1,720,987 research outputs found
The Prism of Elasticity in Rebound Effect Modelling: An Insight from the Freight Transport Sector
Full text linkIf the rebound effect is to be considered a major obstacle to sustainable freight transport, then action and timely policy must be made in advance. This, however, requires a theoretical understanding of the nature of the rebound effect and an empirical grasp of its underlying mechanism. Elasticity is the centrepiece of current models on the rebound effect (or Jevons paradox). Although elasticity is a metric of indisputable usefulness for empirical purposes, it may be misleading when applied to the complex rebound effect. Drawing on the parallel case of the ‘distance puzzle’ in international economics, it will be shown how elasticity can be misinterpreted or how it can misdirect an investigation of the phenomenon by following a predetermined mindset. This particular bias is shown to widen in the long term and evolving systems in which the elasticity metric continues to output a constant number, eliciting a persistent effect. Drawing on previous research, an alternative approach to studying the rebound effect based on complex network theory and statistical mechanics of networks will be described. It will be shown how the interplay between spatial and non-spatial effects in freight transport networks can inform us about the evolution of the effect of distances on trade relationships, upon which a new metric for the rebound effect can be built
On the relationship between energy efficiency and complexity: Insight on the causality chain
Full text linkThe relationship between the energy efficiency, energy density and complexity level of the system is here addressed from both thermodynamic and evolutionary perspectives. A case study from economic systems is presented to show that, contrary to widespread opinion, energy efficiency is responsible for energy growth and the complexity leap. This article further examines to what extent complexity, on a historical time scale, may evolve to counterbalance conservative effects brought about by energy efficiency. We analyze structural complexity growth by four different paradigms. An evolutionary pattern is then proposed that may encompass the broad dynamics underlying complexity growth. This evolutionary pattern rests on the hypothesis that thermodynamic evolutionary systems are featured from an ever growing influx of energy driven into the system by self-catalytic processes, which must find its way through the constrains of the system. The system initially disposes of the energy by expanding, in extent and in number of components, up to saturation due to inner or outer constraints. The two counteractive forces, constraints and growing energy flux, expose the systems to new gradients. Every new gradient upon the system represents a symmetry rupture in components' space. By exploring a new gradient, the system imposes further restrictions on its components and increases its overall degree of freedom. © 2008 WIT Press
The role of the power/efficiency misconception in the rebound effect's size debate: Does efficiency actually lead to a power enhancement?
No full textThis paper addresses the question of whether the rebound effect's size is bigger or smaller than one. After a brief review of the related economic literature, a thermodynamic perspective tackles this topic by demonstrating that the dispute over the size of the rebound effect relies on a misconception of the thermodynamic nature of energy efficiency. The dichotomy, in fact, concerns the relationship between efficiency and power output rather than the scale of the economic side effects generated by energy efficiency mutations. Early intuitions of the dichotomy efficiency/power belong to the pioneering works of Stanley Jevons, in the field of economics, and Alfred Lotka in that of biology. Their findings are here approached using the basis of finite-time thermodynamics with a simple amendment, the addition of the time variable to the Carnot machinery. The model shows how a process of power maximization always leads to a sub-optimal efficiency level and additionally, that any efficiency improvement, in the context of low energy costs, will shift the power output of the machine instead of reducing energy consumption. A case study taken from the transport system is presented to elucidate this argument. © 2008 Elsevier Ltd. All rights reserved
Hierarchies, Power and the Problem of Governing Complex Systems
No full textThe concept of hierarchy is central to thermodynamics. Energy processes can be evaluated in terms of entropy content and the higher the entropy the lower they are positioned in the hierarchy of irreversibility. Hence, a Joule of heat at 500 K has a higher quality that the same amount of heat at 400 K. Introducing irreversibility into the Carnot machinery—the intellectual device by which we have historically developed the concept of efficiency, leads to the concept of maximum power output at suboptimal efficiency level. Introducing irreversibility—the hierarchal criterion for thermodynamics, means that time becomes a binding variable in thermal machines. Interestingly and perhaps not surprisingly, hierarchy is also a key concept of complexity. Along the line of an increasing hierarchical complexity, economic progress and evolution have been rewarding larger organizations or organisms throughout sentient or accidental selection. From microbes to whales, from villages to nations, from family firms to international corporations, the scaling up of the system has been achieved at the expenses of a growing complexity and hierarchy. To sustain the increasing complexity, processes have been increasing their power capacity thorough evolution and economic history. Is this intriguing parallel important to understand the fate of renewable energy? In this chapter I will try to expand upon the ideas of hierarchical scaling and power maximization to the problem of governing RES, with insights from finite-time thermodynamics, algometric scaling and complex science
Efficiency and the rebound effect in the hegemonic discourse on energy
No full textThe aim of the article is to discuss the unintended consequences of energy efficiency, in the context of defuturization, by addressing the phenomenon of the rebound effect. The energy discourse is presented as ideological discourse protecting the status quo, even if it contemplates alternatives solutions. The interpretation of energy efficiency in the light of the Luhmannian concept of temporal structures in the modern society is proposed, and two types of expert narratives on the rebound effect are outlined: the mechanistic rebound effect and the systemic Jevons paradox. Finally, we explain why none of them are noticeably reflected in public discourse on energy policy and are limited to the scientific milieu
Evaluation of the energy efficiency evolution in the European road freight transport sector
No full textIn this paper, we evaluate energy efficiency in the European freight transport sector over three decades, according to a variety of indicators, methodologies and databases. The aim is, on the one hand, of determining major drawbacks in energy efficiency metrics, on the other hand, identifying a possible trend in the sector. The present analysis shows that energy efficiency evaluation is generally subject to misinterpretation and distortion with regard to the methods and data source adopted. Two different indicators (energy intensity and fuel economy) were initially taken into account to select the most suitable for evaluating vehicles' efficiency. Fuel economy was then adopted and measured according to two different methodologies (top-down and bottom-up). We then considered all the possible sources of distortion (data sources employed, methods of data detection, speed of detection, power enhancement, size factor) with the aim of accomplishing a sound estimation. Fuel economy was eventually divided with the maximum power available (adjusted fuel economy), to account for the power shift of vehicles, that represents a further efficiency improvement. © 2009 Elsevier Ltd. All rights reserved
Energy conservation policies in the light of the energetics of evolution
No full textWith more energy efficiency it is possible to do the same—or even more —with less energy. This is why energy efficiency is prompted by many as an absolute remedy for the evils of energy use, such as the environmental pressure or the security of supply. Nevertheless, historically energy consumptions at the world level have always been growing in spite of—or perhaps because of—an increasing level of energy efficiency. Some scholars have called this paradox the rebound effect. The rebound effect (REE) is an unintended consequence of the introduction of more energy-efficient technology. It occurs when the reduction in energy consumption is less than that expected from the magnitude of the increase in energy efficiency. REE and backfire are caused by behavioural and/or other systemic responses to efficiency gains in production or consumption (Maxwell et al. in Addressing the rebound effect, a report for the European Commission DG Environment, 2011). However, this paradoxical nexus between energy efficiency and energy consumption is not only confined to human-made systems: nature exhibits a same type of linkage among energy efficiency, energy growth and complexity. To what extent can the energetics of evolution help us in understanding this conundrum and forge a doable energy policy aimed at reducing energy use by fostering energy efficiency? In this chapter we will analyse current areas of improvement in energy policy targeting energy efficiency in the light of the rebound effect and we will try to advance a different policy framework, based on a deeper understanding of this phenomenon
Energy and environmental flows: Do most financialised countries within the Mediterranean area export unsustainability?
No full textThe literature dedicated to the problems of transboundary pollution often aims to verify what the environmental and energy interactions between countries are. Little attention is paid to the financial relations of the phenomenon. We analyze how financial, environmental and energy flows have been redistributed within the main Mediterranean countries, with particular reference to pollution. Applying advanced methods of correlation, we verify the dynamics of transfer processes with the aim of assessing whether the link between economic and financial and environmental flows might support the hypothesis that rich countries export environmental emissions to poor ones. Our results show that richer countries have a significant propensity to export energy, financial flows and polluting emissions. The imbalance is even greater for emissions with local impact. This process is accompanied by a substantial increase in the financial activities of the North Mediterranean countries to the detriment of those of the South, which progressively increase their indebtedness. We find out that the economic and financial development of the North Med is accompanied by an increasing environmental impact measured by the various types of emissions covered by our study. The research shows how the most industrialized countries of the Mediterranean area are increasing the economic and financial gap with respect to the Southern Mediterranean countries
Detecting spatial homogeneity in the World Trade Web with Detrended Fluctuation Analysis
No full textIn a spatially embedded network, that is a network where nodes can be uniquely determined in a system of coordinates, links’ weights might be affected by metric distances coupling every pair of nodes (dyads). In order to assess to what extent metric distances affect relationships (link’s weights) in a spatially embedded network, we propose a methodology based on DFA (Detrended Fluctuation Analysis). DFA is a well developed methodology to evaluate autocorrelations and estimate long-range behavior in time series. We argue it can be further extended to spatially ordered series in order to assess autocorrelations in values. A scaling exponent of 0.5 (uncorrelated data) would thereby signal a perfect homogeneous space embedding the network. We apply the proposed methodology to the World Trade Web (WTW) during the years 1949–2000 and we find, in some contrast with predictions of gravity models, a declining influence of distances on trading relationships
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