Compressed Air Energy Storage in a Porous Aquifer in the Baltic Basin: Potential and Geological Risks

Over the past 20 years of extensive CO2 storage studies in the Baltic Basin, a large storage capacity has been evaluated. However, the partial or complete ban on underground CO2 storage (e.g., Lithuania) facilitates the present study of an alternative scenario for the application of the major Cambrian sandstone reservoir distributed within the Baltic Basin. Extensive hydrocarbon exploration fosters CAES opportunities. The largest geologic energy storage capacities were assessed in Latvia, and some potential sites were defined in Lithuania. The growing share of green energy in the region aligns with the rising demand for energy storage. The high reservoir properties (sandstone porosity ca. 22%) and moderate burial depth of ca. 1 km in the Cambrian aquifer are attributable to its high storage capacity. The reservoir in the Baltic basin is covered by thick Ordovician and Silurian shales, providing excellent reservoir sealing. The present study focuses on variations in critical parameters that control energy storage in particular structures and the associated risk factors.