Analysis and feasibility of a compressed air energy storage system (CAES) enriched with ethanol.

• This study shows the technical and economic viability of CAES using Ethanol. • The CAES system was planned to be implemented in abandoned mines. • Geological characteristics, wind speed and thermodynamic aspects was analysed. This paper shows the results of a study that sought to verify the technical and economic viability of implanting a Compressed Air Energy Storage (CAES) energy system that operated connected to a wind farm, in such a way as to guarantee supply even in parts of the day with low wind intensity. Because this study sought implement this system in a state located in the inland of Brazil where there were no mining caverns capable of storing the compressed air, we opted for using abandoned mines that could serve this function. However, it was difficult to find a location with an abandoned mine for storing compressed air, and a location with good air flow for energy generation, and so the endeavor was ultimately economically unviable. This study shows the geological characteristics of the state, the locations of the main wind flow areas, and the thermodynamic and energy calculations required for sizing and specifying the components for the project and gives an economic analysis of the endeavor. Contrary to initial hypothesis, it was not found any favorable sites in the state of Minas Gerais fort storing compressed air generated from wind energy. Furthermore, the cost analysis showed that this type of endeavor needs policies to gain scale. [ABSTRACT FROM AUTHOR]