DEHN outlines technical standards for solar PV lightning protection

DEHN has released updated guidance on lightning and surge protection for roof-mounted photovoltaic (PV) systems. With millions of installations currently in operation, the company highlights that the long-term exposure of PV systems to environmental factors necessitates robust protective measures to prevent damage to solar modules, inverters, and building-integrated electronic systems.

Lightning strikes can cause significant electrical disruptions due to field-based and conductive interference. DEHN advises that risk assessments should be conducted according to DIN EN 62305-2 standards to determine necessary protective measures. While the installation of solar panels does not increase the frequency of lightning strikes, it can exacerbate the impact on internal building systems. The company provides the DEHNsupport toolbox to help stakeholders balance technical requirements with economic efficiency.

Since 2016, DIN VDE 0100-443 has mandated surge protection in all new building projects, including residential homes. This regulation requires the integration of surge protection devices (SPD) on both the AC and DC sides of PV systems. Furthermore, the company emphasizes the importance of cabling geometry; minimizing the size of conductor loops during installation is critical to reducing the risk of induced overvoltages.

Ultimately, the guidance stresses that any new PV installation must not compromise existing lightning protection systems. For most PV applications, a lightning protection system designed to LPL III standards is considered sufficient to meet safety requirements and mitigate risks of fire and operational failure.