Yesterday after maintenance shutdown of a 400kV transmission line in Nordrhein-Westfalen, Germany, led to an emergency shutdown of private customers in many areas of Europe to prevent a full blackout. Several areas of Germany, France, Belgium and Italy were without power for 30 minutes, others experienced brownouts, areas in Austria lost power for 13 minutes.
In Vienna we had a severe brownout, followed by a noticeable overvoltage (very bright incandescent lights) and after some 15 minutes a dip back to normal again (which most people probably wouldn't have noticed at all, it just felt like the dim on startup surges you're used to here in Vienna).
No official explanations. "Actually we don't know how it could happen!" said the spokeswoman of the German power company. The papers aid it might take days or even weeks to determine the real cause of the overload.
Re: Near-breakdown of European grid#146194 11/05/0602:47 PM11/05/0602:47 PM
Sounds like a typically overloaded grid and not checking the loading prior to switching off that 400 kV line.
According to several people, including a former teacher of mine Austria is in for a much bigger potential catastrophy though... Most of our generating capacity is concentrated in the eastern and northern region (hydro, caloric, lots of wind turbines), whereas the south doesn't have much generation capacity but heavy demand. Those two areas are linked by two constantly overloaded 220kV lines. Since they're that heavily loaded it's impossible to shut them down for maintenance. But live maintenance like painting pylons is illegal in Austria, so the pylons can't be painted... So IF one of those lines fails, it'll most likely shut down at least half of Austria, probably taking down large areas of Europe.
Re: Near-breakdown of European grid#146196 11/05/0607:32 PM11/05/0607:32 PM
There are only German articles as far as I've seen. http://www.tagesschau.de/aktuell/meldungen/0,,OID6066150_REF1,00.html According to this one they shut off the 400kV line across a river to let a huge ship pass...