An electron energy measurement based on resonant spin depolarization has been running permanently at BESSY II for several years. This high-precision energy measurement was set up primarily for users of synchrotron radiation for me- teorological applications from the Physikalisch-Technische Bundesanstalt (PTB). Recent investigations have led to a better understanding of the method and the possibility of shortening the measurement time. This allows for new obser- vations and the use of the energy measurement for different applications such as the model-free measurement of the natural chromaticity, the momentum compaction factor or synchrotron sidebands.