Abstract

An optimization model is used to design a hydrogen production system under different constraints for CO2 emissions, focusing on Japan as case of study. Two scenarios were considered: Base scenario, focusing on minimizing cost; and WEC scenario focusing on balancing energy use, water use and CO2 emissions. Domestic natural gas alone is not enough to produce 1 Mt-H2/year and electrolysis is used for all CO2 intensities. For low CO2 intensities, Base scenario uses hydroelectricity and geothermal electricity; while WEC scenario uses solar electricity and wind electricity. Zero-emission hydrogen production needs installed capacities for electrolyzers of 8.45 and 30.3 GW in Base and WEC scenarios, respectively.

Abstract

This work proposes a combined cycle, a gas turbine power generation system and a CO2 cycle power generation system built on the basis of the Ericsson cycle. In this paper, the structure of the combined cycle system is firstly constructed, the temperature-entropy diagram of the gas-CO2 system is plotted, the simulation model is built on the simulation software platform and its accuracy and validity are verified, and the effects of CO2 flow rate, pressure ratio, ambient temperature and gas turbine loading rate on the power generation efficiency and primary energy utilization efficiency of the combined system are studied and analyzed. The simulation results have led to the optimal operating conditions of the gas-CO2 combined cycle, which provides a new technical idea for the future utilization of waste heat energy.

Abstract

In this study, a microcosm experiment for 120 days exposure of microplastics (MPs) on cold seep sediment was conducted. The results showed that different types and doses of MPs addition negatively affected the anaerobic oxidation of CH4. The CH4 oxidation rates with 0.05 % PA and PET addition were only account for approximately 33% of that for the biotic control group. MPs addition did not significantly influence the archaeal community structures but caused a redistribution of bacterial community compositions. The addition of PA, PE, and PET could significantly increase the relative abundance of Desulfobacterota and made Caldatribacteriota almost undetectable. By the present study, we can have a preliminary understanding of the effects of microplastics on anaerobic oxidation of CH4 and prokaryotic communities in the cold seep sediment.

Abstract

In urban driving scenarios, Fuel cell hybrid vehicle (FCHV) needs to face mixed driving scenarios while taking into account multiple objectives such as traffic safety, driving comfort and energy efficiency. The trade-off problem of multi-objective co-optimization is ignored for cruise control and energy management strategy (EMS), which are easily affected by the predefined driving cycle constraints. In this paper, the integrated control framework of cooperative adaptive cruise control (CACC) and EMS is established, and the chaotic multi-objective particle swarm optimization algorithm (CMOPSO) is adopted to optimize the control parameters of the integrated framework. The results show that compared with the control strategy optimized based on WLTC conditions, it can reduce the integrated energy consumption (4.1%) and the following safety (58.1%) while meeting the driving comfort requirements. Compared with the weighted sum method, the proposed method can achieve the balance of multiple optimization objectives.

Abstract

Anaerobic oxidation of methane (AOM) coupled with sulfate reduction (SR) is an important process in cold- seep ecosystems to prevent methane emitted from the seafloor to the atmosphere. However, how the temperature and sulfate in seep habitats drive the SR- AOM process and further affect the methane cycles remains unknown. We simulated the habitat differences in sulfate and temperature using a high-pressure bioreactor system with a fed-batch mode for in vitro incubation of seep sediment. We found that SR-AOM was significantly affected by increased temperature (15 °C). The AOM activity was increased by sulfate supply (+15 mM), even at a low temperature (8 °C). Our findings provide a new insight into the methane budget in cold seeps.

Abstract

This study presents an efficient framework for locating and classifying faulty Photovoltaic (PV) panels from Unmanned Aerial Vehicle (UAV) thermal infrared images. First, aerial triangulation based on photogrammetry is used to obtain thermal infrared images of PV panels with coordinate information, then, individual PV panels are segmented based on High-Resolution Network (HRNetV2-W32), finally, the panels are fed into residual net (ResNet-50) to classify the fault types. Results showed that the panel segmentation accuracy reaches 98.54%, the classification accuracy reaches 88.74%, and the coordinate error is better than 0.033m.

Abstract

In this study, Yongren County, Yunnan Province was selected as the study case, and a photovoltaic (PV) power potential assessment system based on Geographic Information System (GIS) and Multi-Criteria Decision Making (MCDM) method was used to calculate the PV power potential in mountainous areas and to estimate the levelized cost of electricity for PV power generation in mountainous areas. The results show that the ordinal priority approach (OPA)-MCDM is the best among the four different multi-criteria decision methods, and the selected optimal PV construction area fits well with the existing PV facilities, which demonstrates the effectiveness of the proposed method. The PV power generation potential is about 7861.953 million kwh, and the levelized cost of electricity is 0.3963 RMB/kWh. The estimated annual power generation capacity can meet the social power demand of Chuxiong Prefecture.

Abstract

Energy over-consumption, water shortage, and intensive carbon dioxide (CO2) emissions are the three vital environmental issues in the context of global climate change. China is promoting the coordinated development of the Beijing-Tianjin-Hebei region as a national strategy project; this makes it more urgent to integrate water conservation, energy structure transition, and CO2 reduction within process of high-quality development and green transformation.
This study uncovered energy-water nexus patterns within Beijing-Tianjin-Hebei, and carried out dynamic simulation research from the perspective of industrial synergy to facilitate optimization roadmaps. A Beijing-Tianjin-Hebei Energy-Water Nexus Simulator is innovatively developed, which is based on the theories of input and output, system dynamics, and dynamic multi-object planning; and is committed to revealing the regional energy and water consumption, carbon emission, and economic system developing trends. Through policy mix including industrial structure adjustment, collaborative development, and environmental efficiency improvement, multiple scenarios’ comparison can provide the optimization path of Beijing-Tianjin-Hebei during 2020-2035 under overall control of muti-regional energy-water and carbon targets.
The dynamic optimization decision-making model and policy simulator developed in this study is expected to be widely used in the sustainable development planning of Chinese inter-regional economy, and provide scientific support for regional coordinated development and ecological civilization construction.

Abstract

As the world’s largest energy consumer and carbon emitter, China accounted for 26.5% of global energy consumption and 31% of carbon dioxide (CO2) emissions in 2021; Shandong province as a heavy industry intensive base in China, confronted with the most imminent task of energy conservation and emission reduction. With pursue on “carbon peak and neutrality”, Shandong province need to transfer the high-carbon energy system fundamentally to accomplish the high-quality development. To explore the timetable and roadmap of carbon peak in Shandong province, this research integrates the input-output modelling, system dynamics and multi-objective programming, and innovatively develops the carbon peak model. The model focuses on energy structure transformation and energy efficiency improvement, including incentives for electrification level increase, renewable power (such as wind and solar power) penetration enhancement, and low-carbon technology investment, combined with industrial restructure. A dynamic simulation measure is adopted to predict Shandong province’s economy-energy-carbon development from 2020 to 2035. The research can provide a useful reference for formulating operatable energy management and carbon peak schemes in industrially developed regions such as Shandong province.

Abstract

To analysis China’s provincial low carbon transition under the carbon neutrality goals, this study developed a provincial energy-environment-economy model (China TIMES-30PE). Under carbon neutrality target, each province has a different pathway for achieving carbon neutrality and requires deep decarbonization of their energy systems, with a dominant share of non-fossil energy sources, increasing electrification rates, growing hydrogen consumption and significantly reducing energy intensity. The mismatch between wind and solar resources and electricity demand has resulted in an increasing transmission volume across provinces. Power transmission from the northwest and southwest regions continues to grow, while some central provinces have transitioned from net electricity suppliers to net users. The eastern provinces continue to receive increasing long-distance power transmission and rely on ultra-high voltage transmission lines as backbone channels.