The European grid coordinator, ENTSO-e, has released a detailed report on the Iberian Peninsula's electrical grid failure a year ago. The report suggests that a combination of grid-level voltage oscillations and early disconnections were the main factor. The expert committee used data from most major hardware on the Spanish and Portuguese grid, including status logs from major interchanges between the Spanish grid and those in France and Morocco. They also obtained data from two manufacturers of the small inverters used for rooftop solar. The final report provides more detail about what went wrong and provides a clear picture of how the Ibertian grid operators could prevent a similar event in the future. The process for dampening oscillations increased the amount of reactive power on the grid, raising the voltage on main transmission lines in Spain.