188宝金博页面版

Inorganics 2020, 8, 30; doi:10.3390/inorganics8050030 www.mdpi.com/journal/inorganics Article Techno-Economic Assessment of Destabilized Li Hydride Systems for High Temperature Thermal Energy Storage Claudio Corgnale Greenway Energy, LLC, Aiken, SC 29803, USA; claudio.corgnale@greenway-energy.com; Tel.: +1-803-617-9689 Received: 29 March 2020; Accepted: 22 April 2020; Published: 25 April 2020 Abstract: A comprehensive techno-economic analysis of destabilized Li hydrides, used as thermal energy storage systems in concentrating solar power plants, is presented and discussed. Two systems, operating at temperatures on the order of 550–650 °C, are selected as thermal energy storage units for steam power plants, namely the Si-destabilized Li hydride (LiSi) and the Al-destabilized Li hydride (LiAl). Two thermal energy storage systems, operating at temperatures on the order of 700–750 °C, are selected for integration in supercritical CO 2 power plants, namely the Si-destabilized Li hydride (LiSi) and the Sn-destabilized Li hydride (LiSn). Each storage system demonstrates excellent volumetric capacity, achieving values between 100 and 250 kWhth/m 3 . The LiSi-based thermal energy storage systems can be integrated with steam and supercritical CO 2 plants at a specific cost between 107 US$/kWhth and 109 US$/kWhth, with potential to achieve costs on the order of 74 US$/kWhth under enhanced configurations and scenarios. The LiAl-based storage system has the highest potential for large scale applications. The specific cost of the LiAl system, integrated in solar steam power plants, is equal to approximately 74 US$/kWhth, with potential to reach values on the order of 51 US$/kWhth under enhanced performance configurations and scenarios. Keywords: thermal energy storage; concentrating solar power plant; metal hydride; destabilized Li material; techno-economic analysis; cost assessment 1. Introduction Concentrating solar power plants are among the most appealing systems to produce renewable-generated electricity on a large scale [1,2]. In order to achieve efficiencies and costs required to compete with traditional carbon-based power plants, as well as to improve grid operation and stability, concentrating solar power (CSP) plants need to be equipped with suitable thermal energy storage (TES) systems that can overcome the intrinsic intermittent nature of the solar radiation [1,3]. Currently, three main storage concepts are under investigation for practical applications: (1) sensible heat-based storage systems; (2) latent heat-based storage systems, storing and releasing the heat associated with material phase change; and (3) thermochemical heat-based storage systems, storing and releasing the heat related to chemical reactions occurring inside the material [4–8]. TES systems based on metal hydrides are part of the third category and exploit the heat associated with hydrogen absorption (exothermic reaction) and desorption (endothermic reaction) in metal hydride materials. When concentrated thermal power is available from solar radiation, the material stores the high temperature heat desorbing hydrogen through an endothermic reaction. When the direct solar radiation is unavailable, the hydrogen is reabsorbed in the hydride, through an exothermic reaction, releasing high temperature heat. The hydrogen absorbed and released from the metal hydride is