# Researchers Trace a Mysterious One-Minute Rhythm in Power Grids Worldwide to Synchronized Batteries and UPS Units

*2026-11-08 23:01 UTC · Science · 2 min read*

> Grid frequency dips every 60 seconds on several continents; a Jülich-led team links it to data-center UPSes and batteries that all check their charge at once.

For years, grid operators have seen frequency dip slightly every 60 seconds, at the same moment on grids in different countries. Tennet Germany asked a team led by Dirk Witthaut of Forschungszentrum Jülich to find the cause. Hydropower control systems could produce a one-minute resonance in models, but not one that persists indefinitely, so the team looked for something running on a fixed timer.

With more than 80 power quality meters on the Jülich campus, they found a transformer attached to a battery storage system peaking every minute. Many stationary batteries, including data-center uninterruptible power supplies (UPSes), check their state of charge once a minute, and because they are internet-connected their clocks are nearly perfectly synchronized. In Ireland, where data centers made up 18% of grid load by 2022, the minute-by-minute drop grew from 3 mHz in 2016 to 12 mHz in 2021, with some later drops above 20 mHz.

The swings are still small against Ireland's tolerance of 200 mHz, but they can add to other loads and stress equipment such as hydropower turbines as data centers and storage expand. The researchers urge manufacturers to randomize the timing of charge checks, and say regulators may need to require it, which will take international coordination.

## Sources

- [techcrunch.com](https://techcrunch.com/2026/11/08/coordinated-disturbances-haunt-grids-worldwide-heres-how-researchers-solved-the-mystery/)

---
TechTools News · https://techtools.cz/tools/news/article/2659-researchers-trace-a-mysterious-one-minute-rhythm-in-power-grids-worldwide-to
Česká verze: https://techtools.cz/tools/news/clanek/2733-vedci-vysvetlili-zahadny-minutovy-rytmus-v-elektrickych-sitich-po-celem-svete