The morphology of urban areas plays a crucial role in determining solar potential,which directly affects photovoltaic capacity and the achievement of net-zero outcomes.This study focuses on the City of Melbourne to in...The morphology of urban areas plays a crucial role in determining solar potential,which directly affects photovoltaic capacity and the achievement of net-zero outcomes.This study focuses on the City of Melbourne to investigate the utilization of solar energy across different urban densities and proposes optimized morphologies.The analysis encompasses blocks with diverse population densities,examining medium and high-density areas.By utilizing a multi-objective genetic optimization approach,the urban morphology of these blocks is refined.The findings indicate that low-density blocks exhibit photovoltaic potential ranging from 1 to 6.6 times their total energy consumption.Medium and high-density blocks achieve photovoltaic potential levels approximately equivalent to 40%-85%of their overall energy consumption.Moreover,significant variations in photovoltaic potential are observed among different urban forms within medium and high-density blocks.An“elevated corners with central valley”prototype is proposed as an effective approach,enhancing the overall photovoltaic potential by approximately 14%.This study introduces novel analytical concepts,shedding light on the intricate relationship between urban morphologies and photovoltaic potential.展开更多
Battery energy storage systems(BESSs)serve a crucial role in balancing energy fluctuations and reducing carbon emissions in net-zero power systems.However,the efficiency and cost performance have remained significant ...Battery energy storage systems(BESSs)serve a crucial role in balancing energy fluctuations and reducing carbon emissions in net-zero power systems.However,the efficiency and cost performance have remained significant challenges,which hinders the widespread adoption and development of BESSs.To address these challenges,this paper proposes a real-time energy management scheme that considers the involvement of prosumers to support net-zero power systems.The scheme is based on two shared energy storage models,referred to as energy storage sale model and power line lease model.The energy storage sale model balances real-time power deviations by energy interaction with the goal of minimizing system costs while generating revenue for shared energy storage providers(ESPs).Additionally,power line lease model supports peer-to-peer(P2P)power trading among prosumers through the power lines laid by ESPs to connect each prosumer.This model allows ESP to earn profits from the use of power lines while balancing power deviations and better consuming renewable energy.Experimental results validate the effectiveness of the proposed scheme,ensuring stable power supply for net-zero power systems and providing benefits for both the ESP and prosumers.展开更多
To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where ...To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where the impact of battery energy storage system(BESS)flexibility is considered.First,we introduce distributionally robust chance constraints on network security and energy/carbon net-zero requirements,which form the upper and lower bounds of the feasible region.Then,the formulation and solution of the feasible region is proposed.The resulting analytical expression is a set of linear inequalities,illustrating that the feasible region is a polyhedron in a high-dimensional space.A procedure is designed to verify and adjust the feasible region,ensuring that it satisfies network loss constraints under alternating current(AC)power flow.Case studies on the 4-bus system,the IEEE 33-bus system,and the IEEE 123-bus system verify the effectiveness of the proposed method.It is demonstrated that the proposed method fully captures the spatio-temporal coupling relationship among PVs,loads,and BESSs,while also quantifying the impact of this relationship on the boundaries of the feasible region.展开更多
To begin with, rating systems are a beneficial tool in determining the efficiency of a building’s ability to utilise its resources effectively. In this study, the two elements under comparison are the Building Rating...To begin with, rating systems are a beneficial tool in determining the efficiency of a building’s ability to utilise its resources effectively. In this study, the two elements under comparison are the Building Rating Systems (BRSs) and Occupant Rating Systems (ORSs). The main objective of this paper is to be able to examine the most commonly applied international and national BRS and ORS and, based on that, discover the possibility of developing an integration of both the BRS and ORS into one rating system. Quite simply, a BRS is a method by which buildings are assessed and given a score based on numerous features such as the efficiency of each of the services, total energy consumption, and alternate options of consumption. There are various BRSs that are implemented globally, each with its own set of criteria and specifications. Thus, based on the analysis of the benefits and drawbacks of both types of rating systems, it could be deduced that a well-rounded rating system with all technical and non-technical aspects combined would be beneficial to both the efficiency of the building as well as the building occupants’ health and well-being.展开更多
Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consump...Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consumption by modulating the transmitted solar radiation.However,previous studies mainly focused on the material development and performance characterization,lack of comfort assessment and energy saving potential of its application to buildings.To address this issue,an adjustable semi-transparent photovoltaic(ATPV)window which integrates CdTe-based photovoltaic and WO3-based electrochromic,was taken as the research object,and a novel rule-based control strategy taking the beam solar radiation luminous efficacy(CtrlEff)as decision variable was proposed for the first time.The ATPV window model was established in WINDOW software based on the measured data,and then it was exported to integrated with a medium office building model in EnergyPlus for performance evaluation including the visual comfort,thermal comfort,net energy consumption,and net-zero energy ratio.The results of a case study in Changsha(E 112°,N 28°)indicated that the ATPV window under the CtrlEff strategy can effectively reduce the southward and westward intolerable glare by 86.9%and 94.9%,respectively,and increase the thermal comfort hours by 5%and 2%,compared to the Low-E window.Furthermore,the net-zero energy consumption can be decreased by 58.7%,65.7%,64.1%,and 53.8%for south,west,east,and north orientations,and the corresponding net-zero energy ratios are 65.1%,54.6%,62.7%,and 61.6%,respectively.The findings of this study provide new strategies for the control and optimization of the adjustable window.展开更多
Net-zero energy buildings and communities, which are receiving increasing interest, and the role of energy storage in them, are described. A net-zero energy building or community is defined as one that, in an average ...Net-zero energy buildings and communities, which are receiving increasing interest, and the role of energy storage in them, are described. A net-zero energy building or community is defined as one that, in an average year, produces as much energy from renewable energy as it consumes. Net-zero energy buildings and communities and the manner in which energy sustainability is facilitated by them are described and examples are given. Also, energy storage is discussed and the role and importance of energy storage as part of net-zero buildings and communities are explained. The NSERC Smart Net-zero Energy Buildings Research Network, a major Canadian research effort in smart net-zero energy buildings and communities, is described.展开更多
Growing energy demand,diminishing fossil fuel reserves and geopolitical tensions are serious concerns for any country’s energy strategy and security.These factors have a greater impact on developing countries,as many...Growing energy demand,diminishing fossil fuel reserves and geopolitical tensions are serious concerns for any country’s energy strategy and security.These factors have a greater impact on developing countries,as many of them rely largely on traditional energy resources.Cleaner energy generation is the viable alternative for mitigating these problems,as well as achieving energy independ-ence and tackling climate change.The article discusses planning and design optimization of a residential community microgrid based on multiple renewable resources.In particular,the design and techno-economic assessment of a grid-tied hybrid microgrid for meeting the electricity demand of an alluvial region,Urir Char,located in southern Bangladesh,was addressed.Hybrid Optimization of Multiple Energy Resources is used for the evaluation and it is supplemented by a fuzzy-logic-based load profile design strategy.In addition to the analysis,a predictive load-shifting-based demand management is also introduced.Several cases were considered for the studies and,after considering several criteria,a grid-tied system comprising a photovoltaic array,wind turbine and energy storage system was found to be the best fit for powering the loads.The suggested system reduces the life-cycle cost by 18.3%,the levelized cost of energy by 61.9%and emissions by 77.2%when compared with the grid-only option.Along with the microgrid design,cooking emissions and energy categorization were also discussed.展开更多
Rooftop photovoltaic(PV)systems are represented as projected technology to achieve net-zero energy building(NEZB).In this research,a novel energy structure based on rooftop PV with electric-hydrogen-thermal hybrid ene...Rooftop photovoltaic(PV)systems are represented as projected technology to achieve net-zero energy building(NEZB).In this research,a novel energy structure based on rooftop PV with electric-hydrogen-thermal hybrid energy storage is analyzed and optimized to provide electricity and heating load of residential buildings.First,the mathematical model,constraints,objective function,and evaluation indicators are given.Then,the simulation is conducted under the stand-alone condition.The annual return on investment and the levelized cost of energy of the system are 36.37%and 0.1016$/kWh,respectively.Residential building with the proposed system decreases annual carbon emission by 25.5 t.In the third part,simulation analysis under different grid-connected modes shows that building system will obtain better economics when connected to the grid,but the low-carbon performance will be reduced.Finally,the cumulative seasonal impact of the countywide rooftop PV buildings is discussed.The result indicates that the energy structure proposed in this paper can effectively reduce the grid-connected impact on the local grid.This model and optimization method developed in this paper is applicable to different climate zones and can provide management support to the investors of NZEB before the field test.展开更多
Carbon capture and storage will play a crucial role in industrial decarbonisation.However,the current literature presents a large variability in the techno-economic feasibility of CO_(2)capture technologies.Consequent...Carbon capture and storage will play a crucial role in industrial decarbonisation.However,the current literature presents a large variability in the techno-economic feasibility of CO_(2)capture technologies.Consequently,reliable pathways for carbon capture deployment in energyintensive industries are still missing.This work provides a comprehensive review of the state-of-the-art CO_(2)capture technologies for decarbonisation of the iron and steel,cement,petroleum refining,and pulp and paper industries.Amine scrubbing was shown to be the least feasible option,resulting in the average avoided CO_(2)cost of between 62.7∈t_(CO_(2))^(-1)for the pulp and paper and 104.6∈t_(CO_(2))^(-1)for the iron and steel industry.Its average equivalent energy requirement varied between 2.7(iron and steel)and 5.1MJ_(th)·kg_(CO_(2))^(-1)(cement).Retrofits of emerging calcium looping were shown to improve the overall viability of CO_(2)capture for industrial decarbonisation.Calcium looping was shown to result in the average avoided CO_(2)cost of between 32.7(iron and steel)and 42.9(cement).Its average equivalent energy requirement varied between 2.0(iron and steel)and 3.7(pulp and paper).Such performance demonstrated the superiority of calcium looping for industrial decarbonisation.Further work should focus on standardising the techno-economic assessment of technologies for industrial decarbonisation.展开更多
Energy consumption in buildings is considered a significant portion of gross power dissipation, so a great effort is required to design efficient construction. In severe hot weather conditions as Kuwait, energy requir...Energy consumption in buildings is considered a significant portion of gross power dissipation, so a great effort is required to design efficient construction. In severe hot weather conditions as Kuwait, energy required for building cooling and heating results in a huge energy loads and consumption and accordingly high emission rates of carbon dioxide. So, the main purpose of the current work is to convert the existing institutional building to near net-zero energy building (nNZEB) or into a net-zero energy building (NZEB). A combination of integrated high concentrated photovoltaic (HCPV) solar modules and evacuated tube collectors (ETC) are proposed to provide domestic water heating, electricity load as well as cooling consumption of an institutional facility. An equivalent circuit model for single diode is implemented to evaluate triple junction HCPV modules efficiency considering concentration level and temperature effects. A code compatible with TRNSYS subroutines is introduced to optimize evacuated tube collector efficiency. The developed models are validated through comparison with experimental data available from literature. The efficiency of integrated HCPV-ETC unit is optimized by varying the different system parameters. Transient simulation program (TRNSYS) is adapted to determine the performance of various parts of HCPV-ETC system. Furthermore, a theoretical code is introduced to evaluate the environmental effects of the proposed building when integrated with renewable energy systems. The integrated HCPV-ETC fully satisfies the energy required for building lighting and equipment. Utilizing HCPV modules of orientation 25? accomplishes a minimum energy payback time of about 8 years. Integrated solar absorption chiller provides about 64% of the annual air conditioning consumption needed for the studied building. The energy payback period (EPT) or solar cooling system is about 18 years which is significantly larger than that corresponding to HCPV due to the extra expenses of solar absorption system. The li展开更多
The increasing applications of net-zero energy buildings (NZEBs) will lead to more frequent and larger energy interactions with the connected power grid, thereby being able to result in severe grid overvoltage risks. ...The increasing applications of net-zero energy buildings (NZEBs) will lead to more frequent and larger energy interactions with the connected power grid, thereby being able to result in severe grid overvoltage risks. Control optimization has been proven effective to reduce such risks. Existing controls have oversimplified the overvoltage quantification by simply using the aggregated power exchanges to represent the connected grid overvoltages. Ignoring the complex voltage influences among the grid nodes, such oversimplification can easily result in low-accuracy impact evaluations of the NZEB-grid energy interactions, thereby causing non-optimal/unsatisfying overvoltage mitigations. Therefore, this study proposes a novel coordinated control method in which a power-distribution-network model has been adopted for more accurate overvoltage quantification. Meanwhile, the battery operations of individual NZEBs are iteratively coordinated using a sequential optimization approach for achieving the global optimum with substantially reduced computation complexity. For verifications, the proposed coordinated control has been systematically compared with an uncoordinated control and a conventional coordinated control in grid overvoltage minimization. The study results show that the overvoltage improvements can reach 23.5% and 12.3% compared with the uncoordinated control and the conventional coordinated control, respectively. The reasons behind the improvements have also been analyzed in detail. The proposed coordinated control can be used in practice to improve NZEB-clusters’ grid friendliness.展开更多
Reaching carbon neutrality will require investment on an unprecedented scale.Here we suggest that there is an underappreciated opportunity to leverage public funds to mobilize private capital in support of these aims....Reaching carbon neutrality will require investment on an unprecedented scale.Here we suggest that there is an underappreciated opportunity to leverage public funds to mobilize private capital in support of these aims.We illustrate the point using examples from public transit.Although the fuelling energy requirements of public fleets represent a small fraction of the eventual total demand across the transportation sector,the predictable and long-term nature of the refuelling profiles can reduce the financing risk.With appropriate coordination across the energy supply chain,near-term investments can be used to support scale-up of wider efforts to decarbonize the transportation sector and electric grid.We present two examples from California-one related to overnight power for battery electric bus charging and the other related to medium-scale supply chains for zero-carbon hydrogen production-to illustrate how this might be achieved.展开更多
No-tillage practices have a recognised beneficial impact on soil and water conservation while reducing erosion processes and enhancing soil organic matter content.However,scientists continue to debate the effectivenes...No-tillage practices have a recognised beneficial impact on soil and water conservation while reducing erosion processes and enhancing soil organic matter content.However,scientists continue to debate the effectiveness of no-tillage in reducing soil carbon dioxide(CO_(2))emissions from farming.Following the same line of inquiry pursued by the authors who reviewed the impact of conservative practices on direct CO_(2)emissions,we applied meta-analytic and machine learning techniques to unravel the effect of no-tillage under contrasting pedo-environmental conditions and agricultural management.We analysed fifty-six experimental studies investigating direct soil CO_(2)emissions from no-tillage and conventional tillage practices(102 paired observations),considering pedological(soil texture,soil organic carbon content),environmental(climate type),and management(crop rotation,experiment duration)factors.We estimated the effect of different practices on the daily amount of soil CO_(2)emissions,and the impact of tillage in the period immediately following the event.The main insights of this study are:(i)the conditions leading to the highest reduction of CO_(2)emissions due to no-tillage were long-term experiments(standardised mean differenceβ=0.64)conducted in arid environments(β=0.76)and clay soils(β=0.81),with low organic carbon content(β=0.79)where crop rotations(β=0.65)were performed;(ii)the same conditions were associated with the lowest absolute CO_(2)emissions,irrespective of soil management;(iii)the highest contribution to the variability of absolute soil CO_(2)emissions was associated with soil texture(mean decrease in accuracy of Random Forest models,MDA=4.57),rotation(MDA=3.07),experiment duration(MDA=2.93)and soil organic carbon content(MDA=2.24),rather than to tillage practices;(iv)soil CO_(2)emissions almost doubled in the first day after a tillage event,consistently across studies(p=0.001).This meta-analysis offers quantitative figures on the impact of tillage practices on soil CO_(2)emissions and rele展开更多
The implementation of alternative fuels,such as biodiesel,in engines has been shown to be a feasible strategy to control greenhouse gas(GHG)emissions.The blending of biodiesel with diesel can reduce emissions of carbo...The implementation of alternative fuels,such as biodiesel,in engines has been shown to be a feasible strategy to control greenhouse gas(GHG)emissions.The blending of biodiesel with diesel can reduce emissions of carbon monoxide(CO)and carbon dioxide and reduce soot formation.Nonetheless,biodiesel combustion comes with low thermal efficiency,elevated emissions of nitrogen oxides(NOx)and carbon deposition issues.Recently,the addition of gasoline to diesel-biodiesel blends has been proposed to compensate for the downsides of biodiesel combustion.In the current review,the viability of using this ternary fuel blend in engines is thoroughly reviewed.The review first assesses the environmental and health issues caused by conventional fuels,mitigation schemes to control GHG emissions and alternative fuels as a decarbonizing technology.The combustion and emissions characteristics of diesel-bio-diesel-gasoline mixtures are discussed in detail.Finally,the status,challenges and prospects of applying the alternative fuel mixture in engines are appraised.This work has revealed that the mixing of gasoline with diesel-biodiesel blends brings about elongated ignition delay,increased heat release rate and in-cylinder pressure at high loads.Additionally,by adding gasoline,the combustion duration is shortened and soot,CO and unburned hydrocarbon emissions are suppressed,while NOx emissions are slightly increased.Combustion stability is found to be partially disrupted in the presence of gasoline whereas fuel economy(at medium and high loads)is improved by the addition of gasoline.To support the wider deployment and commercialization of this fuelling strategy in the transportation sector,favourable legislation and/or fiscal incentives are needed in countries around the world.This would encourage researchers,fuel producers and engine manufacturers alike to solve challenges such as biodiesel feedstock costs,fuel quality,fuel storage management and engine warranty issues.展开更多
For three weeks in October 2009, the U.S. Department of Energy hosted the Solar Decathlon Competition in which 20 teams of college and university students competed to design, build, and operate their own version of a ...For three weeks in October 2009, the U.S. Department of Energy hosted the Solar Decathlon Competition in which 20 teams of college and university students competed to design, build, and operate their own version of a solar-powered house. Team North＇s mission was to deliver North House, a compelling, marketable solar powered home for people with active lifestyles, while building Canada＇s next generation of leaders in sustainable engineering, business and design. This paper deals with a solar-assisted space heating system that was studied as a potential design for the competition. Among several other conclusions, it was found that using a solar-assisted in-floor heating system can decrease the energy consumption to only 8% of the case without the in-floor loop.展开更多
文摘The morphology of urban areas plays a crucial role in determining solar potential,which directly affects photovoltaic capacity and the achievement of net-zero outcomes.This study focuses on the City of Melbourne to investigate the utilization of solar energy across different urban densities and proposes optimized morphologies.The analysis encompasses blocks with diverse population densities,examining medium and high-density areas.By utilizing a multi-objective genetic optimization approach,the urban morphology of these blocks is refined.The findings indicate that low-density blocks exhibit photovoltaic potential ranging from 1 to 6.6 times their total energy consumption.Medium and high-density blocks achieve photovoltaic potential levels approximately equivalent to 40%-85%of their overall energy consumption.Moreover,significant variations in photovoltaic potential are observed among different urban forms within medium and high-density blocks.An“elevated corners with central valley”prototype is proposed as an effective approach,enhancing the overall photovoltaic potential by approximately 14%.This study introduces novel analytical concepts,shedding light on the intricate relationship between urban morphologies and photovoltaic potential.
基金supported in part by the National Key Research and Development Program of China(No.2018YFA0702200)the National Natural Science Foundation of China(No.52377079)the Liaoning Revitalization Talents Program(No.XLYC2007181)。
文摘Battery energy storage systems(BESSs)serve a crucial role in balancing energy fluctuations and reducing carbon emissions in net-zero power systems.However,the efficiency and cost performance have remained significant challenges,which hinders the widespread adoption and development of BESSs.To address these challenges,this paper proposes a real-time energy management scheme that considers the involvement of prosumers to support net-zero power systems.The scheme is based on two shared energy storage models,referred to as energy storage sale model and power line lease model.The energy storage sale model balances real-time power deviations by energy interaction with the goal of minimizing system costs while generating revenue for shared energy storage providers(ESPs).Additionally,power line lease model supports peer-to-peer(P2P)power trading among prosumers through the power lines laid by ESPs to connect each prosumer.This model allows ESP to earn profits from the use of power lines while balancing power deviations and better consuming renewable energy.Experimental results validate the effectiveness of the proposed scheme,ensuring stable power supply for net-zero power systems and providing benefits for both the ESP and prosumers.
基金supported by the Natural Science Foundation of Tianjin(No.22JCZDJC00820)。
文摘To provide guidance for photovoltaic(PV)system integration in net-zero distribution systems(DSs),this paper proposes an analytical method for delineating the feasible region for PV integration capacities(PVICs),where the impact of battery energy storage system(BESS)flexibility is considered.First,we introduce distributionally robust chance constraints on network security and energy/carbon net-zero requirements,which form the upper and lower bounds of the feasible region.Then,the formulation and solution of the feasible region is proposed.The resulting analytical expression is a set of linear inequalities,illustrating that the feasible region is a polyhedron in a high-dimensional space.A procedure is designed to verify and adjust the feasible region,ensuring that it satisfies network loss constraints under alternating current(AC)power flow.Case studies on the 4-bus system,the IEEE 33-bus system,and the IEEE 123-bus system verify the effectiveness of the proposed method.It is demonstrated that the proposed method fully captures the spatio-temporal coupling relationship among PVs,loads,and BESSs,while also quantifying the impact of this relationship on the boundaries of the feasible region.
文摘To begin with, rating systems are a beneficial tool in determining the efficiency of a building’s ability to utilise its resources effectively. In this study, the two elements under comparison are the Building Rating Systems (BRSs) and Occupant Rating Systems (ORSs). The main objective of this paper is to be able to examine the most commonly applied international and national BRS and ORS and, based on that, discover the possibility of developing an integration of both the BRS and ORS into one rating system. Quite simply, a BRS is a method by which buildings are assessed and given a score based on numerous features such as the efficiency of each of the services, total energy consumption, and alternate options of consumption. There are various BRSs that are implemented globally, each with its own set of criteria and specifications. Thus, based on the analysis of the benefits and drawbacks of both types of rating systems, it could be deduced that a well-rounded rating system with all technical and non-technical aspects combined would be beneficial to both the efficiency of the building as well as the building occupants’ health and well-being.
基金the National Natural Science Foundation of China(No.51978252)the High-tech Industry Technology Innovation Leading Plan of Hunan Province(2020GK2076)+2 种基金the Science and Technology Innovation Program of Hunan Province(2020RC5003)the Hunan Province Innovation Development Program(2020RC4045)the Hunan Province Key R&D Program(2021SK2045).
文摘Self-powered photovoltaic windows,which integrate photovoltaic with electrochromic devices,have attracted widespread attention of scholars since they can generate electricity in situ and reduce building energy consumption by modulating the transmitted solar radiation.However,previous studies mainly focused on the material development and performance characterization,lack of comfort assessment and energy saving potential of its application to buildings.To address this issue,an adjustable semi-transparent photovoltaic(ATPV)window which integrates CdTe-based photovoltaic and WO3-based electrochromic,was taken as the research object,and a novel rule-based control strategy taking the beam solar radiation luminous efficacy(CtrlEff)as decision variable was proposed for the first time.The ATPV window model was established in WINDOW software based on the measured data,and then it was exported to integrated with a medium office building model in EnergyPlus for performance evaluation including the visual comfort,thermal comfort,net energy consumption,and net-zero energy ratio.The results of a case study in Changsha(E 112°,N 28°)indicated that the ATPV window under the CtrlEff strategy can effectively reduce the southward and westward intolerable glare by 86.9%and 94.9%,respectively,and increase the thermal comfort hours by 5%and 2%,compared to the Low-E window.Furthermore,the net-zero energy consumption can be decreased by 58.7%,65.7%,64.1%,and 53.8%for south,west,east,and north orientations,and the corresponding net-zero energy ratios are 65.1%,54.6%,62.7%,and 61.6%,respectively.The findings of this study provide new strategies for the control and optimization of the adjustable window.
文摘Net-zero energy buildings and communities, which are receiving increasing interest, and the role of energy storage in them, are described. A net-zero energy building or community is defined as one that, in an average year, produces as much energy from renewable energy as it consumes. Net-zero energy buildings and communities and the manner in which energy sustainability is facilitated by them are described and examples are given. Also, energy storage is discussed and the role and importance of energy storage as part of net-zero buildings and communities are explained. The NSERC Smart Net-zero Energy Buildings Research Network, a major Canadian research effort in smart net-zero energy buildings and communities, is described.
基金The data were obtained from the National Aeronautics and Space Administration(NASA)Langley Research Center Prediction of Worldwide Energy Resource(POWER)Project funded through the NASA Earth Science/Applied Science Program.The data were obtained from the POWER Project’s Hourly 2.0.0 version on 11 November 2022.
文摘Growing energy demand,diminishing fossil fuel reserves and geopolitical tensions are serious concerns for any country’s energy strategy and security.These factors have a greater impact on developing countries,as many of them rely largely on traditional energy resources.Cleaner energy generation is the viable alternative for mitigating these problems,as well as achieving energy independ-ence and tackling climate change.The article discusses planning and design optimization of a residential community microgrid based on multiple renewable resources.In particular,the design and techno-economic assessment of a grid-tied hybrid microgrid for meeting the electricity demand of an alluvial region,Urir Char,located in southern Bangladesh,was addressed.Hybrid Optimization of Multiple Energy Resources is used for the evaluation and it is supplemented by a fuzzy-logic-based load profile design strategy.In addition to the analysis,a predictive load-shifting-based demand management is also introduced.Several cases were considered for the studies and,after considering several criteria,a grid-tied system comprising a photovoltaic array,wind turbine and energy storage system was found to be the best fit for powering the loads.The suggested system reduces the life-cycle cost by 18.3%,the levelized cost of energy by 61.9%and emissions by 77.2%when compared with the grid-only option.Along with the microgrid design,cooking emissions and energy categorization were also discussed.
基金the National Key Research and Development Program of China(No.2021YFE0102400)the Social Science Foundation of Beijing(22JCC092)State Key Laboratory of Power System Operation and Control(SKLD22KM16).
文摘Rooftop photovoltaic(PV)systems are represented as projected technology to achieve net-zero energy building(NEZB).In this research,a novel energy structure based on rooftop PV with electric-hydrogen-thermal hybrid energy storage is analyzed and optimized to provide electricity and heating load of residential buildings.First,the mathematical model,constraints,objective function,and evaluation indicators are given.Then,the simulation is conducted under the stand-alone condition.The annual return on investment and the levelized cost of energy of the system are 36.37%and 0.1016$/kWh,respectively.Residential building with the proposed system decreases annual carbon emission by 25.5 t.In the third part,simulation analysis under different grid-connected modes shows that building system will obtain better economics when connected to the grid,but the low-carbon performance will be reduced.Finally,the cumulative seasonal impact of the countywide rooftop PV buildings is discussed.The result indicates that the energy structure proposed in this paper can effectively reduce the grid-connected impact on the local grid.This model and optimization method developed in this paper is applicable to different climate zones and can provide management support to the investors of NZEB before the field test.
基金Acknowledgements This publication is based on research conducted within the“Clean heat,power and hydrogen from biomass and waste”project funded by UK Engineering and Physical Sciences Research Council(EPSRC reference:EP/R513027/1).
文摘Carbon capture and storage will play a crucial role in industrial decarbonisation.However,the current literature presents a large variability in the techno-economic feasibility of CO_(2)capture technologies.Consequently,reliable pathways for carbon capture deployment in energyintensive industries are still missing.This work provides a comprehensive review of the state-of-the-art CO_(2)capture technologies for decarbonisation of the iron and steel,cement,petroleum refining,and pulp and paper industries.Amine scrubbing was shown to be the least feasible option,resulting in the average avoided CO_(2)cost of between 62.7∈t_(CO_(2))^(-1)for the pulp and paper and 104.6∈t_(CO_(2))^(-1)for the iron and steel industry.Its average equivalent energy requirement varied between 2.7(iron and steel)and 5.1MJ_(th)·kg_(CO_(2))^(-1)(cement).Retrofits of emerging calcium looping were shown to improve the overall viability of CO_(2)capture for industrial decarbonisation.Calcium looping was shown to result in the average avoided CO_(2)cost of between 32.7(iron and steel)and 42.9(cement).Its average equivalent energy requirement varied between 2.0(iron and steel)and 3.7(pulp and paper).Such performance demonstrated the superiority of calcium looping for industrial decarbonisation.Further work should focus on standardising the techno-economic assessment of technologies for industrial decarbonisation.
文摘Energy consumption in buildings is considered a significant portion of gross power dissipation, so a great effort is required to design efficient construction. In severe hot weather conditions as Kuwait, energy required for building cooling and heating results in a huge energy loads and consumption and accordingly high emission rates of carbon dioxide. So, the main purpose of the current work is to convert the existing institutional building to near net-zero energy building (nNZEB) or into a net-zero energy building (NZEB). A combination of integrated high concentrated photovoltaic (HCPV) solar modules and evacuated tube collectors (ETC) are proposed to provide domestic water heating, electricity load as well as cooling consumption of an institutional facility. An equivalent circuit model for single diode is implemented to evaluate triple junction HCPV modules efficiency considering concentration level and temperature effects. A code compatible with TRNSYS subroutines is introduced to optimize evacuated tube collector efficiency. The developed models are validated through comparison with experimental data available from literature. The efficiency of integrated HCPV-ETC unit is optimized by varying the different system parameters. Transient simulation program (TRNSYS) is adapted to determine the performance of various parts of HCPV-ETC system. Furthermore, a theoretical code is introduced to evaluate the environmental effects of the proposed building when integrated with renewable energy systems. The integrated HCPV-ETC fully satisfies the energy required for building lighting and equipment. Utilizing HCPV modules of orientation 25? accomplishes a minimum energy payback time of about 8 years. Integrated solar absorption chiller provides about 64% of the annual air conditioning consumption needed for the studied building. The energy payback period (EPT) or solar cooling system is about 18 years which is significantly larger than that corresponding to HCPV due to the extra expenses of solar absorption system. The li
文摘The increasing applications of net-zero energy buildings (NZEBs) will lead to more frequent and larger energy interactions with the connected power grid, thereby being able to result in severe grid overvoltage risks. Control optimization has been proven effective to reduce such risks. Existing controls have oversimplified the overvoltage quantification by simply using the aggregated power exchanges to represent the connected grid overvoltages. Ignoring the complex voltage influences among the grid nodes, such oversimplification can easily result in low-accuracy impact evaluations of the NZEB-grid energy interactions, thereby causing non-optimal/unsatisfying overvoltage mitigations. Therefore, this study proposes a novel coordinated control method in which a power-distribution-network model has been adopted for more accurate overvoltage quantification. Meanwhile, the battery operations of individual NZEBs are iteratively coordinated using a sequential optimization approach for achieving the global optimum with substantially reduced computation complexity. For verifications, the proposed coordinated control has been systematically compared with an uncoordinated control and a conventional coordinated control in grid overvoltage minimization. The study results show that the overvoltage improvements can reach 23.5% and 12.3% compared with the uncoordinated control and the conventional coordinated control, respectively. The reasons behind the improvements have also been analyzed in detail. The proposed coordinated control can be used in practice to improve NZEB-clusters’ grid friendliness.
文摘Reaching carbon neutrality will require investment on an unprecedented scale.Here we suggest that there is an underappreciated opportunity to leverage public funds to mobilize private capital in support of these aims.We illustrate the point using examples from public transit.Although the fuelling energy requirements of public fleets represent a small fraction of the eventual total demand across the transportation sector,the predictable and long-term nature of the refuelling profiles can reduce the financing risk.With appropriate coordination across the energy supply chain,near-term investments can be used to support scale-up of wider efforts to decarbonize the transportation sector and electric grid.We present two examples from California-one related to overnight power for battery electric bus charging and the other related to medium-scale supply chains for zero-carbon hydrogen production-to illustrate how this might be achieved.
基金This work received support from the AgriDigit-Agromodelli project(DM n.36502 of 20/12/2018)funded by the Italian Ministry of Agricultural,Food and Forestry Policies(MIPAAF).
文摘No-tillage practices have a recognised beneficial impact on soil and water conservation while reducing erosion processes and enhancing soil organic matter content.However,scientists continue to debate the effectiveness of no-tillage in reducing soil carbon dioxide(CO_(2))emissions from farming.Following the same line of inquiry pursued by the authors who reviewed the impact of conservative practices on direct CO_(2)emissions,we applied meta-analytic and machine learning techniques to unravel the effect of no-tillage under contrasting pedo-environmental conditions and agricultural management.We analysed fifty-six experimental studies investigating direct soil CO_(2)emissions from no-tillage and conventional tillage practices(102 paired observations),considering pedological(soil texture,soil organic carbon content),environmental(climate type),and management(crop rotation,experiment duration)factors.We estimated the effect of different practices on the daily amount of soil CO_(2)emissions,and the impact of tillage in the period immediately following the event.The main insights of this study are:(i)the conditions leading to the highest reduction of CO_(2)emissions due to no-tillage were long-term experiments(standardised mean differenceβ=0.64)conducted in arid environments(β=0.76)and clay soils(β=0.81),with low organic carbon content(β=0.79)where crop rotations(β=0.65)were performed;(ii)the same conditions were associated with the lowest absolute CO_(2)emissions,irrespective of soil management;(iii)the highest contribution to the variability of absolute soil CO_(2)emissions was associated with soil texture(mean decrease in accuracy of Random Forest models,MDA=4.57),rotation(MDA=3.07),experiment duration(MDA=2.93)and soil organic carbon content(MDA=2.24),rather than to tillage practices;(iv)soil CO_(2)emissions almost doubled in the first day after a tillage event,consistently across studies(p=0.001).This meta-analysis offers quantitative figures on the impact of tillage practices on soil CO_(2)emissions and rele
基金Higher Education(MOHE),Malaysia,is gratefully acknowledged for the financial support towards this project under the Fundamental Research Grant Scheme FRGS/1/2019/TK03/UNIM/01/1.
文摘The implementation of alternative fuels,such as biodiesel,in engines has been shown to be a feasible strategy to control greenhouse gas(GHG)emissions.The blending of biodiesel with diesel can reduce emissions of carbon monoxide(CO)and carbon dioxide and reduce soot formation.Nonetheless,biodiesel combustion comes with low thermal efficiency,elevated emissions of nitrogen oxides(NOx)and carbon deposition issues.Recently,the addition of gasoline to diesel-biodiesel blends has been proposed to compensate for the downsides of biodiesel combustion.In the current review,the viability of using this ternary fuel blend in engines is thoroughly reviewed.The review first assesses the environmental and health issues caused by conventional fuels,mitigation schemes to control GHG emissions and alternative fuels as a decarbonizing technology.The combustion and emissions characteristics of diesel-bio-diesel-gasoline mixtures are discussed in detail.Finally,the status,challenges and prospects of applying the alternative fuel mixture in engines are appraised.This work has revealed that the mixing of gasoline with diesel-biodiesel blends brings about elongated ignition delay,increased heat release rate and in-cylinder pressure at high loads.Additionally,by adding gasoline,the combustion duration is shortened and soot,CO and unburned hydrocarbon emissions are suppressed,while NOx emissions are slightly increased.Combustion stability is found to be partially disrupted in the presence of gasoline whereas fuel economy(at medium and high loads)is improved by the addition of gasoline.To support the wider deployment and commercialization of this fuelling strategy in the transportation sector,favourable legislation and/or fiscal incentives are needed in countries around the world.This would encourage researchers,fuel producers and engine manufacturers alike to solve challenges such as biodiesel feedstock costs,fuel quality,fuel storage management and engine warranty issues.
文摘For three weeks in October 2009, the U.S. Department of Energy hosted the Solar Decathlon Competition in which 20 teams of college and university students competed to design, build, and operate their own version of a solar-powered house. Team North＇s mission was to deliver North House, a compelling, marketable solar powered home for people with active lifestyles, while building Canada＇s next generation of leaders in sustainable engineering, business and design. This paper deals with a solar-assisted space heating system that was studied as a potential design for the competition. Among several other conclusions, it was found that using a solar-assisted in-floor heating system can decrease the energy consumption to only 8% of the case without the in-floor loop.
