A $17.6 billion plan to rebuild and modernize Puerto Rico’s electric power system was released on 11 December.
Prepared by more than a dozen entities, including the island’s electric power authority (PREPA), the 63-page plan calls for a decade-long series of projects and operational improvements. The plan is aimed at building an electric power system capable of surviving an “upper Category 4 event” (250-kilometer-per-hour winds) and heavy flood waters.
Hurricane Maria largely destroyed the island’s electric infrastructure in September. Work continues to restore electric power service knocked out by high winds and flooding.
Key elements of the plan were earlier shared with the Energywise blog in an interview with New York Power Authority President and CEO Gil Quiniones. He was one of seven industry leaders who made up a steering committee to oversee the plan’s creation.
In broad terms, the plan is modeled on work under way on Long Island, New York, in response to the destruction caused by Hurricane Sandy, Quiniones told IEEE Spectrum. Sandy hit Long Island and the Northeast in 2012, causing widespread damage to the grid.
From Microgrids to Tree Trimming
Among the projects included in the newly released Puerto Rico recovery and enhancement plan are:
1. Reinforcing existing direct-embedded poles with perimeter-injected concrete grout or other soil stabilization
2. Upgrading damaged poles and structures to a higher wind loading standard
3. Strengthening poles with guy wires
4. Installing underground power lines in areas prone to high wind damage
5. Modernizing the T&D system through smart grid investments to make the system less prone to extended outages
6. Installing automated distribution feeder fault sectionalizing switches to enable fault isolation and reduce outage impact
7. Deploying control systems to enable distributed energy resource integration and encourage their development
8. Adopting asset management strategies, such as the targeted inventory of critical spares
9. Instituting consistent vegetation management practices that take into consideration the island’s tropical conditions
10. Applying enhanced design standards for equipment and facilities damaged in the recent storms.
The price tag for all of the work is pegged at around $17.6 billion through 2027. That includes $5.3 billion for overhead and underground distribution lines; $4.9 billion for overhead and underground transmission lines; $1.7 billion for substation upgrades; $3.1 billion for generating assets; and nearly $1.5 billion for distributed energy resources.
A Costly Recovery
In addition to the grid plan, Puerto Rico’s Governor Ricardo Rosselló, members of the New York congressional delegation, and New York Governor Andrew Cuomo called on Congress to approve $94.4 billion in funds to aid in the island’s recovery.
A report released in November found that more than 472,000 housing units were destroyed and severely impacted by the storm. In addition, the island’s agricultural sector was almost entirely destroyed, including the loss of almost 80 percent of planted crops. Nearly all of the island’s water and wastewater assets also were disabled.
Microgrids for Resiliency
The electric modernization plan recommends that microgrids be deployed to make the system more resilient in the event of power outages and interruptions. It outlines a two-pronged approach.
In the first, hospitals, police and fire stations, emergency shelters, communications infrastructure, water treatment plants, airports, sea ports, and commercial and industrial centers would operate in isolation as microgrids and be ready to provide vital services immediately after a natural disaster. Technologies such as onsite backup generation, combined heat and power systems, rooftop solar, battery storage, and building energy management systems would be capable of creating centers that can help in post-storm recovery.
The second approach calls for microgrids located in remote communities to remain disconnected from the larger grid and continue to provide electricity to critical infrastructure as well as grocery stores, gas stations, and community centers. The installation of solar, battery storage, feeder automation control systems, load control equipment, and similar technologies could allow these communities to more quickly recover from natural disasters.
Substation and Transmission Automation
The plan also recommends that substations be enhanced by upgrading relay protection equipment and SCADA systems. Doing so would enable improved system control, reinforced and hardened substation facilities through defense-in-depth flood protection, and additional security access and monitoring systems.
In its 2015 integrated resource planning document, PREPA laid out its intent to pursue more flexible generating capacity to handle the intermittency of renewable resources. The modernization plan now says that the grid can be rebuilt with smaller distributed generating units that provide more flexibility and redundancy, and that help maintain operating and spinning reserve margins.
“The PREPA power system could also serve as a model for the future development of advanced power generation, transmission, and distribution systems and the use of renewable resources throughout the Caribbean or other similar global locations,” the plan says.
Widespread use of substation and distribution automation is recommended to better enable the system to respond to real-time events and enable deployment of distributed energy resources.
The plan also envisions that technologies such as centralized energy management systems, automated mapping and facilities management, and geographic information systems will become integral to day-to-day operations.
Turning to operations and maintenance, the plan says that PREPA should adopt a “robust asset management approach” that includes “aggressive vegetation management and optimized maintenance programs with adequate staffing.” Because of the tropical growth in Puerto Rico, PREPA will likely need to adopt vegetation management programs that are more aggressive than the industry norm.
The Puerto Rico Energy Resiliency Working Group developed the plan with help from Navigant Consulting. Group members include PREPA, the Puerto Rico Energy Commission, the U.S. Department of Energy, the Electric Power Research Institute, NYPA, Consolidated Edison, Edison International, the Long Island Power Authority, the Smart Electric Power Alliance, Brookhaven National Laboratory, the National Renewable Energy Laboratory, the Grid Modernization Lab Consortium, and Pacific Northwest National Laboratory.