Search Results (218)

Urban agriculture (UA) is emerging as a promising strategy for sustainable food production in response to growing environmental pressures. Indoor vertical farming (IVF), combining Controlled Environment Agriculture (CEA) with Building-Integrated Agriculture (BIA), enables efficient resource use and year-round crop cultivation in urban settings. This study assesses the environmental performance of a prospective IVF system located on a university campus in Portugal, focusing on the integration of photovoltaic (PV) energy as an alternative to the conventional electricity grid (GM). A Life Cycle Assessment (LCA) was conducted using the Environmental Footprint (EF) method and the LANCA model to account for land use and soil-related impacts. The PV-powered system demonstrated lower overall environmental impacts, with notable reductions across most impact categories, but important trade-offs with decreased soil quality. The LANCA results highlighted cultivation and packaging as key contributors to land occupation and transformation, while also revealing trade-offs associated with upstream material demands. By combining EF and LANCA, the study shows that IVF systems that are not soil-based can still impact soil quality indirectly. These findings contribute to a broader understanding of sustainability in urban farming and underscore the importance of multi-dimensional assessment approaches when evaluating emerging agricultural technologies. Full article

The use of a rock-bed accumulator for a short-term heat storage and air exchange in a building facility is an economical and energy-efficient technological solution to balance and optimize the energy supplied to the facility. Existing scientific studies have not addressed, as yet, the environmental impacts of using a rock bed for heat storage. The purpose of the research is the environmental life cycle assessment (LCA) of a heat storage system in a rock-bed accumulator supported by a photovoltaic installation. The boundaries of the analyzed system include manufacturing the components of the storage device, land preparation for the construction of the accumulator, the entire construction process, including transportation of materials, and its operation in cooperation with a horticultural facility (foil tunnel) during one growing season, as well as the photovoltaic installation. The functional unit in the analysis is 1 square meter of rock-bed accumulator surface area. SimaPro 8.1 software and Ecoinvent database were used to perform the LCA, applying the ReCiPe model to analyze environmental impact. The analysis showed the largest negative environmental impact occurs during raw materials extraction and component manufacturing (32.38 Pt). The heat stored during one season (April to October) at a greenhouse facility reduces this negative impact by approx. 7%, mainly due to the reduction in the use of fossil fuels to heat the facility. A 3 °C increase in average air temperature results in an average reduction of 0.7% per year in the negative environmental impact of the rock-bed thermal energy storage system. Full article

In recent years, population growth, the enhancement of carbon emissions generation, and higher energy consumption have caused the movement to nearly zero-energy buildings. Additionally, the various strategies, phase change materials (PCMs) are suitable for reducing the energy consumption of a building. The focus of this study is to investigate the results of three scenarios that explore all the effective parameters for selecting a suitable Phase Change Material (PCM) for hot climate conditions in Saudi Arabia. The first scenario worked on choosing the best phase change material based on the climatic conditions and the selected area. To complete the optimization, the best thickness and placement of the two-layer phase change material were investigated in the second and third scenarios. The results indicated that optimized building using PCM 29 with 50 mm thickness reduced the energy consumption and carbon dioxide production by 20.72% and 21.05%, respectively. Furthermore, the outcomes of the study on two-layer phase change materials with different arrangements illustrated that the most proper location of PCMs caused 255.38 MWh of electricity consumption and 155.71 × 10³ kg of carbon dioxide production. Finally, as a novel integration, the results of using one-layer and two-layer PCM were added to the HOMER software to find the optimal hybrid energy systems. The findings showed that by integrating photovoltaic panels, diesel generation, batteries, and the grid, the cost of energy reached USD 0.162. Additionally, the grid purchase by using one-layer and two-layer phase change material was decreased by 21.2% and 24.3% compared to the base case. Full article

Buildings account for about a third of global energy and it is thus imperative to eliminate the use of fossil fuels to power and provide for their thermal needs. Solar photovoltaic (PV) technology can provide power and with electrification, heating/cooling, but there is often a load mismatch with the intermittent solar supply. Electric batteries can overcome this challenge at high solar penetration rates but are still capital-intensive. A promising solution is thermal energy storage (TES), which has a low cost per unit of energy. This review provides an in-depth analysis of TES but specifically focuses on phase change material (PCM)-based TES, and its significance in the building sector. The classification, characterization, properties, applications, challenges, and modeling of PCM-TES are detailed. Finally, the potential for integrating TES with PV and heat pump (HP) technologies to decarbonize the residential sector is detailed. Although many studies show proof of carbon reduction for the individual and coupled systems, the integration of PV+HP+PCM-TES systems as a whole unit has not been developed to achieve carbon neutrality and facilitate net zero emission goals. Overall, there is still a lack of available literature and experimental datasets for these complex systems which are needed to develop models for global implementation as well as studies to quantify their economic and environmental performance. Full article

Efficient carbon reduction pathways in the building sector are critical for urban decarbonization. This study predicts urban carbon emissions and establishes models to evaluate the carbon emission reduction potential of applying building low-carbon technologies (LCTs) at the urban scale. The models under consideration encompass a spectrum of active strategies, specifically heat pump (HP), rooftop photovoltaic (PV) systems, and smart heating, ventilation, and air conditioning (HVAC) systems, alongside passive strategies encompassing advanced building materials and building envelopes. The predictive calculations consider building typologies, technological evolution, adoption rates, and local policy constraints. Results indicate that by 2030, the building sector in Xi’an will account for over 30% of the city’s total carbon emissions. The integrated emission reduction effect of LCTs reaches 25.8%, with building materials contributing the most significantly at 9%. Notably, rooftop PV systems demonstrate the highest carbon reduction potential among active strategies, while HP exhibits the fastest annual growth rate in mitigation. Furthermore, the study evaluates the feasibility of these LCTs to accelerate progress toward carbon reduction goals in the building sector. Full article

Metalloporphyrins and porphyrins (MPs) have garnered increasing attention as potential candidates for molecular-based electronic devices and single-atom catalysis. Recent studies have found that electronic structure calculations are important factors in controlling the performance of MPs as building blocks for single-molecule devices. Our study investigates metalloporphyrins with central 3d-metals from Sc to Cu and chalcogen containing anchoring groups such as -SH, -SeH, and -TeH substituted at the meso-position of the porphyrin rings. We carried out Density Function Theory (DFT)-based calculations to determine the ground state geometry, spin multiplicity, spatial distribution of the molecular orbitals, and electronic structure descriptors to gain insights into the reactivity trends and possible impact on factors influencing electron transport properties. The results suggest that the central metal shapes the spin multiplicity, while variations between sulfur, selenium, and tellurium play a role in charge distribution. This study provides insights into how the selection of the central metal and control of spin channels influence the electronic structure and reactivity of metalloporphyrin molecules. The knowledge provided here can play a role in the design of porphyrin-based molecular materials for diverse applications in molecular junctions, catalysis, photovoltaics, and sensing. Full article

One of the most important trends in today’s construction is energy efficiency. Nowadays, construction is undergoing a revolution thanks to modern technologies. Technological innovations not only speed up the construction process but also improve the quality, durability, and safety of the structure, ensure energy efficiency, as well as aesthetics and comfort of use. Modern technologies, such as photovoltaic panels and heat pumps, can produce their own electricity and heat for buildings’ own needs with minimal use of fossil fuels. This not only leads to economic benefits, but also has a positive impact on the environment. Furthermore, choosing the right materials is the key factor in sustainable construction. Concrete, steel and other traditional building materials, although durable, have a negative impact on the environment due to the high energy consumption during their production. This study employed a SWOT-TOWS analysis to determine the strengths, weaknesses, opportunities, and threats of the basic construction materials used for sustainable building. Its purpose was to compile all construction materials and evaluate them using the same technological, environmental, and socio-economic indicators. The results of the analysis allowed for the comparison of materials in terms of their usability in sustainable construction and provided the opportunity to determine strategies for their further application, thereby filling the research gap in this area. Taking into account care of the natural environment, the article presents current trends in modern sustainable construction in the world. Using SWOT analysis, the advantages and disadvantages of sustainable construction were indicated, and the economic, social, legal, environmental, and technological barriers to their development were discussed. Particular attention was paid to the use of pro-ecological technologies that reduce energy consumption and greenhouse gas emissions. Full article

With the intensification of global climate change, buildings in hot climate zones face increasing challenges related to high energy consumption and thermal comfort. Building integrated photovoltaic (BIPV) façades, which combine power generation and energy saving potential, require further optimization in their climate-adaptive design. Most existing studies primarily focus on the photoelectric conversion efficiency of PV modules, yet there is a lack of systematic analysis of the coupled effects of temperature, humidity, and solar radiation intensity on PV performance. Moreover, the current literature rarely addresses the regional material degradation patterns, integrated cooling solutions, or intelligent control systems suitable for hot and humid climates. There is also a lack of practical, climate specific design guidelines that connect theoretical technologies with real world applications. This paper systematically reviews BIPV façade design strategies following a climate zoning framework, summarizing research progress from 2019 to 2025 in the areas of material innovation, thermal management, light regulation strategies, and parametric design. A climate responsive strategy is proposed to address the distinct challenges of humid hot and dry hot climates. Finally, this study discusses the barriers and challenges of BIPV system applications in hot climates and highlights future research directions. Unlike previous reviews, this paper offers a multi-dimensional synthesis that integrates climatic classification, material suitability, passive and active cooling strategies, and intelligent optimization technologies. It further provides regionally differentiated recommendations for façade design and outlines a unified framework to guide future research and practical deployment of BIPV systems in hot climates. Full article

Traditional photovoltaic-powered forced air-cooling systems face significant challenges in balancing energy efficiency and thermal comfort due to temperature sensitivity, mechanical ventilation energy consumption, and spatial constraints. This study aims to enhance building energy efficiency by integrating a radiant cooling ceiling (RCC) with a phase change material (PCM) thermal storage system, addressing the limitations of traditional photovoltaic-powered cooling systems through optimized material design and dynamic energy management. A ternary PCM mixture (glycerol–alcohol–water) was optimized using differential scanning calorimetry (DSC), demonstrating superior latent heat storage (361.66 J/g) and phase transition temperature (1.91 °C) in the selected “Slushy Ice” formulation. A 3D transient thermal model and experimental validation revealed that the RCC system achieved 57% energy savings under quasi-steady operation, with radiative heat transfer contributing 55% of total cooling capacity. The system dynamically stores cold energy during peak photovoltaic generation and releases it via RCC during low-power periods, resolving the “cooling energy consumption paradox”. Key challenges, including PCM cycling stability and thermal response time mismatches, were identified, with future research directions emphasizing multi-scale simulations and intelligent encapsulation. This work provides a viable pathway for improving building energy efficiency while maintaining thermal comfort and for improving building energy efficiency in temperate zones, with future extensions to arid and tropical climates requiring targeted material and system optimizations. Full article

This study focuses on a residential project in the Haidian District of Beijing, China, employing life cycle assessment (LCA) integrated with building information modeling (BIM) to quantitatively analyze carbon emissions throughout the building life-cycle, including material production, transportation, construction, operation, demolition, and recycling. The results show that the operation and production stages are the primary sources of carbon emissions, accounting for 72.51% and 47.17%, respectively. In contrast, transportation, construction, and demolition contribute relatively minor emissions, at 3.94%, 2.08%, and 0.69%, respectively. Furthermore, renewable energy systems, building recycling, and urban green spaces as carbon sinks contribute negative emissions of −10.96%, −10.48%, and −4.95%, respectively. It should be noted that these percentages reflect the net contributions to total carbon emissions throughout the building’s life-cycle, taking into account both emission sources and sinks. As such, the inclusion of negative emissions from renewable energy systems, recycling, and urban green spaces leads to some stages having a cumulative percentage exceeding 100%. Based on these findings, this paper recommends adopting low-carbon building materials over traditional ones and widely promoting photovoltaic (PV) systems with energy storage technologies to effectively reduce carbon emissions. This study serves as a valuable reference for Beijing and other regions with similar climatic conditions, highlighting the importance of integrated emission reduction strategies to promote a green transition in the construction sector. Full article

Dynamic building envelopes integrated with renewable energy sources, termed Dynamic and Renewable Source Building Envelopes (DREBE), provide an innovative approach to optimizing building envelope designs. Yet, these systems are not mature enough and not widely adopted in the industry and few literature resources are employed to understand them. These systems dynamically respond and adapt to various environmental, energy, and occupancy demands for higher energy efficiency and comfort levels compared to traditional building envelopes while simultaneously producing energy. Their potential in climate change mitigation and fostering sustainable urban development warrants great attention from industry and urban planners. Especially in positive energy districts, which aim to reach net-positive energy goals through utilizing smart energy efficient building systems on the district level. This paper reviews innovative systems like dynamic photovoltaic shading devices and phase change materials and evaluates their performance by answering two research questions, what are the current DBE trends and are they feasible in achieving net-positive energy consumption? The analysis conducted reveals the dominance of solar-based dynamic renewable energy systems and a great need for alternatives. The study suggests that alternatives like wind as a renewable energy source should be studied with dynamic systems. Moreover, the study highlights current research gaps including insufficient data on long-term application and economic costs associated with such systems. To address this gap, the study suggests exploring in depth some of these systems and then branching into various combinations of dynamic envelope systems with multiple renewable or adaptive components to further enhance the overall building performance. By synthesizing the current body of literature, this paper gives insights into advancing the application of the dynamic building envelope systems and highlights their crucial role in the future of sustainable urban environments. Full article

In response to the significant increase in cooling needs for the built environment due to climate change, hybrid air conditioning units can provide energy efficient alternatives to vapor compression systems. This paper reviews the reported energy performance of integrated air conditioning systems consisting of three types of hybrid options: direct expansion (DX) combined with evaporative cooling, DX with desiccant, and evaporative cooling combined with desiccant. In addition, the reported analyses of integrating these hybrid systems with phase change materials (PCMs) and/or photovoltaic (PV) systems are considered. The evaluated analyses generally confirm that integrated air conditioning systems offer substantial energy saving potential compared to traditional vapor compression cooling units, resulting in substantial economic and environmental benefits. Specifically, hybrid systems can reduce the annual energy consumption for space cooling by 87% compared to traditional air conditioning units. This review analysis indicates that hybrid systems can have a coefficient of performance (COP) ranging from 6 to 16 compared to merely 3 to 5 for conventional systems. Additionally, liquid desiccant cooling systems have reported notable improvements in dehumidification efficiency and energy savings, with payback periods as low as three years. Future work should focus more on real-building applications and on conducting more comprehensive cost–benefit analyses, especially when integrating more than two technologies together. Full article

Thin-film solar cells (TFSCs) represent a promising frontier in renewable energy technologies due to their potential for cost reduction, material efficiency, and adaptability. This literature review examines the key materials and advancements that make up TFSC technologies, with a focus on Cu(In,Ga)Se₂ (CIGS), cadmium telluride (CdTe), and Cu₂ZnSnS₄ (CZTS) and its sulfo-selenide counterpart Cu₂ZnSn(S,Se)₄ (CZTSSe). Each material’s unique properties—including tuneable bandgaps, high absorption coefficients, and low-cost scalability—make them viable candidates for a wide range of applications, from building-integrated photovoltaics (BIPV) to portable energy solutions. This review explores recent progress in the enhancement of power conversion efficiency (PCE), particularly through bandgap engineering, alkali metal doping, and interface optimization. Key innovations such as silver (Ag) alloying in CIGS, selenium (Se) alloying in CdTe, and sulfur (S) to Se ratio optimization in CZTSSe have driven PCE improvements and expanded the range of practical uses. Additionally, the adaptability of TFSCs for roll-to-roll manufacturing on flexible substrates has further cemented their role in advancing renewable energy adoption. Challenges remain, including environmental concerns, but ongoing research addresses these limitations, paving the way for TFSCs to become a crucial technology for transitioning to sustainable energy systems. Full article

Amidst global warming and energy crises, low-carbon building design is essential. China, the largest carbon emitter, commits to peaking emissions by 2030 and achieving carbon neutrality by 2060. This study focuses on low-carbon strategies for industrial buildings in cold regions, aiming to develop optimization designs centered on carbon emissions. Using ENERGYPLUS and the “standard coal method”, it quantifies operational carbon emissions and analyzes the impact of design methods on energy consumption across architectural layout, materials, and photovoltaic technology. This study, set in Xi’an and Yulin, assesses low-carbon techniques in cold and severely cold climate zones. It demonstrates that, for the architectural layout, the orientation of the building has a relatively small impact on carbon emissions, while an increase in the window-to-wall ratio significantly increases the carbon emissions of the building. For the building materials, the form of window glass, the reflectivity of roofs and walls, and the thickness of roof and wall insulation significantly affect carbon emissions. For the photovoltaic technology, the angle of photovoltaic roofs has no significant impact on carbon emissions. By further comparing the effectiveness of various low-carbon design technologies in reducing building carbon emissions, it was found that choosing more appropriate wall insulation boards can provide more significant carbon reduction effects at the same cost. Full article

Building-integrated photovoltaic (BIPV) systems present a promising avenue for integrating renewable energy generation into urban environments. However, they pose unique challenges, including higher planning efforts and reduced yield generation compared to conventional rooftop systems. Despite these challenges, the double use of area and the high potential in urban landscapes offer compelling advantages. Modules have become highly customizable to fit architect’s requirements in sustainable yet also aesthetic building material. This paper discusses the results of a “living laboratory” in Berlin, which is both a typical building with a ventilated curtain wall and a unique showcase for BIPV technology. Through careful analysis of various factors, including module positioning, ventilation, and shading, this study demonstrates the feasibility and practicality of BIPV integration. The “living lab” not only highlights the technical viability of BIPV systems but also underscores their potential to enhance architectural aesthetics and promote sustainability and carbon-neutrality in urban landscapes. Full article