Overview
- The newly published recordings, obtained Wednesday by La Vanguardia and El Periódico, reveal control rooms had logged severe voltage swings for months ahead of the April 28, 2025 blackout.
- One call from January 31, 2025 captures near-panic at the Ascó nuclear plant after a 1,000 megawatt flip in flows and a sharp drop in voltage that operators linked to a mass solar disconnect.
- Multiple excerpts blame quarter-hour market scheduling that prompts many solar plants to connect or disconnect at the same time, which drives voltage to surge or sag in big jumps.
- Technicians said too few gas and nuclear units were online to provide inertia and soak up imbalances, citing only the Arcos gas station and Almaraz nuclear unit as available to steady the south.
- Staff warned a major “zero” was likely and discussed meetings and reports inside REE, a record now feeding scrutiny of the grid operator’s dispatch choices and utilities’ claims of thin thermal scheduling.