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Concentrated solar power (CSP), a technology that provides electricity by concentrating solar energy into a single focal point, shows great potential for large-scale utilization. In this study, an integrated hybrid life cycle assessment (LCA) model for multiple regions of China is presented to evaluate the life cycle CO 2 emission, energy consumption, and energy payback time of a 10-MW power tower CSP plant located in China. Over its life cycle of 25 years, the CSP plant is estimated to have CO 2 emissions of 35 g/kWh, consume 514 kJ/kWh of energy, and have an energy payback time close to four years. Using the proposed hybrid model, a significant advantage is the ability to compare the life cycle impact sourced from each sector in input-output economic background. Based on the regionalization of economic background at the province level, the most noteworthy impact is from Hubei province; besides, the CO 2 emission from the electricity sector in each province is the largest contributor. The majority (54%) of the life cycle CO 2 emission of the CSP plant is contributed by the northern region of China due to the higher utilization of coal in the economy of that region, yet most of the energy consumption comes from the southern part of China because of the concentration of manufacturing there. For the life cycle impact of a CSP plant, thermal energy storage using molten salt, and solar collection demanding lots of steel are the two most significant contributors to CO 2 emission and energy consumption. Image 1 • Propose an integrated hybrid LCA model for Chinese situation. • Quantify the CO 2 emission and energy consumption for a CSP plant in China. • Discuss the regional contribution difference for the life cycle impacts. • Analyze a major contributor — manufacture phase — for the CSP's CO 2 emission. • Propose the solutions to decrease the impact sourced from fossil fuel consumption. [ABSTRACT FROM AUTHOR]

With the promotion of renewable energy, natural gas's advantage is being cut as its prices fluctuate largely. This study proposes a robust mathematical model to simulate the changes in electricity structure and hydrogen supply with the fluctuation of natural gas prices. The simulation model is applied to explore the impact of soaring natural gas prices on the electricity market in China. The results demonstrate that high natural gas prices are more likely to promote the development of low-cost nonrenewable power generation rather than renewable power generation under a policy of low-carbon tax. Coal power still dominates the electricity market with a share of 42% and accounts for 66% in hydrogen production due to its low price and mature craftsmanship. Natural gas is the indispensable transitional energy for the transformation of the power structure despite its high prices, occupying 17% in the electricity market and 15% in hydrogen production. In conclusion, fossil energy will gradually change from direct combustion and utilization to the production of renewable energy such as hydrogen energy. Finally, policy recommendations for the structure of the electricity market and the supply of hydrogen energy are proposed. • A R-MILP model has been developed to simulate the changes in electricity market. • Energy prices uncertainty is considered for reflecting energy competitiveness. • A universal approach for analyzing the evolution of energy structure is proposed. • Explore energy structure changes brought by high gas prices in China. [ABSTRACT FROM AUTHOR]

As the demand of fossil fuel declines, improving the infrastructure development of fossil fuel supply chain is the efficient way to reduce cost and carbon emissions. This paper analyzes the impact of declining oil demand on the infrastructure development of the oil products delivery system. A mathematical model is proposed to simulate the transportation and storage schemes, and then is generalized to different forms based on four disposal strategies of idle depots and five sub-scenarios of declining demand. The discussed disposal strategies include storage of other fuels, relocation, destruction and to be sold. A comprehensive evaluation system is also formulated to evaluate the utilization efficiency of the transit depots. Finally, the oil products delivery system in Northwestern China is used to validate the proposed method. Compared with the current system, improving the utilization rate of the depot under declining demand sub-scenarios can improve the economic efficiency by 10.6%, 8.9%, 17.3%,21.3% and 21.6%. With the decline in demand, the economy of destruction of transit depot is better than others, while the environmental benefit of storing other fuels is better than other strategies. • A mathematical model simulated the schemes of the oil products delivery system is developed. • A comprehensive evaluation system of depot's utilization efficiency is proposed. • The simulation model is generalized to different models based on four depot disposal strategies. • Different disposal strategies bring different economy and environment effects. [ABSTRACT FROM AUTHOR]

Electrolysis hydrogen generation technology is one of the feasible ways to alleviate the problem of wind electricity curtailment. One promising hydrogen value-added application is to blend hydrogen into the natural gas grid and sell it as the heat energy carrier. This paper aims to discuss the feasibility of a roadmap to urban energy internet with wind electricity-natural gas nexus. Firstly, a framework is raised to integrate wind electricity generation, electrolysis hydrogen generation, and hydrogen-natural gas blending systems. Secondly, a series of reasonable hydrogen supply profiles are provided based on annual electricity curtailment and realistic natural gas scheduling. Then, an energy optimisation model and a techno-economic model are applied to simulate the generation of electricity and hydrogen, as well as determine the most economical hydrogen supply scheme. Finally, a case study in the Beijing-Tianjin-Hebei region of China is taken to validate the benefits of the proposed roadmap. The preferred scheme is worked out with the net present value of 88.8 M$, including the economy configurations of the electricity-hydrogen hybrid generation system, as well as the hydrogen-natural gas blending plan. The results also indicate that annual electricity curtailment and annual carbon emission are decreased by 204 GWh (48.8%) and 40.2 kt (49.9%). • Raise a roadmap to urban energy internet with wind electricity-natural gas nexus. • Set a framework to integrate electrolysis hydrogen generation and blending systems. • Propose an overall optimisation model for economic and environmental analysis. • Hydrogen supply depends on wind electricity curtailment and natural gas scheduling. • The improved economic and environmental benefits in a real case are identified. [ABSTRACT FROM AUTHOR]

Distributed energy systems (DES) with hybrid sources has become a more effective way to increase the flexibility of energy supply. Current relevant research on DES design optimization strives to improve system efficiency and sustainability through independent application of subsystem interconnection and demand response. This paper aims to analyze the coupling impact of the above two strategies on the performance of DES. A general multi-objective mathematical programming model is proposed to work out the optimal design and operation scheme of DES, as well as flexible management of electricity, cooling energy, heating energy and steam. The minimum annual cost, carbon emission and energy demand deviation are set as objective functions. Additionally, the augmented ε-constraint method is introduced to search for the trade-off among three indicators. A composite community in China is taken as a case and three scenarios are carried out for comparison. Results reveal that the annual cost and carbon emission are further decreased by 7.3% and 32.1% under the coupling impact of subsystem interconnection and demand response. Eventually, the preferred strategy is analyzed in detailed to illustrate how this coupling strategy further improves the performance of DES. • The coupling impact of subsystem interconnection and demand response is analyzed. • DES is evaluated by economic, environmental and demand deviation indicators. • A tri-objective MILP model is built to determine the optimal coupling strategy. • The AUGMECON is introduced to search for the trade-off between three indicators. • The annual cost and carbon emission are further decreased by 7.3% and 32.1%. [ABSTRACT FROM AUTHOR]