Use of an Under-Water Compressed Air Energy Storage (UWCAES) to Fully Power the Sicily Region (Italy) With Renewable Energy: A Case Study

Abstract

The high concentration of CO2 in the atmosphere and the increase in sea and land temperatures make the use of renewable energy sources increasingly urgent. To overcome the problem of non-programmability of renewable sources, this study analyzes an energy storage system consisting of under water compressed air energy storage (UWCAES). A case study for fully power the Sicily region (Italy) with renewable energy source (wind and photovoltaic) is presented. From the real annual capacity values of the renewable plants installed in Sicily, a sizing of both the energy production and the storage system and its auxiliary services is evaluated. The optimization of the operation of the system as a whole, modeled with mathematical models already validated in previous studies, is obtained through dynamic programming. The electricity consumed annually by the region, equal to 19048.4 GWh, can be entirely satisfied by renewable energy sources. A sizing of plants powered by renewable sources for a nominal power of 15, 000 MW equally divided between photovoltaic and wind power is considered. The underwater air storage system has a maximum volume of 2.1 × 108 m3, while the compression and generation units have a total nominal power of 6, 900 and 3, 100 MW, respectively. The study finally presents a sensitivity analysis for the evaluation of the effects of the variation of the power produced by renewable energy sources and of Sicily energy consumption. The results show that carbon-free feeding is possible and that all the boundary conditions on the operation of the system can be met.

Compressed Air Energy Storage as a Battery Energy Storage System for Various Application Domains: A Review

“…This was explored by Hydrostor of Canada in [108], using water bags placed on the sea floor. Using similar principle, the authors of [154] proposed underground pumped storage in which surface-reservoir-stored fluid can flow via gravity to maintain the pressure of air trapped in the shafts of disused mines. The authors of [155] used a surface reservoir as a pressure-compensating water column.…”

Recent Advances in Energy Storage Systems for Renewable Source Grid Integration: A Comprehensive Review

“…During peakhours the air can be released and converted back to electrical power to make sure that there is no curtailment in the renewable source. Storing fresh air in salt caverns is a proven, reliable and safe method of ensuring that excess energy is not wasted [72][73][74][75]. The authors of [76] compared CAES and battery energy storage systems based on a levelized cost of storage.…”

Underwater Compressed Gas Energy Storage (UWCGES): Current Status, Challenges, and Future Perspectives

“…It was found that an efficiency of 59% was achievable in terms of UWCAES subsystem [44]. Tiano and Rizzo from the University of Salerno investigated the feasibility of carbon-free renewable energy feeding in Sicily by introducing UWCAES [45]. Guandalini et al from Polytechnic University of Milan conducted a preliminary design and performance assessment of UWCAES considering the off-design properties of the overall system and realistic power input.…”