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To promote the continuous operating of solar energy systems and increase the proportion of renewable energy consumption, solar devices are often integrated with conventional energy systems to reduce greenhouse gas emissions. In this study, a solar-natural gas coupling system is constructed, utilizing solar photovoltaics, thermal collectors, and high-efficiency energy conversion devices. After modelling the energy system, the operating modes are illustrated considering working sequences of water-cooled devices. A modified genetic algorithm, which incorporates reverse learning, controlled elite, and dynamic crowding distance theory, is constructed to optimize the configurations of the proposed energy system, with the aim of minimizing carbon and economic prices of the products. The performance of the energy system is compared with different algorithms and cases, and the results demonstrate that the proposed algorithm addresses the limitations of conventional methods, albeit with increased optimization times. Moreover, the proposed operating mode (Case 1) exhibits a stable performance, leading to a higher environmental and economic performance compared to conventional modes, with carbon and economic prices of 0.242 kg/kWh and 0.067 $/kWh, respectively. This study provides new insights into carbon footprints and economic performance evaluation of high-efficiency energy systems, offering valuable directions for future research in this field. [Display omitted] • A solar-natural gas coupling system to fulfill building multiple demands. • Comparisons of fours cases considering operating sequences of two types of chillers. • Modified genetic algorithm using reverse learning, elite controlled, dynamic crowding distance theory. • Carbon and economic prices of the products are illustrated. [ABSTRACT FROM AUTHOR]

The objective of this paper is to propose and analyze the performance of a novel hybrid combined cooling heating and power (CCHP) system coupled with compound parabolic concentrator-photovoltaic thermal (CPC-PVT) collectors. The electricity and hot water from CPC-PVT are integrated with the electricity and waste heat carried by exhaust gas and jacket water from the internal combustion engine to improve the energy performance. The thermodynamic models were constructed and validated by comparing the simulation results to those from existing studies. The thermodynamic performances were analyzed and the impacts of key parameters on the performances were discussed at the off-design condition. The levelized primary energy saving ratio (PESR) and carbon dioxide emission reduction ratio (CDERR) of the hybrid CCHP system in comparison to the CCHP system without solar energy were employed to evaluate the contribution of solar energy. The results indicated that the energy and exergy efficiencies at the design condition are 63.3% and 21.8% in summer, respectively, and 61.8% and 27.1% in winter, respectively. Compared to the CCHP system without solar energy, the hybrid system has more flexible ability to adjust the heating to electricity ratio and achieves the maximum levelized PESR of 28.6% and CDERR of 36.7%, respectively. • Propose a novel CCHP system integrated with CPC-PVT solar collectors. • Define the levelized primary energy saving ratio of the hybrid system. • Analyze the thermodynamic performances on the design and off-design operation conditions. • Discuss the performances and contributions of CPC-PVT solar collectors. [ABSTRACT FROM AUTHOR]

The aim of this work is to optimize and minimize the thermo-ecological cost (TEC) of a novel hybrid combined cooling heating and power (CCHP) system integrated with solar energy. A basic natural gas CCHP system based on internal combustion engine (ICE) is coupled with compound parabolic concentrated-photovoltaic thermal (CPC-PVT) collectors to construct a novel hybrid CCHP system. To minimize the TEC, an optimization methodology was proposed to optimize the configurations and installations of ICE and CPC-PVT, as well as the operation strategies. The TECs of multi-products of the CCHP system were assessed and compared in the following electrical load (FEL) and following thermal load (FTL) modes. The impacts of key parameters on TEC were analyzed and discussed. The results of a case study indicated that the system integrated with 100% photovoltaic covered ratio and 400 kW ICE gets the lowest TEC of 2.36 J/J in the FTL mode. The TECs of electricity decline 28.8% and 17.0% in the FEL and FTL modes, respectively when the photovoltaic covered ratio increases from 0 to 1.0. The increasing heat storage ratio leads to the increase of TEC of heat exergy carried by water due to the heat loss. • Propose a novel CCHP system integrated with CPC-PVT solar collectors. • Optimize the system configuration to minimize thermo-ecological cost. • Assess and compare the thermo-ecological costs of multi-products in different operation modes. • Discuss the impact of key parameters on TEC of the hybrid energy system. [ABSTRACT FROM AUTHOR]

Advanced solar driven tri-generation systems are highly relevant to reduce emissions and increase energy security. Here, solar collectors and photovoltaics are coupled to a tri-generation system to produce multiple final energy forms simultaneously for an office building. The excess solar electricity is employed for cooling/heating through a power-to-heat conversion employing thermal energy storage. Comprehensive optimization is performed to maximize the energy, environmental, and economic benefits, and the carbon tax is included to monetize the emissions. A coupled decision-making method is then used to choose the ideal scheme from the optimized sets of system configuration accompanied with a sensitivity analysis against key parameters. Compared to the conventional system, the proposed system improves the energy performance by 41.4% and the environmental benefits by 41.7% with the highest solar energy utilization rate. The economic performance improves in the best case by 14.4% only, but with the lowest utilization rate of solar energy. The ideal solution covers 30%, 54%, and 62% of the electricity, cooling, and heating loads, respectively, and the corresponded energy, environmental, and economic performance improves by 29.1%, 34.6%, and 7.7%, respectively. The sensitivity analysis shows that the economic performance is more sensitive to the electricity price than to the carbon tax. • A novel solar powered trigeneration system considering excess PV power to heat storage. • Equivalent coal consumption and carbon tax in energy and economic performance. • Coupling decision-making method after multi-objective optimization. • Solar energy covers 30% of electric, 54% of cooling and 62% of heating loads. • Sensitivity analysis against key parameters. [ABSTRACT FROM AUTHOR]

[Display omitted] • Solar-driven adjustable tri-generation system for building heating and cooling. • Energy, exergy, and adjustable performance in variable conditions is explored. • Energy levels and investment recovery are considered in exergo-economic optimization. • Optimal solar heat allocation ratio is 0.86 with a minimum exergy cost of 0.83 $/kWh. Solar-driven trigeneration system producing cooling, heating and power (CCHP) is an effective way to increase the utilization rate of solar energy. Here, a novel adjustable CCHP system is proposed by employing parabolic trough collectors (PTC), Organic Rankine Cycle (ORC), absorption chiller (AC) and electrical chiller/heater (EC/H) to meet building cooling and heating demand. A full thermal simulation model of the system is constructed and validated. The thermal and adjustable performance of a hybrid system with variable solar irradiance and solar thermal allocation ratio is explored by carrying out energy, exergy and heat to electricity ratio. Considering the energy levels of products and investment recovery coefficient of units at the end of service life, a modified exergo-economic method is utilized to optimize the thermal allocation ratio among the system components based on a specific working condition converted from yearly building parameters. The thermal analysis shows that except for the energy efficiency with increasing allocation ratio, the irradiance and allocation ratio have positive impacts on energy, and exergy performance, and the proposed system has a higher adjustable performance with a higher heat to electricity ratio than other studies. The exergo-economic optimization shows that 86% of the solar heat is fed to the ORC-unit at optimum point with an unit exergy cost of 0.826 $/kWh. Compared to conventional exergo-economic method, the specific costs of the products are lower owing to the function of cost recovery coefficient. This research illustrates a new way to effectively utilize solar thermal energy for district energy systems. [ABSTRACT FROM AUTHOR]

This study proposes a combined cooling, heating, and power (CCHP) system driven by biomass and solar energy integrated with an organic Rankine cycle (ORC). Its exergy, exergoeconomic, and exergoenvironmental performances are investigated. First, the thermodynamic parameters of each material and energy flow for the proposed CCHP system are simulated using Aspen Plus. Second, the exergy and exergoeconomic performances of the system are investigated, and an exergoenvironmental analysis of the system is performed. The results show that the unit exergy costs (UEC) of domestic hot water, electricity generated by an internal combustion engine (ICE) and the ORC, and chilled/heated water under summer/winter conditions are 2.742/2.742, 6.713/6.629, 12.930/12.930, and 27.100/12.530 MW/MW, respectively, with corresponding unit exergoeconomic costs (UEEC) of 41.11/41.11, 124.40/139.20, 181.80/181.80, and 507.10/302.60 USD/MWh, respectively. Meanwhile, the corresponding environmental impact rates per exergy unit are 0.616/0.616, 2.988/3.023, 0.030/0.030, and 6.567/3.072 mPts/MJ, respectively. The results highlight the urgency to prioritize improvements to the solar collector performance to reduce the UEC of electricity generated by the ORC. The absorption chiller/heater, heat exchanger, and ICE exhibit significant potential for enhancing their exergoeconomic performance. Additionally, the gasifier, ICE, and ORC can be optimized to mitigate their environmental impact with relatively minimal exertion. [Display omitted] • A new solar- and biomass-driven CCHP system integrated with the ORC is proposed. • The biomass gasification, ICE, ORC and, AC are simulated and validated. • The exergy performance of each component of the proposed CCHP system is investigated. • Exergoeconomic and exergoenvironmental analyses are performed for the proposed CCHP system. [ABSTRACT FROM AUTHOR]