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In March 2026, HelioVolta, a private company that provides technical services to safeguard renewable energy investments, published a white paper highly critical of photovoltaic (PV) rapid shutdown devices (RSD). In the document, HelioVolta identifies 74 thermal safety events since 2021 attributed to RSD (photo 1-3). According to the document, the research included inspections of more than 500 rooftop PV systems in the commercial and industrial (C&I) space.  
HelioVolta states that PV systems with RSD are 66% more likely to have critical safety risks than those without module-level power equipment (MLPE). The document goes on to identify resolutions for this safety concern, including removing these devices preemptively. This, in itself, would violate National Electrical Code (NEC) expectations for systems installed after 2014. To be clear, the document recognizes this option as not viable. The report also theorizes why RSDs are so problematic, citing the following: 
This report is both damning and frustrating on many levels. As a firefighter who recognizes the handwringing and assiduous work that went into creating the safety requirements afforded by RSD, it really hits home. I believe in the language captured in the NEC that speaks to the safety requirements for rooftop PV. And I understand the compounding nature of adding electrical shock hazards to an already perilous firefighter rooftop operation. 
I understand that the presence of RSD does not fully eliminate the electrical hazards inherent in rooftop PV systems. But the idea of rolling back even this margin of safety for firefighters, who are often forced to work in proximity to these hazards is, in my opinion, not viable. The fire service simply cannot support the unwinding of code language designed to enhance the safety of our members.   
But what the HelioVolta report reveals has merit. It is well written and well researched. They kept the guardrails narrow, limiting the research to rooftops systems in the C&I space, ensuring that the data field would be impactful. However, after reading the 17-page report, I arrived at a very different conclusion.  
There may be design flaws and unforeseen gaps within the technology itself. The report also cites installation problems and difficulties within the PV industry. Both issues are reflective of a maturing process inherent with technological advancements. These are what I call “innovative blind spots.” They are predictable and manageable. And they will not be the last problem this industry will encounter. The market response to this can drive innovation without hurting the overarching concept, which is to increase safety for firefighters.  
It is critical that we do not throw the baby out with the bathwater. The concept and intention of supporting firefighter safety is simply too important. Consider the Takata airbag fiasco. Problems with these safety devices resulted in the largest recall in U.S. history, affecting more than 67 million airbag inflators across more than 42 million vehicles. Globally, approximately 100 million inflators have been recalled to date. Despite this, we did not abandon the safety afforded by these devices, nor should we abandon the firefighter safety expectations captured in the NEC for rooftop PV systems.  
A couple of things jump outwithin this space: 
The operational expectations when working at a structure with PV energy hazards remains static (Figure1): 
The work that went into this white paper will aid in ensuring that this valuable technology matures in a way that we can all benefit from. I encourage you to reach out to members of the PV industry and strengthen your understanding and relations with these trade partners. Because safety is a responsibility that is best supported through open, familiar dialogue, and prescriptive code language.   
Rapid Shutdown Devices and Safety in Commercial Solar, HelioVolta, March 2026, heliovolta.com/resources/rapid-shutdown-devices-unintended-consequences.
Greene, C. G., and Granato, T., “Rapid Shutdown: The Photovoltaic Safety Feature You’ve Never Heard Of,” Fire Engineering, vol 178, issue 2, bit.ly/4cN9LMo. 
CHRIS G. GREENE is a captain (ret.) with the Seattle (WA) Fire Department and a national speaker on energy response hazards. He is the creator of Seattle Fire’s Energy Response Team and assisted in designing its “Energy One” response apparatus. Greene is a contributing author to Fire Engineering for energy emergencies and creator of the “Lithium-Ion Revolution” teaching platform. He was the 2017 Seattle Fire Officer of the Year, keynote speaker at the 2024 Washington State Energy Hazards and Lithium-Ion Battery Symposium, and keynote speaker at the 2025 TEEX Electric Vehicle and Stored Energy Summit. Greene is a technical panel member for UL Research Institutes’ Fire Safety Research Institute Safety of Batteries and Electric Vehicles. He represents the IAFF on the following NFPA standards committees: NFPA 12, 30A, 850, 855, and the NFPA 800 “proposed” Battery Safety Standards Committee.
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