Techno-Economic Analysis of CAES Systems Integrated into Gas-Steam Combined Plants

Abstract

In the present paper, an energy storage concept based on the integration of a Compressed Air Energy Storage system into a Gas Steam Combined Cycle plants is investigated. The integration of CAES results in a noticeable power augmentation in respect to normal GSCC plant operations. Being such a power increase obtained without using additional fuel, the storage system can be compared to PHS, BES and A-CAES. Two CAES integrated into medium size GSCC plants arranged with Aero Derivative and Heavy Duty Gas Turbines have been investigated. A techno economic analysis aimed at assessing plant performance and investment costs has been performed. Despite the relatively high investment costs and the storage efficiency lesser than those featuring alternative storage approaches, the proposed system may be considered of interest due to the long life duration and the established technologies available for the key plant components

CAES Systems Integrated into a Gas-Steam Combined Plant: Design Point Performance Assessment

“…In the previously cited author's paper [17], the integrated system storage efficiency was evaluated according to the following formula:…”

“…In order to explore the practical feasibility of the proposed system, a techno-economic analysis aimed at assessing plant performance and investment costs has been carried out [17]. Results have shown that, despite the relatively high investment costs and the storage efficiency being less than those featuring alternative storage approaches, the proposed system may be considered of interest due to the long life duration and to the proven technologies available for the key plant components.…”

“…In the aim of achieving a fuel free energy storage system, the author proposed a novel concept integrating a D-CAES into a gas-steam combined cycle (GSCC) plant [17].…”

“…As reported in [17], evaluations had been performed by adopting conservative assumptions and, for sake of simplification, by neglecting some aspects related to GSCC plant operations expected to give a positive contribution to the performance of the whole integrated system. air: if the electricity produced per kilogram of GT exhaust gas is higher than that obtained during normal GSCC operation, such an electricity surplus can be deemed as being achieved without using additional fuel.…”

“…As reported in [17], evaluations had been performed by adopting conservative assumptions and, for sake of simplification, by neglecting some aspects related to GSCC plant operations expected to give a positive contribution to the performance of the whole integrated system. : gas mass flow rate entering the HRSG during gas-steam combined cycle (GSCC) normal operation; , : gas mass flow rate entering the HRSG during the compressed air energy storage (CAES) discharge phase; , : gas mass flow rate entering the AH during the CAES discharge phase.…”