US Commercial Solar Has a Rapid Shutdown Problem

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Introduction to Rapid Shutdown Devices

Guest Introduction: David Penalva
Differentiating Services in Solar Operations
Insights from SolarGrade PV Health Reports
Identifying Risks in Solar Portfolios
Inspection Standards vs. Safety Standards
Focus on Rapid Shutdown Devices (RSDs)
Understanding RSD Failures
Addressing RSD-Linked Fires
The Need for Industry Standards and Data
Construction Mistakes in Solar Projects
The Role of Field Inspection Data
The Call for Third-Party Inspections
Future Predictions for Solar and Storage
Conclusion and Resources

David Penalva, CEO and Co-Founder of SolarGrade and HelioVolta, explains why systems with rapid shutdown devices are 66% more likely to have critical safety issues.

Eighty percent of the commercial solar projects HelioVolta inspects have connector and wire management defects on the DC side. David Penalva tells Sean why the devices installed to improve rooftop safety are showing up in his inspection data as a source of new risk: systems equipped with rapid shutdown devices are 66% more likely to have critical safety issues, and his team has documented 21 rooftop thermal events linked to RSDs since 2021.

David also breaks down why NEC 690.12 rapid shutdown requirements, written to protect firefighters, have produced a set of unintended consequences that now put more people and property at risk than the original hazard they were designed to prevent. No other country in the world requires these devices, and no available data shows firefighters have actually been harmed by solar systems. He walks through the owner’s dilemma when RSDs fail, his published risk severity methodology for standardizing how the industry classifies field defects, and why EPCs policing their own construction quality is a structural conflict of interest the industry still hasn’t solved.

Topics discussed:

• Connector and wire management defects found in 80% of inspected commercial solar projects
• Systems with rapid shutdown devices being 66% more likely to have critical safety issues
• 21 rooftop thermal events linked to RSDs since 2021 with no national database tracking component-level fire causes
• NEC 690.12 written to prevent firefighter injuries despite no available data showing firefighters harmed by solar systems
• The US as the only market in the world requiring rapid shutdown devices on commercial solar installations
• RSDs doubling or tripling connector counts on site, compounding the industry’s existing DC-side quality problems
• The owner’s dilemma: four options when RSDs fail, from losing code compliance to costly retrofits under UL 3741
• RSD manufacturers blaming installers for failures despite evidence that devices combust independent of installation quality
• HelioVolta’s published risk severity methodology addressing the lack of standardized defect classification across the industry
• Third-party QC providing cross-company benchmarking data that EPCs cannot generate when inspecting their own work

Transcript

Sean Swentek: Rapid shutdown devices were brought into our industry to prevent safety issues, is my understanding. So how is it that they are causing a worse situation to occur when they are installed on a site?
David Penalva: These small components can fail catastrophically and cause fires. That is ultimately the worst-case scenario.

Sean Swentek: Welcome to The Future Current. I’m your host, Sean Swentek. I’ve got a special guest live in the studio with me today, David Penalva, CEO and founder of both SolarGrade and HelioVolta, two incredible companies in our industry doing amazing work. David Penalva, thanks for joining me today.

David Penalva: Thank you for having me.

Sean Swentek: I’m really excited to hear everything you have to share. Can you provide some top-level numbers from past reports?

David Penalva: In fact, eighty percent of the projects we inspect have connector and wire management issues.

Sean Swentek: Eighty percent?

David Penalva: Yes, eighty percent.

Sean Swentek: If I’m a big institutional investor putting capital into big commercial projects, I may not even understand the actual risk.

David Penalva: A lot of companies don’t really have processes, procedures in place, and standardization around QA/QC. Without data, there is no way to act. We need to raise our standards for quality, safety, and reliability.

Sean Swentek: That is really insightful. Can you explain the most dangerous thing hiding in plain sight in a solar portfolio?

David Penalva: The biggest issue is a widespread lack of standards around how wire management is executed and how connectors are procured under the latest code cycles.

Sean Swentek: That's definitely concerning.

David Penalva: A robust sampling methodology to assess quality across the entire site is key.

Sean Swentek: Let's get into RSDs. How did you deduce that solar systems with RSDs are sixty-six percent more likely to have critical safety issues?

David Penalva: By analyzing data under my published risk severity methodology.

Sean Swentek: I hear what you're saying. So, what's your response if another industry player accuses you of fear-mongering?
David Penalva: I rely entirely on a scientific, fact-based approach. It is a highly scientific way of classifying risk, and you can’t argue with science.

Sean Swentek: What bold prediction can you make about where our industry will be in the next five to ten years?

David Penalva: I am all about solar and storage. Storage is the only solution right now that will help us bridge the gap with ongoing electrification.