Technology
Synchronised data-centre batteries are leaving a 60-second fingerprint on power grids
Researchers traced a once-a-minute frequency dip observed on grids in several countries to internet-synchronised batteries and uninterruptible power supplies that check their state of charge on the minute. More than 80 power-quality meters at a German research campus tied the signal to a battery-backed transformer. On Ireland's grid, where data centres reached 18 percent of load by 2022, the dip quadrupled from 3 millihertz in 2016 to 12 millihertz in 2021, with some readings above 20. Randomising the check schedule would remove the effect.