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• A Stirling engine based gasification CCHP system with food waste was introduced. • The optimal equivalence ratio was determined based on the cold gas efficiency. • Levelized total cost and primary energy saving ratio were used to optimize systems. • The monthly energetic, economic, and environmental analysis was conducted. • Sensitivity analyses of efficiencies, costs and CO 2 emission were carried out. Due to the tar contamination caused by the gasification process of biomass, the internal combustion engine (ICE) based gasification cogeneration systems require complicated gas cleaning devices to purify producer gas. In this paper, a Stirling engine based gasification combined cooling, heat and power (CCHP) system was introduced, which has the capability of mitigating tar condensation and contamination. The gasification CCHP system, including the gasification system, the Stirling engine system, and the absorption chiller system, can provide electricity, heat and cooling for a commercial building. The effects of the equivalence ratio on syngas composition and cold gas efficiency of the gasification process were analyzed herein. The optimal systems in Singapore and Shanghai can save respectively 75.9% and 70.5% levelized total cost compared to a conventional reference system. The Stirling engine based CCHP system had advantages over the ICE systems on overall consideration of the levelized total cost and the primary energy saving ratio. The monthly energetic, economic and environmental performance of the CCHP systems was evaluated under different modes and the above two systems' primary energy saving ratios, operation cost reduction ratios and CO 2 equivalent reduction ratios respectively reached 0.886, 0.462 and 0.701 in Singapore and 0.908, 0.535 and 0.710 in Shanghai in annual operation. The outcomes of this paper contribute to the design and deployment of such a CCHP system, and the developed models and analysis framework can be extended to different climate areas. [ABSTRACT FROM AUTHOR]

Due to the high dehumidification performance realized by removing adsorption heat by inner cooing, desiccant coated heat exchanger (DCHE) has been proposed and widely studied. The heat pump is usually used as the cooling and heat sources of the dehumidification system composed of DCHE because the cooling and heat capacity could be provided by the heat pump at the same time. Moreover, considering the advantage of low-grade thermal energy utilization, solar thermal energy can be used to further enhance the regeneration of DCHE to improve dehumidification performance and energy efficiency. In this paper, the solar-enhanced fresh air dehumidification system using DCHE driven by heat pump was proposed and a series of experiments were conducted under typical Shanghai summer high humidity conditions. The typical moisture removal of the system can be increased by about 15% to 10.14 g/kgDA and the COP could be further increased by over 25% to 5.39. In addition, the influence of different regeneration temperatures enhanced by solar thermal energy on the system has also been studied. Considering the dehumidification performance improvement and energy utilization efficiency, the optimal regeneration temperature is between 60 °C and 65 °C for the system proposed in this paper. • Moisture removal and COP can be increased by 6%–28% by solar enhanced. • Performance enhanced is more obvious when regeneration temperature is below 65 °C. • Solar enhanced dehumidification 1.43 (g·kgDA−1)/kW and 1.12 kg/kWh can be achieved. • Higher efficiency solar collectors will achieve higher solar enhanced performance. [ABSTRACT FROM AUTHOR]

• Grid-connected photovoltaic battery systems are simulated under dynamic electricity tariffs. • Reference sizing combinations are obtained via system techno-economic analysis. • High self-sufficiency leads to more schedulable production, sold energy and less battery usage. • Subsidies impact the revenues obviously especially in high self-sufficiency cases. • Partial grid parity could be achieved under the current market conditions. Battery storage provides an effective solution to alleviate the burden of the intermittent photovoltaic production on the grid and increase photovoltaic penetration in residential houses. Despite several existing work dedicated to the evaluation of photovoltaic battery system, the research on system sizing and operation strategy of the household system still has substantial areas to be explored such as techno-economic analysis under different electricity tariffs and comprehensive parametric analyses. In this paper, the mathematical model of a photovoltaic battery system is developed to investigate system performance, based on the various economic and technical indicators. This study demonstrates that the integration of battery energy storage could increase the value of self-consumption and self-sufficiency rates while making payback period longer. Substantial photovoltaic battery systems have been simulated under practical dynamic electricity tariffs in a typical electricity market. Eight cases with different technical performances from the recommended reference combinations are compared and studied in detail. The energy flows among photovoltaic, battery bank, grid and household user are discussed, revealing that systems with high self-sufficiency rate lead to more schedulable photovoltaic production, sold electricity and lower battery usage rate than those with high self-consumption rate. Besides, the entire lifecycle economic analysis indicates that a higher self-sufficiency rate refers to higher initial investment but shorter payback period and larger profit. The revenues breakdown of the cases shows that subsidies have a significant impact, especially for cases with high self-sufficiency rate. The levelized cost of electricity of photovoltaic and photovoltaic battery systems ranges from 0.373 to 0.628 CNY/kWh, demonstrating the possibility of partial grid parity under the current situation in Shanghai. [ABSTRACT FROM AUTHOR]