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 [PDF] 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.

The plan calls for a grid that can withstand 155 mph winds and heavy flooding

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

Puerto Rico Governor Ricardo Rossello Nevares, New York Gov. Andrew Cuomo, and Puerto Rico Adjutant General Brig. Gen. Isabelo Rivera, the Puerto Rico National Guard commander, visit flooded communities in Puerto Rico, Sept. 22, 2017. Puerto Rico’s governor, Ricardo Rosselló Nevares; New York’s governor, Andrew Cuomo; and Puerto Rico’s Adjutant General Brig. Gen. Isabelo Rivera visit flooded communities in Puerto Rico, 22 Sept 2017.Photo: Sgt. Jose Ahiram Diaz-Ramos/National Guard

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.

Map of Puerto Rico showing hospitals, emergency shelters, wastewater and drinking water treatment facilities, fire, and police stations.Image: SEPA/New York Power Authority

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.

Tree Trimming

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.

The Conversation (0)
This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

The number of charging stations in Utrecht has risen sharply over the past decade.

“People are buying more and more electric cars,” says Eerenberg, the alderman. City officials noticed a surge in such purchases in recent years, only to hear complaints from Utrechters that they then had to go through a long application process to have a charger installed where they could use it. Eerenberg, a computer scientist by training, is still working to unwind these knots. He realizes that the city has to go faster if it is to meet the Dutch government’s mandate for all new cars to be zero-emission in eight years.

The amount of energy being used to charge EVs in Utrecht has skyrocketed in recent years.

Although similar mandates to put more zero-emission vehicles on the road in New York and California failed in the past, the pressure for vehicle electrification is higher now. And Utrecht city officials want to get ahead of demand for greener transportation solutions. This is a city that just built a central underground parking garage for 12,500 bicycles and spent years digging up a freeway that ran through the center of town, replacing it with a canal in the name of clean air and healthy urban living.

A driving force in shaping these changes is Matthijs Kok, the city’s energy-transition manager. He took me on a tour—by bicycle, naturally—of Utrecht’s new green infrastructure, pointing to some recent additions, like a stationary battery designed to store solar energy from the many panels slated for installation at a local public housing development.

This map of Utrecht shows the city’s EV-charging infrastructure. Orange dots are the locations of existing charging stations; red dots denote charging stations under development. Green dots are possible sites for future charging stations.

“This is why we all do it,” Kok says, stepping away from his propped-up bike and pointing to a brick shed that houses a 400-kilowatt transformer. These transformers are the final link in the chain that runs from the power-generating plant to high-tension wires to medium-voltage substations to low-voltage transformers to people’s kitchens.

There are thousands of these transformers in a typical city. But if too many electric cars in one area need charging, transformers like this can easily become overloaded. Bidirectional charging promises to ease such problems.

Kok works with others in city government to compile data and create maps, dividing the city into neighborhoods. Each one is annotated with data on population, types of households, vehicles, and other data. Together with a contracted data-science group, and with input from ordinary citizens, they developed a policy-driven algorithm to help pick the best locations for new charging stations. The city also included incentives for deploying bidirectional chargers in its 10-year contracts with vehicle charge-station operators. So, in these chargers went.

Experts expect bidirectional charging to work particularly well for vehicles that are part of a fleet whose movements are predictable. In such cases, an operator can readily program when to charge and discharge a car’s battery.

We Drive Solar earns credit by sending battery power from its fleet to the local grid during times of peak demand and charges the cars’ batteries back up during off-peak hours. If it does that well, drivers don’t lose any range they might need when they pick up their cars. And these daily energy trades help to keep prices down for subscribers.

Encouraging car-sharing schemes like We Drive Solar appeals to Utrecht officials because of the struggle with parking—a chronic ailment common to most growing cities. A huge construction site near the Utrecht city center will soon add 10,000 new apartments. Additional housing is welcome, but 10,000 additional cars would not be. Planners want the ratio to be more like one car for every 10 households—and the amount of dedicated public parking in the new neighborhoods will reflect that goal.

This photograph shows four parked vehicles, each with the words \u201cWe Drive Solar\u201d prominently displayed, and each plugged into a charge point.Some of the cars available from We Drive Solar, including these Hyundai Ioniq 5s, are capable of bidirectional charging.We Drive Solar

Projections for the large-scale electrification of transportation in Europe are daunting. According to a Eurelectric/Deloitte report, there could be 50 million to 70 million electric vehicles in Europe by 2030, requiring several million new charging points, bidirectional or otherwise. Power-distribution grids will need hundreds of billions of euros in investment to support these new stations.

The morning before Eerenberg sat down with me at city hall to explain Utrecht’s charge-station planning algorithm, war broke out in Ukraine. Energy prices now strain many households to the breaking point. Gasoline has reached $6 a gallon (if not more) in some places in the United States. In Germany in mid-June, the driver of a modest VW Golf had to pay about €100 (more than $100) to fill the tank. In the U.K., utility bills shot up on average by more than 50 percent on the first of April.

The war upended energy policies across the European continent and around the world, focusing people’s attention on energy independence and security, and reinforcing policies already in motion, such as the creation of emission-free zones in city centers and the replacement of conventional cars with electric ones. How best to bring about the needed changes is often unclear, but modeling can help.

Nico Brinkel, who is working on his doctorate in Wilfried van Sark’s photovoltaics-integration lab at Utrecht University, focuses his models at the local level. In his calculations, he figures that, in and around Utrecht, low-voltage grid reinforcements cost about €17,000 per transformer and about €100,000 per kilometer of replacement cable. “If we are moving to a fully electrical system, if we’re adding a lot of wind energy, a lot of solar, a lot of heat pumps, a lot of electric vehicles…,” his voice trails off. “Our grid was not designed for this.”

But the electrical infrastructure will have to keep up. One of Brinkel’s studies suggests that if a good fraction of the EV chargers are bidirectional, such costs could be spread out in a more manageable way. “Ideally, I think it would be best if all of the new chargers were bidirectional,” he says. “The extra costs are not that high.”

Berg doesn’t need convincing. He has been thinking about what bidirectional charging offers the whole of the Netherlands. He figures that 1.5 million EVs with bidirectional capabilities—in a country of 8 million cars—would balance the national grid. “You could do anything with renewable energy then,” he says.

Seeing that his country is starting with just hundreds of cars capable of bidirectional charging, 1.5 million is a big number. But one day, the Dutch might actually get there.

This article appears in the August 2022 print issue as “A Road Test for Vehicle-to-Grid Tech.”

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