How EPCs can de-risk solar carport projects

This story is about solar carports — the covered parking structures with solar panels on top that schools, hospitals, and businesses are building over parking lots. It's mainly aimed at the companies that build them, but it explains why these projects cost more and take longer than rooftop solar, which is useful context if your workplace, town, or a nearby business is considering one.

The big lesson from builders interviewed is that what's underground makes or breaks a carport project. Unlike a roof, a parking lot can hide old pipes, buried debris, uncompacted fill, or even parts of a demolished building, and digging into rock instead of soft soil can push foundation costs up sharply. Because of this, carports typically cost two to three times as much per watt of power as a rooftop solar system, and builders often add a financial cushion to cover ground surprises. Steel framing, by contrast, is the more predictable cost, since some companies keep material on hand to avoid supply delays.

For homeowners, the practical takeaway is limited: this isn't about your roof or your electric bill. But if you're weighing a solar carport for a driveway, business, or community project, it helps to know that the ground beneath it, not the panels themselves, is usually the biggest source of cost and delay, and that a proper soil check before construction tends to prevent expensive surprises later.