District heating systems fully based on renewable energies require very large storages that allow seasonal storage of large amounts of renewable heat or waste heat respectively. Additionally these large storages are able to raise flexibility of the district heating networks.

Compared to currently installed heat storages the storage volume has to be increased tenfold and at the same time it is necessary to place the required huge volume subsurface. This is quite challenging in respect of materials and construction of these giga-scale storages.

The Austrian lead project giga_TES aims at developing giga-scale storage concepts for urban districts with integrating large shares of renewables focusing on Austrian implementations.