewable energy solution. However, like any electrical system, they are vulnerable to natural events such as lightning strikes and overvoltage incidents. In our new blog post, we will examine the importance of protecting rooftop solar power plants from lightning and overvoltage, highlight potential risks, and outline key measures to safeguard these valuable facilities.

In recent years, significant reductions have been observed in the costs of solar energy technologies in Türkiye. This has made solar energy systems economically more attractive. Licensed solar power plants and rooftop solar projects, in particular, represent important steps toward utilizing the country’s solar energy potential.

Lightning strikes and overvoltage events pose significant risks to rooftop solar power plants. Lightning carries immense power, and a direct strike on a solar array can cause severe damage, leading to system shutdown and potentially endangering property and occupants. Moreover, lightning-induced surges can propagate through the electrical grid, affecting other connected devices and even causing electrical fires. Similarly, overvoltage events such as grid fluctuations or electrical faults can damage the sensitive electronic components of solar energy systems, resulting in system failures and financial losses.

Rooftop solar power plants are particularly vulnerable to lightning and overvoltage events due to their exposed locations and proximity to electrical infrastructure. Photovoltaic (PV) modules, inverters, and associated cabling are sensitive to voltage fluctuations, making them prone to damage from sudden surges caused by lightning strikes or grid disturbances. In addition, rooftop installations are often positioned at higher elevations, increasing the likelihood of lightning strikes.

IEC 62305-Based Protection System Is the Golden Rule in Lightning Protection.

To mitigate the risks associated with lightning and overvoltage, various protective measures can be implemented in rooftop solar power plants. These measures represent a critical stage for rooftop solar systems expected to operate for 25 years.

External Lightning Protection Systems: Installing a comprehensive lightning protection system within the scope of IEC 62305, including air terminals, conductors, and grounding systems, helps safely direct the electrical energy resulting from lightning strikes into the ground, thereby protecting the solar array and other connected equipment. At this point, we recommend the use of passive protection systems to minimize risk.

Low Voltage Surge Protective Devices: The use of SPDs at various points within the electrical system of a solar power plant can divert harmful surges away from sensitive components. To provide multilayer protection, SPDs should be installed at the string level, inverter level, and main distribution board. The combined use of AC and DC low-voltage SPDs will ensure long-term protection.

Grounding and Equipotential Bonding: Ensuring proper grounding and equipotential bonding of PV arrays, inverters, and related equipment is essential for maintaining electrical safety. Effective grounding helps dissipate excess electrical energy and provides a low-resistance path for lightning-induced currents.

In Türkiye, 1–4 lightning strikes occur per kilometer annually.

In addition to these protective measures, regular maintenance and inspection are crucial to ensure continuous protection of rooftop solar power plants. Periodic inspections of the lightning protection system, grounding connections, SPDs, and overall system performance can identify potential issues and enable timely repair or replacement. Furthermore, following industry standards and guidelines, such as those outlined by the National Fire Protection Association (NFPA), can provide valuable insights for maintaining system integrity.

Rooftop solar power plants offer numerous environmental and economic benefits; however, it is vital to recognize and address their vulnerabilities. Lightning strikes and overvoltage events can cause severe damage and financial losses if not adequately protected. By implementing comprehensive protection measures, including lightning protection systems, SPDs, and proper grounding, we can ensure the longevity and reliability of rooftop solar installations and maximize their contribution to a sustainable future.

Providing air terminal design according to the rolling sphere method, using Type 1-2-3 staged AC and DC SPDs, and correctly implementing grounding and equipotential bonding with the right products will protect you from many risks in rooftop solar installations.

The Lightning Protection Center holds the record by protecting 7 GW of solar power plants nationwide, and with this experience, we are here to offer you the most accurate solutions.

Contact Yılkomer engineers now to protect your rooftop solar investments.

Remember, Yılkomer ‘Protects Your Values’!