The accuracy of occupancy and energy-consuming equipment schedules significantly influences build... more The accuracy of occupancy and energy-consuming equipment schedules significantly influences building energy simulations. Existing standards provide generalized schedules that do not fully capture variations across different office building types and periods. This study utilizes questionnaire data from office buildings across four Chinese cities to extract refined prototypes for occupancy and equipment usage schedules using hierarchical clustering analysis. Specific schedules are developed for summer workdays, winter workdays, summer weekends, and winter weekends, covering HVAC, lighting, and office equipment. For instance, the extracted lighting schedule increases annual energy consumption intensity by 25.35% compared to standard schedules. Additionally, XGBoost models identify key factors influencing equipment usage; for HVAC, floor number emerges as most significant. The study's prototypes offer more realistic inputs for building energy simulations, enhancing accuracy and guiding energy-efficient building design and management strategies in China.
Harnessing energy surpluses and technological advances from positive energy buildings (PEBs) with... more Harnessing energy surpluses and technological advances from positive energy buildings (PEBs) within a community offers a logical transition pathway from PEBs to positive energy communities (PECs). This study proposes a set of reasonable performance indicators (KPIs) for streamlining site planning assessments based on existing PEBs, aiming to transition to PECs for achieving energy autonomy in off-grid states. The proposed KPIs include energy surplus ratio, PEB area coverage ratio, community energy difference, shared energy matching ratio, and PEB impact coefficient. A sample of 81 PEBs provided by a real database in North America was selected for testifying these KPIs, and relevant geographic analyses and simulations were performed. Four PV installation scenarios and three radius ranges were considered for building energy generation and energy consumption. The results show that the establishment of a PEC through a PEB is promising. In existing communities, the physical boundary of the transition from PEB to PEC can be determined to be between 150 and 250 m. The study also found that educational buildings should be closely integrated with residential buildings in the energy resilience planning process. KPIs offer crucial insights for initial PEC site selection, offering practical guidance for PEC development and informing strategic decisions in planning PECs through PEBs. This study’s findings serve as actionable guidance for stakeholders, such as urban planners, policymakers, developers, and researchers, facilitating the creation of sustainable and energy-positive communities.
The complexity of urban form can have a significant impact on the utilization of solar energy. Wh... more The complexity of urban form can have a significant impact on the utilization of solar energy. While numerous studies have examined the influence of urban form on solar potential, the optimization of solar energy use in cities located at high latitudes remains a challenging subject. In this study, we focus on the high-latitude city of Glasgow, using residential buildings in urban grid cells as our sample. We calculate solar potential and urban form indicators for these buildings using the Digimap database and the ArcGIS Pro platform. Employing eight machine learning algorithms, we analyze the data and extract eight key morphological indicators that affect the solar potential of urban grid cells. Among these indicators, we select four indicators-roof slope, building density, plot ratio, and building perimeter shape factor-for cluster analysis, enabling us to classify urban building forms into five types based on their characteristics and solar potential. Our calculations demonstrate that effective utilization of solar energy offers significant zero energy potential for Glasgow. The findings of this research can provide valuable guidance in the early stages of urban planning and design, assisting policymakers in rationalizing the use of solar energy resources for sustainable urban development. Furthermore, the results help urban stakeholders identify variations in the solar potential of different building forms, aiding them in selecting appropriate building types and zones to maximize solar energy utilization.
Assessing BIPV (Building Integrated Photovoltaic) potential is of great significance for the comp... more Assessing BIPV (Building Integrated Photovoltaic) potential is of great significance for the comprehensive promotion and deployment of solar energy. Traditional models mostly rely on morphological parameters for PV potential assessment, presenting challenges such as subjective knowledge of urban forms and difficulty in generalization within dense urban areas. This study employs Convolutional Neural Network (CNN) for 3D modeling to evaluate BIPV potential at medium and large urban scales, introducing a framework for a multidimensional single-channel one-dimensional CNN model. The model utilizes the Gaussian Mixture Model combined with building point cloud data to extract the building window-to-wall ratio, thereby enhancing individual features in the building cluster point cloud. It also utilizes the 3D physical model to extract building geographic orientation information, integrating point cloud distribution through spatial connectivity to address the issue of missing geographic orientation due to rotational invariance of point cloud convolution. Additionally, it uses the surface area of the 3D model as the weight for surface point cloud sampling and combines it with normal estimation to retain building entity information, solving the disorder of point cloud convolution. This modeling framework enables accurate prediction of PV potentials in urban blocks by utilizing city point cloud data and predicting urban block boundaries. Using Melbourne City as a case study, the model demonstrates superior performance compared to traditional morphological parameter-based prediction models, with a root mean square error of 2415.548 kWh/year and an R2 SCORE of 0.937 in 75 training sets. The proposed modeling framework enables the prediction of multi-scale BIPV potential, which is beneficial for the staged promotion of BIPV and the development of effective energy deployment strategies. This study offers new insights for urban building energy modeling, deep learning, and energy prediction in complex scenarios at medium and large scales for sustainable urban development.
In the midst of a global energy crisis, fuel poverty has become increasingly prevalent. This stud... more In the midst of a global energy crisis, fuel poverty has become increasingly prevalent. This study examines the effectiveness of energy efficiency retrofits (EERs) in alleviating fuel poverty in the United Kingdom. Using the England fuel poverty dataset with XGBoost and interpretive analyses like Individual Conditional Expectation (ICE) and SHapley Additive exPlanations (SHAP), the research investigates the impact of EERs on fuel poverty. Findings reveal that while energy efficiency enhancements hold potential for improving conditions for vulnerable households, their effectiveness diminishes beyond a certain threshold. The study identifies solid wall and cavity wall insulation, condensing boilers, well-insulated lofts, and central heating systems as the most effective retrofit measures. However, the optimal selection of retrofit methods varies depending on household and dwelling conditions due to interactive effects. Additionally, comprehensive cost-efficiency analyses show that installing condensing combination boilers in homes without existing boilers and adding cavity wall insulation to houses with uninsulated cavity walls are more cost-efficient options. These insights shed light on the complex relationship between energy efficiency retrofits and fuel poverty, informing the development of targeted strategies to address this pressing issue in the UK and globally.
With the rapid growth of cloud computing, the number of data centers (DCs) continuously increases... more With the rapid growth of cloud computing, the number of data centers (DCs) continuously increases, leading to a high-energy consumption dilemma. Cooling, apart from IT equipment, represents the largest energy consumption in DCs. Passive design (PD) and active design (AD) are two important approaches in architectural design to reduce energy consumption. However, for DC cooling, few studies have summarized AD, and there are almost no studies on PD. Based on existing international research (2005-2024), this paper summarizes the current state of cooling strategies for DCs. PD encompasses floors, ceilings, and layout and zoning of racks. Additionally, other passive strategies not yet studied in DCs are critically examined. AD includes air, liquid, free, and two-phase cooling. This paper systematically compares the performance of different AD technologies on various KPIs, including energy, economic, and environmental indicators. This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs. This study reveals that free cooling is widely employed, with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy. Finally, this paper suggests four future directions for reducing cooling energy in DCs, with a focus on the development of passive strategies. This paper provides an overview and guide to DC energy-consumption issues, emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption, and provides directions and references for future energy-efficient DC designs.
This study investigated the climatic risks and vulnerabilities of informal settlements in the Glo... more This study investigated the climatic risks and vulnerabilities of informal settlements in the Global South, as well as the extent to which these risks impact the vulnerabilities. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 methodology and deductive content analysis, this study critically examined 69 documents, including 28 scholarly journal articles obtained from Scopus and ScienceDirect and 41 web-based releases identified through the Google search engine and snowballing technique. Document inclusion criteria focused on the relevance to climate risks and vulnerabilities, excluding non-peer-reviewed, non-English, and unreliable sources, as well as irrelevant studies. Seven major climate risks impacting informal settlements were identified: floods (44), temperature changes (41), storms (31), sea level rise (30), drought (28), rainfall (23), and landslides (14). The primary vulnerabilities highlighted were poor housing conditions (64), health risks (50), lack of basic services (49), inadequate sanitation (41), inadequate hygiene (39), and limited access to water (38). The combination of vulnerabilities and climate risks creates considerable direct, indirect, and low-level threats to informal settlements. Despite Asia, Africa, and Latin America’s vulnerability, most studies focused on formal and developed areas. The findings highlight the critical need for climate adaptation strategies in informal settlements of the Global South to ensure the United Nations Sustainable Development Goals (SDGs) are met.
In this study, an evaluation framework for retrofitting traditional electric vehicle charging sta... more In this study, an evaluation framework for retrofitting traditional electric vehicle charging stations (EVCSs) into photovoltaic-energy storage-integrated charging stations (PV-ES-I CSs) to improve green and low-carbon energy supply systems is proposed. Using existing EVCSs in the "10-minute living circle residential areas" of seven central urban districts in Wuhan city, we comprehensively consider factors such as the site distribution, sky view factor and service population to assess the economic and environmental benefits of PV-ES-I CS systems at different locations and scales. The research results show that the central urban districts have high retrofitting potential, with 44 stations north of the Yangtze River and 20 stations south of the Yangtze River being most suitable for retrofitting. The economic and environmental benefits vary significantly across building types; the retrofitting/construction of PV-ES-I CSs near hotels yields the greatest economic benefit and carbon dioxide emission reduction per unit investment.
In recent years, the urgency to address climate challenges has driven the need to achieve net-zer... more In recent years, the urgency to address climate challenges has driven the need to achieve net-zero carbon goals by 2050. The construction industry, as a major contributor to carbon emissions, plays a vital role in achieving this target. While numerous net-zero energy building approaches have been proposed globally, there is limited comparative research between developed and developing countries. This study aims to address this research gap by selecting the top three carbon-emitting countries in the world-China, India, and the United States (US)-as the research subjects. Through a comparison of their net-zero energy building approaches and typical cases, it is evident that there exists a significant disparity between developed and developing nations. Specifically, differences are observed in the following aspects: net-zero building approaches in the United States have an earlier start and involve collaborations between the government and multiple organizations, while China and India started relatively later and rely primarily on government initiatives. China's consideration of applicable building types in net-zero approaches is not inclusive enough, particularly lacking coverage on industrial buildings. It is encouraging to observe that China and India pay more attention to embodied carbon emissions compared, while their decarbonization strategies for embodied carbon emissions are not as comprehensive as those in the United States when it comes to actual building applications. Regarding carbon offset options, the United States and India demonstrate more comprehensive considerations, while China currently lacks consideration for off-site power generation and negative carbon technologies. The United States boasts a larger number of net-zero buildings, most of which have been certified through the country's own net-zero building approaches. In contrast, China and India have fewer certified net-zero buildings, and only a small percentage have been certified using their own methods, especially in China. The technologies employed in zero-carbon buildings in the United States are more advanced compared to China and India. These findings underline how the disparities in economic levels between developed and developing countries are reflected in net-zero building approaches. Based on these insights, professionals in the field can develop tailored strategies to bridge the gap in net-zero building development between developed and developing nations. This study provides a foundation and recommendations for achieving carbon neutrality in the construction industry for the world's top three economies by 2030.
Occupant behavior plays a crucial role in enhancing indoor thermal comfort and achieving energy e... more Occupant behavior plays a crucial role in enhancing indoor thermal comfort and achieving energy efficiency by influencing the operational modes of Heating, Ventilation, and Air Conditioning (HVAC) systems as well as windows. However, accurately quantifying the impact of occupant behavior on the indoor environment presents significant challenges in practical applications. This study introduces an innovative approach by leveraging the ASHRAE Global Building Occupant Behavior Database and harnessing the power of XGBoost in conjunction with Deep Q Networks (DQN) to construct a reinforcement learning model. This model enables precise prediction of the impact of occupant behavior on the indoor environment at the next time step under varying indoor-outdoor conditions, simultaneously targeting the dual objectives of indoor thermal comfort and energy conservation. By applying the XGB-DQN model in sample rooms of four international cities with distinct features, the results demonstrate a significant increase in indoor thermal comfort duration by 24 %, accompanied by a 24.7 % decrease in air conditioning usage compared to baseline models and actual occupant data. This research represents a pioneering effort in applying reinforcement learning techniques to accurately predict occupant behavior's impact on indoor environments, offering valuable insights for intelligent building design and energy management.
Global warming and the urban heat island effect have led to a decline in the quality of urban ope... more Global warming and the urban heat island effect have led to a decline in the quality of urban open spaces. Although many studies have been conducted on the thermal environment of urban open spaces, there is a lack of a detailed analysis of the time dimension. This study is to propose a method for analyzing long-term time series data on thermal environment, to more comprehensively evaluate the comfort of urban open spaces. We employed thermal environment data from urban open spaces in Melbourne and conducted a time series comfort analysis using a Gaussian mixture model. The research findings indicate that urban open spaces surrounded by low-rise buildings exhibit the highest thermal comfort, whereas those encompassed by a combination of buildings and green spaces exhibit the lowest comfort level. More importantly, we discovered similarities in the comfortable time periods across the five types of urban open spaces, with the majority falling between 6:00 AM and 10:00 AM. These discoveries can assist in achieving a more objective evaluation of the thermal environment in urban open spaces and provide scientific guidance for urban planning and landscape design, thus enhancing the quality of life for urban residents.
Achieving net-zero energy (NZE) in buildings involves laying down photovoltaics (PV) over large b... more Achieving net-zero energy (NZE) in buildings involves laying down photovoltaics (PV) over large building areas, and the issue of dissipating surplus PV capacity has been a challenge. With the popularity of electric vehicles (EVs), parking lots attached to buildings offer such a possible solution. In order to assess the possibility of applying PV surplus power to electric vehicle charging stations (EVCSs) in parking lots, a workflow based on the p-center model was developed in this study using scenario analysis. Considering New York City as the research focus, 100 buildings satisfying the prescribed criteria were screened. Subsequently, the potential of the parking facilities of the selected buildings was evaluated for dissipating surplus PV capacity, focusing on achieving both NZE and green power goals. The results show that the NZE goal is achieved between 3 % and 13 %, while the GP goal is determined as 20 %. The shape factor of the buildings and the goal completion rate from the four clusters reflect the improvements in the four types of parking lots. The average reduction in greenhouse gas (GHG) emissions for the five PV installation scenarios was 67.10, 112.94, 147.41, 171.00, and 187.24 MTCO 2 e, with an average payback period of 0.71, 1.87, 2.21, 2.47, and 2.22 years, respectively. In addition, 13 samples met the NZE goal, and 29 samples met the GP goal, representing 13 % and 29 % of the sample size sample, respectively. The study confirms the advantages of the building-to-vehicle-to-building (B2V2B) model, and the results can be used as a tool and reference for formulating PV development strategies in cities.
The morphology of urban areas plays a crucial role in determining solar potential, which directly... more 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.
The photovoltaic-energy storage-integrated charging station (PV-ES-I CS), as an emerging electric... more The photovoltaic-energy storage-integrated charging station (PV-ES-I CS), as an emerging electric vehicle (EV) charging infrastructure, plays a crucial role in carbon reduction and alleviating distribution grid pressure. To promote the widespread adoption of PV-ES-I CS in urban residential areas (mainly EV parking and charging locations), this study conducts a thorough assessment of its social acceptance and the economic and environmental benefits. Firstly, this study establishes a conceptual model based on the diffusion of innovations theory and conducted a statistical analysis using partial least squares structural equation modeling on 347 usable questionnaires, aiming to comprehend the psychological determinants influencing the intention of non-users in Chinese households to adopt PV-ES-I CS. Secondly, the equipment configuration of the Wuhan community PV-ES-I CS demonstration project was optimally designed using PVsyst software, and its energy production, economic and environmental benefits were exhaustively analyzed. The research findings indicate that the conceptual model effectively elucidates the behavioral intentions of non-users in Chinese households towards adopting PV-ES-I CS. Furthermore, despite simulation results indicating that the annual electricity generation of the 21.78 kW PV-ES-I CS system is only 15.39 MWh, with an average performance ratio of only 57.1%, this system still has great economic benefits (accumulated balance reaching up to 1,350,809.14 CNY over 20 years) and emission reduction potential (such as a total reduction of 183.9 tons of carbon dioxide emissions over 20 years) in urban residential areas. These research outcomes provide vital insights for stakeholders involved in planning, evaluating, and implementing PV-ES-I CS within residential areas.
Many studies have demonstrated the importance of green spaces in promoting human physical and men... more Many studies have demonstrated the importance of green spaces in promoting human physical and mental health. However, traditional static green space assessment and planning methods with core indicators, such as green space ratio, cannot effectively assess an individual's level of green space exposure. This study explores a method to calculate dynamic real-time green space exposure indices, such as total green space exposure level, green space exposure per unit time, and green space exposure per unit distance, and analyzes their relationship with static green space exposure indices measured using green space accessibility, availability, and visibility. A field study in a central business district in Shenzhen revealed that people whose workplaces had high levels of static green space exposure maintained relatively high levels of dynamic green space exposure. In addition, dynamic green space exposure was influenced by individuals' green space usage behaviors and travel time preferences. This study built an interactive analysis framework for dynamic and static green space exposure based on individual behaviour.
The decarbonization of urban energy systems relies heavily on Building Integrated Photovoltaic (B... more The decarbonization of urban energy systems relies heavily on Building Integrated Photovoltaic (BIPV) technology, which harnesses solar energy from building envelopes. While rooftops have been the focus of solar potential studies, walls also hold significant potential despite receiving less solar radiation. This study aims to quantify the solar potential of building facades in various urban forms, using Adelaide as an example. It first simulated and predicted the solar radiation potential of building facades, then conducted a cluster analysis of urban morphology factors and wall solar potential based on parameters chosen from existing studies to yield five clusters. Five block prototypes were identified for deploying solar on the walls in mixed-use urban neighborhoods. The solar potential was evaluated by calculating the electricity output from solar photovoltaic systems. The results indicate that the ranking of the solar potential of walls from highest to lowest is Cluster 4 (low density and nonuniform size, 1079.83 kWh/m2/year), Cluster 5 (low-rise, low density and uniform size, 1048.83 kWh/m2/year), Cluster 2 (low-rise and high density, 1027.80 kWh/m2/year), Cluster 3 (high-low mixed rise and high density, 985.59 kWh/m2/year), and Cluster 1 (high-rise and high density, 926.16 kWh/m2/year). The rooftop solar potential in Adelaide is capable of meeting the electricity demand, while the total facade solar potential in the entire city can reach 76% of the electricity demand. Specifically, the facade solar power generation of commercial buildings can account for 28% of the electricity demand, and the façade solar power generation of residential buildings can reach 39% of the electricity demand. The results of this study provide a simplified process to explore the solar potential of building facades and rooftops in different block types, which may provide a design benchmark for mixed types of blocks with high solar potential in the early phases of city planning and building design.
Passivhaus has gained recognition as a reliable solution for low-energy residential housing. Howe... more Passivhaus has gained recognition as a reliable solution for low-energy residential housing. However, existing studies lack comprehensive quantitative analysis of real-life cases, restricting the availability of evidence and experience from certified buildings. This study addresses this gap by examining the relationship between characteristics of certified passive houses and their energy performance. The objective is to establish dependable statistical models and best practices for early design stages of passive houses. The study analyzes a significant number of certified cases (n=785) in residential settings situated in two climate zones: Temperate, no dry season, warm summer (n=328, 41.78%) and Cold, no dry season, warm summer (n=457, 58.22%). To assess whether residential buildings meet passive house energy standards, models using logistic regression and gradient boosting decision trees were developed employing
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
The accuracy of occupancy and energy-consuming equipment schedules significantly influences build... more The accuracy of occupancy and energy-consuming equipment schedules significantly influences building energy simulations. Existing standards provide generalized schedules that do not fully capture variations across different office building types and periods. This study utilizes questionnaire data from office buildings across four Chinese cities to extract refined prototypes for occupancy and equipment usage schedules using hierarchical clustering analysis. Specific schedules are developed for summer workdays, winter workdays, summer weekends, and winter weekends, covering HVAC, lighting, and office equipment. For instance, the extracted lighting schedule increases annual energy consumption intensity by 25.35% compared to standard schedules. Additionally, XGBoost models identify key factors influencing equipment usage; for HVAC, floor number emerges as most significant. The study's prototypes offer more realistic inputs for building energy simulations, enhancing accuracy and guiding energy-efficient building design and management strategies in China.
Harnessing energy surpluses and technological advances from positive energy buildings (PEBs) with... more Harnessing energy surpluses and technological advances from positive energy buildings (PEBs) within a community offers a logical transition pathway from PEBs to positive energy communities (PECs). This study proposes a set of reasonable performance indicators (KPIs) for streamlining site planning assessments based on existing PEBs, aiming to transition to PECs for achieving energy autonomy in off-grid states. The proposed KPIs include energy surplus ratio, PEB area coverage ratio, community energy difference, shared energy matching ratio, and PEB impact coefficient. A sample of 81 PEBs provided by a real database in North America was selected for testifying these KPIs, and relevant geographic analyses and simulations were performed. Four PV installation scenarios and three radius ranges were considered for building energy generation and energy consumption. The results show that the establishment of a PEC through a PEB is promising. In existing communities, the physical boundary of the transition from PEB to PEC can be determined to be between 150 and 250 m. The study also found that educational buildings should be closely integrated with residential buildings in the energy resilience planning process. KPIs offer crucial insights for initial PEC site selection, offering practical guidance for PEC development and informing strategic decisions in planning PECs through PEBs. This study’s findings serve as actionable guidance for stakeholders, such as urban planners, policymakers, developers, and researchers, facilitating the creation of sustainable and energy-positive communities.
The complexity of urban form can have a significant impact on the utilization of solar energy. Wh... more The complexity of urban form can have a significant impact on the utilization of solar energy. While numerous studies have examined the influence of urban form on solar potential, the optimization of solar energy use in cities located at high latitudes remains a challenging subject. In this study, we focus on the high-latitude city of Glasgow, using residential buildings in urban grid cells as our sample. We calculate solar potential and urban form indicators for these buildings using the Digimap database and the ArcGIS Pro platform. Employing eight machine learning algorithms, we analyze the data and extract eight key morphological indicators that affect the solar potential of urban grid cells. Among these indicators, we select four indicators-roof slope, building density, plot ratio, and building perimeter shape factor-for cluster analysis, enabling us to classify urban building forms into five types based on their characteristics and solar potential. Our calculations demonstrate that effective utilization of solar energy offers significant zero energy potential for Glasgow. The findings of this research can provide valuable guidance in the early stages of urban planning and design, assisting policymakers in rationalizing the use of solar energy resources for sustainable urban development. Furthermore, the results help urban stakeholders identify variations in the solar potential of different building forms, aiding them in selecting appropriate building types and zones to maximize solar energy utilization.
Assessing BIPV (Building Integrated Photovoltaic) potential is of great significance for the comp... more Assessing BIPV (Building Integrated Photovoltaic) potential is of great significance for the comprehensive promotion and deployment of solar energy. Traditional models mostly rely on morphological parameters for PV potential assessment, presenting challenges such as subjective knowledge of urban forms and difficulty in generalization within dense urban areas. This study employs Convolutional Neural Network (CNN) for 3D modeling to evaluate BIPV potential at medium and large urban scales, introducing a framework for a multidimensional single-channel one-dimensional CNN model. The model utilizes the Gaussian Mixture Model combined with building point cloud data to extract the building window-to-wall ratio, thereby enhancing individual features in the building cluster point cloud. It also utilizes the 3D physical model to extract building geographic orientation information, integrating point cloud distribution through spatial connectivity to address the issue of missing geographic orientation due to rotational invariance of point cloud convolution. Additionally, it uses the surface area of the 3D model as the weight for surface point cloud sampling and combines it with normal estimation to retain building entity information, solving the disorder of point cloud convolution. This modeling framework enables accurate prediction of PV potentials in urban blocks by utilizing city point cloud data and predicting urban block boundaries. Using Melbourne City as a case study, the model demonstrates superior performance compared to traditional morphological parameter-based prediction models, with a root mean square error of 2415.548 kWh/year and an R2 SCORE of 0.937 in 75 training sets. The proposed modeling framework enables the prediction of multi-scale BIPV potential, which is beneficial for the staged promotion of BIPV and the development of effective energy deployment strategies. This study offers new insights for urban building energy modeling, deep learning, and energy prediction in complex scenarios at medium and large scales for sustainable urban development.
In the midst of a global energy crisis, fuel poverty has become increasingly prevalent. This stud... more In the midst of a global energy crisis, fuel poverty has become increasingly prevalent. This study examines the effectiveness of energy efficiency retrofits (EERs) in alleviating fuel poverty in the United Kingdom. Using the England fuel poverty dataset with XGBoost and interpretive analyses like Individual Conditional Expectation (ICE) and SHapley Additive exPlanations (SHAP), the research investigates the impact of EERs on fuel poverty. Findings reveal that while energy efficiency enhancements hold potential for improving conditions for vulnerable households, their effectiveness diminishes beyond a certain threshold. The study identifies solid wall and cavity wall insulation, condensing boilers, well-insulated lofts, and central heating systems as the most effective retrofit measures. However, the optimal selection of retrofit methods varies depending on household and dwelling conditions due to interactive effects. Additionally, comprehensive cost-efficiency analyses show that installing condensing combination boilers in homes without existing boilers and adding cavity wall insulation to houses with uninsulated cavity walls are more cost-efficient options. These insights shed light on the complex relationship between energy efficiency retrofits and fuel poverty, informing the development of targeted strategies to address this pressing issue in the UK and globally.
With the rapid growth of cloud computing, the number of data centers (DCs) continuously increases... more With the rapid growth of cloud computing, the number of data centers (DCs) continuously increases, leading to a high-energy consumption dilemma. Cooling, apart from IT equipment, represents the largest energy consumption in DCs. Passive design (PD) and active design (AD) are two important approaches in architectural design to reduce energy consumption. However, for DC cooling, few studies have summarized AD, and there are almost no studies on PD. Based on existing international research (2005-2024), this paper summarizes the current state of cooling strategies for DCs. PD encompasses floors, ceilings, and layout and zoning of racks. Additionally, other passive strategies not yet studied in DCs are critically examined. AD includes air, liquid, free, and two-phase cooling. This paper systematically compares the performance of different AD technologies on various KPIs, including energy, economic, and environmental indicators. This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs. This study reveals that free cooling is widely employed, with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy. Finally, this paper suggests four future directions for reducing cooling energy in DCs, with a focus on the development of passive strategies. This paper provides an overview and guide to DC energy-consumption issues, emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption, and provides directions and references for future energy-efficient DC designs.
This study investigated the climatic risks and vulnerabilities of informal settlements in the Glo... more This study investigated the climatic risks and vulnerabilities of informal settlements in the Global South, as well as the extent to which these risks impact the vulnerabilities. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 methodology and deductive content analysis, this study critically examined 69 documents, including 28 scholarly journal articles obtained from Scopus and ScienceDirect and 41 web-based releases identified through the Google search engine and snowballing technique. Document inclusion criteria focused on the relevance to climate risks and vulnerabilities, excluding non-peer-reviewed, non-English, and unreliable sources, as well as irrelevant studies. Seven major climate risks impacting informal settlements were identified: floods (44), temperature changes (41), storms (31), sea level rise (30), drought (28), rainfall (23), and landslides (14). The primary vulnerabilities highlighted were poor housing conditions (64), health risks (50), lack of basic services (49), inadequate sanitation (41), inadequate hygiene (39), and limited access to water (38). The combination of vulnerabilities and climate risks creates considerable direct, indirect, and low-level threats to informal settlements. Despite Asia, Africa, and Latin America’s vulnerability, most studies focused on formal and developed areas. The findings highlight the critical need for climate adaptation strategies in informal settlements of the Global South to ensure the United Nations Sustainable Development Goals (SDGs) are met.
In this study, an evaluation framework for retrofitting traditional electric vehicle charging sta... more In this study, an evaluation framework for retrofitting traditional electric vehicle charging stations (EVCSs) into photovoltaic-energy storage-integrated charging stations (PV-ES-I CSs) to improve green and low-carbon energy supply systems is proposed. Using existing EVCSs in the "10-minute living circle residential areas" of seven central urban districts in Wuhan city, we comprehensively consider factors such as the site distribution, sky view factor and service population to assess the economic and environmental benefits of PV-ES-I CS systems at different locations and scales. The research results show that the central urban districts have high retrofitting potential, with 44 stations north of the Yangtze River and 20 stations south of the Yangtze River being most suitable for retrofitting. The economic and environmental benefits vary significantly across building types; the retrofitting/construction of PV-ES-I CSs near hotels yields the greatest economic benefit and carbon dioxide emission reduction per unit investment.
In recent years, the urgency to address climate challenges has driven the need to achieve net-zer... more In recent years, the urgency to address climate challenges has driven the need to achieve net-zero carbon goals by 2050. The construction industry, as a major contributor to carbon emissions, plays a vital role in achieving this target. While numerous net-zero energy building approaches have been proposed globally, there is limited comparative research between developed and developing countries. This study aims to address this research gap by selecting the top three carbon-emitting countries in the world-China, India, and the United States (US)-as the research subjects. Through a comparison of their net-zero energy building approaches and typical cases, it is evident that there exists a significant disparity between developed and developing nations. Specifically, differences are observed in the following aspects: net-zero building approaches in the United States have an earlier start and involve collaborations between the government and multiple organizations, while China and India started relatively later and rely primarily on government initiatives. China's consideration of applicable building types in net-zero approaches is not inclusive enough, particularly lacking coverage on industrial buildings. It is encouraging to observe that China and India pay more attention to embodied carbon emissions compared, while their decarbonization strategies for embodied carbon emissions are not as comprehensive as those in the United States when it comes to actual building applications. Regarding carbon offset options, the United States and India demonstrate more comprehensive considerations, while China currently lacks consideration for off-site power generation and negative carbon technologies. The United States boasts a larger number of net-zero buildings, most of which have been certified through the country's own net-zero building approaches. In contrast, China and India have fewer certified net-zero buildings, and only a small percentage have been certified using their own methods, especially in China. The technologies employed in zero-carbon buildings in the United States are more advanced compared to China and India. These findings underline how the disparities in economic levels between developed and developing countries are reflected in net-zero building approaches. Based on these insights, professionals in the field can develop tailored strategies to bridge the gap in net-zero building development between developed and developing nations. This study provides a foundation and recommendations for achieving carbon neutrality in the construction industry for the world's top three economies by 2030.
Occupant behavior plays a crucial role in enhancing indoor thermal comfort and achieving energy e... more Occupant behavior plays a crucial role in enhancing indoor thermal comfort and achieving energy efficiency by influencing the operational modes of Heating, Ventilation, and Air Conditioning (HVAC) systems as well as windows. However, accurately quantifying the impact of occupant behavior on the indoor environment presents significant challenges in practical applications. This study introduces an innovative approach by leveraging the ASHRAE Global Building Occupant Behavior Database and harnessing the power of XGBoost in conjunction with Deep Q Networks (DQN) to construct a reinforcement learning model. This model enables precise prediction of the impact of occupant behavior on the indoor environment at the next time step under varying indoor-outdoor conditions, simultaneously targeting the dual objectives of indoor thermal comfort and energy conservation. By applying the XGB-DQN model in sample rooms of four international cities with distinct features, the results demonstrate a significant increase in indoor thermal comfort duration by 24 %, accompanied by a 24.7 % decrease in air conditioning usage compared to baseline models and actual occupant data. This research represents a pioneering effort in applying reinforcement learning techniques to accurately predict occupant behavior's impact on indoor environments, offering valuable insights for intelligent building design and energy management.
Global warming and the urban heat island effect have led to a decline in the quality of urban ope... more Global warming and the urban heat island effect have led to a decline in the quality of urban open spaces. Although many studies have been conducted on the thermal environment of urban open spaces, there is a lack of a detailed analysis of the time dimension. This study is to propose a method for analyzing long-term time series data on thermal environment, to more comprehensively evaluate the comfort of urban open spaces. We employed thermal environment data from urban open spaces in Melbourne and conducted a time series comfort analysis using a Gaussian mixture model. The research findings indicate that urban open spaces surrounded by low-rise buildings exhibit the highest thermal comfort, whereas those encompassed by a combination of buildings and green spaces exhibit the lowest comfort level. More importantly, we discovered similarities in the comfortable time periods across the five types of urban open spaces, with the majority falling between 6:00 AM and 10:00 AM. These discoveries can assist in achieving a more objective evaluation of the thermal environment in urban open spaces and provide scientific guidance for urban planning and landscape design, thus enhancing the quality of life for urban residents.
Achieving net-zero energy (NZE) in buildings involves laying down photovoltaics (PV) over large b... more Achieving net-zero energy (NZE) in buildings involves laying down photovoltaics (PV) over large building areas, and the issue of dissipating surplus PV capacity has been a challenge. With the popularity of electric vehicles (EVs), parking lots attached to buildings offer such a possible solution. In order to assess the possibility of applying PV surplus power to electric vehicle charging stations (EVCSs) in parking lots, a workflow based on the p-center model was developed in this study using scenario analysis. Considering New York City as the research focus, 100 buildings satisfying the prescribed criteria were screened. Subsequently, the potential of the parking facilities of the selected buildings was evaluated for dissipating surplus PV capacity, focusing on achieving both NZE and green power goals. The results show that the NZE goal is achieved between 3 % and 13 %, while the GP goal is determined as 20 %. The shape factor of the buildings and the goal completion rate from the four clusters reflect the improvements in the four types of parking lots. The average reduction in greenhouse gas (GHG) emissions for the five PV installation scenarios was 67.10, 112.94, 147.41, 171.00, and 187.24 MTCO 2 e, with an average payback period of 0.71, 1.87, 2.21, 2.47, and 2.22 years, respectively. In addition, 13 samples met the NZE goal, and 29 samples met the GP goal, representing 13 % and 29 % of the sample size sample, respectively. The study confirms the advantages of the building-to-vehicle-to-building (B2V2B) model, and the results can be used as a tool and reference for formulating PV development strategies in cities.
The morphology of urban areas plays a crucial role in determining solar potential, which directly... more 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.
The photovoltaic-energy storage-integrated charging station (PV-ES-I CS), as an emerging electric... more The photovoltaic-energy storage-integrated charging station (PV-ES-I CS), as an emerging electric vehicle (EV) charging infrastructure, plays a crucial role in carbon reduction and alleviating distribution grid pressure. To promote the widespread adoption of PV-ES-I CS in urban residential areas (mainly EV parking and charging locations), this study conducts a thorough assessment of its social acceptance and the economic and environmental benefits. Firstly, this study establishes a conceptual model based on the diffusion of innovations theory and conducted a statistical analysis using partial least squares structural equation modeling on 347 usable questionnaires, aiming to comprehend the psychological determinants influencing the intention of non-users in Chinese households to adopt PV-ES-I CS. Secondly, the equipment configuration of the Wuhan community PV-ES-I CS demonstration project was optimally designed using PVsyst software, and its energy production, economic and environmental benefits were exhaustively analyzed. The research findings indicate that the conceptual model effectively elucidates the behavioral intentions of non-users in Chinese households towards adopting PV-ES-I CS. Furthermore, despite simulation results indicating that the annual electricity generation of the 21.78 kW PV-ES-I CS system is only 15.39 MWh, with an average performance ratio of only 57.1%, this system still has great economic benefits (accumulated balance reaching up to 1,350,809.14 CNY over 20 years) and emission reduction potential (such as a total reduction of 183.9 tons of carbon dioxide emissions over 20 years) in urban residential areas. These research outcomes provide vital insights for stakeholders involved in planning, evaluating, and implementing PV-ES-I CS within residential areas.
Many studies have demonstrated the importance of green spaces in promoting human physical and men... more Many studies have demonstrated the importance of green spaces in promoting human physical and mental health. However, traditional static green space assessment and planning methods with core indicators, such as green space ratio, cannot effectively assess an individual's level of green space exposure. This study explores a method to calculate dynamic real-time green space exposure indices, such as total green space exposure level, green space exposure per unit time, and green space exposure per unit distance, and analyzes their relationship with static green space exposure indices measured using green space accessibility, availability, and visibility. A field study in a central business district in Shenzhen revealed that people whose workplaces had high levels of static green space exposure maintained relatively high levels of dynamic green space exposure. In addition, dynamic green space exposure was influenced by individuals' green space usage behaviors and travel time preferences. This study built an interactive analysis framework for dynamic and static green space exposure based on individual behaviour.
The decarbonization of urban energy systems relies heavily on Building Integrated Photovoltaic (B... more The decarbonization of urban energy systems relies heavily on Building Integrated Photovoltaic (BIPV) technology, which harnesses solar energy from building envelopes. While rooftops have been the focus of solar potential studies, walls also hold significant potential despite receiving less solar radiation. This study aims to quantify the solar potential of building facades in various urban forms, using Adelaide as an example. It first simulated and predicted the solar radiation potential of building facades, then conducted a cluster analysis of urban morphology factors and wall solar potential based on parameters chosen from existing studies to yield five clusters. Five block prototypes were identified for deploying solar on the walls in mixed-use urban neighborhoods. The solar potential was evaluated by calculating the electricity output from solar photovoltaic systems. The results indicate that the ranking of the solar potential of walls from highest to lowest is Cluster 4 (low density and nonuniform size, 1079.83 kWh/m2/year), Cluster 5 (low-rise, low density and uniform size, 1048.83 kWh/m2/year), Cluster 2 (low-rise and high density, 1027.80 kWh/m2/year), Cluster 3 (high-low mixed rise and high density, 985.59 kWh/m2/year), and Cluster 1 (high-rise and high density, 926.16 kWh/m2/year). The rooftop solar potential in Adelaide is capable of meeting the electricity demand, while the total facade solar potential in the entire city can reach 76% of the electricity demand. Specifically, the facade solar power generation of commercial buildings can account for 28% of the electricity demand, and the façade solar power generation of residential buildings can reach 39% of the electricity demand. The results of this study provide a simplified process to explore the solar potential of building facades and rooftops in different block types, which may provide a design benchmark for mixed types of blocks with high solar potential in the early phases of city planning and building design.
Passivhaus has gained recognition as a reliable solution for low-energy residential housing. Howe... more Passivhaus has gained recognition as a reliable solution for low-energy residential housing. However, existing studies lack comprehensive quantitative analysis of real-life cases, restricting the availability of evidence and experience from certified buildings. This study addresses this gap by examining the relationship between characteristics of certified passive houses and their energy performance. The objective is to establish dependable statistical models and best practices for early design stages of passive houses. The study analyzes a significant number of certified cases (n=785) in residential settings situated in two climate zones: Temperate, no dry season, warm summer (n=328, 41.78%) and Cold, no dry season, warm summer (n=457, 58.22%). To assess whether residential buildings meet passive house energy standards, models using logistic regression and gradient boosting decision trees were developed employing
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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