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This research investigates the energy efficiency of a novel double-glazing system incorporating solid–solid phase change materials (SSPCMs), which offer significant advantages over traditional liquid–solid phase change materials. The primary objective of this study is to develop a 3D numerical model using the finite volume method, which will be followed by a parametric study under real climatic boundary conditions. A proposed double-glazing setup featuring a 2 mm layer of SSPCM applied on the inner glass pane within the air gap is modeled and analyzed. The simulations consider various transient temperatures and ranges of the SSPCM to evaluate the energy performance of the system under different weather conditions of Miami, FL during the coldest and hottest days of the year, both in sunny and cloudy conditions. The results demonstrate a notable improvement in energy performance compared to standard double-glazing windows (DGWs), with the most efficient SSPCM configuration exhibiting a phase transition temperature and range of 25 °C and 1 °C, respectively. This configuration achieved energy savings of 24%, 26%, and 23% during summer sunny, winter sunny, and winter cloudy days, respectively, relative to DGWs during cooling and heating degree hours. However, a 3% energy loss was observed during summer cloudy days. Overall, the findings of this study have shown the potential for energy savings by incorporating SSPCM with suitable thermophysical properties into double-glazing systems. [ABSTRACT FROM AUTHOR]

The advancement of society and the raising of people's standards of living depend heavily on electricity in today's world. The ''zero energy buildings'' idea, which recommends that buildings become self-sufficient in renewable energy to prevent the emission of CO2 into the environment, is now one of the most significant initiatives connected to building energy efficiency. This article describes a computational intelligence method to detect anomalous variations in a facility's energy use and infer a potential cause of such changes. The model is built using five sets of historical power consumption data from three buildings spread across four nations (Ecuador, Spain, France, and Canada), which are categorized based on the anomaly type each piece of data represents. Through a statistical study of the confidence interval, the proposed method, first determines the consumption patterns for each day of the week in each of the building's data sets. After normalizing the day to be studied toward its ''Z'' value, it is then cataloged using a machine learning model. The proposed method is evaluated in comparison to a purely statistical method called SAEEC methodology and it is discovered that the proposed method offers a relative improvement in accuracy, false positive rate (FPR), and false negative rate (FNR) of 12.41%, 42, 36%, and 42.45%, respectively, for the detection of atypical values in electrical energy consumption.

Due to global climate change and energy market turmoil, the world is seriously pushing to switch to renewable and diversifying energy sources. The building sector consumes an amount of energy, accounting for approximately 40 % of global energy. Therefore, the concept of zero-energy buildings has become more realistic than before. This study reveals the latest developments in zero-energy buildings through a comprehensive literature review of the past ten years. Emphasis has been placed on buildings' heating, ventilation, and cooling systems, as they constitute the most important part of the energy demand. Also, the role of negative energy resulting from an improved building envelope through the design of a building compatible with the surrounding environment, thermal insulation materials, phase change materials, vegetation cover, etc. A review was also made of the most significant renewable energy technologies, which include solar energy installations, wind turbines, and geothermal heat exchangers. The study showed that three main axes must be achieved to reach an energy-free building: Reducing energy waste through the energy-conserving building envelope and improving HVAC systems. Raising the efficiency of the performance of renewable energy facilities by using hybrid systems with the ability and flexibility to respond to changing energy demand. These three axes are an integrated approach to achieving ZEBs; none can be neglected. This study provides important references for researchers, institutions, and decision-makers to unify efforts to achieve ZEBs. It also aims to attract attention and focus research by raising questions and identifying gaps that future research efforts can address.

In this paper, the energy supply of a zero-energy building with 220 square meters is considered using optimized nanocomposite solar panels with respect to maximum efficiency. An optimized hybrid machine learning method plays a key role in presenting solar panel modeling with over 0.99% accuracy. Predicting the properties of the nanomaterial solar cell in four different seasons is performed by efficient support vector machines (SVM), and k-nearest neighbors (KNN) machine learning algorithms. In addition, the KNN algorithm is optimized by the Particle Swarm Optimization (PSO) method to improve the capabilities of KNN and reveal the best performance criteria for the photovoltaic modeling characteristics. The parameters of the nanocomposite cells are optimized using the proposed novel Multidisciplinary Optimization Method (MDO) to increase the efficiency of the solar panel by up to 170%. Optimization of solar cell performance with nanocomposite material under energy consumption constraints is carried out to propose the best construction of cells with 3 layers. The presented approach as a solution and indicator for the next generation of commercial and residential buildings can increase the potential values of solar cells to at least 70%.

This research investigates the energy efficiency of a novel double-glazing system incorporating solid–solid phase change materials (SSPCMs), which offer significant advantages over traditional liquid–solid phase change materials. The primary objective of this study is to develop a 3D numerical model using the finite volume method, which will be followed by a parametric study under real climatic boundary conditions. A proposed double-glazing setup featuring a 2 mm layer of SSPCM applied on the inner glass pane within the air gap is modeled and analyzed. The simulations consider various transient temperatures and ranges of the SSPCM to evaluate the energy performance of the system under different weather conditions of Miami, FL during the coldest and hottest days of the year, both in sunny and cloudy conditions. The results demonstrate a notable improvement in energy performance compared to standard double-glazing windows (DGWs), with the most efficient SSPCM configuration exhibiting a phase transition temperature and range of 25 °C and 1 °C, respectively. This configuration achieved energy savings of 24%, 26%, and 23% during summer sunny, winter sunny, and winter cloudy days, respectively, relative to DGWs during cooling and heating degree hours. However, a 3% energy loss was observed during summer cloudy days. Overall, the findings of this study have shown the potential for energy savings by incorporating SSPCM with suitable thermophysical properties into double-glazing systems.

This study summarizes the technology level and economic feasibility of two small 500 m2 public office buildings that achieved a first-class Zero Energy Buildings (ZEB) certification for the first time in Korea. In addition, a Life Cycle Assessment (LCA) reflecting the ZEB performance in the operation stage was analyzed, and the LCA factors considering the characteristics of small buildings were reviewed. Moreover, an economic analysis was performed through a Net Present Value (NPV) by reflecting the ZEB and LCA, and the results showed little economic feasibility. However, adding the environmental costs calculated through the LCA to the existing energy-saving costs could offset an additional 11.6–11.7%. Therefore, including the environmental impact and cost through these LCA evaluation techniques could be a positive step toward increasing the effectiveness of ZEB applications. This study is significant in that it conducted a comprehensive analysis through ZEB and LCA in terms of carbon reduction for small buildings that achieved a first-class ZEB certification, but it is limited to only two cases. [ABSTRACT FROM AUTHOR]

Numerous environmental issues have been addressed as a consequence of rapidly increasing global energy consumption. Building energy consumption has risen considerably in the last few decades. In recent years, the zero energy building (ZEB) concept has attained worldwide attention and is now commonly identified as the future criteria for building design. However, there is a lack of uniform definition in this field. This study combines bibliometric and visual analysis of Scopus database publications from 1977 to 2022 to investigate ZEB-related studies. Five topical clusters formed as a result of evaluating the co-occurrence network of the keywords. Finally, the most popular research trends were determined by investigating the overlay network. The scientific knowledge concerning zero energy buildings has been mapped by employing the results of this paper. In addition, they have been utilized to highlight future opportunities and gaps and illustrate the connections between various subject areas. [ABSTRACT FROM AUTHOR]

Along the roadmap to a Sustainable Real Estate-Scape, energy retrofit campaigns on wide city compartments represent a pivotal task, where the importance of the collaboration between the public and private sectors is crucial. Energy retrofit programs on building assets are subject to multiple uncertainty factors (e.g., climate, energy-economy forecasts, etc.) that act as a primary barrier to investment in this field. This paper aims to discuss risk management techniques to understand better how to deal with this kind of uncertainty. The research specifically addresses the techniques of sensitivity analysis and Monte Carlo simulation, focusing first on the phase of variables selection and their probability definition, including climatic, environmental, energy, economic, financial, and stochastic parameters. In this article, it is suggested to include correlation coefficients in the input variables of risk analysis, preferring the two-dimension Monte Carlo simulation to its simple version, since the results are more reliable when separating aleatory from epistemic uncertainty; thus, the results are more reliable. Moreover, it is seen how a sensitivity analysis based on percentile variations of the inputs provides a more accurate representation of risk if compared to the most common sensitivity analysis based on percentage deviations of the inputs. Conducting a sensitivity analysis using percentile variations gives realistic and reliable results, reflecting the tailored definition of uncertainty around the inputs on the basis of specific market analyses or historical series. [ABSTRACT FROM AUTHOR]

Thailand has pledged to be carbon neutral by 2050 at the UN Climate Change Conference (COP26). Promoting all-new buildings to be net-zero energy consumption within 2030 is a strategy to achieve the goal. The previous works have revealed that policymakers and related stakeholders’ supportive strategies could significantly contribute to promoting the zero-energy buildings (ZEB) investment. Moreover, another big challenge in improving high-energy-efficient buildings is the high initial cost and uncertainties of the future costs. As far as we know, no studies have investigated an effect of such a change in economic and relevant costs on the financial benefits of the ZEB project in Thailand. Such parameters are a significant barrier to decision-making on ZEB investment. Consequently, the guidance for affordable financial feasibility and supportive measures could significantly promote ZEB projects. This study used sensitivity analysis to assess the variations of future costs, including initial cost, energy price, maintenance & operation cost, interest rate, and discount rate, influencing the project’s NPVs and the global costs of three representative office buildings. The analyses showed that the total cost was strongly sensitive to the investment cost, with a maximum reduction of 15.76% when the investment cost was reduced by 20%. The NPV was significantly influenced by energy price, with the variations ranging from 2.83% to 15.12%. ZEB development in large buildings provided more financial profitability than in small buildings. Finally, the key effective financial parameters and the key persons responsible for supporting financial measures were proposed to promote ZEB project investment in Thailand. The increase in energy prices and the decrease in initial cost, especially the cost of the air-conditioning systems, will increase investment returns. However, such increments in energy price also affect small and low-income enterprises. For future implementations of ZEB, policymakers should investigate suitable measures and financial incentives.

The increase in global surface temperatures will surpass the 2 °C target set by the Paris Agreement unless carbon emissions are lowered to zero by 2050. To date, the building sector is responsible for 38% of all carbon emissions, thus one of the main targets is represented by the development of building strategies that can facilitate the transition toward carbon-neutral buildings. The main strategies are today represented by nearly zero energy buildings (nZEBs), zero energy buildings (ZEBs)/net zero energy buildings (NZEBs) and net zero carbon buildings (NZCBs). Particularly, NZCBs completely target zero operational and embodied carbon during their life cycles, fulfilling the leadership role in the decarbonization of the construction sector. Moreover, adopting the European Standard EN 15978:2011, carbon emissions can be precisely classified to enhance strategies aimed at reducing them. Commercial viability remains a fundamental economic driver, but the higher initial capital costs hinder the NZCBs. In addition, legislative, socio-cultural, technological, professional and geographical barriers hold back its diffusion. NZCBs can be met by a four-steps program: embodied carbon reduction, operational carbon reduction, increase in renewable energy supply and offset and carbon storage. Circular economy principles are strictly connected to design for disassembly and for adaptability to reduce embodied carbon, while passive design and solar and geothermal energy production can satisfy the renewable energy demand of the building. The aim of this narrative review is to determine and describe which is the current state of the art for NZCB definition, the drivers and barriers toward its application in a broader context and which strategies are eligible to meet the ambitious goal of zero operational and zero embodied carbon emissions. [ABSTRACT FROM AUTHOR]

Increasing demand for energy due to population growth and global warming has led to numerous environmental issues such as deforestation, destruction of the ozone layer, drought, storms, and floods. These have encouraged researchers to seek new ways to use clean, renewable energies. The construction of Zero Energy buildings in Iran cities can be a significant step forward in economic development and pollution reduction in metropolitan areas. This study aims to identify and prioritize suitable cities in Iran to build Zero Energy buildings. For this purpose, the fuzzy Delphi and multi-attribute decision-making (MADM) methods have been used. The cities that are suitable for the construction of zero-energy buildings were selected through interviews with individuals who are experts in the fields of architecture, urban planning, and energy management and who are familiar with the construction of Zero Energy buildings, as well as considering the results of previous research and the characteristics of different cities. Then, with the fuzzy Delphi method, the necessary indicators for the priority of the selected cities were determined, and their weight was determined. After that, the cities were prioritized using MADM methods. The results showed that Yasuj, Shiraz, Tabriz, and Arak are suitable cities to build Zero Energy buildings in Iran.

Without any assistance, the energy matching between air conditioner load demand and PV generation of PV direct driven Air Conditioners (PVACs) is inflexible. Phase Change Materials (PCMs) and building load flexibility can improve the real-time Zero Energy Probability (ZEP). In this paper, a coupling system consisting of PVACs, PCMs, and load flexibility was proposed for an office building. Sensitive analysis were conducted for different PCMs coupled with PVACs and load flexibility to improve the real-time ZEP with considering the PV capacity Factors (PVF), PCM type, and PCM thickness. According to the influence on the ZEP, the key parameters of the coupling system were ranked as follows: PVF > PCM melting temperature > PCM thickness. PCMs can reduce the PVF by 26.67% and assist the system achieving a 90% real-time ZEP in summer. The recommended PVF for the Hot-summer and Warm-winter and the Hot-summer and Cold-winter zone are 1.3 and 1.0, respectively, while the optimized PCM melting temperature are 27 °C and 26 °C, respectively. In summary, a complete evaluation method, a universal design route and different optimization schemes for PVACs coupled with PCMs and load flexibility were proposed in this paper, and it is conducive to the improvement of the real-time ZEP. [ABSTRACT FROM AUTHOR]

A major issue in the renewable energy supply of buildings is to establish a simultaneity of the fluctuating renewable energy generation and the energy consumption in buildings. This work provides a new case for a better understanding of how to establish this simultaneity. Future solutions are being explored in practice on the campus of the FH Westküste University of Applied Sciences in the Lecturing and Exhibition Building (LEB). The motivation was to design and operate a case building for research in energy science for teaching the bachelor's program Green Building Systems as well as for demonstration purposes for the general public. With a floor space of 207 m, the LEB is supplied with renewable energy from the adjacent energy park consisting of a 10 kW wind turbine and photovoltaic modules with 10 kWp. The heat and cold generation system consists of two reversible heat pumps: one is an air–water heat pump with approx. 7 kW heating and 6 kW cooling power, and the second is a brine–water heat pump with approx. 8 kW heating power and a depth of the two boreholes of 80 m. To match the energy generation and the energy consumption, different kinds of storage units, i.e., batteries with 3 × 8 kWh and storage tanks with 1000 L heat storage and 600 L cold storage, were installed as well as a smart automation system with a database. This paper evaluates measurement data from 2021. It is demonstrated that a fully renewable energy supply of the building is possible for most of the time from spring to autumn. In winter, an additional long-term energy storage, e.g., hydrogen, is necessary for certain days. [ABSTRACT FROM AUTHOR]

• Bibliometrics overview of ZEB publications. • Draw of the collaboration networks from ZEB research publications. • Brought out thematic trend of the development ZEB over the time. • Discussions of the main challenges and solutions for ZEB studies. Zero Energy Building (ZEB) is gaining more attention as a solution to significantly mitigate the environment concerns. However, a bibliometric analysis of the topic, a very useful method to analyze the database of published publications and reviews, is lacking. Especially, to provide when and how this concept has been brought out, insights into the state-of-art technology, the findings of the collaboration networks and the challenges of ZEB. To address this gap, in this paper, ZEB studies have been reviewed using multiple perspectives and analytical tools, such as VOSviewer and Biblioshiny to analyze the collaboration networks and the thematic trends of ZEB publications. The original data was retrieved in Scopus, a total of 1051 documents including research articles and reviews published from 1976 to 2020. The analysis of the number of publications over the years shows that the development of Zero energy building research has gone through three stages: a slow development period from 1076 to 1999, followed by a development from 2000 to 2010 and finally a rapid development from 2011 to 2020. The study also reveals different rankings, including the most widely collaborated scholars, the most cited scholars, the most published countries, etc. Therein, the United State, United Kingdom and China have the most research on ZEB. Based on the analysis of co-occurrence network and evolution of thematic keywords, it is found that energy efficiency and life cycle assessment (LCA) are the main challenges for the achievement of ZEB target. Finally, these challenges have been discussed and solutions provided. [ABSTRACT FROM AUTHOR]

Nearly-zero energy buildings (NZEB) would effectively improve building energy efficiency and promote building electrification. By using a carbon emission model integrated into a bottom-up mid-to-long term energy consumption model, this study analyzes the contribution of NZEB standards to carbon emission targets in the urban area of China by 2060. Three scenarios are set, namely BAU, steady development (S1), and high-speed development (S2). For BAU, the total carbon emissions will reach a peak of 1.94 Gt CO2 by 2040. In S1 scenario, total building carbon emissions will reach the peak of 1.72 Gt CO2 by 2030. In S2 scenario, the carbon emissions will reach a peak by 2025 with 1.64 Gt CO2. Under S1 scenario, which features consistency with NZEB market development and periodic improvement of building energy-efficiency standards, the carbon emission peak in 2030 will be accomplished. To achieve carbon neutrality by 2060, the upgrading of building energy standards to NZEB will contribute 50.1%, while zero-carbon electricity contribution is 49.9%. It is concluded that 2025, 2030, and 2035 could be set as mandatory enforcement years for ultra-low energy buildings, NZEB and zero energy building (ZEB), respectively.

This study summarizes the technology level and economic feasibility of two small 500 m2 public office buildings that achieved a first-class Zero Energy Buildings (ZEB) certification for the first time in Korea. In addition, a Life Cycle Assessment (LCA) reflecting the ZEB performance in the operation stage was analyzed, and the LCA factors considering the characteristics of small buildings were reviewed. Moreover, an economic analysis was performed through a Net Present Value (NPV) by reflecting the ZEB and LCA, and the results showed little economic feasibility. However, adding the environmental costs calculated through the LCA to the existing energy-saving costs could offset an additional 11.6–11.7%. Therefore, including the environmental impact and cost through these LCA evaluation techniques could be a positive step toward increasing the effectiveness of ZEB applications. This study is significant in that it conducted a comprehensive analysis through ZEB and LCA in terms of carbon reduction for small buildings that achieved a first-class ZEB certification, but it is limited to only two cases.

Along the roadmap to a Sustainable Real Estate-Scape, energy retrofit campaigns on wide city compartments represent a pivotal task, where the importance of the collaboration between the public and private sectors is crucial. Energy retrofit programs on building assets are subject to multiple uncertainty factors (e.g., climate, energy-economy forecasts, etc.) that act as a primary barrier to investment in this field. This paper aims to discuss risk management techniques to understand better how to deal with this kind of uncertainty. The research specifically addresses the techniques of sensitivity analysis and Monte Carlo simulation, focusing first on the phase of variables selection and their probability definition, including climatic, environmental, energy, economic, financial, and stochastic parameters. In this article, it is suggested to include correlation coefficients in the input variables of risk analysis, preferring the two-dimension Monte Carlo simulation to its simple version, since the results are more reliable when separating aleatory from epistemic uncertainty; thus, the results are more reliable. Moreover, it is seen how a sensitivity analysis based on percentile variations of the inputs provides a more accurate representation of risk if compared to the most common sensitivity analysis based on percentage deviations of the inputs. Conducting a sensitivity analysis using percentile variations gives realistic and reliable results, reflecting the tailored definition of uncertainty around the inputs on the basis of specific market analyses or historical series.

The Internet of Things (IoT) fosters the development of smart city systems for sustainable living and increases comfort for people. One of the current challenges for sustainable buildings is the optimization of energy management. Temperature monitoring in buildings is of prime importance, as heating account for a great part of the total energy consumption. Here, a solar optical temperature sensor is presented with a thermal sensitivity of up to 1.23% °C−1 based on sustainable aqueous solutions of enhanced green fluorescent protein and C‐phycocyanin from biological feedstocks. These photonic sensors are presented under the configuration of luminescent solar concentrators widely proposed as a solution to integrate energy‐generating devices in buildings, as windows or façades. The developed mobile sensor is inserted in IoT context through the development of a self‐powered system able to measure, record, and send data to a user‐friendly website. [ABSTRACT FROM AUTHOR]

Buildings are a major contributor to global energy consumption and energy-related carbon dioxide emissions. In light of the climate crisis, changes in the way we design, construct and use buildings are needed to reduce their environmental impact. Green Building Codes (GBCs) and rating systems have been developed around the world as a basis for green building practices. However, several studies raised doubts about the actual performance of certified buildings. Moreover, they use a per unit area approach to assess the use of resources rather than per capita, penalizing small buildings or those with high occupancy, ignoring the concepts of equity and shared common effort which are central to sustainable design. In this paper we propose adjustments to GBCs to encourage new ways of designing and evaluating green buildings. We introduce the Occupancy Correction Factor (OCF) which prioritizes smaller and more densely occupied buildings reducing land use, total operational energy consumption and embodied energy. Results show changes in their energy ratings of one to three levels both up and down, compared to their original ratings. In addition, we propose the prioritization of high-efficiency Low-Energy and Nearly Zero-Energy buildings over Net Zero Energy buildings, encouraging innovative urban design to enhance solar access and electricity production potential on-site or nearby. [ABSTRACT FROM AUTHOR]

Byconsuming35% of the final global energy, buildings are among major contributors to greenhouse gas emissions and global warming. If the economic justification challenge is addressed, zero energy buildings (ZEB), which are defined as buildings that generate as much renewable-based energy as they consume annually, can be a promising solution for energy efficiency improvement in the building sector. In this article, we propose a stochastic ZEB device sizing model considering uncertain parameters (i.e., building's electrical and thermal demands, solar irradiation, and outdoor temperature) and their correlation. The proposed model finds the optimal size of the thermal and electrical devices considering their nonlinear behaviors and temperature-dependent dynamics. Furthermore, two parallel computing-based solution algorithms (i.e., parallelism in the algebraic level using Schur complement decomposition and parallelism in the problem (scenario) level by progressive hedging) are proposed to solve the stochastic model. Using the real historical data, numerical studies on the Woodward library building, located on the University of British Columbia campus, illustrate the efficacy of the solution algorithms to handle large-scale nonlinear programming models with more than 32.8 million variables, which is the largest one reported in the literature so far. [ABSTRACT FROM AUTHOR]

The increase in global surface temperatures will surpass the 2 °C target set by the Paris Agreement unless carbon emissions are lowered to zero by 2050. To date, the building sector is responsible for 38% of all carbon emissions, thus one of the main targets is represented by the development of building strategies that can facilitate the transition toward carbon-neutral buildings. The main strategies are today represented by nearly zero energy buildings (nZEBs), zero energy buildings (ZEBs)/net zero energy buildings (NZEBs) and net zero carbon buildings (NZCBs). Particularly, NZCBs completely target zero operational and embodied carbon during their life cycles, fulfilling the leadership role in the decarbonization of the construction sector. Moreover, adopting the European Standard EN 15978:2011, carbon emissions can be precisely classified to enhance strategies aimed at reducing them. Commercial viability remains a fundamental economic driver, but the higher initial capital costs hinder the NZCBs. In addition, legislative, socio-cultural, technological, professional and geographical barriers hold back its diffusion. NZCBs can be met by a four-steps program: embodied carbon reduction, operational carbon reduction, increase in renewable energy supply and offset and carbon storage. Circular economy principles are strictly connected to design for disassembly and for adaptability to reduce embodied carbon, while passive design and solar and geothermal energy production can satisfy the renewable energy demand of the building. The aim of this narrative review is to determine and describe which is the current state of the art for NZCB definition, the drivers and barriers toward its application in a broader context and which strategies are eligible to meet the ambitious goal of zero operational and zero embodied carbon emissions.

The building sector is one of the leading contributors to global climate change. In recent decades, sustainable building assessment systems have been introduced in developed countries to improve the overall performance of buildings and to prevent greenhouse gas emissions, the main culprit of human activities in the current climate change. SBTool is a sustainable building evaluation system that can be calibrated according to the region, project type and phase of development, making SBTool a tailormade assessment system for a specific project. In this study, SBTool was adapted for the first time to an educational facility in Marmara/Turkey climate. The assessment parameters and their weights are arranged according to climate zone, building type, and accommodation characteristics. The created assessment tool was applied analytically to the Engineering Faculty Building of Yalova University/Turkey as a case study. The study showed that the government-run educational facilities could be evaluated with a tool that has 7 Issues, 21 Categories and 45 Criteria after adjustments made to follow its specific regional and local conditions. The assessed building got a Weighted Score of 3.30 points compared to the Target Weighted Score established at 3.08 points. The relative performance score was assigned to "B" which means an acceptable standard for a sustainable building. The methodology of assessment is presented step by step ending up with a graphical interpretation of the evaluation. [ABSTRACT FROM AUTHOR]

In Jordan, the residential sector is responsible for 43% of all power use and 21% of total energy usage. The use of energy for space heating and cooling accounts for more than 60% of residential energy use. The computer-generated residence, a typical one-storey Jordanian home with a functional floor area of 186 m2, is located in Amman and was modelled to be more energy efficient by incorporating renovating techniques to lower heating and cooling demand, attain marginal energy demand, and produce a high-quality indoor living environment. To get at the idea of passive design houses as appropriately depicted in this paper, various passive design tactics and methodologies were employed. Using DesignBuilder simulation software, Revit modelling software, solar energy analysis software, and assessment of the total energy consumption before and after the deployment of passive design approaches, the effects of each retrofit method were evaluated. The results of this study show that the yearly energy savings for heating is about 78%, and the indoor air quality and temperature of the residence can be significantly enhanced compared to its original situation. The total employed energy in the virtual building was scaled down from 56.57 kWh/m2 to 15.25 kWh/m² each year. [ABSTRACT FROM AUTHOR]

Sustainability has gained popularity and importance around the globe due to the ever-increasing effects of climate change and global warming on Earth. As of the 21st century, human endeavour has caused an enormous amount of damage to the environmental ecological system. Among which, one of the major contributors to the increase in the environmental issues and CO2 emissions are the conventional sources of energy, especially in the built environment. Globally, the built environment accounts for 12 percent of the world’s drinkable water, 40 percent of energy wastage and 35 percent of scarce natural resources, which in turn produces 40 percent of the total global carbon emission. Among which are educational buildings which tend to be a major contributor (as most of these facilities are old and conventionally built in the mid-1900s) Thus, with the education sector being an essential part of society, it becomes important to determine the energy performance and carbon footprint of these buildings. The United Arab Emirates (UAE) vision 2021 highlights the country's approach to the importance of providing the best education and adopting sustainable environmental infrastructure. Therefore, this study adopts a methodological approach based on semi-structured interviews and surveys, in order to compare the energy performance of three educational buildings within Higher Education establishments in the UAE as a case study. The study also evaluates the end user’s awareness of the importance of sustainable practices in the buildings and their preference for these buildings. The findings of this study conclude that Net Zero Energy Buildings (NZEBs) are the most efficient buildings in terms of energy performance, carbon consumption and heat generated. Therefore, it is important that the integration of these types of buildings is considered in educational establishments.

• An optimization method for energy system in zero energy buildings is presented. • The grid-friendly interaction index between building and the grid is introduced. • The uncertainty of design parameters is quantified by Monte Carlo method. • An optimization framework based on the results of deterministic optimization is presented. • The method is applied to an actual ZEB in Hong Kong. The intermittency and fluctuation of renewable energy sources cause large uncertainties in energy generation, not only leading to an energy imbalance between energy generation and utilization in Zero Energy Buildings (ZEBs) but also causing potential risks to the connected electricity grid. To address this issue, we propose a method for optimizing the design of the energy system in ZEBs, which emphasizes grid-friendly interaction with grids and considers the uncertainty quantification in renewable resources and cooling demand. This study introduces the grid-friendly interaction index to evaluate the compatibility of ZEB energy exchanges with the power grid. The aim is to optimize these exchanges for better grid integration. Utilizing 26 years of historical weather data, the Monte Carlo method is used to quantify the uncertainty of design parameters, thereby informing our optimization process. A comprehensive analysis, centered on an actual ZEB in Hong Kong, compares our uncertainty-based design methodology against traditional, deterministic design approach. The results demonstrate that the proposed method can achieve up to a 9 % cost reduction, a 6.8 % reduction in carbon dioxide emissions, and a 10.8 % improvement in grid-friendliness compared to deterministic design schemes. These results affirm the efficacy of the proposed methods in providing appropriate design options to meet diverse reliability demands. [ABSTRACT FROM AUTHOR]

The energy matching of PV driven air conditioners is influenced by building load demand and PV generation. Merely increasing energy performance of building or PV capacity separately may improve the energy balance on a large time resolution, the real-time energy mismatching problem is still serious. In this study, a coordinated optimization method of PV capacity, building design, and load flexibility is proposed for improving the real-time energy matching of PVAC system. Then, a methodology integrating data mining method (XG Boost) and parametric simulation was developed to identify the determinant parameters of PV system and building design, exploring feature importance and correlations. The results of XG Boost indicate that the PV capacity, shape factor, and SHGC are the most critical factors. Finally, based on the optimized building design, the PCM layer was appli ed to improve the real time energy matching. To achieve a goal of 90 % ZEP, the PCM capacity can be decreased by 50.4 % and 62.8 % in Guangzhou and Shanghai in the optimized building. Moreover, the PV capacity can be reduced by 23 % in Guangzhou. The findings of this study provide practical guidance for designing PVAC system coupling with building design and energy storage devices. [ABSTRACT FROM AUTHOR]

Buildings are a major contributor to global energy consumption and energy-related carbon dioxide emissions. In light of the climate crisis, changes in the way we design, construct and use buildings are needed to reduce their environmental impact. Green Building Codes (GBCs) and rating systems have been developed around the world as a basis for green building practices. However, several studies raised doubts about the actual performance of certified buildings. Moreover, they use a per unit area approach to assess the use of resources rather than per capita, penalizing small buildings or those with high occupancy, ignoring the concepts of equity and shared common effort which are central to sustainable design. In this paper we propose adjustments to GBCs to encourage new ways of designing and evaluating green buildings. We introduce the Occupancy Correction Factor (OCF) which prioritizes smaller and more densely occupied buildings reducing land use, total operational energy consumption and embodied energy. Results show changes in their energy ratings of one to three levels both up and down, compared to their original ratings. In addition, we propose the prioritization of high-efficiency Low-Energy and Nearly Zero-Energy buildings over Net Zero Energy buildings, encouraging innovative urban design to enhance solar access and electricity production potential on-site or nearby.

The building sector is the largest consumer of the primary sources of energy worldwide. The most commonly used primary sources of energy to generate electricity are oil, coal, peat, shale, natural gas, nuclear, hydro, renewables, biofuels, and waste. The energy demand by the building sector is about 40% of the world's energy production. Net Zero Energy Buildings (NZEBs) is the best solution recommended by the energy experts to reduce substantial pressure on primary sources of energy contributed by the building sector. There is a marginal gap between estimates made during the design stage and actual energy performance of residential buildings, primarily due to a lack of understanding of the factors affecting energy use and whole building simulations software limitations. The purpose of this research work was to conduct a comparative analysis of a predicted versus actual energy consumption of prototype Net Zero Energy Building (NZEB) constructed at Higher College of Technology, Muscat. Hourly Analysis Program (HAP V4.2) was used to predict energy demand of NZEB at HCT and same size regular house in Muscat. PVWatts calculator was used to determining possible power generation by the PV system installed on the roof in the form of a canopy. The constructed house was tested for one month to perform multiple tasks as per competition requirements in which one of the major tasks was to produce onsite energy production by PV panel's equivalent to the energy consumed by the house. The actual energy consumption results were compared with the simulated result and observed that actual energy demand of house was approximately 20% lower than that predicted by the simulation tool. The comparison of simulation results between NZEB and regular house indicated 61.24% less energy demand of NZEB, mainly due to less HVAC load. The simulation result for BEI of NZEB showed 87.20 kWh/m2/year as compare to 225.1 kWh/m2/year for same size regular house. The simulated result obtained from PVWatts calculator for competition period and actual production of an installed PV system at the top roof showed a minor deviation of 0.73% only. It is also observed from the results during the competition period house exported 1221 kWh energy to the grid. [ABSTRACT FROM AUTHOR]

• The way how is the building industry dealing with the concept of Demand Side Management is discussed. • International policies and initiatives are presented. • European initiatives, legislation and incentive programmes are presented. • The implementation of the nZEB requirement using the Passive House standard is presented. • A new approach is proposed - Early Stage Design method to ensure dwellings sustainability. Energy is now intrinsically linked to technological development, given it powers all such systems. The use of fossil fuels to supply the required energy is causing global environmental and health issues and is impacting on all life forms on the planet. Given increasing energy consumption, anthropogenic greenhouse gas emissions are consequentially increasing. Therefore, it is necessary to replace fossil fuels with renewable energies, biofuels and eco materials and related technologies and to try and find a way to develop sustainable zero emission solutions for all areas including constructions, transport and water resources. A critical and evolutionary way of thinking about the energy (and other resources) demand, management and supply is necessary because there are clear concerns about irreversible impacts to the world and a scarcity of the resources as well. Energy supplies should be mostly or entirely through renewable resources and highly efficient technologies put in place to achieve solution such as nearly Zero Energy Buildings (nZEB). At the same time, all the energy and resource use processes should be optimised in order to maximise the benefits, reduce the costs and promote stakeholders (consumers, companies or governments) network, toward a circular economy. This could be the way to supply the demand without increasing the scarcity of the resources and to simultaneously achieve environmental benefits. Therefore, it should be possible to improve productivity with the same amount of resources, by e.g. maximising the potential of smart grids and heuristically develop solutions with stakeholders. The concept of Demand Side Management (DSM) emerged after the energy crisis and it employs solutions such as reducing the daily peak load. At the same time, creating an educational grid is important to change the established paradigms, in order to promote critical thinking about the wasted resources and thinking holistically about overall consumption. This paradigm shift is changing the market, making it more competitive and reducing inefficiency by promoting the efficient use of resources including the deployment of energy storage during the periods of low consumption in daily peak shift. All these issues present a new way of thinking in the path towards sustainability, maximising the circular economy and reducing environmental impacts, making connections and using the Internet of Things to provide more information to all stakeholders. All these changes in social behaviour are related to the rational use of resources and make it easier to improve the existing infrastructures instead of building new ones. This paper analyses the state of the art at the European level in the production and use of renewable resources. A survey and analysis of the incentives to consumers and the policies to encourage the circular economy, and parallel analysis of benefits and drawbacks, was made. It is intended to identify the main forms of intervention and improvement, culminating in a reflection on how they should be applied to improve the expected results and make them more efficient and sustainable. This is intended to be an evolutionary framework of this concept, from the first stage of use of energy to its final utilisation. By approaching the task in a heuristic fashion, it is hoped to make the environment healthier, and it is envisaged that this concept will evolve from a linear to a life cycle approach. [ABSTRACT FROM AUTHOR]

In support of the clean energy transition, rooftop photovoltaics (RTPV) deployment has been globally advocated, enabling citizens as energy prosumers within their localised building environment. However, the effectiveness of RTPV implementation is influenced by diverse bioclimatic conditions. Here, we provide a critical climate-related RTPV characterisation across the globe, consisting of a comprehensive assessment of RTPV performance, taking into account global horizontal irradiation (GHI) and local environmental parameters, including space conditioning requirements in different climatic zones. Additionally, we examine the technological advancements aimed at improving efficiency in RTPV systems. Within a meta-data analysis, we find that the RTPV systems offer various advantages in terms of building overall energy performance, particularly in moderate and warm climates. We observe that typical or increased insulation values can offset the RTPV effect in uninsulated roofs. This is essential in regions with cold climates and helps to mitigate increased heating requirements during winters or higher cooling demands during summer nights. A relationship between the ratio of building space coverage to PV surface and GHI is proposed for low-energy buildings to calculate the space requirements for achieving net zero buildings, globally. Moreover, in hot climates, cooling the RTPV surfaces can enhance efficiency by up to 20 % and increase power output by up to 15 %. By advancing RTPV efficiency to 30 % with emerging technologies, the decarbonisation of high-rise buildings can be facilitated, alongside energy efficiency and RTPV implementation measures. Striking a balance between thermal insulation needs, we conclude that RTPV offers wide benefits across different climatic conditions. [Display omitted] • Rooftop PV deployment is crucial for decarbonisation and clean energy transition. • RTPV is energy-beneficial in moderate and warm climate conditions. • RTPV energy drawbacks in cold climate and hot climates can be mitigated. • PV efficiency of 30 % can accelerate the transition to NZEB in all climatic conditions. [ABSTRACT FROM AUTHOR]

In recent decades, European countries have developed concepts, definitions, and construction technologies for Zero Energy Building (ZEB) that are effective and correspond to their specific climates. Latin American countries are still trying to find adequate solutions which respond to the local climatic, cultural, social, technical, and economic context. As such, this paper aims to establish the basis of the minimum energy efficiency and the renewable threshold for the definition of ZEB in order to better understand the application in Panama, based on assessing the energy regulations implemented in Panama. To achieve this aim, a review concentrated on the concept-definition and implementation adopted by Latin American countries is presented first before the paper converges into defining a framework for application in Panama. Finally, a case-study-based theoretical framework proposing a ZEB definition for Panama is discussed. The results of this study showed a net primary energy balance, of which the range falls into a plus energy building definition, indicating that all of the cases studied could supply their electricity needs using Photovoltaic generation. All dwellings studied have the potential to become a plus energy building, depending on the available roof surface area. Finally, a strengths, weaknesses, opportunities and threats analysis is presented in order to assess and support the introduction of such a ZEB definition and framework.

Buildings are responsible for 35% of greenhouse gas emissions released in Europe. The highest potential for reduction of the environmental impacts is in the existing buildings' energy efficiency improvement. The paper introduces a development of new methodology for a rapid deep energy retrofitting of existing buildings applicable to residential housing stock in Central Europe. It briefly describes the steps from production of building information model of existing building to complete renovation. It presents experience from pre-production phases on a case study from the Czech Republic. Technical and non-technical barriers to be solved in the near future are summarised in the discussion.

Zero energy buildings (ZEBs) are targeted by several developed countries around the world which consequently promotes the progress toward achieving ZEBs. The concept of ZEBs is, however, uncommon in developing economies such as Oman. In 2011, The Research Council of Oman has announced a competition to design, construct and operate buildings that embrace sustainability principles. The first five eco-friendly buildings were designed and constructed by academic institutions in different climatic conditions of Oman. This project has significantly contributed toward raising awareness of energy efficiency and renewable energy systems in buildings. This paper outlines the design of sustainable energy systems of one of these five buildings. The ZEB prototype is located at the Sultan Qaboos University campus in Muscat, which is an extremely hot climate as classified by the ASHRAE Standard 169-2013. The ZEB building was designed with full manipulation of natural energy. This paper also reports the experimental results of its one year of operation. The results showed that energy use intensity (EUI) of 103 kWh/m2 was achieved by this building. The building was less than 3% from achieving its net-zero energy source/site/emissions status. Nonetheless, it was able to achieve a positive energy cost status because of the financial credits received from the exported energy, which is subjected to high cost feed-in tariffs. When grid interaction was considered, 40% of the building load was met by site generation. For 33% of the time, this building was independent of the electrical grid, which is comparable to other net-zero energy buildings located in other climates. While several experimental studies for ZEB performance have been described in literature for heating dominated climates, very few experimental studies have been published for cooling dominated climates. Hence, this study aims to fill the gap in the knowledge of energy performance of ZEBs located in this region. • The design of sustainable energy systems for ZEB in a hot climate is described. • ZEB is feasible in cooling dominated climate. • Experimental result for one year of operation for a prototype ZEB is described. • For 33% of the time, the building was independent of the electrical grid. 40% of the building load was met by the site generation. [ABSTRACT FROM AUTHOR]

In recent years, net zero or plus-energy buildings (PEB) have been widely analyzed and discussed for their benefits of increasing energy savings and reducing greenhouse gas emissions. A successful transition to energy-efficient buildings must, however, develop an efficient method that examines technical, economic, environmental and social criteria. In this paper, a method for design optimization based on spatial analysis combined with multi-criteria decision-making was proposed for achieving plus-energy buildings in Algeria. To apply the proposed method, a single family residential building was chosen. First, the annual energy consumption of the building at 40 locations was evaluated and the results are then interpolated for the whole country. The best energy efficiency measures and renewable energy are then chosen using the Analytic Hierarchy Process (AHP) method. Finally, energy balance and spatial analysis were carried out based on the geographical information system. The results showed the energy plus target was achieved in large parts of the country using a high-performance envelope, more efficient appliances and solar energy (solar photovoltaic and thermal). In addition, the southern provinces, mainly Adrar, Tindouf, Bechar, Ouargla, and Illizi, have identified the most suitable areas for setting up new buildings with an energy-plus target. In addition, applying the method will reduce the overall energy demand by 43 % and reduce GHG emissions in the country by around 23 % by 2030. Therefore, the method will have a significant impact on sustainability locally and worldwide. [ABSTRACT FROM AUTHOR]

Residential and service (office) buildings consume a large proportion of primary energy in Europe in the form of electricity and all other energy carriers. In response to this, the concept of near Zero Energy Buildings (nZEB) has been developed. These buildings have very low energy demands and integrate renewable energy to supply residual demand. nZEBs aim to increase energy efficiency from a demand-side user perspective. When looking at the entire energy system, there are also energy efficiency gains to be achieved on the supply-side. For example, from a district heating system. If an energy system becomes more efficient on the supply-side, then the question is how much energy needs to be saved on the demand-side, for instance by low energy buildings such as nZEBs. The purpose of this paper is to analyse and understand the implications from building new low energy buildings, i.e. nZEBs, within an energy system that is (a) transitioning to 100% renewable energy and (b) has substantially improved supply-side energy efficiency. A case study from Denmark is used to understand the outcome for the energy system when these new buildings are built in this context. The methodology and results of this study could be replicated for other European countries as well. The analysis looks at the total energy system heat savings, costs and biomass consumption. The paper shows that these new low energy buildings with very low heat demand do not deliver the expected benefits for the 100% renewable energy system transition in Denmark. This is due to the increased efficiency and flexibility of the energy supply system in the future. However, deep renovations of existing buildings are necessary. Furthermore, this paper demonstrates based on the Danish case, that as European countries decarbonise their energy systems over the next decades, they will need to carry out detailed energy system analysis to determine the extent to which heat demand should be reduced in buildings within the context of the transitioning energy system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Accurate building energy simulations need high modeling and computational burden. • ANN-based MPC is performed through a genetic algorithm for a nearly-zero energy building. • Multi-objective optimization of heating cost and thermal comfort is obtained. • Optimal control strategies for HVAC systems are achieved through MPC. • High benefits in terms of both heating cost and thermal comfort are proved. Using a simulation- and optimization-based framework that leverages artificial neural networks for the model predictive control of space heating operation, machine learning techniques are explored to predict the energy performance of a real nearly zero energy building located in Benevento (Southern Italy, Mediterranean climate). The framework's goal is to minimize heating energy costs and thermal discomfort by providing optimal values of setpoint temperatures on a day-ahead planning horizon based on weather forecasts. To achieve this, a Pareto multi-objective approach is applied, which considers thermal comfort via the adaptive theory of ASHRAE 55, assessing a comfort penalty function. The optimization problem is solved using a genetic algorithm in the MATLAB® environment. Objective functions are evaluated using the coupling between MATLAB® and EnergyPlus, which is used as building performance simulation tool. Multi-criteria decision-making is performed to select an optimal solution from the Pareto front while setting a limit to the comfort penalty. To test the framework, EnergyPlus weather data is used to simulate weather forecasts for typical days of the winter season. Two different economic scenarios are simulated in order to be able to analyze both conditions and given the variability of the electricity price. For the different days tested, the best results in terms of savings achieved through the proposed solution are on Feb. 28, corresponding to the coldest day and the highest energy cost, with daily savings of 26% compared to a reference control with a fixed setpoint of 21 °C, while maintaining similar comfort performance. The results suggest that optimized control is a crucial aspect of sustainable building design, and the proposed framework can be virtually implemented or integrated into automation systems for real-time model predictive control. [ABSTRACT FROM AUTHOR]