Logistics Complicate Puerto Rico’s Electric Grid Recovery

Like a careless driver in a fast car, Hurricane Irma plowed through the Leeward Islands in early September. It sideswiped Puerto Rico, knocking out electric power to 1 million people. It ran over Caribbean resort islands including Saint Kitts and Saint Martin, then skidded north at Key West. Careening up the Florida peninsula, Irma left millions of people without power.

A multi-billion-dollar smart grid investment and an unprecedented repair effort helped Florida Power & Light—the state’s largest utility—restore most service to 4.4 million customers by 22 September.

In a statement, the utility credited what it said was one of the largest restoration workforces assembled in U.S. history. Some 28,000 workers from 30 states and Canada had the power back on within 10 days.

Then, almost improbably, a second storm plowed through the Leeward Islands two weeks after Irma. This time, Puerto Rico was hit head-on by Hurricane Maria. Essentially 100 percent of its power was knocked out.

A week after Maria hit, the Defense Department said that 56 percent of the island’s residents had no potable drinking water. In addition, 80 percent of the island’s electricity transmission system and all of its distribution system were said to be damaged. 

Full recovery likely will take months, complicated by the U.S. territory’s financial straits, by the damage across an area the size of Connecticut, and by the island’s distance from the mainland; San Juan is more than 1,000 miles from Miami.

“I can’t tell my guys to put trucks on I-95 and drive south,” said Mike Hyland, senior vice president of engineering services for the American Public Power Association (APPA). The Puerto Rico Electric Power Authority (PREPA) is an APPA member. That makes it eligible for mutual aid from other members. Some of those members in South Carolina, Georgia, and Florida received aid from APPA after Irma crashed through.

Indeed, recovery for Puerto Rico and for other islands mowed down by Irma and Maria hinges on logistics as much as engineering.

Not only do trucks, equipment, and personnel need to be moved by barge and airplane to the islands, but arrangements need to be made for fuel, food, water, security, and housing. Across the region, demand for all of that is high. If a line worker takes a San Juan hotel room, will a permanent resident have to move?

A trip down I-95 to help Florida “seems like an easy problem when you look at an island event,” said Hyland. As he spoke, he made his way toward a meeting at the Federal Emergency Management Agency. FEMA, along with the U.S. Department of Energy, is working with commonwealth and PREPA officials to organize the recovery.

In the days immediately after Maria, attention focused on ensuring that electric power was supplied by emergency generators at hospitals, critical care facilities, and other locations with a humanitarian need for power.

The Defense Department said that as of 27 September, 11 of 69 hospitals had fuel or power. Reports said that fuel for some critical care facilities was being delivered by armed guards to discourage looting. At some gasoline stations, wait times for motorists were measured in hours.

Encouragingly, early reports suggested that only minor damage was suffered by most electric generating assets, many of them along the island’s southern coast.

For example, Pattern Energy’s 101-megawatt Santa Isabel wind farm rode out the storm with no damage to turbines or blades, said spokesman Matt Dallas in an email. The facility’s grid connection was harder to reach behind a locked fence on private property. In a follow-up, Dallas said, “We have also now confirmed that there does not appear to be any damage to our connection to the grid including the interconnecting switchyard.”

Indeed, early inspection showed that generating assets are “relatively OK,” said Gil Quiniones, CEO of the New York Power Authority (NYPA). He and 10 NYPA generation and transmission experts joined a 22 September trip with Governor Andrew Cuomo in response to a governor-to-governor request from Puerto Rico Governor Ricardo Rosselló for assistance.

“Damage has been more to the [transmission and distribution] system,” Quiniones said. “The only buildings with electricity are those with their own power supplies.”

The PREPA transmission system is based on 115-kilovolt (kV) and 230-kV lines, similar to NYPA’s. “We can add a lot of value in planning and restoration,” Quiniones said.

Florida’s relatively fast service restoration was due in part to some $3 billion spent over the past decade on smart meters, smart grid, and infrastructure hardening, said Chris McGrath, an FPL spokesperson.

Upgrades to distribution poles, including shorter line spans between poles, helped to harden the FPL system. In addition, nearly 83,000 smart devices—including automated feeder switches and automated lateral switches—enabled the system to detect trouble on a line and reroute power.

McGrath said that even on a sunny day, if a palm frond brushed against a line, an automated lateral switch would close after detecting a fault on the line. A momentary outage might occur, then the switch would reopen as the fault cleared. Known as “trip savers,” McGrath said the devices help reduce the number of times crews must travel into the field to reset a switch. During Irma, those devices helped to avoid multiple outages that would have required crews to roll.

What’s more, around 90 percent of new construction in the heavily populated counties of Palm Beach, Broward, and Miami/Dade uses underground utilities. The practice can be expensive, but reduces the threat of outages during wind events such as hurricanes. Underground facilities are no magic bullet, said McGrath. “An outage could be longer during a major flood.”

Those upgrades may be impractical for Puerto Rico as it recovers from Hurricane Maria. Distributed generation and microgrids may be attractive ideas, but would take a long time to plan and require a lot of money, said APPA’s Hyland. For now, work needs to focus on protecting “life and safety.” That means restoring the existing grid as quickly as possible.

Paying for the restoration may also be a challenge. The commonwealth was in financial crisis before the September hurricanes and the state-run utility PREPA was in a form of bankruptcy.

On 26 September, the White House increased the level of federal funding for debris removal and “emergency protective measures” from 75 percent to 100 percent of Puerto Rico’s costs over the next 180 days. 

“It’s difficult when PREPA is basically bankrupt,” said NYPA’s Quiniones. As a result, just who will pick up the tab for long-term restoration work “is still a question mark.”