Compression and Air Storage Systems for Small Size CAES Plants: Design and Off-design Analysis

The paper deals with the design and off-design analysis of a compression and storage system for small size Compressed Air Energy Storage (CAES) plants. The system is constituted by a multi-stage reciprocating compressor coupled with an artificial air reservoir. A methodology for preliminary sizing and off-design modelling has been developed. In order to ensure an appropriately wide range of operations, particular attention has been paid to the selection of the most suitable compressor capacity control devices. Given the compressor capacity regulation margins and the actual level of charge of the reservoir, the proposed approach allows the instant-by-instant evaluation of minimum and maximum absorbable electric power. The developed tool gives useful information to appropriately size the compression system and to manage it in the most effective way.