On Wednesday the Department of Energy (DOE) released a report detailing its vision for rebuilding a resilient energy system in Puerto Rico. It suggested hardening infrastructure, as well as integrating clean energy technologies such as solar and energy storage into the island’s energy portfolio.

The report is intended to assist the island’s government in drafting recovery plans and guiding the use of federal aid. While the DOE recognized that a singular vision for the island’s future must be determined by the Commonwealth, it said its report should serve as a guideline in drafting that plan.

This document is just the latest in a growing group of energy concepts that cropped up after Hurricane Maria disrupted nearly all of the island’s energy infrastructure in September. Like many of them, the DOE report attributed some of the ruin to a lack of maintenance by the Puerto Rico Electric Power Authority. 

“DOE observed that, generally, PREPA designed the electricity system well, as evidenced by the uncompromised power stations and effective ‘dead end’ structures,” the report reads, but it adds, “It became clear that the system was weakened over time to the point of catastrophic failure.” 

According to data from Lawrence Berkeley National Laboratory, several measures of PREPA system interruptions were above average and in the third quartile among U.S. utilities.

To prevent a similar situation in the future, the DOE recommended updates to transmission and distribution infrastructure and a reconsideration of generation resources on the island.

Source: Department of Energy 

In updating transmission and distribution infrastructure, DOE recommended that the system be rebuilt, at a minimum, to follow the Rural Utilities Service standards used by utilities in the rural U.S. The DOE also said PREPA should follow standards laid out in the National Electrical Safety Code and National Electrical Code.

DOE suggested that corrosion caused the failure of some guy wire anchor rods, which add stability to poles. The department suggests more aggressive maintenance of these structures and consideration of stronger materials and wood alternatives for both transmission and distribution poles that can withstand 150-mile-per-hour winds. 

Authors proposed using roads built to rewire areas of the island’s mountainous middle for more aggressive vegetation management, which in some instances could ease trees taking out lines. They also recommended moving all substations to the Federal Emergency Management Agency’s 0.2 percent flood elevation level, areas that would only be reached in a 500-year flood, which is something of a moving target because of climate change.

The report also suggested the island’s electric commission (PREC) and PREPA work together on microgrid regulations.   

Moving forward, Puerto Rico will likely need less generation than its current levels in part because of the great number of Puerto Ricans who have left the island — estimated at 100,000 since the hurricanes. Looking ahead to 2026, PREPA has estimated it will need 1,500 megawatts of average load and 2,250 megawatts of peak load. Current capacity is over 5,000 megawatts. 

Currently, over 90 percent of Puerto Rico’s capacity generation comes from oil, much like many island systems. If the island transitions away from its current fuel mix, it could save about 10 percent on fuel and its levelized cost of electricity. The island also has among the highest electricity costs in the nation. 

While the department recognizes that some of this capacity can be replaced with energy efficiency programs and demand response initiatives, DOE also recommends replacing generation with plentiful U.S. natural gas. Because the island only has one gas import terminal, though, this would require building out capacity at that location and building another terminal.

The Jones Act, which requires that ships traveling between U.S. ports be U.S.-built and crewed, restricts this option. There are currently no compliant ships available to deliver large amounts of liquid natural gas to Puerto Rico. According to DOE, a shipyard in the U.S. may not be able to build that vessel until the mid-2020s, but freight containers could manage smaller shipments. 

That leaves the island with another option, one favored by many of the companies that converged on the island in the wake of the storms and by many academics on the island: renewables. 

Puerto Rico has a legal requirement to get 20 percent of electricity sales from clean energy by 2035, requiring about 1,200 megawatts in capacity. In 2015, its integrated resource plan process estimated the grid would include 322 megawatts of distributed solar by 2035, and this number likely increased with the interest in solar and off-grid systems post-Maria. 

A recent study from the National Renewal Energy Laboratory found that clean energy integrated into PREPA’s system, using its existing infrastructure, could outperform “traditional operational practices.” The solar already in operation in Puerto Rico provides lower-cost electricity than all of PREPA’s generating stations, and prices will continue to decline.

Source: Department of Energy 

DOE noted that energy storage, in addition to supporting intermittency of renewables, can also help black-start natural gas turbines.

The department also recognized the wealth of expert resources on the island, citing a group of academics working under the Instituto Nacional de Energía y Sostenibilidad Isleña (INESI). 

“INESI could provide the foundation on which to firmly establish Puerto Rico as a Center of Excellence on distributed grid operations, and could provide both the supply of interdisciplinary engineers and policymakers Puerto Rico will need and the expertise other island and remote grid systems will need in their transition to a distributed, resilient electricity sector,” read the report.

INESI is hosting a workshop starting this week to bring together universities, community groups and municipalities to work on a resilience platform for future climate related events and their impact on Puerto Rico’s electric system. Several academics in the group have criticized the response to the hurricanes and the lack of effort to engage local experts, including by the federal government.

Alongside these long-range plans, DOE proposed a handful of immediate actions including updating mutual aid agreements to prepare for future storms and prioritizing replacement of transmission towers installed for emergency power restoration. On June 18 the island’s electric authority said 99.7 percent of customers had been energized and on June 19 generation reached about 95 percent. 

Ultimately, a great deal of investment is needed to repair the $65 billion to $115 billion in damages that the National Oceanic and Atmospheric Administration estimates Hurricanes Maria and Irma caused. To that end, Governor Ricardo Rosselló continues to push for PREPA’s privatization.

But the report “recognizes that capital investment alone will likely be insufficient to achieve Puerto Rico’s goal of an electric sector that is technically reliable, resilient and affordable.”

Instead, it notes that “success ultimately depends on the leadership and commitment of the Government of Puerto Rico and entities such as PREC and PREPA to carefully identify Puerto Rico’s electricity needs, assess the options, and make their own determination of a strategy that meets long-term goals and instills confidence for existing and new industries to invest on the island.”