I came across this solar array in NE DC at 315 Franklin St. It was the inclined solar water heating panels that I spotted. Generally, these are what you're going to notice if you look to the roof tops. They're three times bigger than the flat-lying PVs (top picture).
As I was up there, I inspected the names on the different elements and learned that solar is a very fragmented market.
On this project alone, I found: Schletter (mounting systems), Erico (grounding, bonding, connectivity in the center left photo), SolarBos (combiner boxes), and Solar Edge (inverters).
By my count, there are 18 water heating panels and around 90 PVs. That's the biggest roof project I've seen so far.
Finally, after I visited, I did some follow up research and found that it wasn't even on Google Maps yet (middle right photo). So you're seeing a brand-spanking-new project!