| 1. |
- Zhang, Haoran, et al.
(författare)
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1.6 Million transactions replicate distributed PV market slowdown by COVID-19 lockdown
- 2021
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Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 283
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Tidskriftsartikel (refereegranskat)abstract
- Solar PV has seen a spectacular market development in recent years and has become a cost competitive source of electricity in many parts of the world. Yet, prospective observations show that the coronavirus pandemic could impact renewable energy projects, especially in the distributed market. Tracking and attributing the economic footprint of COVID-19 lockdowns in the photovoltaic sector poses a significant research challenge. Based on millions of financial transaction records and 44 thousand photovoltaic installation records, we tracked the spatiotemporal sale network of the distributed photovoltaic market and explored the extent of market slowdown. We found that a two-month lockdown duration can be assessed as a high-risk threshold value. When the lockdown duration exceeds the threshold value, the monthly value-added loss reaches 67.7%, and emission reduction capacity is cut by 64.2% over the whole year. We show that risks of a slowdown in PV deployment due to COVID19 lockdowns can be mitigated by comprehensive incentive strategies for the distributed PV market amid market uncertainties.
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| 2. |
- Ding, Jing, et al.
(författare)
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Molecular dynamics simulations of the local structures and thermodynamic properties on molten alkali carbonate K2CO3
- 2018
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 220, s. 536-544
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Tidskriftsartikel (refereegranskat)abstract
- Molten carbonate salts have received particular attention for high-temperature thermal energy storage and heat Molecular dynamics simulation transfer applications due to desirable thermal characteristics, such as wide operating temperature range, low Molten alkali carbonates causticity and excellent thermal stability. In this study, molecular dynamics (MD) simulations were performed Local structures on molten alkali carbonate K2CO3 based on an effective pair potential model, a Born-Mayer type combined with Thermodynamic properties a Coulomb term. The radial distribution functions (RDF) and coordination number curves of the molten salt were characterized to explore the temperature dependences of macroscopic properties from microscopic view. The results suggest that the distance between K2CO3 particles is getting larger with temperature increasing, resulting in the increase of molar volume and the diminished ability of resistance to shear deformation and heat transfer by vibration between ions. Besides, it can be concluded that the structure of CO32- is inferred reasonably to be ortho-triangular pyramid from the comprehensive analysis of local structures including the angular distribution functions (ADF). Moreover, the thermodynamic properties were simulated in detail from 1200 to 1600 K including the density, thermal expansion coefficient, specific heat capacity, sheer viscosity, thermal conductivity and ion self-diffusion coefficient, which was hard to be measured from experiments under high-temperature extreme conditions, All the simulation results are in satisfactory agreement with available experimental data with high accuracy, and the minimum simulation error is as low as 1.42%.
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| 3. |
- Jiang, M., et al.
(författare)
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National level assessment of using existing airport infrastructures for photovoltaic deployment
- 2021
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 298
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Tidskriftsartikel (refereegranskat)abstract
- The airport is one of the most fundamental infrastructures in our society, its terminal buildings and parking lots are ideal locations for photovoltaic (PV) installation. The future trend of the electrification of the aviation and automobile industries will increase the electricity demand at airports calls for the integration of PV systems with airport infrastructure. Understanding the benefits of airport PV systems is crucial for the stakeholders including investors, project developers and policymakers to promote PV sector development. Thus, evaluation of the PV potential and relevant economic performance of airports is essential. Combined with the geographic information system (GIS), the PV potential of the civil airports in China is investigated. The results show that potential PV capacity of China's 239 civil airports reaches up to 2.50 GW. The annual electricity demand of the aviation industry in 8 provinces can be self-satisfied via airport PV generation. Detailed economic analysis shows that all airport PV systems are profitable through appropriate investment and operation strategies. © 2021
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| 4. |
- Jiang, Mingkun, et al.
(författare)
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Using Existing Infrastructure to Realize Low-Cost and Flexible Photovoltaic Power Generation in Areas with High-Power Demand in China
- 2020
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Ingår i: iScience. - : Elsevier Inc.. - 2589-0042. ; 23:12
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Tidskriftsartikel (refereegranskat)abstract
- Energy Policy; Energy Resources; Energy Systems; Energy Management © 2020 This study develops a new concept involving using the existing infrastructure for photovoltaic (PV) generation to reduce the costs associated with increased land use and to avoid curtailment due to the mismatch between power supply and demand. We establish a method to estimate the technological potential and economic performance of the PV systems deployed in coal-fired power plants in China. The potential capacity of the examined 1,082 units in China reaches 4 GWe, which is equivalent to 32% of China's newly installed distributed PV capacity in 2019. A total of 87% of PV systems achieve plant-side grid parity compared with desulfurized coal benchmark electricity prices. To the best of our knowledge, this is the first study that investigates the use of rooftops and coal storage sheds in power plants to facilitate low-cost, flexible PV power generation, thus opening a new channel for future PV generation development.
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| 5. |
- Li, Y., et al.
(författare)
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A Decision-making Framework for the Site Selection of PV Deployment along High-speed Railway
- 2021
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Ingår i: Energy Proceedings. - : Scanditale AB.
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Konferensbidrag (refereegranskat)abstract
- The development of photovoltaic industry can effectively alleviate the energy crisis and environmental pollution. The deployment of photovoltaic power stations along the high-speed railway is a new mode combining photovoltaic new energy with infrastructure. This paper constructs a comprehensive decision-making framework for the site selection of PV power station along high-speed railway combining the subjective method and the objective method. A scientific and reasonable evaluation index system comprehensively considering multiple factors is constructed in this framework. Analytic hierarchy process and Entropy weight method are combined to determine the weight of every index, which combines the expert knowledge and data information effectively, relatively reducing systematic error and random error. Grey relational analysis is used to choose scheme among several alternatives, which greatly deal with the strong grey correlations among indexes. The framework established in this paper is used to select PV power stations along the Beijing-Shanghai high-speed railway, which also verifies the effectiveness of the framework.
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| 6. |
- Li, Y., et al.
(författare)
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CO2 emissions reduction by switching conference online : Uncertainty analysis of global air travel
- 2020
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Ingår i: Energy Proceedings. - : Scanditale AB.
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Konferensbidrag (refereegranskat)abstract
- Ideally, primary data collection is recommended for every life cycle assessment (LCA) study. However, due to limited availability or accessibility to first-hand data, related sources of secondary data can be a good alternative in practice. In this work, the uncertainty of using secondary data from the Ecoinvent Life Cycle Inventory (LCI) database is illustrated with an LCA case study on global air travel. Inside the database, both parameters’ basic uncertainty from measurements and additional uncertainty from data quality criteria are considered with the pedigree approach. The effect of updated pedigree matrix coefficients is also evaluated. Furthermore, the sensitivity with respect to the choice of system boundary is studied with a hotspot analysis for air travel. Outside the database, the uncertainty associated with mapping real world processes to those available in the database is analyzed. In particular, the influence of flight specific parameters, e.g. plane type and occupancy level, is assessed by comparing the International Civil Aviation Organizations (ICAO) carbon emissions calculator with database calculations. The results show that emissions calculated by ICAO generally lie on the lower end of confidence intervals provided by uncertainty analysis of the database, especially for very long-haul flights. Finally, for the LCA case study on air travel, a two-step method combining the advantages of both the ICAO calculator and the Ecoinvent database is proposed.
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| 7. |
- Li, Y., et al.
(författare)
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Study on Environmental and Economic Benefits of Photovoltaic integration with Iron and Steel Plants in Hebei Province
- 2021
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Ingår i: Energy Proceedings. - : Scanditale AB.
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Konferensbidrag (refereegranskat)abstract
- Under the strategic goal of "peak carbon dioxide emissions and carbon neutrality" in China, industries with high energy consumption and high pollution, such as iron and steel plants, are facing great pressure of energy conservation and emission reduction, and are in urgent need of green and low-carbon transformation. In this paper, 46 iron and steel plants in Hebei province are taken as examples. GIS spatial analysis and environmental emission list method are used to build a comprehensive evaluation model of rooftop photovoltaic, and to calculate the technical potential, energy saving and emission reduction benefits and economic feasibility of deploying rooftop photovoltaic in iron and steel plants. Finally, carbon trading mechanism is introduced to analyze its impact on the carbon trading market. It is found that 46 iron and steel plants save 216,700 tons of standard coal, reduce 144,700 tons of CO2 emissions and reduce 1,500 tons of SO2, NOX, PM and other air pollutants every year. The economic benefit of power generation self-use mode is greater than that of grid-fed mode, with an average return on investment of 140% and a payback period of 5.5 years. The results verify that rooftop photovoltaic in iron and steel plants has dual benefits of energy saving and emission reduction and economy, and this data can provide a feasible path for iron and steel plants to use photovoltaic for green and low-carbon transformation.
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| 8. |
- Sun, H., et al.
(författare)
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Methane hydrate re-formation and blockage mechanism in a pore-level water-gas flow process
- 2023
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Ingår i: Energy. - : Elsevier Ltd. - 0360-5442 .- 1873-6785. ; 263
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Tidskriftsartikel (refereegranskat)abstract
- Hydrate re-formation increases blockage risk and further reduces gas production efficiency. Considering the huge water production and gas migration, it is essential to determine the key parameters that control hydrate re-formation and blockage in the two-phase flow process. However, little research reveals the mechanism of hydrate re-formation in the water-dominated two-phase flow system. In this study, two-phase flow in hydrate sediment is simulated by controlling the water-gas flow rate, and the effect of effective sectional velocity on hydrate re-formation characteristics is analyzed. The experimental results showed that temperature and pressure followed a three-stage change trend in the water-dominated two-phase flow process: including hydrate re-formation induction stage I, mass hydrate re-formation and agglomeration stage II, and pore gas consumption stage III. Moreover, a lower effective sectional velocity of water (WESV) would reduce the gas concentration gradient between water and hydrate to enhance the hydrate re-formation process. Meanwhile, the gas phase impeded the mass transfer on the water-hydrate interface and acted as the nucleation site to promote hydrate re-formation. Furthermore, it was noticed that the relationship between the onset time of flow blockage and WESV was linearly positive, however, the amount of hydrate re-formation reduced with increasing WESV.
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