Puerto Rico outage duration rose 19% in 2025 as rooftop solar reshapes capacity mix
Slower restoration times on an island where distributed solar now covers a fifth of capacity point to a reliability trade-off with wider grid implications.
The duration of power outages in Puerto Rico not caused by major events increased 19% in 2025, a deterioration that coincides with rooftop solar reaching 20% of the island's capacity mix. Rooftop photovoltaic capacity totaled 1,456 megawatts at the end of last year, and between 2016 and 2025 those installations accounted for 81% of all new generating capacity added to the system.7
The 19% rise in non-major-event outage duration is the kind of metric regulators and traders watch as a leading indicator of system strain, particularly when the generation mix shifts toward sources that do not contribute the same inertia or voltage support as thermal plants. The island is effectively running a live test of how fast distributed generation can be absorbed by a grid that still struggles with routine reliability.7
Puerto Rico is not alone in this bind. The North American Electric Reliability Corp. said in its 2026 State of Reliability report that conventional generation availability fell last year, largely driven by worsening performance of coal and gas units, which saw unavailable energy jump by 39.8 terawatt-hours and 19.1 terawatt-hours, respectively. Coal forced outage rates are rising exactly when deployable reserves are shrinking, and NERC flags the trend as a growing concern for summer peak periods.6
The economics of rooftop solar on the island follow a familiar pattern. Every additional megawatt of distributed PV reduces demand that the legacy transmission and distribution network must carry, but it also erodes the revenue base that funds maintenance of that same network. The result is a system where capacity grows while the infrastructure needed to keep outages short gets relatively less investment.7
Ohio offers a mainland parallel. Four of the state's six regulated electric utilities failed in 2025 to meet their own reliability benchmarks for preventing outages and restoring service quickly, according to Canary Media reporting. The utilities are now seeking to lower the performance bar, a regulatory fight over how much pressure they face to improve operations.1
The broader US picture is one of squeezing margins. NERC's Summer Reliability Assessment for 2026 shows resource adequacy improving on paper, with bulk power system resources up over 58.5 gigawatts thanks to solar, batteries and some new gas. Sixteen of 23 assessment areas have increased available capacity, and over 16 gigawatts of nameplate battery storage has been added to the grid.2
But the same report identifies above-normal summer temperatures as the dominant operational concern, with NOAA putting a 61% chance on El Niño conditions. Solar PV is the leading new resource at 30.5 gigawatts of nameplate additions, contributing 16.4 gigawatts at peak demand, yet the Eastern Interconnection and ERCOT have already observed load-reduction events tied to low spring snowpack affecting hydropower availability.2,4
Batteries help with frequency stability, and the additions are real. Yet they do not cure forced outage rates on thermal plants. NERC's data shows the reliability cushion is thinner than the headline capacity numbers suggest, because the new resources are not dispatchable in the same way as the coal and gas units whose performance is deteriorating.6,2
This is where the Puerto Rico numbers gain wider relevance. Rooftop solar is the most distributed form of generation there is, and the island has the highest penetration in the US system. Its 19% degradation in outage duration is the kind of empirical data point that mainland utilities and regulators will scrutinize as distributed capacity offers like the one from Sunrun, Tesla and Renew Home, which could deliver nearly 17 gigawatts to congested US grids, move from proposal to deployment.5,7
Grid-enhancing technologies such as dynamic line rating can lift capacity by 10% to 40% using real-time data without new lines, and more than 90% of customer outages originate in distribution networks where aging infrastructure is reaching end of life. Those fixes are cheaper than new transmission but slower to deploy at scale.3
Forecasters expect at least 10 named storms in the 2026 Atlantic hurricane season, with at least three projected to hit the US directly. Puerto Rico is no stranger to hurricane-driven outage events, but the 2025 data covers the periods between storms, when the system should be performing at its baseline. It is not.3
Distributed solar is still growing faster than any other source on the island, and the maintenance backlog is not shrinking. The next concrete signal to watch is how Puerto Rico's regulator handles the revenue decoupling question, because the network operator's financial headroom to shorten outage durations before the next major storm season depends on how that mechanism is structured.7