Implications For Energy Conservation Research Articles

Energy literacy levels and energy investment choices of faith-based organisations in Accra Metropolitan Assembly, Ghana: Implications for energy conservation

Achieving energy literacy is now considered both a necessary and sufficient condition to ensure strict adherence to energy conservation/efficiency programs. While the existing literature has considered the energy literacy of different end-users, a gap exists in the energy literacy levels of faith-based organisations and how they impact energy conservation in faith-based organisations. This study surveyed responses of church leaders connected to energy decision-making in the church from randomly selected 44 faith-based organisations in Accra Metropolitan Assembly (AMA), Ghana, to explore energy literacy levels (i.e. multifaceted and individual dimensions) of these leaders, how it connects with energy expenditures of churches and what influences energy appliance investment choices among faith-based organisations. Lighting and cooling appliance of churches were generally found to be inefficient, and churches consider the brand name of the appliance as the most important factor when making energy appliance investments. The findings also demonstrate that, generally, church leaders have very low multifaceted energy literacy levels, but are much more promising for action energy literacy with a mean score of about 66 percent. Finally, churches with energy-literate leaders experience a lower risk of high electricity expenditure compared to their compatriots who are energy illiterate. Specifically, leaders with action energy literacy exert a significant negative effect on electricity expenditure. In addition, churches with utility committees experience a lower risk of higher electricity expenditure, but the size of the church positively correlates with electricity expenditure. Our findings demonstrate the need to strengthen energy education in churches.

Modeling and analysis for cleaner operation of a process to remove BTX from coke oven gas

Coke oven gas (COG) is a by-product of the coke production process which can be used as a fuel or in the production of chemicals such as methanol. In this research, a model of a BTX (Benzene, Toluene, Xylene) removal process for COG purification is developed, validated with commercial-scale plant data, and applied to improve performance and reduce energy consumption. The process includes a BTX scrubbing column and a distillation column for regeneration of the washing oil. Washing oil is represented as a mixture of BTX, naphthalene and pseudo-components.Three important phenomena with implications for energy conservation were identified using the model. First, the scrubbing efficiency is higher when the ASTM D20 distillation curve of the washing oil is lower. This phenomenon can be explained by the phase equilibrium and the difference in molar volume of the washing oil components. Second, it was found that if the setpoint of the distillation column top temperature exceeds 95 °C, the temperature in the upper portion of the column will increase significantly, which increases the amount of naphthalene in the light oil and decreases its quality. Third, the total energy consuption of the distillation column can be reduced without compromising the purification efficiency if feed temperature is decreased and the low-pressure steam flowrate is increased. Plant test result and model analysis showed that for an exisiting plant with a large vapor heat exchanger and small washing oil heat exchanger, the medium-pressure steam flowrate to the preheater can be reduced without modifying any equipment.

The impact of walker height positions and their influence on triceps activity and energy conservation: a pilot study

Background/Aims Millions of adults use walkers for functional mobility. Inappropriate walker use is associated with incorrect height, forward-leaning posture, and increased energy expenditure. Few studies have investigated the impact of walker positions and their influence on triceps activity. The present study assessed walker height and baseline positioning for individuals with a 50% weight bearing restriction of the lower extremity, and implications for energy conservation. Methods A total of 38 young adults (mean age = 24.95 years; 84.2% female; 15.8% male) participated in this study with a two-wheeled walker. Participants executed five walker positions while maintaining 50% weight bearing of the lower extremity to determine the effect on triceps electromyography activity. Results Triceps electromyography activity did significantly change across the five walker positions assessed (X2 [df=37, P<0.001]). This study showed that the median electromyography activity for positions B (median=0.268) and A (median=0.280) was significantly less than the median electromyography activity for position E (median=0.452; P<0.001). The effect sizes for comparisons of positions B and E (r=0.49) as well as A and E were the largest (r=0.53). Conclusions These findings suggest an elbow angle of 26–35° (position B), followed by an elbow angle of 15–25° (position A), with the walker in line with the heels of the participant, to be superior in minimising exertion of the triceps.

Galerkin Variational Integrators for Orbit Propagation with Applications to Small Bodies

The development of fixed-step higher-order variational integrators based on geometric integration methods is presented. These methods are symplectic, preserve energy in Hamiltonian conservative systems, and are highly accurate for long-term integration. By properly selecting a quadrature rule and control points in the polynomial approximation of the trajectory, a fast algorithm that reduces the number of computations of the gravitational force terms is constructed. Numerical simulations are presented for different scenarios, comparing Galerkin variational integrators against traditional fixed-step propagators used in astrodynamics applications. An error analysis is then performed, focusing on the implications of energy conservation and the accuracy of the methods. It is found that, under certain conditions, Galerkin methods are superior to nonsymplectic integrators for long-term orbital propagation, reducing simulation times significantly for long integration periods. This makes the methods suitable for long-term orbital dynamics applications about small bodies, such as asteroids.

ON THE EFFECT OF ENERGY CONSERVATION ON BLACK HOLE EVAPORATION

We consider the emission of Hawking radiation by black holes as a consequence of a tunneling process. By requiring energy conservation in the derivation of the emission rate we get a well-known deviation from an exact thermal spectrum. A model that takes into account the implications of energy conservation, as well as the back-scattered radiation, is then constructed in order to describe the evolution of black holes as they evaporate. The evaporation process in this model is compared with the results in the standard "thermal" approximation. This allows us to point out the relevance that energy conservation might have in the last stages of black hole evaporation. We also comment about the possible implications of energy conservation in the information loss paradox.

Life Cycle and Green Cost Analysis of Energy-Efficient Lighting for Hotels

About 20% of the electricity use in Hong Kong's hotel operations is for electric lighting. Life cycle cost technique was used in the analysis ofreplacing general lighting service (GLS) lamps with energy saving light bulbs in hotel corridors. Discounting approach was adopted to compute the net present value of electricity cost over a life cycle of five years. Two city hotels in Hong Kong were selected for the case studies. It was found that the simple payback period was about one year, and the reduction in electricity consumption and hence running cost could be up to 70% over the life cycle taken in this study. The corresponding reductions in green cost of electrical power generation and greenhouse gas (CO2) emission were estimated to be HK$114,800 and 420x103 kg, respectively, per year for the two case studies. This paper presents the work and discusses its findings and implications for energy conservation.

Life-Cycle Costing of Energy-Efficient Measures for Commercial Buildings

More them. 40% of electricity is consumed in commercial buildings in Hong Kong. Life-cycle cost analyses of energy-efficient measures for existing fully air-conditioned buildings have been carried out. These measures include electronic ballasts for fluorescent lamps, air-to-air energy recovery, sequence control of multiple identical chillers andvariable speed drives. It has been found that sequence control of multiple identical chillers is the most attractive measure with a pay-back period of 2 years. This paper presents the findings and discusses the implications for energy conservation in existing commercial buildings.

The effect of expected energy prices on energy demand: implications for energy conservation and carbon taxes

This paper describes an empirical method for estimating the effect of expected prices on energy demand. Data for expected oil prices are compiled from forecasts for real oil prices. The effect of expectations on energy demand is simulated with an expectation variable that proxies the return on investment for energy efficient capital. Econometric results indicate that expected prices have a significant effect on energy demand in the US between 1975 and 1989. A model built from the econometric results indicates that the way in which consumers anticipate changes in energy prices that are generated by a carbon tax affects the quantity of emissions abated by the tax.

Scattering of acoustic waves by a circular disc in the interface between two fluids

The scattering of acoustic waves by a sound-hard circular disc situated in the planar interface between two different fluids is considered. The incident wave is taken as a plane wave and a Hankel transform representation of the scattered field is used. After some manipulations using the boundary conditions, this leads to an integral equation over the disc for the potential jump across the disc. This jump is expanded in a series of Legendre functions which fulfill the correct edge condition and the integral equation is projected on the same set of Legendre functions. The far fields are calculated and the implications of energy conservation are explored and used as a numerical check. A few numerical computations showing the disc-scattered far-field amplitude and the total scattered energy are given and are shown to compare favorably with the expectations from simple ray theory at higher frequencies.

Scattering of acoustic waves by a sphere outside an infinite circular cylinder

By employing the null-field approach, the scattering of acoustic waves by an infinite cylinder and a sphere is considered. Sound-hard boundary conditions are assumed and the incident wave is taken as a plane wave. The scattered field is obtained as a complicated mode sum containing the transition matrix of the sphere and the reflection matrix of the cylinder. Also, the transformation functions between the cylindrical and spherical wave functions and the translation functions for the cylindrical wave functions enter into this sum. The farfields are calculated and the implications of energy conservation are explored and used as a numerical check. Numerical results showing the scattering cross section and the farfield amplitude are presented.

Indoor climate and thermal comfort in high-rise public housing in an equatorial climate: A field-study in Singapore

Urban residential development in Singapore has been focussed on clusters of high-rise public housing known locally as ‘new towns’. Indoor climatic conditions were assessed in a sample of 214 flats in the new towns. Also a sample of 583 occupants were interviewed about their experiences of thermal comfort. Separate body-environment heat-balances were estimated for each respondent and these data were input to the PMV (ISO 7730) mathematical model of thermal comfort. The operative temperature actually preferred by the respondents was about 1°C cooler than the mean value of 29.6°C recorded in their flats. However, their empirically derived temperature preference was about 2°C warmer than the value predicted by the PMV model and ISO standard. Processes of physiological acclimatization and perceptual habituation are put forward as possible explanations for the discrepancy between temperate climate comfort theory and actual human response in the tropics. The implications for energy conservation in tropical cities are also discussed.

The passive solar heated school in Wallasey. VI. Thermal sensation and comfort in the classroom: A year-long study of the subjective and adaptive responses of children

In order to examine relationships between thermal parameters and subjective response, a class of 33 13-year-old children was studied over a period of 63 weeks. Children completed 7 point rating scales of thermal sensation, air movement and dryness and 5 point scales of perceived comfort and wakefulness. Information was collected about clothes worn, windows open and lights in use, as well as data on concurrent thermal variables. In general the classroom was perceived as warm, dry and airless. Children were found to maintain thermal neutrality down to globe temperatures of 17°C by adjusting clothing, windows and lighting. The adaptive responses served to moderate the effect of physical fluctuations on thermal sensation but appeared to be ineffective at globe temperatures over 24°C. A theoretical model of adaptive control of the environment would suggest low correlations between thermal sensation and variables which the children could adjust (clothing, ventilation, heating), and high correlations between these moderator variables and objective room temperatures. The observed set of correlations supports this model. Children seem to be sensitive to differences between mean surface and air temperatures but not to ceiling-floor temperature differences within the ranges studied. There are low correlations between thermal sensation and ‘comfort’. This has implications for energy conservation.

Energy used by electric motors in a papermill

The electric motors in a papermill were monitored for several days. Though many of the motors were unmetered, it proved possible to determine the pattern of energy use in considerable detail. The results are presented and some implications for energy conservation are noted.

Energy Conservation in New Housing Design

The potential implications of energy cost and availability for new housing design over the rest of the century are examined. The discussion is based on the premise that the rise in the price of fuels relative to that of labor and materials is focusing the attention of home builders and home buyers on total life-cycle costs. This shift in emphasis from first-cost, short-term, and speculative factors to the energy conservation technologies stimulated by life-cycle cost analyses portends a number of major physical changes in new residences over the next few decades. This thesis is developed by looking first at the housing market, the historical influences of certain building practices, and fuel price changes in recent years. Attention is directed primarily to single-family detached dwellings including mobile homes, single-family attached homes, townhouses, garden apartments, and low-rise housing units. Next, major design parameters related to energy are examined in the context of a simplified life-cycle cost model, with numerical examples. The constraints imposed by existing technology, building and occupancy practices, and energy costs on total life-cycle costs are examined for their implications to future housing design practices. Then, the technological opportunities for energy conservation as a design consideration are discussed, with anmore » emphasis on identifying the extent to which many design parameters related to energy will change in the next few decades. Finally, the question of the implications of energy conservation on new housing design, ownership, and operation and on the identification of several specific research and policy issues is examined. 26 references. (auth)« less