MLPE Isn’t the Problem. Our Standards Are.
- Snarky Solar Guy
- Mar 23
- 4 min read
There’s a new Heliovolta report making the rounds claiming that MLPE - and specifically rapid shutdown devices (RSDs) - are increasing fire risk in commercial solar. And like clockwork, people are running with the headline instead of reading the report- or worse, using the report as anti-MLPE ammo.
Let’s get something straight: This report does not prove that “MLPE causes fires.”
What it actually shows is something a lot less comfortable and icky:
We have a workmanship problem in this industry.
What the Report Actually Says
The report focuses specifically on rapid shutdown devices (RSDs)—not all MLPE.
It also clearly states:
The data comes from ~500 inspected systems
It is not representative of the entire U.S. market
There is no comprehensive national root cause database
This is field-observation data from problem systems, not a comprehensive statistical picture of the industry. That doesn’t make it useless, but it does mean you shouldn’t be rewriting system design philosophy based on it.
Yes, MLPE Adds Complexity. That’s Not the Argument.
The report points out:
MLPE systems have more connector issues
MLPE increases wiring complexity
More components = more potential failure points
None of that is controversial. If you take a system and:
Double or triple the number of connectors
Add more wiring
Increase installation requirements
Then, yes, YOU increase the likelihood of failure.
The Real Root Cause: Installation Quality
Look at the failure modes identified:
Improper connector terminations
Mismatched connectors
Poor wire routing
Violations of bend radius
Lack of strain relief
Inadequate clearance
None of those are “MLPE failures.” Those are installation failures.
And they’ve existed long before MLPE showed up.
MLPE Didn’t Create the Problem. It Exposed It.
More components. More connections. More opportunities to get it wrong. If your crews are sloppy, MLPE will absolutely make that show up faster and more often.
But removing MLPE doesn’t fix that. It just hides it.
The Industry’s Favorite Shortcut
“If MLPE increases risk… just remove it.”
That’s the path of least resistance. And it’s a terrible, lazy, and dangerous mindset.
If your solution to poor workmanship is to remove complexity, you’re not fixing the problem. You’re designing around it.
That might reduce failure rates on paper. But:
It doesn’t improve the quality of the work.
It doesn’t raise the standards of the workforce.
It doesn’t move the industry forward.
I really tried to cram an RTFM reference in here somewhere, but this goes far beyond that.
Let’s Talk About Connectors
Hot Take: We’ve built an industry where everyone certifies their "thing", and nobody owns the outcome on the roof.
The report highlights a key point: MLPE can increase connector count by 2–3x.
That’s not trivial. But connectors have always been one of the most common failure points in PV systems:
Poor crimps
Cross-mating incompatible connectors
Incomplete engagement
Mechanical strain
These are not new problems. They’re just easier to ignore when there are fewer of them.
Speaking of connectors
This earlier HelioVolta/PVEL/NREL connector report (from 2022) was pretty direct about where the real risk lies in PV systems: connectors and how they’re installed.
It called out, in plain terms, that failures tied to improper crimps, cross-mating, incomplete engagement, and poor wire management are among the leading contributors to arc faults and thermal events.
It also called out a root cause of these issues:
However, the 2026 report does not overtly come out and say: "The industry has a workforce training and competency problem."
Very sneakily, they describe a training problem without calling it a training problem, then change course to a hardware conclusion.
Connectors have been a leading failure point for over a decade, so I think it’s fair to ask why the interface itself hasn’t evolved.
I learned during my time at SMA that the industry has placed a lot of system-level safety responsibilities on inverters: arc-fault, ground-fault, and rapid shutdown.
This really bugged me as a technical trainer for the world's largest inverter manufacturer, "We don't cause these issues. Why are we the ones responsible for finding them?"
The upstream components largely operate within their own certification boundaries. The result is a system where no single party owns real-world performance.
The Right Conversation We Should Be Having
If this report proves anything, it’s this:
System complexity increases risk when installation quality is inconsistent.
That’s not a product issue. That’s an industry maturity issue.
We have to decide what kind of industry we want to be:
Option A:
Reduce system complexity to accommodate a lower-skilled workforce.
Option B:
Raise the standard of training, installation, and inspection.
Only one of those leads to long-term credibility and customer trust. The other just makes the failures less visible - until they aren’t.
Every time our industry has an incident, the naysayers say, "See, I told you that solar shit doesn't work."
Hot Take
This industry doesn’t need fewer components. It needs better electricians.
MLPE isn’t the problem. It’s just less forgiving of bad work.
And that’s exactly what we need.
Related post:
Comments