Businesses Using Microgrids to Ensure Power in Puerto Rico

Puerto Rico continues to struggle with its power supply, with the island’s aging electricity infrastructure contributing to continued blackouts and reliability issues more than four years after hurricanes Irma and Maria kicked off a series of devastating major hurricanes and tropical storms that have battered the U.S. territory. Ongoing issues with the supply of electricity have repeatedly left tens of thousands of the island’s residents and businesses without power, and have led to protests against LUMA Energy and the Puerto Rico Electric Power Authority (PREPA), the two entities in charge of the territory’s power supply. Both those groups have said they are not able to generate enough electricity to meet demand, citing continued problems with maintenance of the power grid and other events that have contributed to outages. PREPA, a public corporation, contracted with LUMA—a private company—this past summer, hiring the group to manage the island’s electric transmission and distribution system.

The power providers also drew ire with a recent request to increase the price of electricity for customers, the fourth such increase this year, in a country where government data shows almost 44% of the Puerto Rican population lives in poverty. Puerto Rico residents reportedly pay about 21.4 cents per kilowatt-hour for electricity, or more than double the average rate for electricity customers in Texas. It’s prompted the island’s power customers, both residential and business, to search for more cost-effective solutions. The Solar & Energy Storage Association of Puerto Rico recently said about 30,000 island homes and businesses have installed a combined 150 MW of solar and backup battery systems; the group said two-thirds of those systems have been installed by Houston, Texas–based Sunnova Energy, which was the first company to offer solar power as a service on the island.

Other companies have launched projects in Puerto Rico in recent years, installations designed to support new power generation sources as the island remains challenged in trying to rebuild its power grid. Eaton, a global power management company doing business in more than 175 countries, and Enel X, the Enel Group’s advanced energy services business line, recently announced plans for a second joint microgrid project in Puerto Rico, part of a wave of microgrid installations that have come online on the island in recent years. The companies said the projects will reduce demand on regional energy infrastructure, and enable Eaton to power more of its own operations on the island with renewable resources, while also increasing energy resilience. The newest joint project is a solar-plus-storage microgrid at Eaton’s Las Piedras facility, where the company manufactures residential circuit breakers.

Craig Gob, vice president and general manager of the Electrical Engineering & Systems division for Eaton, told POWER, “I think 2017 was quite different in the fact that the length of the outages has really created for Eaton and other companies like ours, just some unique challenges. Most companies that are used to operating on the island tend to have some backup power supply, but if you go back to 2017, the ability to get fuel for your backup system was suddenly challenged. That was probably a turning point for us, and we definitely saw the writing on the wall with regard to the grid infrastructure there.” Gob said as solar and battery energy storage became more affordable—“along with our learnings from 2017”—it prompted Eaton “down the path” for the microgrid solution for its manufacturing plants.

Brian Brickhouse, president of Eaton’s Electrical Sector, Americas region, said, “The increasing frequency and impact of climate emergencies underscore the need for far more sustainable and resilient power. Around the world, we’re applying our ‘Everything as a Grid’ approach to strengthen operations with low-carbon energy sources and the ability to withstand extreme weather emergencies. With our partner Enel X, we established a replicable energy-as-a-service model that exemplifies how to keep the power on—no matter what.”

1. Workers make repairs to electric power infrastructure in Puerto Rico after Hurricane Maria in 2017. Damage to the island’s transmission and distribution network, and the slow pace of power restoration after recent storms and continued problems with blackouts, has prompted businesses in Puerto Rico to design their own microgrids to support the reliability of the power supply. Source: Army Corps of Engineers

The Eaton-Enel X projects in Puerto Rico are designed to withstand Category 5 hurricanes, the same intensity as Irma and Maria in 2017 (Figure 1), storms that arrived two weeks apart in September of that year and essentially destroyed the island’s entire power grid. The slow pace of repairs to aging baseload power plants led the embattled PREPA—already in poor financial condition prior to the 2017 storms—in October of this year to say the island’s power system is in a “state of emergency.” Josue Colon, PREPA’s executive director, said the island’s power units are in “critical condition,” and said an emergency designation would help expedite “the acquisition of needed goods and services.”

Some 97% of the island’s power generation comes from imports of coal, petroleum, and liquefied natural gas. A PREPA report in early October says less than 40% of the agency’s 4,714 MW of power generation capacity was online as of Oct. 3, and says generation from hydropower was at just 22% of installed capacity. Fernando Gil, president of PREPA’s governing board, on Oct. 6 told the U.S. House Committee on Natural Resources that the agency’s youngest baseload power unit is 25 years old. Gil said that on average, the group’s power plants are 40 years old. “PREPA’s generation fleet is old, outmoded, inefficient, and expensive to run,” he said.

Matt Barnes, director of business development for Enel X, told POWER his group is hearing requests from businesses for “resiliency… and more and more recently, as you’ve got the increasing frequency of extreme weather, whether that’s heat or cold, or hurricanes and storms… after those events is not necessarily the best time to solve [the problem], but you’ve got to start those conversations.” He continued: “Maria was really a wakeup call, and it’s taken some time to solve that, but we’ve worked collaboratively with Eaton and a local team to put together these solutions that we’re seeing now come to fruition.”

The solar-plus-storage microgrid at the Las Piedras manufacturing facility will integrate nearly 5 MW of solar photovoltaic and about 1.1 MW/2.2 MWh of battery storage into the facility’s onsite power generation systems. Eaton’s other microgrid at a manufacturing site on the island is at the company’s Arecibo facility, which is a similar solar PV and battery storage installation. As with some other microgrids across Puerto Rico, the business model involves a contractor building the system on behalf of a commercial and industrial customer. In this case, Enel X will build, own, and operate the system on behalf of Eaton.

Enel X will finance the project under an energy-as-a-service model, shifting Eaton’s investment in the microgrid system from a capital to an operational expense. Eaton will provide installation expertise and key technologies for the microgrid system, including the microgrid controller and plant electrical distribution equipment. In addition to increasing the facility’s resiliency, the solar-plus-storage system will enable Eaton to generate, store, and consume renewable energy, and support the local grid by discharging that renewable energy back to the grid, reducing emissions by limiting the need for carbon-intensive electricity during peak demand periods.

The Puerto Rico Energy Bureau, an energy regulator, in its latest integrated resource plan mandates increased development of microgrids and renewable energy on the island, including at least 3.5 GW of solar power, and more than 1.3 GW of energy storage, by 2025. That in part is driving some of the consideration for microgrid design.

“Energy is becoming a far greater consideration on location,” said Gob, asked whether geography and local weather enter into discussions about where to site manufacturing plants. “The affordability of solar PV and battery energy storage systems are really giving manufacturers options on how they select [locations]. Most manufacturing companies… do have goals around improving their carbon footprint, and so looking for ways to do that is a definite consideration.”

Barnes noted three key considerations for the microgrid design at Eaton’s facilities: “It delivers resiliency, it delivers cost savings, and it delivers it in a sustainable way.” He said the availability of solar power in Puerto Rico means solar “just makes sense” as an energy source, and said “we talk a lot about how these microgrids are here for the storms and the aftermath of storms. It’s also about helping industrials meet those sustainability targets the other 350 days of the year.”

—Darrell Proctor is a senior associate editor for POWER (@POWERmagazine).