Search Results (208)

Developing positive energy districts (PEDs) is a key strategy in the global energy transition to reduce the high energy use and greenhouse gas emissions from the built environment. While the creation of new, energy-efficient urban areas as PEDs is essential, transforming existing districts is even more challenging, as they contain buildings of different types, ages, and energy performance levels. This study investigated energy efficiency improvements to facilitate the transition of an existing university campus toward PED operation. The NTNU Gløshaugen campus in Trondheim, Norway, was analyzed using a calibrated multi-building energy model (MBEM) developed using the URBANopt tool. Buildings were clustered into four age-based cohorts to assess the impact of targeted energy conservation measures (ECMs) on different construction periods. In addition, three energy efficiency scenarios were evaluated over the period 2025–2030 to capture the combined effects of new construction and renovation of existing buildings. Results showed that applying envelope improvement ECMs was more effective in older buildings, where lower baseline energy performance allowed for higher relative reductions in energy use. By the end of the simulation period, the specific energy use of the entire campus decreased from 252.2 kWh/m² in 2025 to 161.7 kWh/m² under moderate and 85.9 kWh/m² under deep retrofit conditions. These improvements create more favorable conditions for meeting the remaining energy demand through renewable sources, achieving an overall renewable coverage of 97%, and moving the campus closer to meeting PED targets. Full article

Distributed energy systems (DESs) are crucial for renewable deployment, but decentralised generation substantially increases flexibility requirements. Flexibility is framed as a system property that emerges from the coordinated operation of demand, storage and dispatchable generation across multi-energy carriers. Demand response schemes and demand-side management can provide flexibility, but their effective potential is constrained by user participation. Sector-coupling strategies and energy storage systems enable temporal and cross-sector decoupling between renewable generation and demand. Electrochemical batteries are technically mature and well suited for short-term balancing, but costs and environmental impacts are significant. Power-to-Heat with heat pumps and thermal energy storage is a cost-effective solution, especially when combined with low-temperature district heating. Electric vehicles, when operated under smart-charging and vehicle-to-grid schemes, can shift large charging demands feeding energy into the grid, facing battery degradation and infrastructure costs. Power-to-Gas and Power-to-X use hydrogen and electrofuels as long-term storage but are penalised by low round-trip efficiencies and significant capital costs if power-to-power with fuel cells is applied. On the supply side, micro-CHP can provide dispatchable capacity when fuelled by renewable fuels and combined with seasonal storage. Costs and efficiencies are strongly scale-dependent, and markets, regulation, digital infrastructure and social acceptance are key enablers of flexibility. Full article

This study investigates the transition to the circular economy (CE) model and its increasing application in industrial companies. The research context is the textile district of Prato, Tuscany region, that relies on a long historical tradition of CE application. Some industrial companies have been contacted, and their Administrators and CEOs have been interviewed, focusing on their understanding of the role of circular start-ups (CSUs) in the collaboration and relationships with large companies. The results show that this collaboration started for commercial purposes, since the companies interviewed in this study are producers of recycled yarns used by their customers, including CSUs, for the manufacturing of their garments. Over time, the collaboration further advanced, adding new types of interactions, characterized by environmentally and socially positive outcomes. This study shows that the collaboration between the small CSU Rifò and two of the largest companies of the Prato district as well as the outcomes in terms of environmental, energy and social benefits well extend over the micro, meso and macro levels of the CE model and reveal that the circular and sustainability performances of the selected CSU and its large partners are aligned with the goals of the district and the city of Prato towards consolidating themselves as a reference center of a CE and a circular city, respectively. This is an important result compared to the previous literature that encourages further future research to provide more generalizable results. Further, the case study of the Rifò regenerative circular business model shows the current “limits” of recycling and the need to thoroughly consider the CE model by implementing all CE principles and promoting a timeless and responsible fashion, conveying the emotional, environmental and social values behind garments. Full article

District energy is one of the most efficient heat distribution systems. The interface between the pipe network and buildings is made of thermal and hydraulic separation units named stations. The control of temperature on the secondary side is handled in substations. Several parameters influence control stability, such as differential pressure, mass flow, temperatures, valve inherent characteristics and controller tuning. There are different design approaches for stations in different geographies. However, one option is a generalist control loop setup, which is analysed here. Four sites in Sweden were monitored for performance (during the winter period and with the same hardware setups), and an analysis of the variability of controller tuning parameters was performed. For the purposes of laboratory comparison, the tests were executed with different configurations of generic control loop setups. The results, arranged into distribution histograms, show similarities between the laboratory and field setups. One can see that well-performing setups are close to a normal distribution, while the others are not. One key parameter is the controller setup and algorithm used. Proper tuning of the controller, together with differential pressure control, secures optimal performance of district energy stations. District heating stations with operations closer to the set point positively influence the performance of the whole grid and therefore improve the energy efficiency of the stations. Full article

As an integrated framework linking resource use and environmental sustainability, the WEF (Water–Energy–Food) system plays a vital role in achieving sustainable agricultural development. Focusing on the irrigation districts in the lower reaches of the Yellow River, this study constructed and applied a Super-Undesirable-SBM (super-efficiency undesirable slacks-based measure) model and a GTWR (geographically and temporally weighted regression) model from a WEF perspective to systematically analyze the spatiotemporal evolution and driving mechanisms of WEFSE (Water–Energy–Food Synergistic Efficiency) from 2000 to 2020. The overall WEFSE exhibited a continuous upward trend, with the spatial pattern gradually shifting from the southwest to the northeast and regional disparities becoming more pronounced. The efficiency demonstrated a significant positive spatial autocorrelation, indicating a stable clustering pattern of “high–high” and “low–low” efficiency areas. In terms of driving mechanisms, WEFSE evolved from being dominated by socio-economic drivers to a composite system jointly influenced by ecological and structural factors. Among these, PD (population density) and WP (proportion of water area) had increasingly positive effects, whereas PRE (precipitation) and NDVI (normalized difference vegetation index) imposed notable constraints. Meanwhile, PCL (proportion of cultivated land), GP (proportion of grassland), and AT (average temperature) exhibited significant spatial differentiation. This study highlights that the assessment of WEFSE and identification of its driving mechanisms using the Super-Undesirable-SBM and GTWR models can help to uncover the spatiotemporal dynamics of agricultural resource utilization, providing methodological support and decision-making insights for optimizing resource allocation and promoting sustainable development in the Yellow River irrigation districts and other complex agricultural systems. Full article

This study investigates the application of the Positive Energy District paradigm to two existing and morphologically diverse urban districts in Rome: Testaccio and Valco San Paolo. The research aims to evaluate the feasibility and effectiveness of district-scale energy retrofitting strategies, integrating dynamic simulation tools to model current energy behavior and assess future scenarios. The methodology combines a range of interventions including envelope insulation, high-performance glazing, HVAC system upgrades, efficient lighting solutions, and large-scale photovoltaic deployment. Additionally, the study explores the potential benefits of energy storage systems, with particular focus on the optimal sizing of lithium-ion battery solutions to enhance local self-consumption and reduce grid dependency. Key performance indicators are used to analyze the alignment between renewable energy generation and district demand, as well as the interaction with the electrical grid. By calibrating simulation models with real thermophysical and consumption data, the research ensures methodological robustness and enables the replicability of the proposed approach in other urban contexts. The study offers a comprehensive framework for planners and policymakers seeking to support the decarbonization and resilience of urban districts through the implementation of PEDs. Future developments will focus on optimizing storage management, assessing the environmental impact of battery life cycles, and integrating PEDs within broader urban energy ecosystems. Full article

This study proposes a practical manual for community engagement in Positive Energy District (PED) development. It integrates evidence from three European pilot cases (Austria, Sweden, Spain). Using a dual-tier framework, it integrates an engagement framework, the Theory-of-Change (ToC) sequence for dynamic stakeholder roadmaps, with an assessment framework (an eight-aspect PED Matrix). The ToC model clarifies the socio-organizational pathway from urgency to institutionalization while the roadmaps translate these steps into actionable involvement for public, private, civil, and academic actors across top-down, bottom-up, and hybrid approaches. The proposed ToC framework is further supported by the PED Matrix, covering technology, process, environmental, financial, managerial, governance, social, and legal dimensions, which aims to ensure a holistic and target-oriented assessment using a simple 0–3 maturity scale. Guided by the central research question, “How can community engagement be systematically conceptualized, implemented, and tested throughout the PED life cycle using an integrated ToC model, stakeholder roadmap, and multi-aspect evaluation Matrix?”, this study provides practical instruments for stakeholder profiling and adaptive participation design and demonstrates application across contrasting governance, cultural, and climatic contexts. The three use cases show how engagement strategies can be tailored to secure early wins, sustain momentum, and support long-term ownership and replication. The study thus offers decision-makers and practitioners a scalable, evidence-based approach to embed inclusive participation within technical PED delivery and to strengthen the social robustness of district-scale energy transitions. Full article

Background: Nutrition problems among primary school children increase the risk of illness, reduce school attendance, and impair academic performance. The Indonesian national school feeding program (ProGAS—Program Gizi Anak Sekolah) was developed to address these issues through the provision of healthy breakfast, nutrition education, and character building. Methods: This study employed a mixed-methods design involving 454 primary school students aged 8–14 years from 24 schools across four provinces. Data collection included structured questionnaires, 24 h dietary recalls, and anthropometric measurements. In-depth interviews with school principals, teachers, cooking teams, parents, students, nutritionists, and district education office staff were conducted to capture experiences and opinions on the ProGAS implementation. Results: ProGAS significantly improved students’ dietary diversity, meal frequency, handwashing with soap, and nutrition knowledge, alongside a positive trend in school attendance. Improvements included higher mean dietary diversity, increased proportion of students eating ≥3 meals/day, greater correct responses on balanced nutrition, and higher rates of handwashing before meals (all p < 0.01). Children also developed positive behaviors such as praying before meals, queuing, and taking responsibility for cleaning dishes. However, students’ breakfast habits did not significantly improve, the delivery of nutrition education was suboptimal, and no significant changes were observed in nutrient intakes or nutritional status based on BMI-for-age. While the energy and protein contributions of the ProGAS menu met the recommended 25–30% of daily requirements for breakfast, its micronutrient contributions remained below the recommended levels. Key management gaps include the delivery of nutrition education to students and the monitoring of implementation by local and national authorities. Conclusions: ProGAS demonstrated positive impacts on some dietary and hygiene practices as well as learning environment. To achieve greater improvements in breakfast habits, nutrient intake and nutritional status, it is recommended to strengthen the school feeding menus not only for dietary diversity but also for nutrient density, enhance capacity building for teachers, deliver regular and engaging nutrition education, and reinforce program monitoring. Full article

The increasing demand for decarbonized urban environments has intensified interest in integrating renewable energy systems within cities. This review investigates the potential of urban wind energy as a promising technology in the development of Positive Energy Districts, supporting the transition toward climate-neutral urban areas. A systematic analysis of recent literature is presented, covering methodologies for urban wind resource assessment, including Geographic Information Systems (GIS)-based mapping, wind tunnel experiments, and Computational Fluid Dynamics simulations. The study also reviews available small-scale wind technologies, with emphasis on building-integrated wind turbines, and evaluates their contribution to local energy self-sufficiency. The integration of urban wind systems with energy storage, Power-to-Heat solutions, and smart district networks is discussed within the PED framework. Despite technical, economic, and social challenges, such as low wind speeds, turbulence, and public acceptance, urban wind energy offers temporal complementarity to solar power and can enhance district-level energy resilience. The review identifies key technological and methodological gaps and proposes strategic directions for optimizing urban wind deployment in future sustainable city planning. Full article

In recent years, Positive Energy Districts (PEDs) have been interpreted in many—and often conflicting—ways. We recast PEDs as a vehicle for verifiable climate neutrality and present a declaration-ready assessment that integrates (i) a cumulative, science-based GHG budget per m² gross floor area (GFA), (ii) full life-cycle accounting, and (iii) time-resolved conversion factors that include everyday motorized individual mobility and quantify flexibility. Two KPIs anchor the framework: the cumulative GHG LCA balance (2025–2075) against a maximum compliant budget of 320 kg_CO2e·m⁻²_GFA and the annual primary energy balance used to declare PED status with or without mobility. We follow EN 15978 and apply time-resolved emission factors that decline to zero by 2050. Its applicability is demonstrated on six Austrian districts spanning new builds and renovations, diverse energy systems, densities, and mobility contexts. The baseline scenarios show heterogeneous outcomes—only two out of six meet both the cumulative GHG budget and the positive primary energy balance—but design iterations indicate that all six districts can reach the targets with realistic, ambitious packages (e.g., high energy efficiency and flexibility, local renewables, ecological building materials, BESS/V2G, and mobility electrification). Hourly emission factors and flexibility signals can lower import-weighted emission intensity versus monthly or annual factors by up to 15% and reveal seasonal import–export asymmetries. Built on transparent, auditable rules and open tooling, this framework both diagnoses performance gaps and maps credible pathways to compliance—steering PED design away from project-specific targets toward verifiable climate neutrality. It now serves as the basis for the national labeling/declaration scheme klimaaktiv “Climate-Neutral Positive Energy Districts”. Full article

Balconies are widely recognized for enhancing urban livability, making them attractive elements to incorporate in building renovation projects. However, their impact on energy performance remains insufficiently studied, particularly in temperate climates, like the Mediterranean, where both heating and cooling demands must be considered. This article evaluates the energy impacts of integrating open balconies into housing retrofits on the space conditioning demand of dwellings through spatialized analysis at the urban block scale. Focusing on Barcelona’s Eixample district, a parametric Urban Building Energy Modeling (UBEM) was employed to assess how balcony design interacts with urban morphology (orientation, obstructions), building features (window-to-wall ratio, WWR), and balcony length. Results reveal a seasonal trade-off at the block scale: balconies increase heating demand (0.1–1.6 kWh/m²·yr) by reducing winter solar gain but decrease cooling demand (0.1–3.8 kWh/m²·yr) through summer shading. Net effects vary by unit position, with south-facing and moderately glazed dwellings benefiting the most. Deeper balconies (1.5–2 m) amplify both effects, while optimal depth depends on the window-to-wall ratio. Under future climates, retrofits combining insulation and balconies mitigate rising cooling demands more effectively than insulation alone, reducing block-level demand by up to 16%. Although balconies alone show modest energy savings at the block scale, they enhance localized thermal resilience. The study highlights the need for integrated retrofit strategies that balance thermal insulation with solar protection to address both current and future energy challenges while enhancing occupant well-being. Full article

To address the global challenge of sustainable energy transition in cities, there is a growing demand for innovative solutions to provide flexible, low-carbon, and socio-economically profitable energy systems. In this context, there is a need for holistic evaluation frameworks for the prioritization and economic optimization of interventions. This paper provides a literature review on sustainable planning and economic impact assessment of innovative urban areas, such as Positive Energy Districts (PEDs), to analyze research trends in terms of evaluation methods, impacts, system boundaries, and identify conceptual and methodological gaps. A dedicated search was conducted in the Scopus database using several query strings to conduct a systematic review. At the end, 57 documents were collected and categorized by analysis approach, indicators, project interventions, and other factors. The review shows that the Cost–Benefit Analysis (CBA) is the most frequently adopted method, while Life Cycle Costing and Multi-Criteria Analysis result in a more limited application. Only in a few cases is the reduction in GHG emissions and disposal costs a part of the economic model. Furthermore, cost assessments usually do not consider the integration of the district into the wider energy network, such as the interaction with energy markets. From a more holistic perspective, additional costs and benefits should be included in the analysis and monetized, such as the co-impact on the social and environmental dimensions (e.g., social well-being, thermal comfort improvement, and biodiversity preservation) and other operational benefits (e.g., increase in property value, revenues from Demand Response, and Peer-To-Peer schemes) and disposal costs, considering specific discount rates. By adopting this multi-criteria thinking, future research should also deepen the synergies between urban sectors by focusing more attention on mobility, urban waste and green management, and the integration of district heating networks. According to this vision, investments in PEDs can generate a better social return and favour the development of shared interdisciplinary solutions. Full article

Using 31 provinces (cities and districts) on the Chinese mainland (2013–2023) as the research object, this study analyzes the development level of e-commerce through the entropy weight method and uses panel data to empirically test the driving effect of e-commerce development level on low-carbon development. According to this study, the overall development of e-commerce has a positive driving effect on low-carbon development. E-commerce development lowers the intensity of carbon emissions by optimizing regional industrial structures, innovating green technologies, and establishing resource sharing. Moreover, the analysis of the effects of regional heterogeneity reveals that, although low-level areas still have great development potential, high-level economic development areas have the greatest effect on low-carbon development. In conclusion, we clarify how e-commerce contributes to low-carbon development and provide resources for enhancing the quality and efficiency of e-commerce to conserve energy and reduce emissions. Full article