Geologic Energy Storage

 

The U.S. Geological Survey (USGS) just put out a nice fact sheet with an informative explanation of geologic energy storage with includes some useful graphics.

The following is excerpted from the fact sheet:

Geologic energy storage methods may be divided into three broad categories:

• Chemical methods, where energy is stored as potential energy in chemical bonds. These methods include storage of methane or natural gas, natural gas liquids, and hydrogen.

• Mechanical methods, where energy is stored as potential energy using materials or fluids. These methods include compressed air energy storage, with constant or variable temperatures; gravity energy storage using suspended loads; and pumped hydroelectric energy storage.

• Thermal methods, where energy is stored as a temperature difference in materials or fluids to be used later for heating, cooling, or industrial processes such as drying.

Different geologic settings for energy storage include the following:

• Depleted or abandoned gas reservoirs;

• Abandoned mine tunnels and shafts, both lined and unlined;

• Purpose-drilled boreholes or shafts;

• Mined caverns in salt formations; and

• Freshwater or saline aquifers

Here is a a link to the full PDF  fs20223082.pdf - Geologic Energy Storage (usgs.gov)

 

Reference

Geologic Energy Storage: U.S. Geological Survey. Buursink, M.L., Anderson, S.T., Brennan, S.T., Burns, E.R., Freeman, P.A., Gallotti, J.S., Lohr, C.D., Merrill, M. D., Morrissey, E.A., Plampin, M.R., and Warwick, P.D., 2023, Geologic energy storage: U.S. Geological Survey Fact Sheet 2022–3082, 4 p., https://doi.org/10.3133/fs20223082.