LUMA and AES energize Puerto Rico's first utility-scale battery storage system in Guayama

LUMA Energy and AES Puerto Rico announced on Thursday, September 4, 2026, the energization of the infrastructure connecting the Jobos Solar and Jobos BESS projects to the electrical grid in the Jobos neighborhood of Guayama, a step that activates interconnection testing for the island's first utility-scale battery storage system and targets commercial operation during the fourth quarter of this year ¹. It is the first time a project of this scale has entered the interconnection testing phase in Puerto Rico, nearly two years after the federal government approved the financing that made it possible.

Jobos Solar and Jobos BESS are the first phase of Marahú, a development by Clean Flexible Energy LLC, a joint subsidiary of AES Corporation and TotalEnergies Holdings USA. The full project received an $861.3 million loan guarantee from the U.S. Department of Energy's Loan Programs Office (LPO), under the Energy Infrastructure Reinvestment (EIR) program of Title 17 Section 1706, a closing that was finalized in October 2024 ²³. That financing covers two solar plants with batteries and two standalone storage systems split between the municipalities of Guayama and Salinas.

What was energized this week is only the Guayama portion. According to LUMA, the Jobos phase will add 80 megawatts (MW) of solar generation and 110 MW of battery storage with a four-hour duration, for an approximate capacity of 440 megawatt-hours (MWh) ¹. That solar output is equivalent to the consumption of about 25,000 homes on average, with peaks of up to 40,000 homes during the hours of highest generation around midday ¹. To achieve this, LUMA energized a new 115-kilovolt (kV) transmission line and completed protection and monitoring upgrades at the Jobos TC 4003 substation ¹. Esther Serra, LUMA's senior director of Renewable Energy Projects, said that "this new capacity helps ensure that available generation can be transmitted and distributed reliably, strengthening the system's operational stability" ¹.

The full Marahú project calls for 200 MW of solar generation and up to 285 MW (1,140 MWh) of standalone storage between Guayama and Salinas, with an estimated annual output of 460,000 MWh, enough for about 43,000 homes, and a projected reduction of nearly 2.7 million tons of CO2 per year once complete ²³. The development generated roughly 750 construction jobs and is expected to sustain more than 50 permanent positions ².

What this means for you

If you live or run a business in the Guayama, Salinas, Arroyo, or Patillas area, this project is part of the infrastructure LUMA identifies as key to reducing blackouts tied to generation shortfalls during nighttime peak hours, when the sun has set but demand is still high. The Jobos battery is designed precisely to charge on solar power during the day and discharge during those critical hours, instead of relying exclusively on Genera PR's aging thermal plants ¹. There is still no confirmed commercial operation date beyond "fourth quarter of 2026," so the effect on service reliability will not be immediate and will not be felt the same way across the whole island, but it is a concrete sign that at least part of the post-Hurricane María federal renewable-energy financing is reaching real grid-testing stages, not just financing announcements.

How to do it / Checklist

1. Check whether your community is in the impact zone: the Jobos project is in Guayama; the second Marahú phase is located in Salinas. You can review generation project maps at energia.pr.gov, under the Negociado de Energía section.
2. If you experience frequent outages in the southern area (Guayama, Salinas, Arroyo, Santa Isabel), document the date, time, and duration for your claims; LUMA handles service requests at 1-844-888-5862.
3. Follow the public docket at the Negociado de Energía (NEPR) at energia.pr.gov to verify when Jobos Solar and Jobos BESS receive commercial operation certification, since that is the step that activates firm capacity.
4. If you are a business owner or developer interested in similar solar-plus-storage projects, the same DOE EIR program under Title 17 Section 1706 is still accepting applications; information is available at energy.gov/lpo.
5. For residential customers with rooftop solar systems, this project does not replace net metering or change your bill directly, but it does add backup capacity to the system LUMA uses to balance the whole grid.
6. Sign up for LUMA alerts (lumapr.com) to get notifications about maintenance work at the Jobos TC 4003 substation, which could cause localized interruptions during the testing phase.

What's next

The Salinas phase of the Marahú project, with the remaining portion of the 200 MW of solar and up to 285 MW of standalone storage, is still under development and has no confirmed energization date ²³. Separately, the Negociado de Energía has demanded that developers of temporary and renewable generation projects clarify definitive timelines amid recurring delays in the electrical grid's reconstruction plan ¹. LUMA is also advancing the ASAP program, which calls for up to 800 additional MW of battery storage at various points on the island, as part of the Integrated Resource Plan being discussed in NEPR public hearings. The next milestone to watch is the commercial operation certification for Jobos Solar and Jobos BESS, expected in the fourth quarter of 2026.

Sources

¹ LUMA Energy, "LUMA and AES Announce Energization of Puerto Rico's First Utility-Scale Battery Storage Project," September 4, 2026. https://lumapr.com/news/luma-and-aes-announce-energization-of-puerto-ricos-first-utility-scale-battery-storage-project/?lang=en ² Utility Dive, "DOE finalizes $861M loan guarantee for Puerto Rico solar, storage," October 2024. https://www.utilitydive.com/news/doe-finalizes-861-million-loan-solar-battery-projects-puerto-rico-AES-Total/729960/ ³ U.S. Department of Energy, Loan Programs Office, "AES Marahu." https://www.energy.gov/node/4845644 ⁴ San Juan Daily Star, "AES and Total Energies get federal financing for solar plants Guayama, Salinas." https://www.sanjuandailystar.com/post/aes-and-total-energies-get-federal-financing-for-solar-plants-guayama-salinas