Hurricane Dorian skimmed Puerto Rico late Wednesday, giving the island's utility a brief test as it prepares for hurricane season.
After Hurricane Maria devastated the U.S. territory in 2017, leaving 1.5 million residents without power for months, the Puerto Rico Electric Power Authority (PREPA) is still wrestling with how to sustainably upgrade its aging electric grid and maintain resilience against extreme weather events.
"I do think we have a fragile system. It's still an old system. It still hasn't been elevated to the codes and standards for a Category 4" storm.
Director of Project Management, PREPA
Though the utility remains far from its long-term grid modernization goals — it's been estimated full reconstruction could take up to a decade — stakeholders say infrastructure hardening and improved finances have PREPA prepared to ride out this hurricane season and prevent a repeat of Maria.
But long-term hardening remains a work in progress.
"At this moment, the system itself, there are certain parts of the island where infrastructure is in much better condition than it was before Maria," Director of PREPA's project management office Fernando Padilla told Utility Dive. "But I do think we have a fragile system. It's still an old system. It still hasn't been elevated to the codes and standards for a Category 4" storm.
Road to full resilience
"We have a grid [that first] needs to be upgraded before it can be modernized," Jorge Camacho, a PREPA consultant and former chief system planner for the Washington, D.C. Public Service Commission. The first steps after Hurricane Maria was to bring everything up to code and harden as much infrastructure as possible, starting with the transmission system. But having sufficient back-up generation remains a problem, said Camacho, who was in Puerto Rico this week.
"We can have all these hardened transmission lines, [but] if we don't have resource adequacy in regards to generation, … the system becomes unstable and we are going to start experiencing outages," he said.
PREPA's power plants still make up the majority of the island's peak demand, meaning if a plant goes offline it could be detrimental to the full system, he said.
In March of this year, Puerto Rico passed a 100% renewable portfolio standard, intended to enhance resilience on that front through smaller, more distributed solar and storage systems, as well as through microgrid deployments
"100%, the utility is the one that needs to be calling the shots. That happens on the mainland — that needs to happen in Puerto Rico because the utility is the one that knows its system."
In the shorter term, the territory wants to avoid load shedding, and has deployed back up gas turbines across several metropolitan areas to prevent that. But the territory's commission is in the midst of an initiative that will look into how to deploy technologies such as demand response and energy storage strategically and allowing more intermittent resources such as wind and solar to be dispatchable.
"So from 2017 when Maria occurred to today ... We are in very good shape," said Camacho. The smaller gas units are able to maintain system capacity, a clear aid process has been developed with the American Public Power Association and the island now has over $140 million in poles and transformer inventory, up from "barely" $40 million in 2017, said Padilla.
Another key to the utility's capacity to perform under the pressures of a storm is its ability to take charge of system recovery, which did not happen in 2017.
"100%, the utility is the one that needs to be calling the shots," said Camacho. "That happens on the mainland — that needs to happen in Puerto Rico because the utility is the one that knows its system."
When Maria hit in September of 2017, PREPA had just filed for bankruptcy in July. This upended the financially-struggling utility's ability to take charge of restoration efforts, and because of that the Trump administration directed the U.S. Army Corps of Engineers to start doing transmission work — something that would normally be left to the utility.
That left the Corps' traditional role of providing back up generation to hospitals and other vulnerable areas where quick outage restorations should be prioritized up in the air, while simultaneously slowing down transmission work, because the corps was doing work "that was not in their domain," said Camacho.
"We had different companies and different people doing different things," he said. "That is not normal … [usually] the utility is given a significant amount of latitude to perform work."
Now, the utility says it's better prepared to take charge and step away from the chaos of two years ago.
"The logistics coordinations across our stakeholders … are much more aligned," said Padilla. "The communication has been much more integrated, as of last night."
PREPA is "optimistic" that it will be able to respond quickly and restore any damages to its electric system "much quicker" than for Maria which was "a much larger and a devastating storm than we expect Dorian to be," said Padilla.
After mostly dodging the island, Dorian grew to a Category 3 and is advancing to the eastern side of Florida. And PREPA says it was well prepared for the comparably light storm.
As of Wednesday afternoon, the utility had less than 500 customers without service with a load of 2.2 GW, similar to a typical operation day, said Padilla.
"Our generation plants are at full capacity load. So we're ready."