Search Results (191)

The rapid growth of graphics processing unit (GPU)-accelerated AI workloads has made data centers significant sources of medium-grade waste heat, creating both a sustainability challenge and an urban decarbonization opportunity. This paper presents the Cascaded Exergy-Economic Valorization (CEEV) framework, a three-stage system that converts data-center waste heat through (1) an organic Rankine cycle for GPU liquid-cooling loops at 65–85 °C; (2) a transcritical CO₂ heat pump, upgrading residual heat to 75–90 °C; and (3) thermochemical energy storage using SrBr₂·6H₂O for seasonal heat banking. The framework introduces two metrics: the Exergy Value Index (EVI, $/kJ) and the Levelized Cost of Stored Heat (LCSH, $/kWhth). Results for a 10 MW liquid-cooled data center across three climate zones show cascade exergy utilization of 31.2–38.7%, operational cost reductions of 15–25%, 20-year NPV of $2.2–8.4 million, and payback periods of 5.8–7.8 years. The simpler HP (heat pump) +TCES (thermochemical energy storag) configuration achieves higher deterministic Net Present Value (NPV) because it preserves the full waste-heat temperature for the heat pump; however, the full three-stage cascade becomes preferable when electricity prices exceed approximately $50/MWhe, when revenue diversification is valued, or when real-options flexibility is important. Real-options analysis shows that traditional NPV undervalues cascaded waste-heat recovery investments by 18–32%. Even without carbon credit revenue, NPV remains positive at $1.6–6.1 million, confirming that district-heating sales and electricity revenue alone can support investment. The CEEV framework advances sustainable data-center development by providing quantifiable tools for waste-heat performance assessment, supporting policy instruments such as the EU Energy Efficiency Directive and the German EnEfG, and aligning with SDGs 7, 9, 11, and 13. Full article

The planned Lubiatowo–Kopalino nuclear power plant (NPP) on the Polish Baltic coast requires a cooling technology that balances energy security, economic efficiency, and compliance with a multi-layered framework governing thermal discharge in a sensitive sea. This article integrates regulatory analysis across four instruments (EU Water Framework Directive, Polish discharge standards, HELCOM Baltic guidelines, and IAEA practice) with site-specific evidence from a 2D advection-diffusion thermal plume model. Four cooling options (once-through seawater, closed-loop towers, dry-air, and hybrid) are evaluated against regulatory criteria and against the documented vulnerabilities of the southern Baltic: eutrophication, restricted flushing, and ongoing warming. The modelling indicates that the acute thermal plume (ΔT ≥ 2 °C) remains limited to approximately 1.18 km² even under summer 90th-percentile conditions, whereas low-magnitude warming (ΔT = 0.1–0.5 °C) extends over approximately 1886.6 km². Although the once-through system with a multi-port diffuser satisfies current regulatory criteria, the extensive far-field anomaly represents an additional ecological stressor for an already eutrophic and warming marine ecosystem. A staged hybrid approach, with the first unit on validated once-through cooling and subsequent units on hybrid dry/wet systems, emerges as the most sustainable pathway, balancing empirical learning, regulatory foresight, and long-term climate resilience. The analysis offers a transferable framework for thermal-discharge assessment in shallow, microtidal, nutrient-enriched coastal seas, while demonstrating consistency with established regulatory practice and published knowledge on thermal-plume behaviour. Full article

The article presents selected problems related to the modernization of large-panel buildings in the context of the requirements arising from the EU EPBD (Energy Performance of Buildings Directive). The study has an exploratory character and is based on qualitative case study analyses of selected large-panel residential buildings representing different prefabrication systems and modernization conditions. The characteristic features of prefabricated buildings are outlined, and the main modernization barriers are identified, including structural limitations, insufficient thermal performance of building envelopes, outdated technical systems, and organizational and legal challenges resulting from ownership structures. Particular attention is given to the EPBD requirements concerning energy efficiency improvement, CO₂ emission reduction, and the implementation of the zero-emission building (ZEB) standard. The analysis indicates that the modernization of large-panel buildings requires a systemic approach integrating technical, economic, and organizational measures. The importance of comprehensive thermal retrofitting and the integration of renewable energy sources is emphasized. The findings also suggest that digital tools such as BIM (Building Information Modeling) may support modernization planning and building information management. The conclusions of the article indicate that the effective implementation of the EPBD provisions for large-panel buildings will only be possible with simultaneous systemic support, including financial and regulatory instruments, as well as the development of technical and organizational competencies within the construction sector. Full article

At present, treated wastewater may still contain residual nutrients and micropollutants, including heavy metals, pharmaceuticals, and dyes, which can negatively affect receiving water bodies. Increasingly stringent environmental regulations, including Directive (EU) 2024/3019, require both enhanced removal of these contaminants and greater integration of renewable energy sources in wastewater treatment plants. This paper presents a review of biomass-based wastewater polishing technologies employing biological agents such as microalgae, fungi, bacteria, co-cultures and duckweed for the removal of residual contaminants from treated effluents. The compiled data indicate that while optimal conditions can drive pollutant removal efficiencies beyond 90%, system performance varies widely depending on species selection, wastewater characteristics, and operational conditions (e.g., pH, temperature, salinity, nutrient availability, and light intensity). In addition to effluent polishing, the produced biomass can be valorized for bioenergy generation, contributing to renewable energy production and supporting circular economy principles in wastewater treatment plants. Despite these benefits, biomass harvesting remains a major technical and economic bottleneck, often representing a significant share of operational costs and limiting large-scale implementation. Overall, biomass-based treatment technologies are a promising approach for improving effluent quality and supporting renewable energy objectives; however, further advances in biomass recovery are required for broader application. Full article

Food markets represent a public good essential for urban supply and as intergenerational spaces supporting the small-scale economy, yet they face growing challenges in adapting to sustainability regulations and circular economy requirements. This study examines the current state of sustainability in Madrid’s municipal markets through interviews and questionnaires administered to market managers, analyzing building characteristics, renewable energy systems, passive savings strategies, and energy costs across different market typologies. Results reveal that in December 2025, only 9% of markets had solar thermal installations, while merely 11% were planning photovoltaic solar panel projects—figures insufficient to meet current EU energy efficiency mandates. The findings demonstrate a significant gap between existing infrastructure and the requirements of the Directive (EU) 2023/1791, which supersedes previous directives. These results indicate an urgent need for accelerated implementation of renewable energy systems in market buildings to achieve sustainability targets. The study contributes baseline data for developing intervention strategies that can reduce energy consumption and align Madrid’s market network with European decarbonization goals for 2030 and 2050. Full article

Directive (EU) 2024/3019 updates and introduces new approaches to the collection, treatment, and discharge of urban wastewater. The directive aims to safeguard the environment and human health, reduce greenhouse gas emissions within the wastewater treatment cycle, improve energy efficiency, and foster the transition towards climate neutrality, while promoting the circular economy and the reuse of water resources. Within this framework, the reuse of treated urban wastewater emerges as a strategic lever to confront the growing challenge of water scarcity, to support circular economy principles, and to alleviate pressure on natural water reserves. This paper, starting from the European and Italian regulatory frameworks for urban wastewater management, provides an in-depth analysis of potential reuse pathways, highlighting both the advantages and the challenges associated with their application. Full article

Wastewater treatment plants (WWTPs) are among the most energy-intensive components of urban infrastructure. In light of the revised EU directive on municipal wastewater treatment, which targets energy neutrality by 2045, effective energy management in this sector is becoming essential. This article reviews the current knowledge regarding energy consumption in WWTPs and analyses opportunities to increase their energy self-sufficiency by reducing energy demand and recovering energy. Key factors influencing energy consumption are discussed, including facility size, the range of technological processes used, automation level, and equipment condition. Attention is given to aeration systems, which account for the largest share of electricity consumption, and the possibilities for their modernization and optimization using energy-efficient diffusers and advanced process control systems. The potential for recovering chemical energy from sewage sludge is analyzed, with emphasis on anaerobic digestion and co-digestion with other organic wastes. Alternative sludge conversion methods, such as incineration, pyrolysis, gasification, and hydrothermal carbonization, are also presented. The analysis is complemented by technologies for recovering physical energy from wastewater, including the use of thermal energy via heat pumps and hydraulic energy from wastewater flow. The findings indicate that achieving energy self-sufficiency in WWTPs requires site-specific, hybrid solutions combining energy savings with selective energy recovery, considering technical and economic conditions. Full article

In response to the growing challenges of climate change and environmental degradation, the European Union announced the Green Deal on 11 December 2019, aiming for climate neutrality by 2050. To achieve this, a series of regulatory measures have been introduced to promote sustainability in the construction sector. This paper examines key EU regulations that, while not explicitly mandating wood, create conditions favorable to timber and wood-based products due to their low-carbon and renewable properties. The Carbon Removal Certification Framework (CRCF) encourages timber adoption through voluntary carbon removal incentives, whereas the new Construction Products Regulation (CPR) represents a mandatory intervention, embedding environmental and climate criteria directly into market standards. Additional regulations, including the Ecodesign for Sustainable Products Regulation (ESPR), the Energy Performance of Buildings Directive (EPBD), the Carbon Border Adjustment Mechanism (CBAM), the Nature Restoration Law (NRL), and the Regulation on Deforestation-Free Products (EUDR), further support wood by promoting resource efficiency, responsible sourcing, energy performance, and long-term carbon storage. Together, these measures form a multi-layered framework in which voluntary and binding instruments interact, indirectly supporting sustainable construction practices. Given its ability to store carbon over extended periods and achieve a net negative footprint in life cycle assessments, wood emerges as a strategic material for advancing the EU’s climate objectives. Full article

District heating systems are central to Europe’s decarbonisation strategy and its 2050 climate-neutrality objective. However, district heating is deeply embedded in the socio-economic system and the built environment. This makes compliance with policy targets at the local level particularly challenging. The issues are attributable to two factors. Firstly, the process is characterised by a high degree of complexity and multidimensionality. Secondly, there is a scarcity of local resources (e.g., land, surface waters, waste heat, etc.). In Bucharest, Romania, the largest district heating system in the European Union, the process of decarbonisation represents a particularly complex challenge. The system is characterised by large physical dimensions, high technical wear, heavy dependence on natural gas, significant heat losses and complex governance structures. This paper presents a strategic planning exercise for aligning the Bucharest system with the Energy Efficiency Directive 2023/1791. Drawing on system data, investment modelling, and local resource mapping from the LIFE22-CET-SET_HEAT project, the study evaluates scenarios for 2028 and 2035 that shift heat generation from natural gas to renewable, waste heat, and high-efficiency sources. The central objective is the identification of opportunities and issues. Options include large-scale heat pumps, waste-to-energy, geothermal and solar heat. Heat demand profiles and electricity price dynamics are used to evaluate economic feasibility and operational flexibility. The findings show that the decarbonisation heat supply in Bucharest is technically possible, but financial viability hinges on phased investments, interinstitutional coordination, regulatory reforms and access to EU funding. The study concludes with recommendations for staged implementation, coordinated governance and socio-economic measures to safeguard heat affordability and system reliability. Full article

The shift towards the integration of and transition to renewable energy has led to an increase in renewable energy communities (RECs) and smart grids (SGs). The significance of these RECs is mainly energy self-sufficiency, energy independence, and energy autonomy. Despite this, in low- and middle-income countries and regions like Pakistan and the Middle East, SGs and RECs are still in their initial stage. However, they have potential for green energy solutions rooted in their unique geographic and climatic conditions. SGs offer energy monitoring, communication infrastructure, and automation features to help these communities build flexible and efficient energy systems. This work provides an overview of Pakistani and Middle Eastern energy policies, goals, and initiatives while aligning with European comparisons. This work also highlights technical, regulatory, and economic challenges in those regions. The main objectives of the research are to ensure that residential service sizes are optimized to maximize the economic and environmental benefits of green energy. Furthermore, in line with SDG 7, affordable and clean energy, the focus in this study is on the development and transformation of energy systems for sustainability and creating synergies with other SDGs. The paper presents insights on the European Directive, including the amended Renewable Energy Directive (RED II and III), to recommend policy enhancements and regulatory changes that could strengthen the growth of RECs in Asian countries, Pakistan, and the Middle East, paving the way for a more inclusive and sustainable energy future. Additionally, it addresses the main causes that hinder the expansion of RECs and SGs, and offers strategic recommendations to support their development in order to reduce dependency on national electric grids. To perform this, a perspective study of Pakistan’s indicative generation capacity by 2031, along with comparisons of energy capacity in the EU, the Middle East, and Asia, is presented. Pakistan’s solar, wind, and hydro potential is also explored in detail. This study is a baseline and informative resource for policy makers, researchers, industry stakeholders, and energy communities’ promoters, who are committed to the task of promoting sustainable renewable energy solutions. Full article

This paper addresses the highly important and timely issue of the energy transition, a topic of particular relevance within the European Union (EU), which has long been a global leader in pursuing climate neutrality. The article proposes a novel framework for monitoring energy transition progress and its temporal dynamics across the EU countries, adopting a decade-long analytical horizon. The research employs the Dynamic Energy Transition Assessment (DETA) method, which is structured around five key pillars of the energy transition: (1) decarbonization and the shift toward clean energy; (2) energy security and system resilience; (3) energy justice, health impacts, and affordability; (4) energy efficiency and energy management; (5) development, innovation, and modernization of energy infrastructure. Applying this method enabled the study to meet its central objective: evaluating the level of development of these pillars, analyzing the balance among them, and examining both the direction and speed of changes over time. This dynamic approach integrates three core components of transformation processes, state, quality (coherence), and pace of change, offering an innovative combination of structural and temporal perspectives. The originality of this framework lies in its ability to capture the multidimensional and evolving nature of the energy transition. The study is based on 19 indicators, with indicator weights determined through Entropy and Criteria Importance Through Intercriteria Correlation (CRITIC) analytical methods, while pillar weights were assigned using the AHP method in alignment with EU strategic priorities. The findings reveal substantial variation and dynamism in the implementation of energy transition processes across the EU countries. Denmark, Sweden, Germany, France, Portugal, and Spain demonstrate the highest performance in terms of both quality and dynamism, whereas Malta, Cyprus, and Luxembourg perform the weakest. The proposed methodology and the resulting assessment of the level, quality, and dynamics of transformation processes offer broad practical applications. In particular, they can support the monitoring of progress toward EU climate and energy policy goals and inform management and decision-making aimed at achieving a resilient, sustainable, and equitable energy transition. Full article

This paper examines the impact of industrial energy efficiency on household energy poverty in the twenty-seven Member States of the European Union for the period 2003–2023. Although the literature has widely discussed energy efficiency as an enabler of decarbonisation and economic performance, its direct link to energy poverty at the macro level has rarely been analysed, let alone with respect to structural changes in industry. Filling this gap, this paper evaluates whether reductions in industrial energy intensity result in reduced energy poverty, understood as the share of households unable to maintain adequate indoor thermal comfort. Empirical analysis relies on a balanced panel dataset and uses fixed-effects regression models to take into account unobserved country-specific and time-specific heterogeneity. In addition, potential endogeneity between industrial energy intensity and labour productivity is addressed by the instrumental variable approach using two-stage least squares. The main models also include key macroeconomic and social control variables: real GDP per capita, social benefit expenditure, electricity prices for households, and unit labour costs. The results yield a robust and statistically significant positive link between industrial energy intensity and energy poverty, suggesting that efficiency improvements in industry make a quantifiable difference in household energy deprivation. This effect even increases in strength after the correction for endogeneity, thereby corroborating the causal relevance of productivity-driven efficiency gains. The findings also show substantial heterogeneity between EU Member States, indicating that national structural features will determine baseline levels of energy poverty. However, no strong evidence is found for an indirect price-mediated transmission mechanism or for moderation effects bound to income levels or social expenditure. This study provides sound empirical evidence that industrial energy efficiency is an important but structurally conditioned lever to alleviate energy poverty in the European Union. The results emphasise the integration of industrial efficiency policies with social and institutional frameworks while designing strategies for a just and inclusive energy transition. Full article

The escalating prevalence of counterfeiting and forgery has imposed unprecedented demands on advanced anti-counterfeiting technologies. Traditional luminescent materials, relying on single-mode or static emission, are inherently vulnerable to replication using commercially available phosphors or simple spectral blending. Multimode luminescent materials exhibiting excitation wavelength-dependent emission offer significantly higher encoding capacity and forgery resistance. Herein, we report the colloidal synthesis of lanthanide-doped Cs₂ZrCl₆ nanocrystals (Ln³⁺ = Tb, Eu, Pr, Sm, Dy, Ho) via a robust hot-injection route. These nanocrystals universally exhibit efficient host-to-guest energy transfer from self-trapped excitons (STEs) under 254 nm, yielding sharp characteristic Ln³⁺ f–f emission alongside the intrinsic broadband STE luminescence. Critically, Tb³⁺ enables direct 4f → 5d excitation at ~275 nm, while Eu³⁺ introduces a low-energy Eu³⁺ ← Cl⁻ LMCT band at ~305 nm, completely bypassing STE emission. Due to their multimode luminescent characteristics, we fabricate a triple-mode anti-counterfeiting label displaying different colors under different types of excitation. These findings establish a breakthrough excitation-encoded multimode platform, offering potential applications for next-generation photonic security labels, scintillation detectors, and solid-state lighting applications. Full article

This study investigates the influence of geometric parameters—size, proportions, number of floors, and roof shape—on the environmental efficiency of family houses using a simplified life cycle assessment (LCA) method. The analysis focuses on the product stage (A1–A3), commonly referred to as “cradle to gate,” which encompasses embodied emissions and energy. It demonstrates that even within the limited scope of the product stage (A1–A3), geometric parameters such as floor area, proportions, and compactness exert a decisive influence on embodied environmental impacts. In addition to absolute and per-square-meter indicators, the analysis highlights the importance of the shape factor, defined as the ratio of envelope area to heated volume, as a fairer basis for comparing buildings of different geometries. Similar to its established role in operational energy certification, the shape factor provides a meaningful link between geometry and embodied impacts. The findings suggest that future implementation of the Energy Performance of Building Directive IV (EPBD IV, EU 2024/1275), which mandates the calculation of the global warming potential (GWP) of new buildings from 2028 onwards, could benefit from evaluating both primary energy non-renewable (PENRT) and global warming potential (GWP) in relation to the shape factor, once sufficient data become available. The presented study thus contributes to the ongoing European debate on whole-life-cycle carbon assessment while clarifying its novelty as a geometry-based, product-stage method that can be scaled and adapted to different contexts. The proposed simplified, geometry-oriented approach to estimating embodied impacts (A1–A3) with shape factor-based normalisation enables a fair comparison of buildings with different geometries at the concept stage. Full article

The end-of-life phase of a building, which includes demolition and waste disposal, represents a crucial aspect of sustainable construction. In Europe, construction and demolition (C&D) waste accounts for approximately 40% of the total waste generated in the EU, making its management a global challenge. The EU Construction & Demolition Waste Management Protocol (2024) emphasizes the importance of evaluating, before proceeding with the demolition of a building, whether renovation could be a more efficient solution, considering economic, environmental, and technical aspects. From an economic perspective, demolition costs vary depending on several factors, including project size, structural complexity, techniques employed (conventional or non-conventional), materials to be removed, and local regulations. In addition to the direct costs of the intervention, it is essential to consider indirect impacts, such as the management of construction and demolition (C&D) waste, the removal of hazardous substances, and potential environmental damage to be mitigated. This study analyzes a case located in Italy, in the municipality of Caivano (Metropolitan City of Naples, in Campania region), concerning a building that required energy efficiency improvements and seismic upgrades. The decision to demolish and rebuild proved to be economically more advantageous than renovation, while also allowing a 35% increase in volume, enabling the creation of a greater number of housing units. Through the analysis of this real case study, the aim is to highlight how investments in demolition, if properly planned, designed, assessed, and managed, can effectively contribute to building redevelopment, supporting the transition towards a sustainable construction model in line with the principles of the circular economy. Full article