Abstract

In this research, a solar/wind hybrid energy system assisted with battery storage was proposed to study Japan’s strategies for domestic green hydrogen production in the 2030s. A LP optimization model of the proposed system was developed, and calculations were done using ERA5 meteorological data. A comprehensive sensitivity analysis and a comparison with overseas production in western Australia were also conducted.

Abstract

Cold seep can generate dissolved inorganic carbon (DIC) through various processes, such as anaerobic oxidation of methane. The DIC can be emitted into the sea surface via vertical movement of the water column. This part of DIC can bare the possibility of being released to the atmosphere through air-sea exchange. In this way, cold seep can be a carbon source. Yet the contribution in terms of DIC of cold seep has not been considered hitherto. The present study collected samples from four stations in the Haima cold seep from the South China Sea and measured the carbon content and isotope. The results show that cold seep is not a carbon source because of ocean fertilization by methane. Also, cold seep is not the only contribution of DIC. This part of the contribution demands more study to differentiate.

Abstract

Integrated solar energy storage and charging power station is gradually being promoted and applied because of their energy-saving, environmental protection, and excellent economic characteristics. In this paper, the cost-benefit modeling of integrated solar energy storage and charging power station is carried out considering the multiple benefits of energy storage. The model takes five factors into account, e.g., power station charging service, electricity charge, capacity charge, energy storage cycle cost and network loss cost. Its goal is to improve the economy of the power station by comprehensively considering reducing the cost of electricity, extending the life of energy storage equipment, and reducing the loss of electric energy. The effectiveness of the proposed method is proved by an example analysis, and it is found that the capacity benefit and electricity benefit can be balanced by reasonable optimal scheduling.

Abstract

Under the background of “carbon neutral”, the new energy storage represented by electrochemical energy storage is developing rapidly. Shenzhen, as an electrochemical advantageous industrial city of China, has a strong industrial foundation and technical independence. This paper takes Shenzhen as an example, through technical analysis, policy analysis and patent analysis, the status quo and challenges and opportunities of Shenzhen energy storage systems are deeply analyzed to provide a reference for the future development of new energy storage system in China.

Abstract

This study developed a hybrid louver lighting system that combines daylighting using solar energy and LED to solve the problems of high electric consumption and heat load of LED used in vertical farm. This system can control the LED lamp according to the intensity of daylighting that changes in real time to meet the set target PPFD. The louver is composed of transparent vacuum glass and diffuser, and multiple horizontal slats installed air cavity in louver effectively transmit the daylighting to the indoor and distribute the required PPFD. The vent applied to the upper and lower of the louver discharges unnecessary heat generated from the LED lamp to the outdoor in summer and utilizes the required heat indoor in winter. The electric consumption of the hybrid louver lighting system and the indoor temperature due to the heat load were evaluated using a full scale mock-up facility.

Abstract

Accurate load forecasting is crucial for efficient energy management, particularly due to the increasing adoption of renewable energy sources and the growing need for grid stability. This study introduces an autoregressive transformer encoder-decoder model that advances residential electricity load prediction and synthesis. Unlike the conventional models, our proposed model utilizes temperature and calendar information as primary inputs and can generate an electricity load without relying on the past load. This model’s design is rooted in the observation that temperature and calendar context sufficiently capture residential electricity consumption dynamics. By excluding the reliance on past load data, our model is able to synthesize electricity load for arbitrary temperature and calendar scenarios in addition to effectively predicting the future load. This synthesizing capability is invaluable for optimizing the planning and operation of residential energy systems, including photovoltaic systems and batteries. Experimental results using real-world electricity load data of residential buildings demonstrate the effectiveness of our transformer-based model, offering a robust framework for future load prediction and synthesis under varying conditions.

Abstract

As an emerging micro- or small-scale energy conversion technology, free-piston engine generator (FPEG) features the advantages of high efficiency, high volumetric power density, and multi-fuel adaptability potential. To solve the issues that the previous FPEG prototype (developed in the authors’ group) had, in this work, we developed a new FPEG prototype with a compact structure that is capable of operating at a higher frequency. Some preliminary experimental results are obtained from the new prototype. The results indicate that there is no significant operation inconsistency between the two free-piston engines, and achieving continuous combustion in both of the engines will be the subject of future research.

Abstract

This research aims to propose sustainable urban development strategies that harmonise decarbonisation with urban residents’ well-being through Geographic Information Systems (GIS) scenario analysis. Modern urbanisation enhances quality of life but escalates energy consumption, greenhouse gas emissions, and environmental degradation. In urban areas, CO2 emissions from transportation, industrial activities, and households significantly contribute to global warming, while overcrowding deteriorates living conditions and impacts health and well-being.
Decarbonisation is essential to address these environmental issues, but enhancing urban well-being is equally crucial. This study utilises GIS to explore urban development pathways that balance decarbonisation and well-being. Scenarios evaluate the impact of increased green spaces on CO2 absorption, enhanced public transportation on reducing private vehicle usage, and energy-efficient buildings on lowering energy consumption and emissions.
The study includes practical interventions in The Nihonbashi Initiative Project, comparing sustainable measures such as greening projects, energy efficiency improvements, and well-being initiatives against a control office floor. Spatial analyses assess the environmental and well-being impacts, providing empirical data for sustainable urban planning. Building owners in the area collaborate to promote energy management, with an expected energy savings effect of approximately 10%. This collaborative effort aims to create a model for sustainable urban development that balances decarbonisation and resident well-being.
Expected outcomes throughout the investigation include the development of a new model for sustainable urban development that integrates renewable energy, green space enhancement, and low-carbon transportation. The study contributes a novel framework for GIS-based scenario analysis, advancing the understanding of achieving decarbonisation and well-being concurrently in urban environments, bridging theory and practice with evidence-based insights.

Abstract

As investment in the construction of UGS increases around the world, the operational efficiency and safety of UGS have attracted attention, which includes some problems that need to be faced. Currently, the dissolution of cushion gas in reservoir fluids has been little discussed. However, with the promotion of the use of CO2 cushion gas, the impact of dissolution is one of the problems that has to be faced. We aim to show with this study that the dissolved consumption of cushion gas is critical as this affects the total gas volume. We considered two different scenario models, with and without chemical capture reactions. Through simulation, it was found that the increase in pressure increased the solubility of CO2, but the total dissolved amount decreased. The increase in reservoir temperature reduces the solubility of CO2 and also leads to a decrease in the total dissolved amount. In addition, chemical capture will affect the solubility of CO2 to a certain extent, and its extent is related to pressure. A reduction in dissolved gas means an increase in free gas, potentially making the reservoir more sensitive to gas injection pressure. Therefore, chemical capture and hydration dissolution factors become key considerations in cushion gas design and UGS operation. This research helps promote efficient operation of UGS.

Abstract

The kinetic characteristics of methane conversion to hydrates in deep-sea cold seep sediments have a significant impact on hydrate accumulation and resource distribution. Consequently, they have important implications for the assessment of carbon sequestration and hydrate extraction potential. Nevertheless, the impact of clay minerals in cold seep sediments on the kinetics of methane hydrate formation in sandy environments remains uncertain. To investigate this, quartz sand was employed to simulate a sandy environment, allowing the effect of varying levels of calcium-based montmorillonite on the kinetics of methane hydrate formation in porous media to be studied. The results demonstrated that the initial rate of hydrate formation increased, while the final methane consumption decreased as the mass fraction of calcium-based montmorillonite (MMT) increased in comparison to the pure quartz sand system. The observed effects were mainly attributed to the high specific surface area of MMT and its capacity for adsorbing water. This work contributes to our understanding of the mechanism by which calcium-based montmorillonite affects the transformation of hydrates at varying water contents. Furthermore, it provides scientific support for the estimation of marine carbon sink capacity and carbon sequestration.