An Offshore Compressed Air Energy Storage (OCAES) approach is being considered as a solution to store intermittently generated energy from renewable sources. The operating mechanism is to submerge the storage vessel into the deep ocean, convert the energy into compressed air and store it using the hydrostatic water pressure to balance the compressed air pressure without requiring the storage vessels of high strength. An additional advantage is that the interface of air and water acts as a piston to seal the vessel and maintain the air pressure level. In this study, a rectangular concrete tank and a concrete cylinder are investigated as the configuration of OCAES vessel. Characterization of the induced loading in this case is developed and the vessels’ response under operational loading is investigated. The operational load is a time dependent internal pressure induced by the air/water exchange in the inflation/deflation process. The stress distribution and deformation pattern in the OCAES vessel at different loading stages are studied by using the multi-physics FEM program COMSOL.
