MEDEE 2: A Model for Long-Term Energy Demand Evaluation

This paper describes a simulation model, MEDEE 2, designed to evaluate the long-term energy demand of a country, in combination with a scenario description of the main aspects of the country's social, economic, and technological evolution. This approach considers in a detailed way a national energy demand pattern and breaks down the total demand in a multitude of end-use categories (e.g., residential space heating, service sector cooling, gasoline for intercity cars). By means of this detailed investigation of energy demand we are better able to take into account the influence on energy demand of changes in social needs, economic growth, government policies, or technologies, especially in the present context of high energy prices. In addition, it makes possible the identification of the potential market (i.e. maximum demand that can be technically met) of each final energy form (e.g., electricity, coal, gas, solar, oil products, and district heat). The model calculates useful energy demand in each end-use category for which several energy forms can be used, thus determining the substitution possibilities in energy use. This useful energy matches the energy service needed by the consumer (e.g., heat, mechanical energy). Useful energy differs from final energy, purchased by the consumer, by the efficiency of the enduse appliances. Each useful energy demand is then converted into a demand for final energy, taking into account the fuel mix (i.e., the fraction of the demand supplied by each fuel) and the end-use efficiencies of each fuel. This approach-estimating useful energy-is necessary if one wants to account for the differences in fuel efficiencies: for the same service (let us say 1 kwh of heat) the final demand will vary according to the fuel type because of these different efficiencies (e.g., 1 kwh of electricity, 1.35 kwh of gas, 1.50 kwh of oil, and 2 kwh of coal). The total final demand is projected in MEDEE 2 for the following types of final energy forms: fossil fuel '(substitutable use of coal, oil, and gas), electricity, motor fuel, coke, feedstock, solar, and district heat. MEDEE 2 is driven by a set of scenario elements, the evolution of which is defined in a scenario. The core of the scenario is a characterization through these elements of the development pattern of the country under consideration (life-styles, economic growth patterns, etc.). The scenario description is complemented with technological parameters (e.g., insulation standards, efficiencies, fuel mix), the evolution of which is specified in a way consistent with the macroeconomic assumptions

Impact of Natural and Human Resources of Ethanol Production from Biomass

The Resources Group at IIASA is concentrating an increasing amount of effort on the WELMM analysis and/or comparison of natural and synthetic liquid fuels, conventional oil, shale oil and syncrude from tar sands, liquid fuels from coal, etc. All these are of fossil origin. But a completely different class of synthetic liquid fuel also deserves attention -- one which is derived from so-called biomass. In this class of primary importance are alcohol and methanol (from wood). Methanol is of particular interest since it can also be produced from coal, and a promising process has been developed (by the Mobil Oil Corporation) to convert methanol to much needed high grade gasoline. Economic comparisons are relatively difficult since the stages of development of these various liquid fuels are very different -- some are still in the laboratory stage or at the pilot stage, others are very near commercial application or even already commercialized (tar sands). Also, impact on natural resources differs greatly from one type of fuel to another and from one process to another. We therefore decided to use the WELMM method to achieve a better understanding of some of the systems aspects of these liquid fuels. Various reports and working papers have already been devoted to the topic as far as fossil fuels are concerned. This paper opens up a new field: biomass liquid fuels. It is based on various studies -- with a different initial objective -- carried out by Bruno Lapillonne and colleagues at the IEJE. I thought it would be interesting to reshape some of the results, or reflections, according to the WELMM format. This paper shows the result of this effort, and although still preliminary is very interesting. It is a double pleasure for me to introduce the paper, since a few years ago Bruno Lapillonne helped me to pioneer the "WELMM approach". Finally, the paper is a good and encouraging example of continuation of close cooperation between IIASA scientists -- even long after they have returned to their home institutions

Monitoring of the “Energiewende” – energy efficiency indicators for Germany

The increasing number of energy and climate targets both at national and international level induces a rising demand for regular monitoring. In this paper, we analyse the possibilities and limits of using energy efficiency indicators as a tool for monitoring these targets. We refer to the energy efficiency targets of the German “Energiewende” and calculate and discuss several energy efficiency indicators for Germany both at the level of the overall economy and the main energy consumption sectors. We make use of the energy efficiency indicator toolbox that we have developed within the ODYSSEE database in recent years and find that there is still a considerable gap to close to achieve the overall energy efficiency targets in Germany by 2020. We also show that progress in energy efficiency slowed down between 2008 and 2012, i.e. compared to the base year of most of the German energy efficiency targets and find that energy efficiency progress in the industrial sector during the last decade has been especially slow. We conclude that improvements in energy efficiency have to speed up considerably in order to achieve the targets for 2020. Although the use of energy efficiency indicators is limited by data constraints and some methodological problems, these indicators give a deep insight into the factors determining energy consumption and can therefore complement the official monitoring process of the German “Energiewende” which only relies on highly aggregated indicators for energy efficiency

The WELMM Approach to Energy Strategies and Options

The development of energy resources requires more and more natural or human resources: on the one hand because of the difficulty of "harvesting" primary energy resources. and on the other because of the complexity of the sequence of processes necessary to convert these primary resources into useful resources for an economy (final energy). In this context the WELMM approach has been designed to evaluate the resource requirements for the development of energy resources. WELMM focuses mainly on five limited resources: Eater, Energy, Land, Materials, and Manpower. The WELMM evaluation is implemented at the level of the major facilities concerned in the harvesting and conversion of primary energy resources into find resources. All the WELMM data are stored in three different data bases (Resource Data Base, Component Data Base, and Facility Data Base). They are meant to be used to enlarge and complete the traditional economic comparison of energy processes, energy strategies or energy options

System Analysis and Scenario Approach for Detailed Long Range Energy Demand Forecasting

This paper describes a method of energy demand forecasting based on a system analysis of the economy and a scenario description of its development. After a brief analysis of the limits of the traditional econometric tools, the method is described in detail. An application carried out for the French economy is briefly outlined to show more concretely the feasibility and practicality of such a method. To conclude, some general features of the method are reviewed so as to see how its adaptation to other countries could be envisioned. In this vein, a concrete extension to developing countries is proposed

An SPH study on viscoplastic surges overriding mobile beds: The many regimes of entrainment

Flow-type landslides entrain mobile bed material, but the processes involved are diverse and require systematic study. We perform direct numerical simulations using the open-source SPH package DualSPHysics with a regularized Herschel–Bulkley rheology. We then compare model output with physical test data, and hence investigate the effects of varying the bed yield stress $_{,b}$ and bed depth ℎ$_b$, interpreting the results using a newly-identified set of dimensionless numbers. Results reveal diverse interaction regimes between surges and mobile beds, including ‘‘rigid bed’’, ‘‘lubrication’’, ‘‘shallow ploughing’’, ‘‘surfing’’, ‘‘plunging’’, and ‘‘deep ploughing’’. Shallow, borderline-stable beds ‘‘lubricate’’ the surge: once destabilized, these beds cause strong acceleration of the combined flow front. Deeper borderline-stable beds allow the surge material to ‘‘plunge’’ downward, massively displacing bed material upward and downstream. For stabler beds, ‘‘ploughing’’ and ‘‘surfing’’ are associated with intermediate and high values of $_{,b}$, respectively. In both cases, beds retard the surge, with mobile dams forming for ‘‘ploughing’’ regimes. Across all regimes identified, the influence of $_{,b}$ is non-monotonic, with intermediate values decelerating the combined flow fronts the most. Furthermore, the different interaction regimes exhibit unique velocity profiles. We develop phase diagrams based on three dimensionless numbers, demarcating these regimes

Extremely preterm infants receiving standard care receive very low levels of arachidonic and docosahexaenoic acids

Background & aims Adequate supply of arachidonic (ARA) and docosahexaenoic (DHA) acids is essential for brain development, and extremely preterm infants may be at risk of deficiency. Current levels of ARA and DHA given to extremely preterm infants and the amounts available for accretion have not been established, although recent evidence suggests DHA intake is at a level likely to lead to severe deficits. This study quantified the omega-6 and omega-3 polyunsaturated fatty acid (PUFA) intakes from all sources in the first six weeks of life of preterm infants in standard care. In addition, the relationship between blood levels of circulating cytokines and PUFAs was explored. Methods Single centre longitudinal study with omega-6 and omega-3 PUFA intake data analysed from all sources for 17 infants born <28 weeks gestation. At six weeks of age the infants' whole-blood fatty acid levels were measured along with a range of cytokines and chemokines analysed by Luminex® multiplex array. Results ARA intake was significantly below international recommendations in weeks 1–5 (all p < 0.05), and DHA intake was significantly below recommendations in week 1 (p < 0.0001). The amounts of ARA and DHA available for accretion were significantly below estimated accretion rates in all weeks (all p < 0.001). Mean ARA and DHA intakes were correlated with their respective blood levels (r = 0.568, p = 0.017 and r = 0.704, p = 0.002). There were significant relationships between MIP-1β and blood DHA levels (rs = 0.559, p = 0.02) and between RANTES and omega-6:omega-3 PUFA ratio (rs = −0.498, p = 0.042). Conclusions This study establishes that extremely preterm infants receive insufficient intakes of ARA and DHA. Moreover, blood fatty acid levels may provide a useful measure of intake, where establishing sufficient consumption could have clinical importance. There may also be important interactions between long-chain PUFA status and markers of inflammation, which requires further study

Chloride Balance in Preterm Infants during the First Week of Life

Objective. To describe the chloride balance in infants born 25–32-week gestation, analyze the association of chloride changes with hydroelectrolytic status and their relationship with perinatal conditions, morbidities, and neurological outcome. Methods. For 7 days after birth, sodium and chloride balance, plasma potassium, phosphate, and total carbon dioxide (tCO2) were prospectively determined and strong ion difference (SID) calculated. Three multivariate regression analyses were performed to identify factors associated with high plasma chloride concentration, low SID, and low tCO2. Results. 107 infants were studied. Plasma chloride concentration was significantly positively associated with plasma sodium concentration. Higher plasma chloride and lower SID were significantly associated with lower plasma tCO2. Chloride intake was the main independent factor associated with high plasma chloride, low SID, and low plasma tCO2, with lesser contribution of sodium intake and low gestational age (GA). Also, patent ductus arteriosus and birth weight loss were independent factors affecting plasma chloride and SID. Neither high chloride levels nor low SID were associated to impaired neurological outcome. Conclusions. In preterm infants, chloride balance is influenced by GA and by interrelationship between sodium and chloride intake. High chloride levels are associated with metabolic acidosis but not related to increased risk of impaired neurological outcome

Rapid cortical oscillations and early motor activity in premature human neonate.

International audienceDelta-brush is the dominant pattern of rapid oscillatory activity (8-25 Hz) in the human cortex during the third trimester of gestation. Here, we studied the relationship between delta-brushes in the somatosensory cortex and spontaneous movements of premature human neonates of 29-31 weeks postconceptional age using a combination of scalp electroencephalography and monitoring of motor activity. We found that sporadic hand and foot movements heralded the appearance of delta-brushes in the corresponding areas of the cortex (lateral and medial regions of the contralateral central cortex, respectively). Direct hand and foot stimulation also reliably evoked delta-brushes in the same areas. These results suggest that sensory feedback from spontaneous fetal movements triggers delta-brush oscillations in the central cortex in a somatotopic manner. We propose that in the human fetus in utero, before the brain starts to receive elaborated sensory input from the external world, spontaneous fetal movements provide sensory stimulation and drive delta-brush oscillations in the developing somatosensory cortex contributing to the formation of cortical body maps