L'attuale situazione geopolitica mondiale rende il principio dell'Energy Efficiency First un impegno strategico ineludibile oltre che di grande attualita che va nella direzione dello sviluppo ...sostenibile e dello scenario di carbon neutrality al 2050. Dall'analisi dei prodotti in laterizio oggi disponibili, emerge un processo di innovazione continuo al fine del miglioramento prestazionale; in particolare, per aumentare la resistenza termica dei blocchi sono state condotte sperimentazioni sulla conducibilita e densita dell'impasto, sulla percentuale di foratura e densita degli elementi, sulla geometria dei fori (nel rispetto dei vincoli dettati dalla normativa sismica, nel caso dei blocchi portanti), sui giunti (realizzati con malta termica o annullandoli nel caso dei blocchi a incastro e rettificati), ottenendo prodotti e relative soluzioni tecniche sempre piu performanti. L'architettura vernacolare dell'area mediterranea ha infatti da sempre privilegiato edifici con murature di grosso spessore che unitamente a opportuni sistemi di schermatura solare e di ventilazione naturale, consentono di ottenere buoni livelli di comfort ambientale estivo (Margani, 2012). Transforming the market from "cooling" to "sustainable summer comfort" che vede tra i principali partner l'end-use Efficiency Research Group (eERG) del Politecnico di Milano.
Climate change is recognised as one of the key challenges humankind is facing. The Information and Communication Technology (ICT) sector including data centres generates up to 2% of the global CO2 ...emissions, a number on par to the aviation sector contribution, and data centres are estimated to have the fastest growing carbon footprint from across the whole ICT sector, mainly due to technological advances such as the cloud computing and the rapid growth of the use of Internet services. There are no recent estimations of the total energy consumption of the European data centre and of their energy efficiency. The aim of this paper is to evaluate, analyse and present the current trends in energy consumption and efficiency in data centres in the European Union using the data submitted by companies participating in the European Code of Conduct for Data Centre Energy Efficiency programme, a voluntary initiative created in 2008 in response to the increasing energy consumption in data centres and the need to reduce the related environmental, economic and energy supply security impacts. The analysis shows that the average Power Usage Effectiveness (PUE) of the facilities participating in the programme is declining year after year. This confirms that voluntary approaches could be effective in addressing climate and energy issue.
Energy efficiency is a complex concept which is represented in diverse fields including engineering, economics, energy, computer sciences, environmental sciences, mathematics and physics. The social ...sciences literature on energy efficiency, however, remains significantly underrepresented, comprising just 2.6% of the total energy efficiency literature found in this study. Energy efficiency is an important energy policy strategy globally to reduce energy consumption, secure energy supply, and reduce greenhouse gas emissions. Despite this, however, evidence shows that on a global scale, energy demand is rising and climate mitigation targets are not being met. There is an acknowledgement by scientists that these challenges cannot be viewed as simply technical in nature but rather the product of collective social and cultural factors. Therefore, more social science research is needed to support an energy transition towards cleaner energy sources. Specifically, there is a need to further disentangle what is meant by energy efficiency from a social sciences perspective, including, critically, its conceptual foundations and practical applications. This review seeks to understand these issues by exploring how energy efficiency is conceptualized, both historically and today, by different actors. Research shows that the way that the concept of energy efficiency is applied to the physical, material world is a value judgement that brings with it societal trade-offs that are not fully understood. That is, that applying any given conceptualization or methodology of energy efficiency to physical processes can privilege certain interests over others, and affect society in different ways. For example, such tradeoffs include pollution displacement, lower than expected energy savings and an unfair cost burden on certain groups. Bringing together technical and qualitative insights from economics, energy, engineering, science and technology studies and history, this review builds on the work of efficiency and energy social scientists to illustrate what we need to do in order to bridge a conceptual gap in the energy efficiency literature, and in practice. The findings show a diversity of conceptualizations in the energy efficiency literature, highlighting the fact that energy efficiency can mean different things depending on how it is defined and applied. The review finds that greater efforts are needed to integrate energy efficiency discussions into sociological frames including ethics, equality, philosophy and history for more diverse, comprehensive and balanced research.
Characterising the energy efficiency grades of machining systems (MS) is an effective analytical methodology or management tool that helps to establish the high energy-efficient MS. However, the ...current MS energy efficiency approaches still lack scientific and practical formulation strategies to addresses this issue due to its multi-source and variable energy consumption characteristics. Focusing on this challenge, a new concept of inherent energy efficiency (IEE), which is formed in the design and formation phases of the MS, is proposed. Meanwhile, a novel energy efficiency grade evaluation (EEGE) approach based on IEE is also presented. The proposed EEGE approach not only can evaluate the MS energy efficiency grades, but also can reveal the MS high energy-efficient intervals. According to the analysis of IEE in MS, the EEGE approach is developed in three steps: (i) the establishment of IEE evaluating indicator system from both inherent energy utilisation (IEU) and inherent specific energy (ISE), (ii) the acquisition of the IEE, and (iii) the development of a quantitative method for the EEGE in MS. Finally, a case study of energy efficiency grade evaluation and analysis for an XK714D CNC milling machining centre is examined, illustrating the practicability of the proposed method.
This study measures the response of gasoline consumption to improved vehicle fuel efficiency (miles per gallon). Although an inverse relationship exists, the percentage decline is always less than ...the percentage efficiency improvement. As usually measured by past researchers, the long-run response in this study is approximately 80% of the efficiency improvement. The remaining 20% is the direct rebound effect and comports well with previous estimates. However, this rebound estimate escalates to 40–50% if horsepower or vehicle size are controlled. Even larger estimates (about 70%) are possible if carmakers change both fuel efficiency and horsepower when required to meet energy efficiency standards. Larger rebound effects are also possible when VFE improvements also reduce gasoline prices, but these price reductions may also improve welfare.
•Direct rebound effect is larger than price effect in the long run.•More efficient vehicles permanently change the per-mile cost of driving.•Other vehicle attributes (horsepower) may escalate the rebound effect.•Rebound effect can range between 20% and 70% of the potential improvement.•More efficient vehicles may improve welfare by reducing fuel price.
•EU policy efforts on energy efficiency in buildings stared in the 1970s in response to the oil crisis.•The first comprehensive EU policy was the SAVE directive in 1992, introducing policy actions ...still relevant today.•A major step forward was the Energy Performance of Buildings Directive in 2002 and its subsequent amendments.•Mandatory energy performance standards are progressively converging towards near zero energy buildings.•Additional policies and financing are needed for the full decarbonisation of the building stock.
The reduction of energy demand in buildings through the adoption of energy efficiency policy is a key pillar of the European Union (EU) climate and energy strategy. Energy efficiency first emerged in the EU energy policy agenda in the 1970s and was progressively transformed with shifting global and EU energy and climate policies and priorities. The paper offers a review of EU energy policies spanning over the last half century with a focus on policy instruments to encourage measures on energy efficiency in new and existing buildings. Starting from early policies set by the EU in response to the Oil Embargo in the 1973, the paper discusses the impact of EU policies in stimulating energy efficiency improvements in the building sector ranging from the SAVE Directive to the recently 2018 updated Energy Performance of Buildings Directive and Energy Efficiency Directive. The review explores the progress made over the last 50 years in addressing energy efficiency in buildings and highlights successes as well as remaining challenges. It discusses the impact of political priorities in reshaping how energy efficiency is addressed by EU policymakers, leading to a holistic approach to buildings, and provides insights and suggestions on how to further exploit the EU potential to save energy from buildings.
The concept of energy-efficient networking has begun to spread in the past few years, gaining increasing popularity. Besides the widespread sensitivity to ecological issues, such interest also stems ...from economic needs, since both energy costs and electrical requirements of telcos' and Internet Service Providers' infrastructures around the world show a continuously growing trend. In this respect, a common opinion among networking researchers is that the sole introduction of low consumption silicon technologies may not be enough to effectively curb energy requirements. Thus, for disruptively boosting the network energy efficiency, these hardware enhancements must be integrated with ad-hoc mechanisms that explicitly manage energy saving, by exploiting network-specific features. This paper aims at providing a twofold contribution to green networking. At first, we explore current perspectives in power consumption for next generation networks. Secondly, we provide a detailed survey on emerging technologies, projects, and work-in-progress standards, which can be adopted in networks and related infrastructures in order to reduce their carbon footprint. The considered approaches range from energy saving techniques for networked hosts, to technologies and mechanisms for designing next-generation and energy-aware networks and networking equipment.
Direct Air Capture (DAC) is a promising technology to fight climate change by capturing carbon dioxide (COsub.2) from the air. For DAC to be a negative emissions technology, the captured COsub.2 must ...be removed permanently, but can also be used as a net-zero technology to produce sustainable chemicals, fuels or other materials. This review presents a comprehensive survey of recent advancements, challenges, and potential applications of DAC technology, with an emphasis on the recent rapid increase in the number of DAC developers, the majority of them being founded in the past 4 years. Through pilot projects and recent commercial deployments, several DAC companies have made significant advances and demonstrated their scalability. Cost and energy efficiency remain significant impediments to the wide deployment of DAC. Integration with emission-free energy sources and utilization of waste heat are being researched to boost the total energy efficiency of DAC systems. Further research of electrochemical technologies for regeneration or direct capture are needed, as well as the development of new, modified, or hybrid adsorbents for improved capture efficiencies. Moreover, favorable regulations and financial incentives are crucial for enhancing the viability of DAC projects and will need to substantially increase if Paris Agreement goals are to be achieved.
This paper empirically investigates factors driving the adoption of energy-efficiency measures by small and medium-sized enterprises (SMEs). Our analyses are based on cross-sectional data from SMEs ...which participated in a German energy audit program between 2008 and 2010. In general, our findings appear robust to alternative model specifications and are consistent with the theoretical and still scarce empirical literature on barriers to energy-efficiency in SMEs. More specifically, high investment costs, which are captured by subjective and objective proxies, appear to impede the adoption of energy-efficiency measures, even if these measures are deemed profitable. Similarly, we find that lack of capital slows the adoption of energy-efficiency measures, primarily for larger investments. Hence, investment subsidies or soft loans (for larger investments) may help accelerating the diffusion of energy-efficiency measures in SMEs. Other barriers were not found to be statistically significant. Finally, our findings provide evidence that the quality of energy audits affects the adoption of energy-efficiency measures. Hence, effective regulation should involve quality standards for energy audits, templates for audit reports or mandatory monitoring of energy audits.
► We empirically analyze barriers to the adoption of energy-efficiency measures in SMEs. ► We focus on firms participating in the German energy audit program for SMEs. ► The program overcomes information related barriers. ► High investment costs still impede the adoption even for profitable measures. ► Low audit quality also impedes the adoption of profitable measures.
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