Does Lightning in a Thunderstorm Affect a Solar Inverter?
Lightning strikes during a thunderstorm can significantly impact solar inverters and PV arrays. This article discusses the effects of lightning on solar inverters and provides insights into protecting them from damage. Real-world examples and expert advice from a seasoned solar installer shed light on the importance of having robust lightning protection measures in place.
Literature on Lightning and Solar PV Systems
Studies and field observations have documented instances where lightning can cause extensive damage to solar PV systems, including inverters. A notable case occurred in 2011 when a 5 kW solar PV system assembly endured one of the most intense thunderstorms ever experienced. Despite the absence of direct lightning strikes, the inverter was severely damaged, emphasizing the importance of proper lightning protection measures.
Case Study: Lightning Damage to a Solar Inverter
On a particularly stormy day, the inverter cover was filled with dust from the sacrificial MOV (Metal Oxide Varistor) surge protectors, indicating a lightning surge that had blown the DC fuse. The inverter manufacturer’s tech support recommended either sending the inverter to California for repair or installing additional external surge protection. The latter was recommended, as the manufacturer certified that the inverter could only be serviced by a certified technician, and the repair process could take up to six weeks. By adding external surge protection, the installer was able to restore the system to its net metering functionality.
Leveraging Surge Protectors for Protection
The choice of surge protectors plays a crucial role in safeguarding solar inverters. In the past, Delta lightening arresters were the only devices approved by building codes, despite being mostly ineffective at protecting sensitive electronics. Over time, alternative surge protectors like Midnight Solar models have become more widely used. These devices not only prevent the spread of fire but also provide an additional layer of protection for sensitive electronics.
Comprehensive Protection Strategy
A comprehensive protection strategy includes not only surge protectors but also whole-house surge protection at the utility meter. This method ensures that lightning-induced surges are intercepted before they reach the solar system, providing an additional layer of security. While the initial cost of these devices can be considerable, the long-term savings and peace of mind they provide are invaluable.
Conclusion and Recommendations
The experience shared highlights the critical need for robust lightning protection measures for solar PV systems. Proper installation of surge protectors and whole-house surge protection can significantly reduce the risk of damage to solar inverters and other components during thunderstorms. It is essential for solar system owners to implement these measures to ensure the longevity and reliability of their solar investments.
Keywords:
solar inverter, lightning protection, PV system maintenance