Among the key features of the high-temperature thermal energy storage technology is the use of sand, gravel, rock or stones in a fixed bed as a heat storage medium and ambient air, flue gas or other gases as a heat transfer medium. The main advantages are:

• Air/gases as a heat transfer medium can be moved very easily in large quantities.
• The innovative division of the heat storage medium/material on multiple layers/walls allows high thermal outputs with very low pressure losses.
• The storage material is held by a novel lamellar structure which allows unhindered flow through the material.
• The fine grain of the storage material allows a very compact design due to the large surface area available for the heat transfer.
• The modular design allows easy scaling. The basic standard size has the dimensions of a standard maritime container.
• Very low maintenance costs, as well as low operational power consumption, distinguish the HTTES technology from other storage systems.