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[en] The discussion of energy issues has changed since the 1970s as improvements have been made in energy efficiency. The present capacity for surplus energy production in economically advanced countries reflects a decrease in energy requirements as well as new production sources. At the same time, the energy crisis can be seen as having discouraged improvements in energy efficiency because of its negative impact on growth. And the centrally planned economies remain highly inefficient energy users. Economic growth encourages the use of new technologies which are likely to be less energy-intensive than those they replace. Permanent gains in energy efficiency are derived from structural changes in the economy and from the introduction of energy-efficient technologies. This article addresses the prospect of increased energy conservation, particularly in industry (the end-use which consumes the most energy) and transportation. Although investments in projects to promote energy conservation are more cost-effective and environment-friendly than investments in energy supply, there is still widespread support for the latter. Developing countries naturally give preference to quantitative growth, with an increasing consumption of energy, but in these countries, too, more efficient use of energy could greatly reduce demand. The policies of international development agencies which still favour increasing energy supply over conservation need to change. Awareness of the need to reduce energy demand is, however, growing worldwide. (author)
[en] This volume consists of 18 articles that examine the changing ecological balance of the world and its effect on human prosperity. The problems caused by global warning, climate change and environmental degradation will have serious effects in both the short and the long term. Two of the 18 articles fall within INIS scope: these have been indexed separately. Tabs
[en] In a recent paper Huntington lays some of the groundwork for more meaningful discussions between economists and technologists on the apparent underinvestment in energy efficiency. In a discussion illustrated by a production function, he points out that the technical efficiency of economic actors should be treated as an empirical question. Huntington's groundwork can be further extended by observing that there is a close relationship between production functions and conservation supply curves, an analytical tool routinely used by technologists. Here we show that a conservation supply curve can be obtained from a production function by a simple transformation. (author)
[en] Despite progress that has been made in recent years, further improvements are needed in the methodologies commonly used to evaluate the energy savings arising from voluntary energy-efficiency programs. These voluntary programs are characterized by the fact that they do not involve mandatory codes or standards but instead use information and incentives to further the adoption of energy-efficient technologies and practices. Voluntary programs frequently are aimed at long-term transformation of markets that make lasting changes in consumer patterns of energy use. To date, many of the evaluations of such programs have focused on the direct effects to program participants and have not addressed the associated market transformation to the extent possible. Using information gathered through an extensive methodological review, the authors describe useful approaches taken in previous evaluations and draw conclusions concerning the best methods available for forecasting and measuring the impacts of voluntary programs
[en] Asymmetric information may explain low energy efficiency in rented properties. Energy ratings, while a solution to the information problem, will only lead to higher efficiency levels if renter's willingness-to-pay (WTP) exceeds landlord's investment costs. Using a sample of renters from one university, this paper estimates this WTP using a discrete choice experiment where respondents choose from a hypothetical set of single-bedroom apartments that differ according to a number of attributes including the energy rating. Results show that there is a strong disutility associated with the least efficient properties and that renters will pay significantly more for efficiency improvements at the lower end of the efficiency scale. Importantly, our WTP estimates are calculated in a setting where respondents were informed about the energy rating system prior to choosing and where the rating was shown for every property. Therefore, in order to maximise the impact of energy rating systems, policymakers are encouraged to ensure that both these informational characteristics are in place. - Highlights: •Low energy efficiency in rented properties may be due to asymmetric information. •This paper estimates the willingness-to-pay for energy efficiency improvements. •Our choice experiment has perfect information on apartment energy efficiency. •Renters will pay more for higher energy efficiency levels. •Willingness-to-pay is highest for the least efficient apartments.
[en] How do energy efficiency gains affect energy consumption? The effects are generally called 'rebound effects' in the literature. Previous studies have extensively focused on only part of the global economy to study rebound effects, e.g. energy consumption by households, one industry, or one country. However, since the global economy is highly connected among countries, these studies may lead to misleading conclusions if the rebound effects in the rest of the economy are significant. Recently Saunders (2008) analyzes the demand side by taking the global economy as a whole. Wei (2007) also provides a general analysis by using Cobb-Douglas production functions for the global economy. The present article expands Wei (2007) general analysis to explore the rebound effects from an economist's viewpoint by taking the global economy as a whole and applying general forms of production functions. The analysis provides new insights related to rebound effects: we highlight the role of energy supply as a determinant of rebound. We show that the substitution between energy resources and other productive resources is more relevant to long term rebound. We predict that long term rebound may be lower than short term rebound. And we also discover that super-conservation can happen in both the short term and the long term. (author)
[en] We address measurements of covariant phase observables (CPOs) by means of realistic eight-port homodyne detectors. We do not assume equal quantum efficiencies for the four photodetectors and investigate the conditions under which the measurement of a CPO may be achieved. We show that balancing the efficiencies using an additional beam splitter allows us to achieve a CPO at the price of reducing the overall effective efficiency, and prove that it is never a smearing of the ideal CPO achievable with unit quantum efficiency. An alternative strategy based on employing a squeezed vacuum as a parameter field is also suggested, which allows one to increase the overall efficiency in comparison to the passive case using only a moderate amount of squeezing. Both methods are suitable for implementation with current technology.
[en] In quantum reading, a quantum state of light (transmitter) is applied to read classical information. In the presence of noise or for sufficiently weak signals, quantum reading can outperform classical reading by reason of enhanced state distinguishability. Here we show that enhanced quantum efficiency depends on the presence in the transmitter of a particular type of quantum correlations, the discord of response. Different encodings and transmitters give rise to different levels of efficiency. Considering noisy quantum probes, we show that squeezed thermal transmitters with non-symmetrically distributed noise among the field modes yield higher quantum efficiency compared with coherent thermal quantum states. The noise-enhanced quantum advantage is a consequence of the discord of response being a non-decreasing function of increasing thermal noise under constant squeezing, a behavior that leads to increased state distinguishability. We finally show that, for non-symmetric squeezed thermal states, the probability of error, as measured by the quantum Chernoff bound, vanishes asymptotically with increasing local thermal noise with finite global squeezing. Therefore, with fixed finite squeezing, noisy but strongly discordant quantum states with a large noise imbalance between the field modes can outperform noisy classical resources as well as pure entangled transmitters with the same finite level of squeezing. (paper)
[en] Cities consume 80% of the world's energy; therefore, analyzing urban energy metabolism and the resulting carbon footprint provides basic data for formulating target carbon emission reductions. While energy metabolism includes both direct and indirect consumptions among sectors, few researchers have studied indirect consumption due to a lack of data. In this study, we used input–output analysis to calculate the energy flows among directly linked sectors. Building on this, we used ecological network analysis to develop a model of urban energy flows and also account for energy consumption embodied by the flows among indirectly linked sectors (represented numerically as paths with a length of 2 or more). To illustrate the model, monetary input–output tables for Beijing from 2000 to 2010 were analyzed to determine the embodied energy consumption and associated carbon footprints of these sectors. This analysis reveals the environmental pressure based on the source (energy consumption) and sink (carbon footprint) values. Indirect consumption was Beijing's primary form, and the carbon footprint therefore resulted mainly from indirect consumption (both accounting for ca. 60% of the total, though with considerable variation among sectors). To reduce emissions, the utilization efficiency of indirect consumption must improve. - Highlights: • We quantified the embodied energy transfers among Beijing's socioeconomic sectors. • We calculated the sectors' intensity of energy consumption and carbon footprint. • The indirect energy consumption was higher than the direct for all sectors. • The high-indirect-consumption sectors are at the end of industrial supply chains. • High-indirect-consumption sectors can improve upstream products energy efficiency
[en] Highlights: • Introduce a framework for multiple levels of building energy simulation calibration. • Improve the performance reliability of a calibrated model for different ECMs. • Achieve high simulation accuracies at building level, ECM level and zone level. • Create a classification schema to classify input parameters for calibration. • Use evidence and statistical learning to build energy model and reduce discrepancy. - Abstract: Energy simulation, the virtual representation and reproduction of energy processes for an entire building or a specific space, could assist building professionals with identifying relatively optimal energy conservation measures (ECMs). A review of current work revealed that methods for achieving simultaneous high accuracies in different levels of simulations, such as building level and zone level, have not been systematically explored, especially when there are several zones and multiple HVAC units in a building. Therefore, the objective of this paper is to introduce and validate a novel framework that can calibrate a model with high accuracies at multiple levels. In order to evaluate the performance of the calibration framework, we simulated HVAC-related energy consumption at the building level, at the ECM level and at the zone level. The simulation results were compared with the measured HVAC-related energy consumption. Our findings showed that MBE and CV (RMSE) were below 8.5% and 13.5%, respectively, for all three levels of energy simulation, demonstrating that the proposed framework could accurately simulate the building energy process at multiple levels. In addition, in order to estimate the potential energy efficiency improvements when different ECMs are implemented, the model has to be robust to the changes resulting from the building being operated under different control strategies. Mixed energy ground truths from two ECMs were used to calibrate the energy model. The results demonstrated that the model performed consistently well for both ECMs. Specific contributions of the study presented in this paper are the introduction of a novel calibration framework for multi-level simulation calibration, and improvements to the robustness of the calibrated model for different ECMs