The unique feature of Helios is the combination of energy types and flexibility in use. The unpressurized heat storage tank is 26 meters high and twelve meters in diameter and functions as a decentralized storage unit. The useful volume corresponds to 2,500 m3. This corresponds to one third of the total amount of water in all pools of the Auster sports and wellness pool in Eggenberg. The district heating reservoir is fed, among other things, by the 2,000 m2 solar thermal plant, which was newly built at the site. An expansion of this to up to 10,000 m2 is possible in the final stage of construction. In addition, the landfill gas available on site, which has not been used to date, will be used sensibly in a combined heat and power plant. Primarily, electricity will be generated for the plant's own needs, although in the event of a surplus, heat can also be generated from this via a power-to-heat plant. In the event of a failure of the public power supply, island operation of the plant is possible.