Investigation on zero grid-electricity design strategies of solid oxide fuel cell trigeneration system for high-rise building in hot and humid climate

Trigeneration, which is able to provide cooling, heating and power, has been advocated to be a sustainable solution for building use in the urban area. With the high-temperature feature and maintenance convenience, solid oxide fuel cell (SOFC) becomes a promising prime mover of trigeneration. In this study, two zero grid-electricity design strategies of SOFC-trigeneration system for high-rise building were proposed and evaluated. The first zero design approach, named full-SOFC strategy, is to design the rated capacity of SOFC by matching the demand peak of electrical power without the need of grid connection. The second one, called partial-SOFC strategy, is to satisfy the peak electrical demand partly by the SOFC and partly by the grid, but still maintaining net zero grid-electricity in a year time. In view of the system complexity and the component interaction of SOFC-trigeneration, the environmental and energy performances of different cases were evaluated through year-round dynamic simulation. Compared to the conventional provisions of cooling, heating and power for building, the full- and the partial-SOFC-trigeneration systems could have 51.4% and 23.9% carbon emission cut per annum respectively. In terms of year-round electricity demand, the two zero grid-electricity strategies had corresponding savings of 7.1% and 2.8%. As a whole, the full-SOFC-trigeneration assures both environmental and energy merits for high-rise building in the hot and humid climate.