The superstatistics concept is a useful method borrowed from nonequilibrium statistical mechanics to understand
spatio-temporal inhomogeneous complex systems with separation of time scales.
After a brief introduction to the basic theoretical ideas I will discuss a couple of recent applications.
As a main example to be considered in somewhat more detail, I will discuss the statistics of frequency fluctuations around
the mean frequency of 50 Hz in power grids, which can be well understood using superstatistical concepts. In fact,
multiple types of fluctuations impact the collective dynamics of power grids and thus challenge their robust operation. Fluctuations result from processes as different as dynamically changing demands, energy trading and an increasing share of renewable power feed-in. Analysing frequency time series for a range of power grids, including grids in North America, Japan, the UK and the rest of Europe, one finds a significant deviation from Gaussianity that is very well described by superstatistical models.