> Not sure what this means. FWIW, I'm in the UK, and short brown-outs are not uncommon if, for example, the national grid is adapting to a failure somewhere during severe weather.

I am from Germany. The latest wide-scale power failure I can think of was 2007. I remember another shorter one in Bremen which must have been around ten years ago. They happen really rarely here, in spite of all that FUD that wind and solar energy makes the power supply unreliable.