Craig Morris just kindly pointed on Twitter to this interesting report on the quality of electricity supply in Europe.
Looking at the data at page 115, I find that for the time reported (the five years from 2006 to 2010), Germany beats everyone else in Europe for the title of the most reliable grid. Interruptions were at a grand total of 14.9 minutes in 2010, beating France (62.9 minutes) by a factor of over 4.
The runner-up in 2010 is Denmark with 16.95 minutes (another country with a high renewable share in the mix).
It will be interesting to see how Germany does in that kind of comparison in 2020, once the share of renewable in the mix gets closer to 50%. For the time being, there seems to be no problem with the stability of the system.
As the excellent “German Energy Transition” site points out, the lights stay on in Germany even with higher renewable shares.