Battery storage ensures a secure power supply even in the event of a dark doldrums.
Image: dpa
The energy transition lacks large, strong storage systems. Are sodium and sulfur batteries good for this? These power storage devices are inexpensive, environmentally friendly and can now also be used stably.
With the expansion of renewable energies, stationary battery storage systems are becoming increasingly important. According to calculations by the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg, storage capacities of up to 100 gigawatt hours should be available in Germany by 2030 in order to cushion the natural fluctuations in yield from renewables. This corresponds to thirteen times the current battery capacity. But large-scale storage systems made from rechargeable lithium-ion batteries are and will remain expensive. Efficient and inexpensive solutions are therefore sought.
This is where sodium-sulphur batteries come in handy. They have the great advantage that they do not require expensive and scarce raw materials: seawater contains plenty of sodium. Sulfur is non-toxic and can be obtained via the Claus process from hydrogen sulfide, which is produced in large quantities as a waste product in oil refineries. Long-term stability was a weak point for a long time, but great progress has recently been made here too, so that a market launch seems possible.