The global photovoltaic capacity now exceeds 1,500 GW, with an annual growth rate of over 200 GW. From Europe to Africa, via South America and the Middle East, solar installations are multiplying at an unprecedented pace. Yet, a major risk is often underestimated: lightning. Indeed, a single indirect strike can destroy inverters, damage modules, and interrupt production for several weeks.
Therefore, before investing in a PV array, understanding and correctly sizing your lightning protection is essential. This guide presents the entire regulatory framework and the equipment required according to the international standard IEC 62305.
Why photovoltaic installations are particularly vulnerable
Photovoltaic installations combine several factors of exposure to lightning that conventional buildings do not present:
- Elevated position: roofs, pergolas or ground trackers expose the panels as potential targets.
- Large conductive metallic surfaces: the arrays of modules form veritable antennas capturing and propagating induced overvoltages.
- High voltage DC wiring: DC voltages can exceed 1000 V — any transient overvoltage propagates directly to the inverters.
- Expensive electronic equipment: inverters, optimizers and micro-inverters are extremely sensitive to electromagnetic pulses from indirect lightning.
Therefore, even an impact several hundred meters away can generate destructive overvoltages through the installation's DC and AC cables.
The international normative framework: IEC 62305
In countries applying the IEC 62305 (transposed into NF EN 62305 in Europe), the protection of photovoltaic installations follows a methodical framework in 4 steps:
IEC 62305-2: Risk analysis
Every protection decision begins with a lightning risk analysis. This analysis takes into account:
- Ground lightning density Ng at the site location (expressed in impacts/km²/year, in accordance with IEC 62305-2 and FD C 17-108)
- The dimensions of the structure and the panels
- The value of equipment and the consequences of a disaster
- Operating losses related to the production shutdown
If the calculated risk exceeds the tolerance threshold defined by the standard, protective measures become mandatory.
IEC 62305-3 Annex D: External protection of PV installations
Annex D of IEC 62305-3 deals specifically with photovoltaic installations. In particular, it specifies the separation distances to be observed between down conductors and DC cables — a critical point often overlooked on construction sites.
IEC 62305-4: Internal overvoltage protection
Part 4 of the standard defines the requirements for surge protection devices (SPDs) to protect equipment against indirect lightning. However, these devices do not replace external protection; they complement it.
External protection: the lightning rod for PV installations
The purpose of external protection is to intercept the lightning arc and divert the current to the ground without damaging the installations.
Early streamer emission (ESE) lightning rod: the preferred solution
For roofs equipped with solar panels, the PDA/ESE is often the most suitable solution because:
- Its large protection radius allows it to cover an entire PV area from a single mast
- Its off-screen installation preserves the accessibility and aesthetics of the panels
- It can incorporate a lightning strike counter for annual regulatory verification
LPS France offers for this purpose the Paraton@ir and Ellips — connected PDAs compatible with the Contact@ir.
Separation distances: a critical point
The down conductors of the lightning rod must not run parallel to the DC cables. In practice, separate insulation or routing is often required depending on the Lightning Protection Level (NPF I to IV) determined by the risk assessment.
Internal protection: essential surge protectors
Even with a lightning rod, internal surge protection remains mandatory. Indirect lightning generates transient overvoltages that propagate through electrical and communication networks.
Points to equip as a priority
- DC side: surge arresters at the combiner box level and at the inverter inputs (Type 2 minimum; Type 1+2 in the presence of a lightning rod)
- AC side: surge arresters at the inverter output and at the main low-voltage switchboard (TGBT)
- Communication networks: surge protectors on monitoring links (RS485, Ethernet)
Furthermore, coordination between protection levels (Type 1, Type 2, Type 3) is mandatory according to IEC 62305-4 to ensure the effectiveness of the entire system.
Grounding: the foundation of all PV lightning protection
The quality of the grounding determines the effectiveness of the entire system. For a PV installation, three requirements are essential:
- An earth resistance of less than 10 Ω (less than 1 Ω for classified ICPE sites)
- The chassis of the modules and metal structures must be connected by an Equipotential Spark Gap system
- The ground connections of the lightning rod and the electrical installation must be interconnected
Case of ICPE installations: additional obligations
For PV power plants with a capacity exceeding 250 kW classified as ICPE (Installations Classified for Environmental Protection), specific obligations apply in many countries:
- Completion of a Lightning Risk Analysis (LRA) documented
- Implementation of the protections prescribed by the technical study
- Annual verification of the lightning protection system by a competent body
- Recording the results in a follow-up file
Furthermore, insurers are increasingly requiring proof of compliant lightning protection to maintain coverage for PV equipment.
Supervise and manage compliance over time
A PV installation represents an investment over 25 to 30 years. Lightning protection must therefore be maintained and checked throughout the installation's lifespan.
Therefore, once your PV lightning protection system is in place, it is recommended to manage all compliance monitoring using dedicated software. LPS Manager allows you to centralize records for each site, schedule periodic checks, and archive reports—ensuring long-term compliance with IEC 62305.
Conclusion: Built-in protection to secure your solar investment
Ultimately, lightning protection for a photovoltaic installation is not optional: it is a technical and regulatory requirement in countries applying IEC 62305. It rests on four pillars:
- A rigorous risk analysis according to IEC 62305-2
- External protection designed by a specialist engineering firm
- Coordinated internal protection (DC and AC surge arresters)
- Documented annual compliance monitoring
LPS France supports you throughout the entire process: risk analysis, equipment supply (lightning rods, surge protectors, monitoring systems), and integration into your maintenance approach. Contact our team for a personalized assessment.
