Protection against direct lightning strikes and transient overvoltage

Surge damage resulting from thunderstorms – one of the most frequent causes of damage to PV systems

Surge damage frequently results in the destruction of system parts such as modules, inverters and monitoring systems. This causes high financial loss. Replacement of a faulty inverter, new installation of the PV system, loss of revenue resulting from downtime… all these factors lead to the fact that the break-even point and thus the profit zone is reached much later.

Ensuring system availability

Decide on a professional and comprehensive lightning protection system consisting of

• External lightning protection including an air-termination and down conductor system
• Internal lightning protection including surge protection for lightning equipotential bonding,

thus increasing system availability and securing revenue in the long term.

We are a competent partner with more than 20 years of experience in protecting photovoltaic systems. We will be pleased to help you create tailored protection solutions.

Professional planning based on the lightning protection concept

The most commonly used PV systems are rooftop systems. They are particularly prone to damage caused by direct and indirect lightning effects due to their exposed location.

Since the PV system is directly connected to the electrical installation of the building, lightning effects can have severe consequences:

• Damage to the building resulting from direct lightning effects or fire
• Damage to persons inside the building
• Destruction of or damage to electronic devices caused by direct or indirect lightning effects

Comprehensive protection is necessary and should be carefully planned.

Risk analysis – Prerequisite for professional planning

Professional planning including a risk analysis is indispensable for ensuring safe and reliable operation of PV systems. This risk analysis is performed according to EN 621305-2, must be adapted to the relevant building and must take account of lightning and surge protection.

Coordination between the different trades is important

The most important goal of PV installers is to optimise the use of the roof area. Lightning protection installers, in contrast, have to consider the separation distance1 for the lightning protection system. Lack of coordination may cause considerable problems. Therefore, coordination between roofers / lightning protection installers and installers of photovoltaic systems / electricians is essential not only when constructing a new building, but also when retrofitting roof-mounted systems.

1 Separation distance: Necessary distance between the down conductor and another earthed metal part of the building

Protection against direct lightning strikes and transient overvoltage

A lightning protection system for free field systems and solar parks has two main goals:

• Protection of the power plant area from lightning-related damage
• Protection of the modules, inverters and monitoring systems from the effects of electromagnetic impulses

The investment volume is high and therefore system operators require permanent system availability – For this reason, the lightning-related risk should be calculated according to IEC 62305-2. The results of such a risk analysis form the basis for planning a lightning protection system.