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[en] There is substantial variability in residential energy use, partly driven by heterogeneous behavioral patterns. Time-use is relevant to energy when consumption tracks the time a device is used. Cluster analysis is a promising approach to identify time-use patterns. If clusters with particularly long time use and thus high energy consumption emerge, these groups could merit targeted policy intervention. We investigate these ideas via an empirical study of time use for television watching in the U.S. Three clusters were identified. In 2013, the average time spent watching television by Clusters 1, 2 and 3 are dramatically different: 1.1, 3.5 and 7.7 h per day respectively. While members of Cluster 3 are only 14% of the total population they represent 34% of TV energy consumption. The population of Cluster 3 tends to be older, less employed and less educated. Energy savings per adopter is much larger for Cluster 3, suggesting much higher benefits from efficient devices. These results are relevant to the design of efficiency programs, indicating potential for variable rebates and/or tiered communication. With variable rebates, utilities would offer higher incentives to high-use customers. In tiered communication, utilities would devote more resources to engage customers with larger savings potential. - Highlights: •Utility and other efficiency programs often treat consumers as homogenous groups. •Heterogeneity in consumer behavior affects benefits/costs of efficiency upgrade. •Significant heterogeneity is found in U.S. television watching patterns. •Heavy watchers (7.7 h/day) are 14% of population but consume 34% of energy. •Energy savings of efficient television for heavy watcher is 3 times the average.
[en] The low price of lead-acid, the most popular battery, is often used in setting cost targets for emerging energy storage technologies. Future cost reductions in lead acid batteries could increase investment and time scales needed for emerging storage technologies to reach cost-parity. In this paper the first documented model of cost reductions for lead-acid batteries is developed. Regression to a standard experience curve using 1989–2012 data yield a poor fit, with R"2 values of 0.17 for small batteries and 0.05 for larger systems. To address this problem, battery costs are separated into material and residual costs, and experience curves developed for residual costs. Depending on the year, residual costs account for 41–86% of total battery cost. Using running-time averages to address volatility in material costs, a 4-year time average experience curve for residual costs yield much higher R"2, 0.78 for small and 0.74 for large lead-acid batteries. The learning rate for residual costs in lead-acid batteries is 20%, a discovery with policy implications. Neglecting to consider cost reductions in lead-acid batteries could result in failure of energy storage start-ups and public policy programs. Generalizing this result, learning in incumbent technologies must be understood to assess the potential of emerging ones. -- Highlights: •We analyze potential cost reductions in lead-acid batteries. •Modified experience curve for non-material costs gives good empirical fit. •Historical learning rate for non-material costs from 1985–2012 is 19–24%. •Progress in incumbent technology raises barrier to new entrants
[en] BL 7.2 is a new beamline at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed in the storage ring in August 2003 and commissioning with the ALS electron beam followed immediately after. In this paper the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization
[en] Although the small intestine accounts for over 90% of the surface area of the alimentary tract, tumors of the small intestine represent less than 5% of all gastrointestinal tract neoplasms. Common small bowel tumors typically are well evaluated with cross-sectional imaging modalities such as CT and MR, but accurate identification and differentiation can be challenging. Differentiating normal bowel from abnormal tumor depends on imaging modality and the particular technique. While endoscopic evaluation is typically more sensitive for the detection of intraluminal tumors that can be reached, CT and MR, as well as select nuclear medicine studies, remain superior for evaluating extraluminal neoplasms. Understanding the imaging characteristics of typical benign and malignant small bowel tumors is critical, because of overlapping features and associated secondary complications.
[en] Beamline 7.2 of the Advanced Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL) is a beam diagnostics system that uses the synchrotron radiation emitted by a dipole magnet. It consists of two branches; in the first one the x-ray portion of the radiation is used in a pinhole camera system for measuring the transverse profile of the beam. The second branch is equipped with an x-ray beam position monitor (BPM) and with a multipurpose port where the visible and the far-infrared part of the radiation can be used for various applications such as bunch length measurements and IR coherent synchrotron radiation experiments. The pinhole system has been operating successfully since the end of 2003. The installation of the second branch has been completed recently and the results of its commissioning are presented in this paper together with examples of beam measurements performed at BL 7.2
[en] The U.S. EPRTM is equipped with dedicated ex-vessel systems to accommodate molten core debris, including the entire core inventory and reactor internals, which penetrates the reactor pressure vessel. The goal of the Core Melt Stabilization System and Severe Accident Heat Removal System is to stabilize molten core debris before it can challenge the integrity of the containment. Several unique analyses of the U.S. EPR'sTM core debris coolability control measures were prepared in support of the U.S. EPR'sTM design certification application. These involved both deterministic and best-estimate plus uncertainty analysis, explicitly incorporating several phenomenological uncertainties. This paper presents the analytical methods, results, and conclusions of these analyses. (author)
[en] A number of existing models for the transport of CO2 in carbon capture and storage assume the CO2 will be carried through isolated pipelines that connect each source to the nearest storage site. However storage costs will vary geographically, and it may be more economical to transport the CO2 farther away to a lower cost storage site if the pipelines can be linked to the site via a primary trunkline. We evaluate this alternative by developing an engineering-economic model that computes the levelized cost of transporting captured CO2 through pipes of different diameters and over varying distances. The model also computes the additional energy use and resulting CO2 emissions involved in the transport and is used to arrive at a generalized correlation for estimating the cost of CO2 transport ($/tonne/km) for different mass flow rates. Model results indicate that the cost for transporting CO2 could be significantly reduced using a large-diameter trunkline networked to pipelines from individual CO2 sources. This suggests that the design of CO2 transport systems could be an important influence on the selection of storage sites, particularly where there is a tradeoff between nearby but high-cost sites and distant, low-cost sites. (author)
[en] Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and utilized. Successful utilization will most likely occur if frequent, significant hardware-based milestones can be achieved throughout the program. Achieving these milestones will depend on the capability to perform highly realistic non-nuclear testing of nuclear systems. This paper discusses ongoing and potential research that could help achieve these milestones
[en] The generation of hydrogen can occur in the U.S. EPRTM during a severe accident due to oxidation of fuel cladding and core support materials or molten core-concrete interactions. The U.S. EPR'sTM combustible gas control system (CGCS) is a design feature developed to comply with the hydrogen generation and control requirements. The CGCS is designed to promote hydrogen mixing in the containment atmosphere and reduce the concentration of hydrogen via 47 passive autocatalytic recombiners. A performance analysis of these hydrogen control measures was prepared in support of the U.S. EPR'sTM design certification application. This best-estimate plus uncertainty analysis explicitly incorporated several phenomenological uncertainties convolved with biases addressing regulatory expectations. This paper presents the analytical methodology, results, and conclusions of this performance analysis. (author)
[en] In society's quest to mitigate climate change it is important to consider potential trade-offs in climate solutions impacting other environmental issues. This analysis explores the life cycle water consumption of alternative low-carbon energy sources for transportation. Energy sources analyzed include both biofuels used in internal combustion engines and low-carbon electricity generation methods used in conjunction with electric vehicles. Biofuels considered are corn-based ethanol, soybean biodiesel, cellulosic ethanol from switchgrass, and microbial biodiesel. Electricity sources analyzed are coal with carbon sequestration, photovoltaic cells, and solar concentrators. The assessment method used is hybrid life cycle assessment (LCA), which combines materials-based process method and the economic input-output (EIO) method. To compare these technologies on an even footing the life cycle water use to propel a passenger vehicle one mile is estimated. All technologies evaluated showed an increase in water consumption compared to unleaded gasoline when water use from vehicle manufacturing was included. Scale-up calculations showed that mass adoption of electric vehicles and some configurations of algae and switchgrass systems could potentially contribute to the decarbonization of transportation with tolerable increases in overall water consumption. Irrigated crop based biofuels however were found to have significant potential impact on water resources when scaled up to macroscopic production levels. (author)