"They are definitely one of our preferred contractors," says Piotrowski.

The Chino Valley project also won an ENR Southwest Excellence in Safety award in 2013.

Randy Eskelson, president and COO of Schuff Steel, Phoenix, says a big factor in McCarthy's success not only on solar jobs but on all project types is that they do work properly, with a high level of proficiency.

"In my opinion, McCarthy is, if not the most, one of the most respected contractors in the country," he says.

Eskelson says the firm seems to always be on the cutting edge of engaging customers as well as going "all-in" on new technology.

"As far as a lot of the BIM process is concerned, they were one of the first to tell us that we had to do that," Eskelson says. "They really know how to manage a job. Every job has issues, but they know how to minimize them."

Calbert says much of the credit should be given to the work force, who are also part owners—McCarthy became employee-owned about nine years ago.

"It's all about talent and the quality of that talent," Calbert says.