Plans to modernize Puerto Rico’s power grid likely will include an array of fixes such as stronger electric poles, microgrids, and more renewable energy. The plan, expected to be released later this month, will also focus on reducing the island’s reliance on transmission lines that cross its mountainous interior. These proved to be a weak link when Hurricane Maria struck in September.
Puerto Rico’s electric power authority, PREPA, is writing the plan along with the New York Power Authority (NYPA), the Long Island Power Authority, ConEd, Edison International, the Electric Power Research Institute, and the Smart Electric Power Alliance.
The plan will offer details based on a request made by Gov. Ricardo Rosselló in November for $94 billion in federal aid to rebuild the island. Around $17 billion of that would be earmarked for the electric power system, which was largely destroyed by the storm.
The plan is modeled on work under way on Long Island, New York, that had to be done in the wake of Hurricane Sandy, says Gil Quiniones, NYPA president and CEO. Sandy hit Long Island and the Northeast in 2012, causing widespread damage to the power system. Work to rebuild and harden that system is expected to be completed in 2020. Quiniones says that rebuilding Puerto Rico’s grid could take a decade.
Micro-Grid and Solar
On 20 November, independent power producer AES sent Puerto Rican energy regulators its own plan to modernize portions of the island’s grid. AES owns a 524-megawatt coal-fired power plant and a 24-MW solar farm. Together, they meet around 15 percent of the island’s demand.
AES’s proposal includes mini-grids with weatherized tie lines to connect generation resources to load centers and with each other. AES pegs to price of solar at roughly $40-50 per megawatt-hour for utility-scale projects larger than 50 MW. The cost of a long-duration battery-based energy storage system could be around $55-65/MWh. Once deployed, 15,000 gigawatt-hours of PV could replace 12,000 GWh of diesel or oil generation, AES says.
Complexity and Chaos
The release of long-term plans signals the next stage of recovery for the island’s 1.75 million electric power customers. Until now, the recovery has been marked by complexity and occasional chaos.
The complexity results from the extent of destruction and the logistics involved in getting repair crews and equipment to the island, which is around 1,600 kilometers from Florida ports.
NYPA, for example, deployed a 10-person team of power engineers and two drone pilots the day after the storm hit. By the end of September, the agency had 30 people on the ground helping PREPA inspect 360 substations and nearly a dozen generating assets. At the time, 100 percent of the island was without power.
Soon after the disaster, PREPA awarded a $300 million no-bid contract to Montana-based Whitefish Energy. Within weeks, however, questions about Whitefish’s credentials led to that contract’s cancellation.
A focal point of the controversy, Ricardo L. Ramos, PREPA’s CEO, resigned in mid-November. He had become a “distraction,” Rosselló, told reporters. The governor named Justo Gonzalez as interim PREPA director. And he named former ConEd executive Carlos Torres as the “single point of contact” for efforts to rebuild the electric grid.
In late October, Gov. Rosselló issued mutual aid requests to his counterparts in New York and Florida. A separate scheme was put in place enabling NYPA to bill Puerto Rico’s emergency management agency, PREMA, for work.
Meanwhile, the Federal Emergency Management Agency (FEMA) designated the U.S. Army Corps of Engineers to oversee grid restoration work. FEMA also agreed to pay 100 percent of expenses incurred during the first 180 days of restoration. Fluor Corp., PowerSecure, and Cobra Energy all were hired for different aspects of grid repair work.
By the end of November, some 3,000 workers had arrived in Puerto Rico for restoration work. Ships carrying trucks, equipment, tools, and supplies also sailed, including more than utility 330 trucks from New York state power companies, Quiniones says.
The effort has been enormous. But it’s still dwarfed by the nearly 28,000 workers from 30 states and Canada who restored power in Florida within 10 days of Hurricane Irma hitting the state in early September.
Poles… and more
Indeed, efforts under way since 2006 by Florida Power & Light offer a glimpse into one aspect of Puerto Rico’s anticipated grid hardening. Over the past 11 years, the Florida utility has spent nearly $3 billion to upgrade poles, harden substations, and deploy smart grid technology.
As a result, the utility reported that none of its hardened transmission structures was lost during Irma. All of its substations were up and running within a day after the storm. And although the utility lost around 2,500 poles (roughly 0.2 percent of its 1.2 million), that was a pittance compared with the loss of around 12,000 poles it suffered during Hurricane Wilma in 2005.
Poles are important, but are likely to be just one part of the modernization plan. Quiniones says that other elements likely will include standardized voltages across the distribution system, flood walls to protect critical infrastructure, and bundled conductors to improve transmission line efficiency.
In addition, the plan will call for increased use of renewable energy, microgrids, and distributed energy resources.
“We want them to think about a decentralized, cleaner grid,” Quiniones says. The upgraded system will be less reliant on moving power over mountains that separate the south side of the island—home to the bulk of generating assets—to load centers on the north.
The restoration plan will combine “good, sound engineering principles” with a nod to a more “decentralized, distributed grid,” Quiniones says. What’s more, it “has to be led by PREPA.”
But with a price tag in the billions, the hardest job may be in convincing Congress to allocate money to get the job done.
Contributing Editor David Wagman has been covering energy issues for three decades, focusing on all forms of electric power generation, regulation, and business models. He is particularly interested in the ongoing electrification of advanced economies and the effects that distributed generating resources could have on efforts to decarbonize national grids. Wagman, who is based in Colorado, is currently editorial director for IEEE Engineering 360, a search engine and information resource for the engineering, industrial, and technical communities.