Solar and sodium fast reactor-based integrated energy system developed with thermal energy storage and hydrogen

Abstract

Hybridizing nuclear and renewable energy systems helps enhance the benefits of both sources and eliminate their disadvantages. In order to provide resilience, energy systems need to be designed in a complementary manner to achieve an uninterrupted energy supply. The current study proposes a hybridization of a sodium fast reactor with a concentrated solar plant and molten salt energy storage system. By considering the community requirements, additional subsystems are added that use process heat and power to generate more useful commodities. The proposed nuclear and renewable hybrid energy system generates heat, power, hydrogen, fresh water, and cooling effect for communities in order to meet their needs in a sustainable fashion. The proposed system is a potential alternative to currently available fossil fuel-driven systems. Intermittency and flexibility issues of such systems are overcome with hybridization and integration. Apart from the other commodities, hydrogen is produced and supplied to the community by considering hydrogenization along with the electrification of transportation. Specifically, a parabolic trough collector-type concentrated solar plant, a sodium-cooled fast reactor, a molten salt energy storage unit, a lithium bromide absorption refrigerator, a solid-oxide electrolyser, a multi-effect distillation-type desalination unit, and a district heating system are considered to be used in the integrated system. The proposed system is investigated by considering the first and second laws of thermodynamics, which assess energy and exergy inputs and outputs of the system and subsystems. In order to analyze the system with realistic conditions, actual data for California, the United States, is considered. For a community with 240243 residents, a sodium fast reactor with 1.5 GWth capacity and parabolic trough collectors with 0.5 GWth capacity are considered, along with a 4 GWh of molten salt energy storage system. Annual average energy and exergy efficiencies are found to be 63.54 % and 57.96 %. The maximum energy efficiency is calculated as 84.4 %, and the maximum exergy efficiency is found as 81.28 %. Apart from the current community needs, 53,285.15 tonnes of hydrogen is produced annually.