“So how much do you think you saved just by avoiding all the rapid shutdowns?”
I was doing a third-party inspection for a customer — the customer, EPC and I were walking around the roof, drinking coffee and chatting as the sun rose.
The project manager stopped for a moment, thinking and doing the math in his head. “About 900 modules on site, about $50 per shutdown, so … probably almost $25,000?”
It took me aback for a second. Granted, I’m no project manager who is used to seeing hundreds of thousands of dollars casually pass back and forth between themselves, customers and suppliers, but even in the context of a 450 kW rooftop project, that seemed significant.
“And that’s not even factoring in the labor associated with installing those, right?”
“Oh yeah, for sure.”
PV Hazard Control Systems (PVHCS), or UL 3741, are gaining steam as an alternative to module-level rapid shutdown (MLRS) in the C&I space, and as a service technician, I’m thrilled. Since NEC 2017’s MLRS requirement took effect in 2019, the complexity and instability of rooftop solar has only increased. Not only has the industry had to buy and manage more product, but installers expect to do a few truck rolls in the first year or two to replace optimizers or track down failed connectors due to the tripling of connection points.
