How Does Surge Protection Work?
Lightning strikes can cause significant damage. The Netherlands experiences around 100,000 lightning strikes per year. How can you protect yourself? And do solar panels have any impact?
Do Solar Panels Attract Lightning?
Good news: solar panels do not increase the likelihood of a lightning strike. Although they contain electrically conductive materials, statistics show that houses with solar panels are not struck more often than those without.
However, the effects of a lightning strike can be severe. Power surges can enter your home through wiring, damaging appliances such as televisions, internet routers, and solar inverters.
The Three Types of Protection
Surge protection safeguards your electrical devices and is classified into three levels:
- Class I: Maximum protection against direct lightning strikes.
- Class II: Protection against indirect strikes and power surges.
- Class III: Basic protection against voltage spikes in the vicinity.
How to Fully Protect Your Home
A complete lightning protection system offers the best security. This includes:
- Lightning rods on the roof to capture strikes and safely discharge the energy.
- Metal conductors along the walls directing the current to the ground.
- Surge protection installed on all electrical lines, including AC cables and internet connections.
However, a complete lighning protection system is quite expensive. For most homes this level of protection is not necessary, as the risk of a direct strike is low.
What Protection Is Needed for Most Homes?
According to the Dutch regulation (NEN1010), in the vast majority of cases no additional lightning protection is required for PV inverter(s). Only if the cable between the solar panels and the inverter is exceptionally long (more than 34 meters or even longer, depending on where you live), an SPD (Surge Protection Device) type 2 is recommended. In addition, if there is already a lightning protection system on the roof and the solar panels are placed very close to it, an SPD type 1 is required for the inverter
The types of SPD available are:
- Type 1: Maximum protection but more expensive.
- Type 2: Suitable for homes in high-risk areas.
- Type 3: Provides the least amount of protection and is unnecessary because the inverters are already protected against overvoltage category III events.
Are Solar Inverters Already Protected?
Zonnefabriek inverters come with built-in Class III surge protection, offering basic defense against nearby lightning strikes.
Additional ways in which we protect the system:
- By minimizing the induction loop on the roof to reduce power surges.
- Consider Class II surge protection modules, which can be easily installed in larger inverters like the SMA Sunny TriPower (12 kW and above).
- For smaller inverters, additional protection is more expensive, requiring an external surge protection box, which is rarely cost-effective.
Generally, solar inverters are covered by home insurance policies. While a lightning strike can cause inconvenience, it usually does not result in out-of-pocket replacement costs.
If installing surge protection reduces your insurance premium, this could be an extra incentive. Check with your insurance provider for details.
