Showing papers on "Efficient energy use published in 1992"

Appropriate thermodynamic performance measures for closed systems for thermal energy storage

Abstract: In this paper, several definitions of energy and exergy efficiency for closed systems for thermal energy storage (TES) are developed and discussed. A simple model is utilized in which heat quantities are transferred at specified temperatures to and from a TES. Efficiency definitions are considered for the overall storage process and for the three component periods which comprise a complete storage process (charging, storing, and discharging). It is found that appropriate forms for both energy and exergy efficiency definitions depend on which quantities are considered to be products and inputs; different efficiency definitions are appropriate in different applications; comparisons of different TES systems can only yield logical results it they are based on a common definition, regardless of whether energy or exergy quantities are considered; and exergy efficiencies are generally more meaningful and illuminating than energy efficiencies for evaluating and comparing TES systems. A realistic, but simplified, illustrative example is presented. The efficiency definitions should prove useful in the development of valid and generally accepted standards for the evaluation and comparison of different TES systems.

Energy-Efficiency Improvement Potential of Commercial Aircraft

Abstract: This report examines past trends in the energy-efficiency of air travel and the potnetial for further aircraft efficiency improvements beyond the year 2000. Its purpose is to identify possible future commercial aircraft fleet efficiency improvements, ranging from what seems likely given existing trends and plans, to the maximum achievable given existing technology and the rate of aircraft stock turnover. The first step is to examine historical trends to understand what factors have contributed to past efficiency gains and how they have come about. Fuel-efficiency technologies are then identified based on published reports, and estimates of their impacts documented. Next the author determines the efficiencies of existing aircraft types and develop estimates for the next generation of aircraft to be delivered in the early 1990s. This report concentrates on passenger air travel.

An assessment of desiccant cooling and dehumidification technology

Abstract: Desiccant systems are heat-actuated cooling and dehumidification technology. With the recent advances in this technology, desiccant systems can now achieve a primary energy coefficient of performance (COP) between 1.3 and 1.5, with potential to go to 1.7 and higher. It is becoming one of the most promising alternatives to conventional cooling systems. Two important and well-known advantages of desiccant cooling systems are that they are CFC free and they can reduce the electricity peak load. Another important but lesser-known advantage of desiccant technology is its potential for energy conservation. The energy impact study in this report indicated that a possible 13% energy saving in residential cooling and 8% in commercial cooling is possible. Great energy saving potential also exists in the industrial sector if industrial waste heat can be used for desiccant regeneration. The latest study on desiccant-integrated building heating, ventilating, and air conditioning (HVAC) systems indicated that the initial cost for the conventional cooling equipment was greatly reduced by using desiccant technology because of downsized compressors, fans, and ductworks. This cost reduction was more than enough to offset the cost of desiccant equipment. Besides, the system operation cost was also reduced. All these indicate that desiccant systems are also cost effective. This study provides an updated state-of-the-art assessment forsiccant technology in the field of desiccant materials, systems, computer models, and theoretical analyses. From this information the technology options were derived and the future research and development needs were identified. Because desiccant technology has already been applied in the commercial building sector with very encouraging results, it is expected that future market breakthroughs will probably start in this sector. A market analysis for the commercial building application is therefore included.

Energy use in Denmark: An international perspective

Abstract: This report analyzes the evolution use in Denmark since the early 1970s in order to shed light on the future path of energy use in Denmark, with particular emphasis on the role of energy efficiency The authors found that improvements in end-use energy efficiency reduced primary energy requirements in Denmark by 22% between 1972 and 1988 Focusing on developments in six individual sectors of the Danish economy (residential, manufacturing, other industry, service, travel, and freight), they found that the residential, manufacturing, and service sectors have led the improvements in efficiency Travel showed few significant improvements and the efficiency of freight transportation worsened The international comparisons showed that the structure of energy use in Denmark is less energy-intensive than that of most high-income OECD countries, with the exception of Japan Overall, they concluded that most of the energy savings achieved in Denmark were brought about through improvements in technology They also found that an important stimulus for improved efficiency was higher energy prices, led in no small part by significant taxes imposed on small consumers of heating oil, electricity, and motor fuels Energy-efficiency programs accelerated energy savings in homes and commercial buildings The rate of improvement of energy efficiency in Denmarkmore » has slowed down significantly since 1984, consistent with trends observed in other major countries While many of the energy-efficiency goals stated or implied in Denmark`s Energi 2000 are achievable over a very long period, present trends do not point towards achievement of these goals by 2010 or even 2020 Strong measures will have to be developed by both public and private authorities if energy efficiency is to make a key contributions to reducing environmental problems associated with energy use in Denmark« less

Guidelines for Energy Simulation of Commercial Buildings: Final.

Abstract: This report distills the experience gained from intensive computer building simulation work for the Energy Edge project. The purpose of this report is twofold: to use that experience to guide conservation program managers in their use of modeling, and to improve the accuracy of design-phase computer models. Though the main emphasis of the report is on new commercial construction, it also addresses modeling as it pertains to retrofit construction. To achieve these purposes, this report will: (1) discuss the value of modeling for energy conservation programs; (2) discuss strengths and weaknesses of computer models; (3) provide specific guidelines for model input; (4) discuss input topics that are unusually large drivers of energy use and model inaccuracy; (5) provide guidelines for developing baseline models; (6) discuss types of energy conservation measures (ECMs) and building operation that are not suitable to modeling and present possible alternatives to modeling for analysis; and (7) provide basic requirements for model documentation. This project was initiated to determine whether commercial buildings can be designed and constructed to use at least 30% less energy than if they were designed and built to meet the current regional model energy code, the Model Conservation Standards (MCS) developed by the more » Pacific Northwest Electric Power and Conservation Planning Council. Secondary objectives of the project are to determine the incremental energy savings of a wide variety of ECMs and to compare the predictive accuracy of design-phase models with models that are carefully tuned to monitored building data. « less

Efficient energy use in manufacturing.

Abstract: The potential for improved industrial efficiency is great and a substantial part of that potential is being realized in the course of events. With new technology and increasing affluence, the composition of production is changing such that energy and materials consumption is growing more slowly than the economy. Through new technologies and appropriate public policies, the energy intensities of all production processes should also continue to decline. Potential difficulties facing this relatively rosy scenario are also discussed.

Analysis of federal policy options for improving US lighting energy efficiency: Commercial and residential buildings

Abstract: The US Department of Energy (DOE) has recognized the opportunity to achieve energy, economic, and environmental benefits by promoting energy-efficient lighting through federal policies, including lighting standards, financial incentives, and information programs. To assist in this process, the Office of Conservation and Renewable Energy`s Office of Codes and Standards invited Lawrence Berkeley Laboratory to assess prospective national impacts for a variety of policy options. Some progress has already been made in developing lighting policies at both the federal and state levels. The US DOE`s Office of Building Technologies has evaluated lighting efficiency incentives as part of its analysis for the National Energy Strategy. Fluorescent and incandescent lamp standards are included in the national Energy Policy Act of 1992 (P.L. 102-486, October 24, 1992). A few states have analyzed or implemented lamp and luminaire standards. Many policy-related issues merit further investigation. For example, there is considerable debate over issues such as mandatory or voluntary standards versus component labeling and other education-oriented strategies. Several different technologies are involved that interact with each other-lamps (incandescent, compact fluorescent, and HID), ballasts (for fluorescent and HID lamps), and fixtures with reflectors and lenses. Control systems and operation patterns must also be considered (timers, automated dimming,more » or occupancy sensors). Lighting applications are diverse, ranging from offices, restaurants, hallways, hospital operating rooms, to exterior lights. Lighting energy use influences heating and cooling requirements in buildings. Successful lighting system design must also address interactions between architectural design elements and daylighting availability. Proper system installation and ongoing operation and maintenance are crucial. The economic aspects of the preceding points must also be considered for policy making.« less

Retrofit system for energy efficient lighting

Abstract: A retrofit system for dedicated an Edison-type socket to receive only energy efficient lighting components. The retrofit system includes a power unit, an energy efficient lamp and an adapter. The adapter is arranged to be readily installed in the socket, but once installed it is not removable. The adapter is arranged for the removable mounting of the power unit and the power unit is arranged for the removable mounting of the energy efficient lamp. The retrofit system permits the exchange or replacement of either or both of the power unit and energy efficient lamp as required but does not permit conversion back to the inefficient incandescent lighting.

Commercial energy efficiency and the environment

Abstract: The production and use of energy create serious, extensive environmental affects at every level, in every country, argue the authors. That impact may be more serious in developing than in developed countries as developing countries depend more on natural resources and lack the economic strength to withstand environmental consequences. At the same time, a reliable energy supply is vital to economic growth and development. Energy consumption and economic growth have been somewhat delinked at high income levels, but increased energy consumption (especially of electricity) is inevitable with higher GDP. Greater energy efficiency in developing countries and Eastern Europe is a high-priority way to mitigate the harm to the environment of growing energy consumption, say the authors. They outline four advantages of greater energy efficiency. It requires measures that are in the economic self-interest of those regions. Political obstacles make these measures difficult, but there are well-established techniques for addressing concerns about low-income consumers (such as direct income support or life-line rates). It will help conserve the world supply of nonrenewable (especially fossil) fuels. It will encourage appropriate fuel switching. It addresses every level of concern, up to the global effects of global warming. Any strategy to make energy use and production more efficient must rely more extensively than before on markets that are allowed to function with less government interference. The crucial components of such a straetegy (also crucial to economic development generally) are: more domestic and external competition; the gradual elimination of energy pricing distortions; the reduction of macroeconomic and sectoral distortions (for example, in foreign exchange and credit markets); the reform of energy supply enterprises - reducing state interference, providing more financial autonomy and a greater role for the private sector; consumer incentives to select more efficient lights, space heating, and so on. The authors are not convinced of the need for nonmarket approaches beyond those geared to correct externalities, provide essential information, support basic research and development, and possibly promote pilot projects. They also conclude that a government is far more likely to take action to reduce an environmental externality if it captures benefits within its own national boundaries that exceed the cost of the action. Reducing the large difference between energy prices and economic costs in developing countries and Eastern Europe is a more immediate issue than carbon taxes. The developed countries, say the authors, have an indispensable role to play in improving energy efficiency in the developing countries and Eastern Europe. They can encourage the flow of efficient technology, they can increase conventional aid, and they must accept a greater share of the burden of protecting the global commonalities.

The pattern of energy efficiency measures amongst domestic households in the UK

Abstract: This commentary attempts to analyse the decision by households to invest in energy efficiency measures using the tools of microeconomic analysis.

Human powered four wheel on/off road vehicle

Abstract: A safe, efficient, human powered vehicle for on and off road use. The preferred embodiment has four wheels and seats two operators side by side. The vehicle incorporates several features which drastically reduce the energy required to propel such a vehicle and optimizes the energy produced from the operators. Each operator is provided with an independent foot pedal and drive mechanism. Each independent drive mechanism has multiple speeds which are independently controlled by each operator. The invention allows each operator to provide power to both rear wheels simultaneously. The drive train includes a simple, lightweight, energy efficient freewheel mechanism which acts as a differential and allows each rear wheel to rotate at different speeds when turning corners. This differential mechanism saves energy by eliminating tire skid which occurs when both rear wheels rotate at the same speed during a turn. The suspension system is energy efficient. Both the front and rear suspension systems keep each wheel parallel to the other wheels throughout the suspension travel. The suspension design reduces energy loss due to toe change, bump steer, and the like. The vehicle incorporates a unique braking control mechanism which increases maneuverability and control of the vehicle. The vehicle's four wheel design provides increased stability and safety over conventional two and three wheeled human powered vehicles.

Analysis of energy efficiency of industrial processes

Abstract: This book examines V.S. Stepanov's method of analysis of energy efficients of industrial production schemes, which takes into account the thermodynamic chemical energy and "exergy" of all substances/apparatuses involved, from the acquisition of raw materials to the recycling of waste products. Prognoses are made for large-scale metallurgical plants. Particular emphasis is placed on the assessment of the optimal volume of secondary energy resource use. This volume uses the fundamentals of thermodynamics to interest primarily students and workers in energy resource management and chemical and mechnical engineering.

Impact Assessment and Performance Targets for Lighting and Envelope Systems

Abstract: Electric lighting loads and cooling from solar heat gains and from lights are the two largest components of peak demand in commercial buildings. The most cost effective demand side management solutions are generally those that directly reduce or eliminate these loads. Existing technologies can provide modest reductions, however they are typically applied an a piecemeal manner that yields less than optimal results. The full potential of existing technologies will be realized when they are commercially available in an integrated package easily specifiable by architects and engineers. Emerging technologies can also be developed to provide even greater savings and extend the savings over a greater portion of the building floor area. This report assesses achievable energy and peak demand performance in California commercial buildings with technologies available today and in the future. We characterize energy performance over a large range of building envelope and lighting conditions, both through computer simulation models and through case study measured data, and subsequently determine reasonable energy targets if building design were further optimized with integrated systems of current or new technologies. Energy targets are derived from the study after consideration of industry priorities, design constraints, market forces, energy code influence, and the state of currentmore » building stock.« less

Alberta's Energy Efficiency Branch Conducts Transportation Audits

Abstract: In 1988, the Energy Efficiency Branch of Alberta's Department of Energy launched a computerized transportation audit program. Its purpose is to identify possible savings in the consumption of energy in the transportation sector. In the first 18 audits completed, the potential annual fuel savings averaged 34 percent. The program consists of four segments: vehicle selection, vehicle maintenance, driver training, and vehicle routing. We concentrate here on the development and implementation of the vehicle routing component and its use by Scott National to save 10 percent of its annual fuel costs.

Energy storage system for electrically operated trolley bus network - holds braking energy as kinetic energy via flywheel at stationary point along each line section

Abstract: The energy storage system is used for temporary storage of the braking energy of a trolley bus (8) supplied from an overhead line (4), with subsequent conversion of the stored kinetic energy into electrical energy for providing acceleration. Each section of the line has an associated flywheel (1) at a stationary point, with a smaller flywheel (6) incorporated in each trolley bus, with a microprocessor (9) responding to the charge level of the flywheels and the travel parameters of the bus, to control the regulating devices (2, 5) of each flywheel. ADVANTAGE - Improved energy efficiency and back-up energy supply.

Building energy tools directory

Abstract: A directory of building energy software tools is now available on the web. The directory contains information on more than 100 tools ranging from research software to commercial products with thousands of users. The common thread for all the software is improving energy efficiency or incorporating renewable energy concepts in buildings.

Technologies for a Greenhouse-Constrained Society

Abstract: This conference explored how three technologies might help society adjust to life in a greenhouse-constrained environment. Technology experts and policy makers from around the world met June 11--13, 1991, in Oak Ridge, Tennessee, to address questions about how energy efficiency, biomass, and nuclear technologies can mitigate the greenhouse effect and to explore energy production and use in countries in various stages of development. The conference was organized by Oak Ridge National Laboratory and sponsored by the US Department of Energy. Energy efficiency biomass, and nuclear energy are potential substitutes for fossil fuels that might help slow or even reverse the global warming changes that may result from mankind`s thirst for energy. Many other conferences have questioned whether the greenhouse effect is real and what reductions in greenhouse gas emissions might be necessary to avoid serious ecological consequences; this conference studied how these reductions might actually be achieved. For these conference proceedings, individuals papers are processed separately for the Energy Data Base.

Analysis of agricultural energy systems.

Abstract: General Preface. Preface to Vol. 5. Program Listings. 1. Knowledge Engineering and Energy Systems (J.R. Barrett). 2. A Knowledge-Based Expert Control System for Low-Energy Maize Drying (R.M. Peart). 3. A Knowledge-Based Decision System for Control of Waste Heat for a Greenhouse-Aquaculture Complex (D.R. Price, R.T.H. Chen and R.M. Peart). 4. Teaching Energy Cost Minimization by Linear Programming (G.E. Miles). 5. Energy Crop Selection Using Linear Programming (D.A. Bender and B.A. McCarl). 6. Input-Output Energy Analysis for Agriculture and the Food Chain (R.C. Fluck). 7. Energy Input-Output Simulation of Crop Production (R.E. Muller). 8. Management Strategies for Low Temperature Maize Drying (G.R. VanEe and G.L. Kline). 9. Energy Use in Maize Harvest and Drying (R.M. Peart and J.R. Barrett). 10. Microcomputer Program for Evaluating Energy Consumption in Low-Temperature Grain Drying (E.A. Smith and M.E. Parkes). 11. Models of Scheduling Operations for Improved Energy Efficiency (E. Van Elderen). 12. Integrated Management of Energy and Climate in Animal Houses (J.P.A. Christiaens). 13. A Simulation Model for Analysis of Harvesting and Transport Costs for Biomass Based on Geography, Density and Plant Location (B. Mantovani and H. Gibson). 14. GETOH - A Computer Program for Evaluation of On-Farm Alcohol Production (J.R. Ogilvie). 15. Economic Feasibility of Crop Residue as a Drying Fuel (O.J. Loewer). 16. Analysis of Agricultural Plants for Cogeneration Feasibility in the United States (I.P. Schisler and R.C. Brook). List of Contributors. Subject Index.

An overview of energy supply and demand in China

Abstract: Although China is a poor country, with much of its population still farming for basic subsistence in rural villages, China is rich in energy resources. With the world's largest hydropower potential, and ranking third behind the US and USSR in coal reserves, China is in a better position than many other developing countries when planning for its future energy development and self-sufficiency. China is now the third largest producer and consumer of commercial energy, but its huge populace dilutes this impressive aggregate performance into a per capita figure which is an order of magnitude below the rich industrialized nations. Despite this fact, it is still important to recognize that China's energy system is still one of the largest in the world. A system this size allows risk taking and can capture economies of scale. The Chinese have maintained rapid growth in energy production for several decades. In order to continue and fully utilize its abundant resources however, China must successfully confront development challenges in many areas. For example, the geographic distribution of consumption centers poorly matches the distribution of resources, which makes transportation a vital but often weak link in the energy system. Another example -- capital -- is scarcemore » relative to labor, causing obsolete and inefficiently installed technology to be operated well beyond what would be considered its useful life in the West. Major improvements in industrial processes, buildings, and other energy-using equipment and practices are necessary if China's energy efficiency is to continue to improve. Chinese energy planners have been reluctant to invest in environmental quality at the expense of more tangible production quotas.« less