  The electrical energy system has attracted much attention from an
increasingly diverse research community. Many theoretical predictions have been
made, from scaling laws of fluctuations to propagation velocities of
disturbances. However, to validate any theory, empirical data from large-scale
power systems are necessary but are rarely shared openly. Here, we analyse an
open data base of measurements of electric power grid frequencies across 17
locations in 12 synchronous areas on three continents. The power grid frequency
is of particular interest, as it indicates the balance of supply and demand and
carries information on deterministic, stochastic, and control influences. We
perform a broad analysis of the recorded data, compare different synchronous
areas and validate a previously conjectured scaling law. Furthermore, we show
how fluctuations change from local independent oscillations to a homogeneous
bulk behaviour. Overall, the presented open data base and analyses constitute a
step towards more shared, collaborative
