Compressed air and hydrogen energy storage hybridized with solar energy to supply electricity and hot water for a residential settlement

Abstract

In order to move toward net zero energy buildings, use of new and renewable energy resources parallel with development of high performance energy storage systems is necessary to maximize energy absorption and reduce energy losses with subsequent improvement in the energy performance of systems. In this research, two separate energy storage systems for supplying electricity and hot water for 500 residential buildings in Beijing have been designed and compared based on their performance. 1500 solar panels provide the required power for buildings. The first system is compressed air energy storage (CAES), while the second system is hydrogen energy storage (HES). Simulation has been done in TRNSYS and EES software. Energy and exergy analyses have been done for both systems. In case of the loss of hot water produced by the systems, the annual average energy efficiency of CAES and HES is about 44 % and 42 %, respectively. The energy efficiency of the first system decreases in the hot months of the year and reaches about 42 %, but the efficiency of the HES system is constant throughout the year. If the hot water produced by the systems is used for consumption in residential buildings, the energy efficiency of CAES and HES reaches 93 % and 64 %, respectively. The most exergy destruction in the CAES is related to combustion chambers (41 % of the total exergy destruction) and in the HES, it is related to electrolyzers (71 % of the total exergy destruction). The exergy efficiency of the first system is about 56 %, while for the second system this value is about 34 %.