Renewable power sources’ intermittency could eventually cause problems as our electric grids become increasingly reliant on them. While it’s always sunny somewhere, and always windy somewhere (often somewhere else), relying on weather variations for generating consistent power means integrating power sources across a large geographic region. Many countries, including several leaders in renewable power, don’t have that luxury.

A Swiss-UK research team has now looked at what this means for Europe, where renewable energy has boomed primarily among countries with access to the wind resources of the North Sea. They’ve found that certain weather patterns leave the North Sea region underproducing for over a week. But those same patterns would boost production relatively nearby—in the Balkans, Spain, and Scandinavia. While that would be enough to offset the North Sea’s power slump, it won’t do much to help until Europe integrates its grids.

Regime change

The authors focus on what they call “weather regimes,” periods of similar weather that tend to stick around for five days or more. Most weather services recognize a handful of distinct European regimes, like having a low-pressure system parked south of Iceland, or high pressure just to the west of Ireland. The authors consider seven of these, nearly twice as many as most weather services recognize, because the relatively subtle differences among them can make a big difference to wind power generation.