Evaluation of Small-scaled Compressed Air Energy Storage

Abstract

The ongoing integration of renewable resources in the energy supply system has brought the problem of matching an intermittent supply to demand. This can be solved by energy storage and although there are currently solutions for this purpose, they tend to be either expensive or difficult to recycle. An alternative to these is to compress air using a compressor system, store the air, and then expand it through a turbine to produce energy when it is needed. This approach is called compressed air energy storage (CAES). Compressed air energy storage has been deployed in two large multi-megawatts plants in the world, in Germany (Huntorf 270 MW) and one in the USA (McIntosh 110 MW). However such a plant requires a large geological feature such as a salt cavern and considerable capital investment. To date there has been little interest in adapting compressed air energy storage plant to a small scale. This study explores the potential of such a system using cycle modeling to determine the potential outputs for such a system. The size, weight and cost of such as system is also evaluated. This thesis shows that at present small scale CAES is not competitive with other types of storage as the cost of the components is prohibitive.