Energy storage capacity is crucial to increasing the contribution of renewable energy sources to power supplies and power grid decarbonization. The intermittent nature of wind, solar and other alternative energy systems underscores the need for efficient storage and dispatch systems. The cost-effective deployment of compressed air energy storage (CAES) systems for such application has been analyzed, using California as a case study.

A modeling approach developed by researchers from Stanford University, University of New South Wales (Australia), Hassan II University of Casablanca (Morocco) and Nanyang Technological University (Singapore) was used to explore the CAES capacity required in California to compensate for the variability of increased penetration of wind and solar-based power systems. The levelized cost of electricity was determined based on the availability of generation capacity, wind and solar resources, storage resources and demand.

CAES offers a cost-effective option for the storage and dispatch of solar and wind energy. Source: S. Ashfaq et al.

A scenario assuming no excess wind and solar power generation defines the required CAES capacity to be 3.71 TWh. The storage capacity required would be 3.2% higher with 9.8% increased cost of electricity under implementation of a strict rule of net-zero curtailment. However, CAES capacity needs decline with excess solar and wind power generation. Significant increases in the wind and solar contributions would slash the required CAES capacity with strict zero curtailment by 19.2% and reduce the corresponding cost by up to 29.7%.

The research published in Electric Power Systems Research indicates that CAES can economically augment battery storage systems and that excess wind and solar power generation can be exploited to reduce the required storage needs for a fully renewable power system at reduced cost.