Owners of operating solar projects face a wide range of technical and operational challenges as assets age. While strong relationships with equipment manufacturers can often reduce downtime and accelerate root-cause analysis, there are situations where even consistent communication fails to produce clear answers.
One such issue we are currently facing involves unexpected thermal shutdowns affecting Solectria inverters at one of our operating sites. The experience has raised important questions not only about reliability but also about the level of support available when complex failures occur. In this article, we want to share what has happened so far and invite feedback from owners, operators, engineers, and anyone in the industry who may have encountered similar events.
The Issue: Catastrophic Inverter Failures Caused by Repeated Thermal Events
In July of this year, a number of Yaskawa Solectria XGI 1500 string inverters at our site began experiencing sudden thermal events (Pictures below). Multiple inverters exploded over the course of 2 weeks. Fortunately, none of our contractors were near the affected inverters. Any person within 20 ft of the units would have been at risk of serious danger. In response, we immediately took the site offline.
Our O&M contractor was unable to determine the root cause, and initial troubleshooting provided no conclusive direction. As a result, the site remained offline for nearly a month, representing a significant loss of production and avoidable downtime.
Engaging Solectria: Limited Clarity and Unresolved Questions
Throughout this period, we engaged directly with Solectria to investigate the issue. Although their team has been responsive in acknowledging the situation, we still have not received definitive explanations or the failure reports needed to fully understand what occurred.
Key questions remain unanswered:
- What specifically caused the thermal events across multiple units?
- Is the underlying issue resolved, or simply no longer active?
- Most importantly, is it 100% safe to continue operating the site?
Despite multiple requests, we are still waiting for complete diagnostic reports and a clear assessment of long-term operating risk. Until we receive conclusive information, uncertainty remains.
Why This Matters for All Project Owners
A situation like this highlights a broader industry challenge: when equipment manufacturers cannot, or do not provide complete transparency during equipment failures, project owners must make operational decisions without full confidence in the underlying data.
This presents several risks:
- Unconfirmed safety conditions during operation
- Potential recurrence of the issue
- Unknown impacts on long-term inverter health
- Warranty complications if the root cause is never documented
- Unnecessary downtime if owners choose caution over risk
For aging assets, many of which rely on hardware that may no longer be in active production, these risks are even more pronounced.
A Request for Industry Feedback
Because this issue is still ongoing and the root cause remains unclear, we want to reach out to the solar community for insight.
We would greatly appreciate hearing from anyone who has experienced:
- Similar thermal shutdowns on Solectria inverters
- Intermittent thermal derating or cascading unit failures
- Situations where failure reports were delayed or inconclusive
- Any known design issues affecting Solectria models deployed at scale
- Best practices for diagnosing unexplained thermal events
If you have encountered this at your sites—or if you have technical insight that could help us and others—it would be incredibly valuable.
Conclusion
This incident underscores the importance of open communication, manufacturer transparency, and real-world knowledge-sharing within the solar community. While manufacturer relationships are essential, there are times when the industry must rely on one another’s experience to fill the gaps.
Our primary concern now is ensuring our site is operating safely and reliably. Until the root cause is fully understood, that question remains open. We welcome any feedback, experiences, or ideas that may help shed light on this issue.
