Simulation of a hybrid solar gas-turbine cycle with storage integration

Abstract The interest for hybrid solar gas-turbine systems (HSGT) in solar tower plant technologies is growing This is due to the high conversion efficiency and to the low water consumption that are achieved when a combined cycle is implemented. This paper presents a simulation tool which is dedicated to the performance analysis of the top cycle featuring a thermal energy storage unit (TES). The influence of the TES operating conditions on the power plant production is highlighted. A major advantage of the storage is to stabilize the air temperature at the combustion chamber inlet in order to keep the operating conditions of the combustion chamber close to the design point. This work establishes that a higher and more stable electrical generation is achieved through this concept. According to the storage capacity, the TES unit increases the daily average solar share of the power plant. This study is conducted within the framework of the French PEGASE project (Production of Electricity from Gas and Solar Energy) which aims at setting up and testing at THEMIS site (France) a demonstration plant based on HSGT technology.