Introduction to Lightning Protection in Solar Panels
The exposure of solar panels to lightning strikes can cause severe damage to your system, including your panel charge controller and inverters. While a direct lightning strike is virtually impossible to protect against, there are effective measures you can take to safeguard your solar panel system against the damaging effects of lightning. This guide provides detailed steps to ensure your system remains operational and safe in the face of severe weather events.
The Challenge of Lightning Strikes
No single solution can guarantee protection from a direct lightning strike on your solar panel system. However, lightning's impact can be significantly mitigated by proper grounding and surge protection measures. Contrary to what many believe, it's not just the thunder you need to worry about. The induced voltage spikes from nearby lightning strikes can still damage your solar panel system. This article delves into the best practices to protect your solar equipment against both direct and induced lightning strikes.
Proper Grounding is Key
1. Array Grounding: Install a robust grounding system for your solar array to prevent damage from induced voltage spikes. A good ground connection should be made with a very close by good earth ground. Ensure that the array’s ground is integrally bonded to the home’s electrical ground system. Bonding the array ground to the residential ground provides a pathway for lightning currents to dissipate safely.
2. Surge Protectors: Use surge protectors like Midnight Solar MOV surge protectors to protect the solar modules and your system from induced spikes. These protectors are designed to handle the rapid voltage changes and surges that occur during lightning storms. Installing surge protection at the array level ensures that any surge or induced energy is directed away from your equipment.
Protecting Your Inverters and Connected Devices
3. DC Side Protection: At the point where the wiring enters the home at the PV DC disconnect switch, install additional surge protection. This should include a bonded earth ground to the array and home electrical system. This setup helps to dissipate any voltage gradients and minimize the risk of equipment damage.
4. AC Side Protection: Install AC surge protectors on the inverter side to safeguard the inverters from the induced spikes in the AC wiring. Devices like those from Midnight Solar are highly recommended due to their proven performance and reliability.
Additional Protection Measures
5. Whole Home Protection: If your system is grid-connected, have the utility install a whole-home surge protector at the meter entrance. This will help protect your entire home from surges that might enter via the utility lines during a lightning strike.
6. Communication Lines: Ensure that any communication lines, such as telephone and TV cables, are properly protected with surge protectors to prevent damage to your home's internal systems.
7. Network Connections: If your inverter system is connected to the internet, consider adding surge protection devices to the CAT5 connection to safeguard your online communication.
Protecting External Antennas
8. Lightning Arrestors for Antennas: Install lightning arrestors for any external radio or TV antennas, connecting them to an outside ground. In some jurisdictions, local codes require bonding these arrestors to the house electrical ground, while in others, they prohibit it. Always check your local codes for compliance.
Conclusion: A Comprehensive Approach
To safeguard your solar panel system against lightning, adopt a comprehensive approach that includes proper grounding, the use of surge protectors at multiple points, and additional measures for communication lines and external antennas. By implementing these strategies, you can significantly reduce the risk of damages and extend the operational life of your solar system. Remember, the small steps you take today can protect your investment from the wrath of nature tomorrow.