Increased Energy Use Research Articles

Environmental Trade-Offs in Nitrogen Oxide Removal from Ship Engine Exhausts

The emissions of nitrogen oxides (NO x) from ship engines constitute an increasing part of the total global emissions of NO x while the share from land-based sources is decreasing. In the coming years, new regulations will set limits to emissions in specific areas and various technical countermeasures will be developed and implemented. However, when taking technical measures against emissions on a local scale, there is always a risk of inducing an increase in the total environmental impact related to the technology used, owing to increased energy use and emissions in other places. In the present study, an investigation of the difference in environmental impact from passenger transport vessels with and without catalytic NO x emission purification was performed in a life cycle assessment. The production and transport of chemicals used in the catalyst are included in the study. The study shows that the use of selective catalytic reduction (SCR) gives a considerable decrease in the environmental impact compared with using a diesel engine without a catalyst. The transport of urea solution over a 500 km distance makes a very small contribution to the total environmental impact. The global warming potential is the only impact category for which values are increased when including the urea production and transport. When looking at the contribution from urea to the total impact from the SCR process, the increase is less than 10 per cent for most impact categories.

Exergy-based comparison of two Greek industries

In this work, the potential of the increase in exergy and energy efficiency of the Greek construction and Food, Drink and Tobacco (FDT) industries has been examined using energy and exergy analysis methodology. These two industries play a vital role towards sustainable development of the country. The continuous increase in energy use in these two industries during the years 1971?2000 shows that both remain steadily in an ascendant orbit. The aim was to analyse and compare the energy use and exergy consumption in the Greek construction and FDT industries to gain insights into each sector's efficiency of energy use.

Motivating energy conservation in the workplace: An evaluation of the use of group-level feedback and peer education

Research suggests that curbing consumer demand for energy through behavioral interventions is an essential component of efforts to reduce greenhouse gas emissions, particularly in the short-term. Behavior within organizational settings poses a particular challenge to those wishing to promote energy conservation because employees typically have no direct financial incentive to reduce energy use and rarely have access to information regarding their level of consumption. Two relatively simple and easy-to-implement interventions were evaluated in a workplace setting during the fall of 2008. The first involved group-level feedback presented monthly to employees via e-mail. The second used peer educators to disseminate information and to encourage colleagues to reduce energy use. Both interventions were compared to an information-only control designed to educate employees about how and why to conserve energy. Results indicated that feedback and peer education resulted in a 7% and 4% reduction in energy use, respectively. Buildings that received the control increased energy use by 4%. The effect of peer education was limited by implementation failures in two buildings. The utility of these interventions will be discussed in terms of their overall potential for reducing energy use, as well as the feasibility of their being implemented in future organizational settings.

Does urbanization lead to less energy use and lower CO 2 emissions? A cross-country analysis

Despite the relationship between urbanization, energy use and CO 2 emissions has been extensively studied in recent years, little attention has been paid to differences in development stages or income levels. Most previous studies have implicitly assumed that the impact of urbanization is homogenous for all countries. This assumption can be questionable as there are many characteristic differences among countries of different levels of affluence. This paper investigates empirically the effects of urbanization on energy use and CO 2 emissions with consideration of the different development stages. Using the Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) model and a balanced panel dataset of 99 countries over the period 1975–2005, the findings suggest that the impact of urbanization on energy use and emissions varies across the stages of development. Surprisingly, urbanization decreases energy use in the low-income group, while it increases energy use in the middle- and high-income groups. The impact of urbanization on emissions is positive for all the income groups, but it is more pronounced in the middle-income group than in the other income groups. These novel findings not only help advance the existing literature, but also can be of special interest to policy makers and urban planners.

Effect of ractopamine on whole body and splanchnic energy metabolism in Holstein steers

This study was designed to examine the influence of ractopamine (RAC) on whole-body and splanchnic energy balance. Six growing Holstein steers [body weight (BW) = 402 ± 39.5 kg] surgically fitted with an arterial and portal, hepatic, and mesenteric venous indwelling catheters were used in a repeated measures study. Treatments were a basal diet of alfalfa cubes fed at approximately 1.5&times maintenance energy requirements (days 1-21) and basal plus RAC (430 mg head d-1; days 22-42). On day 14 of each period, splanchnic and portal-drained viscera (PDV) energy balances were determined as the product of arterio-venous O2 difference and blood flow. Blood flow was determined using down-stream dilution of p-aminohippuric acid. Whole-body energy balance was determined on days 15-21 of each period, which included 7 d total excreta collection and 3 d of respiratory gas exchange measurements. Body weight and DM intake were greater (P < 0.05) for steers receiving RAC compared with those receiving the control diet; however, no difference was observed in either BW or DMI when expressed on a BW0.75 basis. Similarly, as a function of BW0.75, whole-body heat production (691 kJ kg BW0.75 d-1; P = 0.96) and retained N (0.85 g kg BW0.75 d-1; P = 0.34) and energy (298 kJ kg BW0.75 d-1; P = 0.71) were unaffected by RAC. In contrast, RAC tended to decrease (P = 0.09) energy use by splanchnic tissues (191 vs. 156 kJ kg BW0.75 d-1), largely due to a reduction (P = 0.12) in energy use by the PDV (100 vs. 86 kJ kg BW0.75 d-1). These data indicate that although whole-body energy use is not affected by RAC, energy use by splanchnic tissues is decreased, thereby increasing energy use by peripheral tissues.Key words: Bovine, ractopamine, beta-agonist, energy balance, metabolism

Influence of Parking Policy on Built Environment and Travel Behavior in Two New England Cities, 1960 to 2007

Over the past 40 to 50 years, most American cities have experienced significant increases in automobile use. Now, to offset increasing energy use and greenhouse gas emissions, many are contemplating measures to reduce automobile use. This study examined Hartford, Connecticut, and Cambridge, Massachusetts, which exhibited an increase and a decrease in automobile use, respectively, between 1960 and 2007. It is hoped that these cities provide lessons in how to successfully reduce automobile travel. The study focused on the cumulative effects of historical policy decisions over decades on parking provisions and changes in travel behavior. The results of this analysis suggest that parking policy affects incremental changes in parking provision that may greatly influence gradual changes in automobile use over time.

Energy use, CO 2 emissions and waste throughout the life cycle of a sample of hotels in the Balearic Islands

Tourism is the most developed economic sector in the Balearic Islands. The great rise in construction activities within the last 50 years, the increase in energy use, in CO 2 emissions and in waste production due to tourism, as well as an electrical energy production system mainly based on coal and fossil fuels is not an environmentally sustainable scenario. The aim of this study is to identify the processes that have had the greatest impact on the life cycle of a tourist building. In order to do this, the energy uses, CO 2 emissions and waste materials generated have been estimated, assuming a life cycle of 50 years, within a sample of hotels from the Balearic Islands. The results show that the operating phase, which represents between 70% and 80% of the total energy use, is the one with the greatest impact; that the energy use due to the manufacture of materials represents a fifth of the total and that electric consumption is the main cause of CO 2 emissions because of the regional energy system.

China's Energy Security: Challenges and Priorities

In a companion paper to the essays comparing China's and India's economic rise (Prime, 2009) as well as India's energy security (Dadwal, 2009), two specialists on China's energy industries review the country's challenges posed by the need to dramatically increase energy use in order to support economic growth while coping with pressures to reduce environmental impacts from emissions of greenhouse gases. After reviewing the current mix of fuels in the economy and discussing each major energy resource (in terms of proven reserves, production, consumption, and foreign import requirements), the authors focus on measures undertaken by the Chinese government and corporations to improve access to vital supplies. The paper covers efforts to enhance the country's energy security, which include diversifying sources of oil supply, purchasing oil and gas concessions and financing of energy infrastructure development in African and Central Asian countries, instituting reforms to encourage more efficient energy use, and developing alternative energy sources. Journal of Economic Literature, Classification Numbers: O130, P280, Q400. 7 figures, 2 tables, 82 references.

A Simulation Study of Gel Pillow Heat Conductance

The gel-filled pillow is a device used to provide a soft surface to support and cradle an infant's head. Little is known about the thermal conductive properties of this device when used in an open crib. This simulation study evaluated the use of the Squishon 2 gel pillow in an open crib to determine the potential cooling effects on a mannequin infant. This simulation study was conducted on a thermal mannequin. A descriptive comparative repeated-measures design was employed. A thermal mannequin with the head placed on the gel pillow was used. The energy required to keep the mannequin head at 37 degrees C in 4 conditions was measured. The 4 conditions were as follows: (1) lying in an open crib on a standard mattress (baseline), (2) lying on the gel pillow with the disposable cover from the manufacturer, (3) the head wearing a cap and lying on the gel pillow, and (4) the head without the hat lying on the gel pillow with an insulated cover over the pillow. Univariate analysis of variance (ANOVA) revealed significant differences in energy required to maintain the mannequin head at 37 degrees C among the 4 conditions (F3 = 283.23, P = .0001). The hat on head condition was found to decrease energy utilization by an average of 6.36 kcal/d when compared with the head on mattress condition (P = .0001). Extrapolation of energy to maintain mannequin head warmth into potential kilocalories utilized revealed that a potential increase in kilocalories needed to maintain thermoneutrality would be needed. The most effective way of conserving heat was in the hat on the mannequin head while lying on a gel pillow condition. The use of a gel pillow without a hat or an insulated barrier caused an increase in energy requirements and kilocalorie usage in this mannequin model. The results of this simulation study suggest that use of the gel pillow outside of a thermally controlled environment and in an open crib environment may increase energy use to maintain thermoneutrality. The Squishon 2 gel pillow conducts heat from the mannequin head and may increase kilocalories per day consumption in the preterm infant. Furthermore, the results of the study support previous findings that a hat helps conserve energy.

Energy efficient design and occupant well-being: Case studies in the UK and India

The purpose of this paper is to demonstrate the relationships between sustainable building design and occupant well-being. It starts with a definition of sustainable design and well-being, and focuses on the relationships between energy performance and occupant feedback. Methodologically it draws on detailed monitoring and surveys of 12 case study office buildings in the UK and India, and the paper uses the data to explore whether energy use and associated CO 2 emissions are correlated to occupant satisfaction and comfort. The results demonstrate that increased energy use in the case study buildings is associated with increased mechanisation (e.g. centralised air conditioning) and reduced occupant control. This reduced control in turn is shown to relate to reduced occupant comfort and satisfaction. Finally, the paper reveals that the reported health conditions of occupants correlates strongly with their levels of satisfaction. The overall conclusion is that energy use in typical office buildings is inversely correlated with the well-being of the occupants: more energy use does not improve well-being.

Incubation temperature and energy expenditure during development in loggerhead sea turtle embryos

The choice of a suitable nest habitat by oviparous reptiles that deposit eggs into a nest and provide no subsequent parental care is likely to play a major role in the survival of the offspring. In particular variations in nest temperature may influence the rate at which embryos utilise their yolk energy. The effects of nest temperature on total energy use are however complex. High temperatures may advance development and shorten the time to hatching, thereby reducing energy use, but they also stimulate metabolic rate increasing energy use. The net effect of temperature on total energy demands is therefore uncertain. Oxygen consumption (VO 2) and carbon dioxide production (VCO 2) were measured by open-flow respirometry during the incubation of loggerhead sea turtle eggs at three temperatures (27.6, 30.0 and 31.8 °C). At each temperature, VO 2 and VCO 2 showed a peak followed by a decline to hatching. Incubation temperature was negatively related to incubation duration and positively related to the maximum metabolic rate of the embryos. Peak VO 2 was 74.8 ml/egg/day at 27.6 °C, 91.9 ml/egg/day at 30.0 °C, and 97.9 ml/egg/day at 31.8 °C. Peak VO 2 occurred closer to hatching in eggs incubated at higher temperatures. Total energy expenditure was greatest at the lowest incubation temperature and lowest at the highest temperature. Total VO 2 and VCO 2 were 1777 ml/egg and 1226 ml/egg, respectively, at 27.6 °C, 1680 ml/egg and 1235 ml/egg at 30.0 °C, and 1613 ml/egg and 1191 ml/egg at 31.8 °C. Using the actual RQ values, this corresponds to a cost of development of 34,963 J/egg at 27.6 °C, 33,403 J/egg at 30.0 °C, and 32,107 J/egg at 31.8 °C. At all temperatures, the calculated respiratory quotient values did not suggest that yolk substrates were oxidised proportionately, but more likely indicated their sequential use. Nest temperatures may play a key role in energy use, with cooler temperature nests increasing the overall energy demands placed on developing embryos.

A study on the energy penalty of various air-side system faults in buildings

Automatic fault detection and diagnosis (FDD) can help enhance building energy efficiency by facilitating early detection of occurrence of system faults, especially those of air-conditioning systems, thus enabling rectification of the faults before much energy is wasted due to such faults. However, building owners may not invest in FDD unless they are convinced of the energy cost savings that can be achieved. This paper presents the results of a study on the energy cost impacts of a range of common system faults in variable air volume (VAV) air-conditioning systems, which are widely adopted for their good part-load energy efficiency. The faults studied include room air temperature sensor offset, stuck VAV box damper, supply air temperature sensor offset, stuck outdoor air damper and stuck/leaking cooling coil valve. The simulation results indicate that some faults may significantly increase energy use in buildings, for example, negative room air temperature sensor offset, stuck open VAV box damper, negative supply air temperature sensor offset, stuck open outdoor air damper and stuck open and leaking cooling coil valve. Since building occupants may adapt to the symptoms of these faults, such as reduced room air temperature, and thus may not complain about them, the occurrence of such faults are not immediately apparent unless a FDD system is available. Some other faults, e.g. positive supply air temperature sensor offset, positive room air temperature sensor offset, stuck closed cooling coil valve and stuck closed VAV box damper, may allow less energy to be used but will lead to unbearable indoor environmental conditions, such as high indoor temperature. Such faults, therefore, can easily be detected even without a FDD system, as there will be feedback from the building occupants.

Building Operations: Balancing Energy Efficiency with Indoor Air Quality

Energy efficiency measures (ECMs) and indoor air quality (IAQ) have different goals, but often have overlapping results; sometimes good, sometimes bad. Many ECMs have potential IAQ complications; conversely many IAQ improvement measures increase energy use. The two are inseparable and competing, so the best overall outcome involves a careful balance. This article illustrates some examples of the overlap between energy and air quality, and provide examples of activities that can spoil the delicate balance between them.

Uncovering energy-efficiency opportunities in data centers

The combination of rapidly increasing energy use of data centers (DCs), which is triggered by dramatic increases in IT (information technology) demands, and increases in energy costs and limited energy supplies has made the energy efficiency of DCs a central concern from both a cost and a sustainability perspective. This paper describes three important technology components that address the energy consumption in DCs. First, we present a mobile measurement technology (MMT) for optimizing the space and energy efficiency of DCs. The technology encompasses the interworking of an advanced metrology technique for rapid data collection at high spatial resolution and measurement-driven modeling techniques, enabling optimal adjustments of a DC environment within a target thermal envelope. Specific example data demonstrating the effectiveness of MMT is shown. Second, the static MMT measurements obtained at high spatial resolution are complemented by and integrated with a real-time sensor network. The requirements and suitable architectures for wired and wireless sensor solutions are discussed. Third, an energy and thermal model analysis for a DC is presented that exploits both the high-spatial-resolution (but static) MMT data and the high-timeresolved (but sparse) sensor data. The combination of these two data types (static and dynamic), in conjunction with innovative modeling techniques, provides the basis for extending the MMT concept toward an interactive energy management solution.

The effect of dietary intervention and physical activities on the lipid profile of obese children

Background Obesity is defined as body weight increase due toexcessive fat accumulation. Obesity during childhood and teenageyears is related to cardiovascular risks including hyperinsulinism,hypercholesterolemia, decreased high density lipoprotein (HOI),and hypertension. The principles of managing obesity are reducingenergy intake and increasing energy use, e.g., by increasing physicalactivities, changing life habits and, most importantly by involvingfamily in the therapeutic process.Objective To evaluate the effect of dietary intervention andphysical activity on obese children.Methods Seventy-six obese primary school children wererandomly allocated to either receive intervention (diet andphysical activities) or no intervention. At the beginning of thestudy, lipid profile was measured in all subjects. Subjects in theintervention group were asked to reduce calorie intake by 200 -500 kCal per day, and participating in a walk of 20-30 minutes forfive days per week over a period of one month. After one month,the lipid profile of both groups was remeasured and compared.Results After one month, 7 3 children had successfully completedthe study and had complete data for analysis. There was asignificant change in the mean HOL level before intervention(47.3 [SO 36.2] mg/dl) compared with after intervention (100.5[SO 35.7] mg/dl, P<0.05) in the group where intervention wasimplemented.Conclusion There are no significant differences in serum lipidvalues after intervention in both groups.

Using a Model of Human Energy Metabolism to Estimate Energy Costs of Turnover

The goal of this research is to use a computational model of nutrient digestion and metabolism in a human to predict energy use and quantify effects of increased futile cycling on energy metabolism. The model is composed of 6 state variables representing amino acids, body protein, visceral protein, glucose, triglyceride, and fatty acids. Differential equations represent carbohydrate, amino acid, and fatty acid uptake and output by tissues. The model estimates metabolizable energy, heat production (HP), respiratory quotient, P/O ratio, energy balance and glucose and fatty acid oxidation based on ATP creation and use, O2 use, CO2 production, heats of combustion, and nutrient flux. Protein deposition is a function of maximum genetic potential for protein accretion. Adipose deposition is a function of energy balance. To examine effects of increasing protein and adipose turnover, protein turnover increased from 2 to 14 %/day and adipose turnover increased from 1.5 to 3.0 %/day for a 70 kg male. Increasing protein turnover increased HP from 11.2 to 20.5 MJ/day, increased glucose oxidation from 1.88 to 2.29 mole/day, increased fatty acid oxidation from 0.132 to 0.873 mole/day and decreased body weight by 6 kg over a 30 day simulation. Increasing adipose turnover decreased HP from 10.8 to 10.7 MJ/day, decreased glucose oxidation from 2.18 to 2.04 mole/day, increased fatty acid oxidation from 0.0200 to 0.0543 mole/day, and decreased body weight by 4.5 kg over a 30 day simulation. Therefore the model is able to predict body weight loss due to increased heat production from increased energy use as a result of changes in muscle and adipose turnover. Since humans are genetically diverse with a range of basal metabolic rates, activity levels and diets, a computational model will quantify diversity and predict metabolic function for a wide range of individuals.

Energy Use and its Economic and Social Impact

Energy use has a significant impact on the environment, economy, and society. The correlation between increased energy use and development has led to excessive energy use and waste. Energy use leads to a vicious circle of increasing natural resource consumption and waste. Much of the energy used in energy production goes towards the manufacturing and installation of energy infrastructure and creates pollution and habitat destruction. A significant amount of energy is wasted in the conversion, transmission, and distribution process. The challenge is to minimize energy losses and waste by using the right form of energy for the right application and understanding the outcome of energy use.

Quantifying the rebound effects of energy efficiency improvements and energy conserving behaviour in Sweden

Doubts have recurrently been raised on the extent to which energy efficiency can reduce the demand for energy. Improvements in efficiency may cause so-called rebound effects by reducing the prices of energy services as well as by increasing the budget for consumption of other goods and services. The magnitude of such effects is crucial to whether energy efficiency should be a strategy for environmental policy or not. This paper aims to derive a general expression of the rebound effects of household consumption in a parameterised form where available data can be tested. The paper analyses how different parameter assumptions affect the quantification of rebound effects and what may be reasonable ranges. Income effects are quantified using data from the Swedish Household Budget Survey of different goods and services split on income classes. The changes in consumption patterns with increasing income are used to establish the composition of marginal consumption. Combined with energy intensities derived from input–output analysis, this gives a model of how money saved on energy use in one sector may lead to increased energy use in other sectors. The total rebound effects of energy efficiency improvements appear to be in the range 5–15% in most cases, but these results are fairly sensitive to assumptions of energy service price elasticities. Cases with low or negative capital costs for energy efficiency improvements may also result in much higher rebound effects as the income effects become more important. Energy-conserving behaviour (reduced energy service demand) affecting direct energy use such as heating and transport gives rise to rebound effects in the order of 10–20%, depending on the household expenditure per primary energy for different fuels and energy carriers.

The energy and monetary implications of the ‘24/7’ ‘always on’ society

This paper reviews the trends in society, technology and energy demand of the past 30 years, together with the growth of the ‘on-demand’ culture. The ‘24/7’ or ‘always on’ society can be defined as one where people demand—and generally receive—what they want ‘now’. It has grown up in parallel with developments in information technology, which have produced the services needed to meet that demand. Larger numbers of appliances, resulting from greater affluence and disposable income, have increased energy use, despite energy efficiencies in other areas. While monetary factors suggest that changes brought about by the 24/7 society will generally be self-correcting at the macro-economic level, there will nevertheless be effects for individuals, such as potentially severe impacts on the fuel poor as electricity prices rise. We conclude with a view of future directions. As the 24/7 culture continues to grow, there is scope for designers and for information technology to manage and reduce energy consumption. This includes buildings, their services systems, and the mix of new technologies that will be deployed over the next 20 years or so, including the possibilities for data exchange and control at the interface between energy suppliers and consumers, coupled with greater understanding of the behaviour of the consumers themselves.

A multiple perspectives view of the market case for green energy

This paper presents an exploratory evaluation of the market case for green energy. These energy sources are widely considered to have less of an ecological impact than conventional energy sources. The case for green energy is viewed from the multiple perspectives TOP (technical, organizational, personal) framework. The green energy technologies will need to meet certain technical, organizational and personal criteria and resolve key issues in order to address the barriers to market adoption. The multiple perspectives approach facilitates the evaluation of green-energy alternatives as potential new products which would enable organizations and individuals to meet both economic and green criteria that impact customer value creation. Given the present trends of increasing energy use and requirements to minimize environmental impact, green energy adoption may become a key element of strategies to ensure long-term economic growth.