Mechanical energy storage in ring tunnel

Can compressed air energy storage be used in underground mine tunnels?

Compressed air energy storage (CAES) in underground mine tunnels using the technique of lined rock cavern (LRC) provides a promising solution to large-scale energy storage. A coupled thermodynamic and thermomechanical modelling for CAES in mine tunnels was implemented. Thermodynamic analysis of air during CAES operation was carried out.

How do energy tunnels work?

Besides their structural purpose, energy tunnels can be used to inject, store and extract heat from the ground by means of a heat carrier fluid circulating through an integrated pipe system embedded within them.

Can energy tunnels be used as underground thermal energy storage systems?

Additionally, Rotta Loria (2021) evaluated the potential of energy tunnels as underground thermal energy storage systems and discovered that storage efficiencies could reach up to 70%.

How efficient are energy tunnels for energy storage?

The rationale behind this work is that Rotta Loria recently highlighted promising storage efficiencies of up to 70% for energy tunnels characterized by favourable subsurface conditions for storage applications (i.e., lacking convection heat transfer).

Are energy tunnels thermo-mechanical?

Experimental and numerical studies on the thermo-mechanical behaviour of energy tunnels. During heat extraction, a contractive thermally induced strain and a decrease in compressive stress in the lining were observed; an expansive strain and an increase in compressive stress were caused during heat injection.

Can underground heat exchangers be used as energy storage systems?

This work focuses on tunnels equipped with ground heat exchangers, typically called energy tunnels, to serve as seasonal, medium-temperature underground thermal energy storage systems (UTES).