LUMA, Puerto Rico’s electric power transmission and distribution system operator, has struggled to restore power to some of its customers in the wake of an outage that left the entire island without power on Dec. 31 at 5:30 a.m. local time. The company activated its Emergency Operations Center soon after the event occurred and said it “has been working tirelessly to restore power to customers as quickly and safely as possible.”
By noon on Jan. 1, LUMA said it had restored power to 1.4 million customers (more than 98.3% of the system), but it didn’t last. At about 2:00 p.m., it reported “a separate issue at Aguirre caused a system-wide event that affected other generating plants. This led to the sudden loss of 550 MW and impacted service for over 600,000 customers.” LUMA said its team temporarily stabilized the system to prevent additional service interruptions, and working in collaboration with power generators, it managed to restore service to more than 200,000 customers by the afternoon.
“At approximately 7:00 p.m. [Jan. 1] and with approximately 73% of our customers in service, another event was reported at the same location [Aguirre], impacting service for customers during peak consumption hours,” LUMA President and CEO Juan Saca wrote in a statement issued online to customers. Saca expected the load-shedding event to last until approximately midnight, and that more generation would be available on Jan. 2. However, he said the overall shortfall in generation compared to total demand could still impact service for customers for a day or more. “It is important to understand that there is still the potential for generation shortfalls in the coming days,” Saca said, noting that the state of the system was “fragile.”
In a separate statement, Saca appealed to customers to limit power usage. “Given the fragile nature of the grid, we will need to manage available generation to customer demand which will likely require rotating temporary outages. To minimize impact of these outages, we are urging our customers to please reduce their energy consumption whenever possible, and to use battery storage when and if available.”
As of 10 a.m. local time on Jan. 2, LUMA reported that service had been restored to 99% of its customers. Three of seven regions—Bayamón, Caguas, and San Juan—were reported to have been almost completely restored, while the Mayagüez region had the most customers (4,850) still without service.
Saca said in one of his statements that the root cause of the event was still under investigation, but Telemundo reported that “a breakdown in an underground power line at the Costa Sur plant” caused the initial blackout on Dec. 31. Meanwhile, Reuters reported, “Ivan Baez, a spokesperson for power generator Genera, said in a local radio interview that the line believed to have failed was operated by LUMA and brought down plants belonging to Genera, as well as private generators.”
On Dec. 20, less than two weeks prior to the island-wide blackout, LUMA reported a “historic year of progress,” saying it had made “key improvements to grid reliability, resiliency, customer service, emergency preparedness & renewable energy adoption.” Among the improvements it said it has made were:
- Replacing 20,500 utility poles.
- Starting or completing 44 equipment upgrades at 22 substations.
- Trimming 5,400 miles of vegetation from powerlines.
- Installing more than 9,300 grid automation devices.
Nonetheless, some customers are unimpressed by the progress. Many took to social media to complain following the outage and during restoration efforts. One wrote, “They are a DISASTER,” while another said, “They have an encyclopedia of excuses.”
In his statement, Saca said he recognized how maddening the situation has been for customers. “We know and understand how frustrating it has been for our customers to be without service for extended periods of time. That’s why our load-shedding plan includes rotating sectors periodically to minimize the impact on your daily life,” he said. “Through this process, we have seen the spirit of collaboration between all sectors of the electrical industry and other stakeholders. Our team will continue to be focused and dedicated to restoring service to our customers as more generation becomes available.”
[Update: LUMA issued a report on Friday, Jan. 3 at 5:00 p.m. local time, saying, “99.94% of customers are in service. However, the system continues to recover following Tuesday’s outage. Due to generation constraints, some customers may experience service interruptions between approximately 6:00 p.m. and 9:00 p.m. today. We encourage our customers to conserve energy whenever possible and to use their batteries when available. Our teams remain steadfast in their commitment to partner with power generators to restore service to our customers based on available capacity.”
On Jan. 4 at 6:00 p.m. local time, LUMA’s system had an available capacity of 2,396 MW against a load of 2,168 MW, maintaining a 228 MW reserve. LUMA forecasted a minimum reserve of 238.9 MW for the following 24-hour period.
By Monday, Jan. 6 at 8:30 a.m. local time, LUMA was reporting load demand of 1,709 MW with a reserve of 1,000 MW. It forecast a peak load for the coming day of 2,100 MW and peak reserve of 728 MW. No additional updates had been released through its social media channels since Friday at 5 p.m.]
—Aaron Larson is POWER’s executive editor (@POWERmagazine).
