Battery storage units can store energy and release it again when required. The short control and start times in the range of 20 milliseconds to full load are a great advantage. This means that battery accumulators can be used to cover peak loads in the minute range, as well as to absorb short-term voltage and frequency fluctuations in the second range. When used in the right way, battery accumulators are effective in electrical energy networks that have reached their capacity limits. Controlling charge and discharge cycles at the right time has a stabilising effect on the system.
Battery storage systems play an increasingly important role in energy supply and can be used in a variety of ways. In Switzerland and Germany they are currently used most frequently in the control energy market and for peak shaving. Two thirds of the battery storage systems used are equipped with lithium-ion batteries, the remainder are based on sodium-sulphur batteries. A very small proportion of these are redox-flow and lead-acid batteries.