What a Bad Connector Costs: Day One vs. Year Three

On a utility-scale solar project, a partially mated connector takes a few seconds to fix on install day. The installer doesn’t hear the click, so they push it until it locks or reseat it. Three years later, that same connector can mean a lockout/tagout on an energized system, lost generation, a root cause investigation, and an owner asking how many more are out there.

Julie Stiglish, a master electrician who now consults on quality and safety for utility-scale solar, makes the simple point in this clip that the fix itself never gets more expensive. Clicking that one connector together takes the same effort in year three as it does on day one. What changes is the cost of getting to it, and the cost of finding out whether it was a one-off or a pattern.

That cost curve sits at the center of her free course, 10 Utility-Scale Solar Defects Hiding in Plain Sight. You play inspector on ten annotated defect photos and see what each one costs depending on when it gets caught. It takes about an hour, and all you need is your free HeatSpring account!

Transcript below.

Walk me through what happens to a small defect, like you mentioned, a partially mated connector. What’s the difference if it’s caught on that first day versus caught a few years later? What is the actual cost difference, and why do you think that gap can surprise people, even experienced project teams?

Sure. On day one, when you catch it, the installer puts the connector together, pulls on it, doesn’t hear the click, and reseats it. That costs basically nothing, because that’s during install. There’s nothing stopping them from fixing that mistake right there.

If you move a little further on and you’re at commissioning, it might show up in testing, like an IV curve or a thermal scan. Now you’re troubleshooting a string instead of just a single module-to-module connection. So you’re pulling a crew back in, maybe retesting.

Then we get to the really scary part, where you’re three years in and that connector’s been heating up on very sunny days. It’s been out in the elements, and a lot has been going on over those three years. Worst case, it arcs, burns, and you’ve got a fire and a damaged combiner box, or something worse, you’ve injured a worker.

Now, to fix this, you’re doing lockout tagout on an energized DC system in a remote field. You’re losing generation to the utility. You’re running a root cause investigation. And here’s the real kicker: if one connector was bad, the owner’s going to ask you, “Are there others?” Suddenly you’re inspecting thousands of them. So you really have to understand what the cost of the defect is.

It doesn’t change. The cost will stay the same as far as just clicking that one connector back together, but the cost of access changes. On day one, everybody’s already there. Three years later, you’re mobilizing people, equipment, permits, outages to get back to a single component. And then you have the owner questioning how many other components are in the same boat.

Construction teams often hand the project off before the cost shows up, so they never see the full bill or what it looks like down the road.

Want to see how Julie builds inspection and defect management into a full project quality system? Explore Utility-Scale Solar QA/QC Fundamentals.