Europe: Oven clocks and the like are running six minutes slow

Winter has turned the clocks of Europe with cold fingers. In Switzerland too, devices that receive their time signals from the power grid are currently not displaying the correct time. The cause may be a bottleneck in the European power grid.

Lower frequency in the power grid

The reason some clocks are currently running several minutes slow is that electricity is reaching households at a lower frequency — something we have been reading about in the media for days, and noticing on our own oven clocks. Clocks that are governed by the rhythm of alternating current at 50 hertz will not display the correct time as soon as the frequency fluctuates. "If frequency-dependent devices are running slower, it could mean that our power grid is overloaded in trying to meet a momentarily high electricity demand," says Urs Elber, head of the Energy research focus at Empa. Another possibility, he says, is that too little electricity is being fed into the grid by suppliers even under normal demand. While Switzerland's winter demand has always exceeded its own production and electricity has traditionally been imported in winter, such situations could become more frequent in the future, Elber believes.

One reason for this is fluctuations in electricity production. Electricity is rarely generated where it is actually needed. "When you're generating electricity with wind turbines in the middle of the North Sea, the consumer is unfortunately somewhere else entirely," explains Elber.

Research into intelligent power grids

So is our historically grown power grid increasingly struggling to cope with the current volumes of electricity and the flexible transmission demands of producers and customers? Edoardo Mazza, head of Empa's "Mechanical Integrity of Energy Systems" department and professor of mechanics at ETH Zurich, is currently working with his team to lay the groundwork for pushing the existing power grid to peak performance when needed, without straining high-voltage lines or creating bottlenecks. "What is crucial for the reliability and longevity of high-voltage lines is how much current you push through them, as they heat up and the material gradually deforms and ages as a result," says the researcher. Mazza's analyses are intended to make it possible to exploit the capacity of the lines more efficiently.

Storage technologies as a solution

Alongside transmission, insufficient electricity storage also contributes to the problem. Electricity generated on sunny days in Europe through solar technology cannot yet be stored efficiently enough. Energy expert Urs Elber sees opportunities in strengthening seasonal storage technologies such as reservoirs and geothermal storage. In addition, scientists at Empa are also researching battery technologies that store electricity using raw materials as varied as sea salt, scrap metal, and crystals. Finally, the "power-to-gas" concept shows how seasonal fluctuations in electricity can be balanced out through gas production. "This way, when energy is scarce in winter, you can heat with gas that was produced the previous summer," says Elber.

Update 7.3.2018: The cause of the inaccurate electric clocks across Europe appears to have been found. It is the result of a dispute over electricity volumes between Kosovo and Serbia, as Spiegel Online reports.