| 1. |
- Ji, Haoran, et al.
(författare)
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Peer-to-Peer Electricity Trading of Interconnected Flexible Distribution Networks Based on Distributed Ledger
- 2022
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Ingår i: IEEE Transactions on Industrial Informatics. - : IEEE Computer Society. - 1551-3203 .- 1941-0050. ; 18:9, s. 5949-5960
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Tidskriftsartikel (refereegranskat)abstract
- The condition of power imbalance in flexible distribution networks (FDNs) is deteriorated due to the high penetration of distributed generators (DGs). Through peer-to-peer (P2P) electricity trading, multiple regions interconnected by soft open points (SOPs) can flexibly exchange power to alleviate power imbalance. As the physical foundation of P2P transactions, SOP regulation guarantees accurate instruction execution. Besides, smart contracts based on distributed ledger technology (DLT) facilitate highly credible P2P transactions. Oriented for the economic operation of interconnected FDNs, this paper proposes a DLT-based P2P electricity trading method based on intelligent SOP regulation. First, a smart contract is designed for P2P transactions of FDNs, in which trading solutions are automatically settled with a modified highest combined offer (HCO) principle. Then, a trading platform is built for the P2P electricity trading of interconnected FDNs. Finally, the effectiveness of the proposed method is verified on a practical FDN with four-terminal SOPs in Tianjin.
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| 2. |
- Zhang, Jie, et al.
(författare)
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The water-food-energy nexus optimization approach to combat agricultural drought : a case study in the United States
- 2018
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Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 227, s. 449-464
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Tidskriftsartikel (refereegranskat)abstract
- The frequent recent drought events in the Great Plains of United States have led to significant crop yield reductions and crop price surges. Using an integrated water-food-energy nexus modelling and optimization approach, this study laid the basis for developing an effective agricultural drought management system by combining real-time drought monitoring with real-time irrigation management. The proposed water-food-energy simulation and optimization method is spatially explicit and was applied to one major corn region in Nebraska. The crop simulations, validated with yield statistics, showed that a drought year like 2012 can potentially reduce the corn yield by 50% as compared to a wet year like 2009. The simulation results show that irrigation can play a key role in halting crop losses due to drought and in sustaining high yields of up to 20 t/ha. Nevertheless, the water-food-energy relationship shows that significant investments on water and energy are required to limit the negative effects of drought. The multi-criteria optimization problem developed in this study shows that the optimal crop yield does not necessarily correspond to the maximum yield, resulting in potential water and energy savings.
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| 3. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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A gridded optimization model for photovoltaic applications
- 2020
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Ingår i: Solar Energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-092X .- 1471-1257. ; 202, s. 465-484
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Tidskriftsartikel (refereegranskat)abstract
- This study aims to develop a gridded optimization model for studying photovoltaic applications in Nordic countries. The model uses the spatial and temporal data generated by the mesoscale models STRANG and MESAN developed by the Swedish Meteorological and Hydrological Institute. The model is developed based on the comparison between five irradiance databases, three decomposition models, two transposition models, and two photovoltaic models. Several techno-economic and environmental aspects of photovoltaic systems and photovoltaic systems integrated with batteries are investigated from a spatial perspective. CM SAF SARAH-2, Engerer2, and Perez1990 have shown the best performances among the irradiance databases, and decomposition and transposition models, respectively. STRANG resulted in the second-best irradiance database to be used in Sweden for photovoltaic applications when comparing hourly global horizontal irradiance with weather station data. The developed model can be employed for carrying out further detailed gridded techno-economic assessments of photovoltaic applications and energy systems in general in Nordic countries. The model structure is generic and can be applied to every gridded climatological database worldwide.
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| 4. |
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| 5. |
- Campana, Pietro Elia, 1984-, et al.
(författare)
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Towards an operational irrigation management system for Sweden with a water–food–energy nexus perspective
- 2022
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Ingår i: Agricultural Water Management. - : Elsevier B.V.. - 0378-3774 .- 1873-2283. ; 271
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Tidskriftsartikel (refereegranskat)abstract
- The 2018 drought in Sweden prompted questions about climate-adaptation and -mitigation measures – especially in the agricultural sector, which suffered the most. This study applies a water–food–energy nexus modelling framework to evaluate drought impacts on irrigation and agriculture in Sweden using 2018 and 2019 as case studies. A previous water–food–energy nexus model was updated to facilitate an investigation of the benefits of data-driven irrigation scheduling as compared to existing irrigation guidelines. Moreover, the benefits of assimilating earth observation data in the crop model have been explored. The assimilation of leaf area index data from the Copernicus Global Land Service improves the crop yield estimation as compared to default crop model parameters. The results show that the irrigation water productivities of the proposed model are measurably improved compared to conventional and static irrigation guidelines for both 2018 and 2019. This is mostly due to the advantage of the proposed model in providing evapotranspiration in cultural condition (ETc)-driven guidelines by using spatially explicit data generated by mesoscale models from the Swedish Meteorological and Hydrological Institute. During the drought year 2018, the developed model showed no irrigation water savings as compared to irrigation scenarios based on conventional irrigation guidelines. Nevertheless, the crop yield increase from the proposed irrigation management system varied between 10% and 60% as compared to conventional irrigation scenarios. During a normal year, the proposed irrigation management system leads to significant water savings as compared to conventional irrigation guidelines. The modelling results show that temperature stress during the 2018 drought also played a key role in reducing crop yields, with yield reductions of up to 30%. From a water–food–energy nexus, this motivates the implementation of new technologies to reduce water and temperature stress to mitigate likely negative effects of climate change and extremes. By using an open-source package for Google Earth®, a demonstrator of cost-effective visualization platform is developed for helping farmers, and water- and energy-management agencies to better understand the connections between water and energy use, and food production. This can be significant, especially during the occurrence of extreme events, but also to adapt to the negative effects on agricultural production of climate changes.
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| 6. |
- Elkadeem, M. R., et al.
(författare)
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Agrivoltaic systems potentials in Sweden : A geospatial-assisted multi-criteria analysis
- 2024
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 356
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Tidskriftsartikel (refereegranskat)abstract
- Agrivoltaic systems represent an intelligent solution combining electricity production from solar photovoltaic technology with agricultural production to avoid land use conflicts. Geographic Information System technologies can support the implementation and spread of agrivoltaic systems by identifying the most suitable areas using useful spatially explicit information concerning techno-agro-socio-economic criteria. In this study, we have developed a procedure to identify and classify suitable areas for agrivoltaic systems in Sweden. An Ordinal Priority Approach based multi-criteria decision-making algorithm is established to calculate the weights of the selected evaluation criteria through expert interviews. The land use data refers to the Corine Land Cover 2018 product. The results show that about 8.6% of the Swedish territory, approximately 38,485 km2, is suitable for installing agrivoltaic systems. Among this area, about 0.2% is classified as “excellent”, about 15% as “very good”, about 72% as “good”, about 13% as “moderate”, and about 0.1% as “poor”. Most “excellent”-classified areas are in Kalmar, Skåne, and Gotland. In contrast, most “very good” sites are in Skåne, Kalmar, and Östergötland. By deploying vertically mounted agrivoltaic systems with bifacial photovoltaic modules, the total potential installed capacity for “excellent” areas is about 2.5 GWp, while for areas classified “excellent” and “very good” is about 221 GWp. The total “excellent” areas can potentially supply about 2.4 TWh of electricity against the electricity consumption in 2021 of about 143 TWh. On the other hand, the land classified as “excellent” and “very good” could potentially provide about 207 TWh. The County of Västra Götaland shows the greatest potentials in terms of total potential electricity supply from agrivoltaic systems with about 227 TWh, followed by Skåne with a total potential of 206 TWh.
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| 7. |
- Guo, Shaopeng, et al.
(författare)
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Numerical study of the improvement of an indirect contact mobilized thermal energy storage container
- 2016
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 161, s. 476-486
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the melting and solidification behaviours of the PCM in an indirect contact mobilized thermal energy storage (ICM-TES) container were numerically investigated to facilitate the further understanding of the phase change mechanism in the container. A 2D model was built based on the simplification and assumptions of experiments, which were validated by comparing the results of computations and measurements. Then, three options, i.e., a high thermal conductivity material (expanded graphite) addition, the tube diameter and the adjustment of the internal structure of the container and fin installation, were analyzed to seek effective approaches for the improvement of the ICM-TES performance. The results show that the optimal parameters of the three options are 10 vol.% (expanded graphite proportion), 22 mm (tube diameter) and 0.468 m(2) (fin area). When the three options are applied simultaneously, the charging time is reduced by approximately 74% and the discharging time by 67%.
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| 8. |
- Zhang, Haoran, et al.
(författare)
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Urban power load profiles under ageing transition integrated with future EVs charging
- 2021
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Ingår i: Advances in Applied Energy. - : Elsevier BV. - 2666-7924. ; 1, s. 100007-100007
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Tidskriftsartikel (refereegranskat)abstract
- Understanding ageing transition caused fine-grained changes of electricity profile is the significant insight for coping with future threatens in grid flexibility management. The research gaps for the hourly-basis knowledge exist due to challenges in microanalysis on user-side behavior. Based on billions of users’ behavior data, we investigated the changes on the load profiles due to population aging. We found that owing to ageing transition, the participation population in high electricity-density activities decreases by about 8%. The corresponding shift in driving behavior rises the 14% difference between peak charging load and valley. We concluded that population aging will dramatically change both the magnitude and shape of future dynamic-load profiles. Therefore, we further suggested a new solution with comprehensive and quantitative management for PVs development and the smart charging market with smooth operation of the grid in coupling the potential challenges caused by the ageing issue.
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