> Currently some companys consider, forging giant conrete containers, sink them out in the ocean, and pump them dry when there is a energy surplus. Compressed

> Currently some companys consider, forging giant conrete containers, sink them out in the ocean, and pump them dry when there is a energy surplus. Compressed Air Energy Storage (CAES) is nothing new per se. CAES plants have been operational in Huntorf, Germany, since the late 1970s and in McIntosh, Alabama, since the late 1990s. The problem with current technology CAES is that it is not energy-efficient (around 30% for the existing installations, though there's room for improvement) and not carbon-neutral. The underlying problem is that compressing air generates heat, which is then dissipated; however, that means that during decompression, the air has to be reheated, usually with natural gas. There are currently projects underway with both Adiabatic [1] and Isothermal [2] CAES to improve efficiency and make the process carbon-neutral. Google "SustainX" and "ADELE RWE" for examples of current projects. [1] http://energystorage.org/advanced-adiabatic-compressed-air-energy-storage-aa-caes http://energystorage.org/advanced-adiabatic-compressed-air-e... [2] http://energystorage.org/energy-storage/technologies/isothermal-caes http://energystorage.org/energy-storage/technologies/isother...