LUMA Energy, the operator of Puerto Rico's electric grid, warned on Sunday evening that there was a high probability of rotating power outages during peak consumption hours beginning around 7:00 p.m., citing a shortfall in electric generation.^[1] The warning follows days of strain on the system. On a Saturday night selective blackout, a LUMA spokesperson said the system faced a generation deficit of about 435 megawatts relative to projected demand at one of the moments of greatest deficiency.^[3] Earlier, LUMA had warned of outages in the late afternoon after the Costa Sur 5 generator unit went offline.^[2] The read here is that the same phrasing keeps recurring: a probability of outages tied to generation, not distribution. The 435-megawatt figure came from LUMA itself, and on the available record it is the clearest measure of how deep Saturday's shortfall ran.