So far, only about 35 percent of the infrastructure condition has been surveyed, and of that 35 percent, 80 percent of the transmission and distribution infrastructure has been lost, Ramos said.
Part of the issue is that most of Puerto Rico's power lines are aerial, Puerto Rico's secretary of state, Luis Rivera Marin, told CNBC on Friday.
"We need to get [the infrastructure] up and running. We established priorities whereby we have our hospitals first in line and certainly the hotels and going into communities," Marin said in an interview with "Power Lunch."
Recovery will take longer in the remote communities in the center of the island, he said. The area is the hardest hit because it is on higher ground and therefore was pummeled by winds.
Utility crews from the U.S. mainland headed to the island to help restore power, including utility companies from New York, Georgia and Florida. Crews are "working from early morning til night trying to get power back," Marin said.
Another issue is getting the materials they sorely need. The island had just committed resources to restoring power after Hurricane Irma. Marin said power was 96 percent back online when Maria hit.
"Many of the supplies and assets were committed to that recovery. FEMA is bringing in tons of supplies," said Marin.