Demographics,energy and our homes

The projected growth in households in the UK is a key factor in future domestic energy consumption, particularly electricity consumption. While every household needs a home and its heating, lighting and appliances, increasing incomes have historically led to significantly higher appliance ownership, higher expectations of levels of energy service and greater usage. In the past this trend was combined with increasing household numbers to drive growth in domestic electricity demand. Official projections for population growth and household composition indicate significant drivers for future growth in energy demand. Curbing this will require policies to reverse the tendency for energy–efficiency improvements to be overwhelmed by growing numbers of households, more widespread appliance ownership and increased service expectations.     

运用10年监测数据解析生产锅炉群的节能运行

整理出江苏油田主力生产锅炉群连续11年的有效节能监测数据,通过对主要参数的处理和分析对比,总结出影响锅炉群动态热效率的主要参数是过剩空气系数,控制好过剩空气系数是行之有效的节能减排方法。     

Evaluating energy security performance from 1990 to 2010 for eighteen countries

This study provides an index for evaluating national energy security policies and performance among the United States, European Union, Australia, New Zealand, China, India, Japan, South Korea, and the ten countries comprising the Association of Southeast Asian Nations (ASEAN). Drawn from research interviews, a survey instrument, and a focused workshop, the article first argues that energy security ought to be comprised of five dimensions related to availability, affordability, technology development, sustainability, and regulation. The article then breaks these dimensions down into 20 components and correlates them with 20 metrics that constitute a comprehensive energy security index. We find that the top three performers of our index for all data points and times are Japan, Brunei, and the United States and the worst performers Vietnam, India, and Myanmar. Malaysia, Australia, and Brunei saw their energy security improve the most from 1990 to 2010 whereas Laos, Cambodia, and Myanmar saw it decline the most. The article concludes by calling for more research on various aspects of our index and its results.     

Evaluating and ranking energy performance of office buildings using Grey relational analysis

Traditional methods of evaluating energy performance of building tend to focus on comparing the observed energy consumption with the average value of energy consumption by regression method or theoretical value calculated by simulation analysis. For evaluating and ranking the energy performance of buildings, this paper proposed a perspective of multiple objective outputs to evaluate the energy performance of buildings and then use a multiple attribute decision-making approach, Grey relational analysis (GRA), to rank the evaluated buildings. The energy performance of 47 office buildings in Taiwan were evaluated and ranked to serve as a case study to illustrate the procedure and effectiveness of the proposed approach.     

Social habits and energy consumption in single-family homes

Personal interviews (response rate = 96.1%) were made with both men and women in an area of 76 similar, all-electric single-family houses (November 15 to December 1, 1981). The total variation in energy consumption in the area is explained by differences in social habits (water consumption, about 50%; ventilation habits, about 35%; indoor temperature, about 15%) among the households. The consumer sociological variables chosen for this study statistically explain more than 60% of total variation in household energy consumption. A relation has been found between attitude to energy consumption and household energy consumption with r = 0.48. The households display no knowledge that they themselves consume about one third of total energy used. When major energy saving activities are undertaken by the households, the motive is often energy consciousness. When minor energy-saving activities are taken, the motive is an economic one. The male energy-related role is of greater importance for the variation in household energy consumption than the female role.In a discussion, the importance of distinguishing between household energy consumption and household energy use in order not to affect the welfare of the households when energy saving actions are undertaken, is maintained.     

福建安溪地热引水工程十年回顾

安溪地热引水工程成功的基本经验是 :领导重视 ,科学决策 ,统一指挥 ,精心施工 ,严格管理 ;措施是加强地热资源勘查评价 ,提高地热资源的保证程度 ,认真宣传贯彻矿产资源法 ,加强地热水源地环境综合治理工作。建议尽快启动安溪第 2期地热引水工程     

Evaluating the performance of wind turbines in selected locations in Oyo state,Nigeria

The wind speed distribution and wind energy potential are investigated in three selected locations in Oyo state using wind speed data that span between 12 and 20 years measured at 10 m height. In addition, the performance of selected small to medium size wind turbines in these sites were examined. The annual energy output and capacity factor for these turbines were determined. It was found that the monthly mean wind speeds in Oyo state ranges from 2.85 m/s to 5.20 m/s. While the monthly mean power density varies between 27.08 W/m² and 164.48 W/m², while the annual mean power density is in the range of 67.28 W/m² and 106.60 W/m². Based on annual energy output, wind turbines with cut-in wind speed of about 2.5 m/s and moderate rated wind speeds will be best suited for all the sites.     

Evaluating potential renewable energy resources in Poultney,Vermont: A GIS-based approach to supporting rural community energy planning

The current electricity infrastructure in the United States relies on a centralized distribution network that carries a heavy carbon footprint and is susceptible to disruption and failure. Rural communities are more susceptible to longer term interruption and should strive towards a local distributed energy model. This transition will require municipalities to engage with and seek input from community stakeholders. This paper describes a possible model for supporting rural community energy projects using a Geographic Information System (GIS), which was used to develop an inventory of energy resource potential in a rural Vermont town for biomass, wind, and solar technologies.     

On the study of applications of solar thermal energy for mobile homes

A great deal of work has been done in the study of applications of solar thermal energy for conventional site-built houses; however, little effort has been directed to the study of these applications for mobile homes although they account virtually for a large portion of low cost single family homes. Mobile homes are different from the conventional home and building in configuration, structure, arrangement and cost. The concept and criteria of designing a solar space heating/cooling system for mobile homes differs somewhat from that of a conventional site-built house or building. The mobile home is a low-cost housing. The solar system developed for mobile homes should be really low in cost before it can appeal to the mobile home community. This paper presents the unique characteristics of mobile homes and their impacts on the design/selection of its solar space heating/cooling system and system for supplying domestic hot water. A typical model mobile home is selected for investigation of the solar system design for four representative climatic regions (cool, temperate, hot-humid and hot-arid) of this country. Economical feasibility study is also discussed. A low-cost solar collector is suggested and its estimated performance is presented.     

Economics of geothermal energy development (In Imperial County,California)

The geothermal resources in Imperial County appear to have the potential of developing somewhere between 3000 and 6000 mW of power. At 3000 mW, the geothermal energy would add 9% to present installed capacity in California. By the year 2000, geothermal energy might supply about 4–5% of total capacity at that time.The steam flash technology presently available would appear to produce energy at competitive costs in the neighborhood of 20–28 mills per kWh, which is somewhat below comparative costs for coal, nuclear and petroleum as energy sources for electricity conversion.Geothermal development would provide benefits to Imperial County in terms of moderate increases in employment and payroll, royalty benefits and most significantly, perhaps, in tax revenues.     

The effect of energy performance regulations on energy consumption

Governments have developed energy performance regulations in order to lower energy consumption in the housing stock. Most of these regulations are based on the thermal quality of the buildings. In the Netherlands, the energy efficiency for new buildings is expressed as the EPC (energy performance coefficient). Studies have indicated that energy regulations are successful in lowering the energy consumption in residential buildings. However, the actual energy consumption is usually different from the expected energy consumption. This paper explores the effectiveness of energy performance regulations in lowering the energy consumption of dwellings built in the Netherlands after 1996. The effect of the EPC and thermal characteristics on energy consumption was determined by statistical analyses of data on actual energy consumption. The results showed that energy reductions are seen in dwellings built after the introduction of energy performance regulations. However, results suggest that to effectively reduce energy consumption, the tightening of the EPC in not enough. Policies aimed at controlling the construction quality and changing occupant behaviour are also necessary to achieve further energy reductions.     

Design, performance, and cost characteristics of high temperaturesuperconducting magnetic energy storage

A conceptual design for superconducting magnetic energy storage (SMES) using oxide superconductors with higher critical temperature than metallic superconductors has been analyzed for design features, refrigeration requirements, and estimated costs of major components. The study covered the energy storage range from 2 to 200 MWh at power levels from 4 to 400 MW. A SMES that uses high temperature superconductors (HTS) and operates at high magnetic field (e.g. 10 T), can be more compact than a comparable, conventional low-temperature device at lower field. The refrigeration power required for a higher temperature unit (20 to 77 K) will be less by 60% to 90%. The improvement in energy efficiency is significant for small units, but less important for large ones. The material cost for HTS units is dominated by the cost of superconductor, so that the total cost of an HTS system will be comparable to a low temperature system only if the superconductor price in $/ampere-meter is made comparable by increasing current density or decreasing wire cost     

Evaluating the transient performance of standby diesel-generatorunits by simulation

The transient behavior of the standby diesel-generator units and the engineered safeguard loads at an operating nuclear power generating station was simulated using the electromagnetic transients program (EMTP). The authors discuss the standby diesel-generator units and the engineered safeguard load model development and the validation and verification of the applicable EMTP modules. The simulation results demonstrating the standby diesel-generator unit capability and illustrating the predicted transient deviations in the generator terminal voltage and frequency are included together with the voltage deviations within the engineered safeguard features distribution system     

Evaluating the performance of forced convection heat transfer enhancement

Two methods for assessing thermal performance were evaluated for four kinds of forced convective heat transfer augmentations. On method uses the first law of thermodynamics, i.e., the heat transfer improvement at (1) constant Reynolds number, (2) constant pressure loss, and (3) constant pumping power. The other method uses the second law of thermodynamics, i.e., the entropy generation. The first method restricts the effective region and the second method supplies the condition for achieving the minimum entropy generation rate. © 1998 Scripta Technica, Heat Trans Jpn Res, 27(2): 142–154, 1998     

Evaluating energy conservation outreach programs: A case study in Minnesota

The Minnesota Energy Agency and the Department of Administration sponsored workshops for boiler operators in 1979. The workshops, attended by engineers from state-owned facilities and from private buisnesses, dealt with improvements to fuel/air ratios for large gas and oil-fired boilers.

The process and costs of developing and running these workshops are documented. Two different surveys of workshop attendees were conducted, one directly after the workshops and the second two months later. The first survey asked attendees about their reactions to the course (instructor, manual, and visuals) and their intentions to make the fuel/air ratio changes that were discussed during the workshops. The responses were remarkably positive, with 82% of the attendees rating the probability of making these changes as either excellent or good.

The followup telephone survey sought to determine how many attendees had actually made these changes in the two months following the workshops. Again, the results were quite positive: 79% of the respondents said that they had made the adjustments to some or all of their boilers. Altogether 60% of the boilers operated by these respondents had been adjusted.

If these responses accurately reflect the changes made because of the workshops, then the State of Minnesota saved $88,000 in fuel bills during 1979. This is three times the cost of running the two March workshops (including the value of the attendees' time). This suggests that this workshop—and by implication, others like it—are an effective use of State resources.     

Benchmarking the energy performance for cooling purposes in buildings using a novel index-total performance of energy for cooling purposes

Benchmarking the energy performance for cooling purposes in buildings is an important tool for energy management. This paper proposes a novel index and develops a benchmarking process for energy performance for cooling purposes by means of data envelopment analysis and cooling degree hour method. The research begins by using climate data to calculate cooling degree hour and proceeds to build an index of total performance of energy for cooling purposes by linear regression method. Finally, data envelopment analysis is adopted to benchmark the energy performance for cooling purposes in buildings with the index of total performance of energy for cooling that has the effect of ventilation factors (floor area and number of occupants) removed. An application to office buildings in Taiwan is presented to illustrate the development and the use of the evaluating method.     

An optimal P2P energy trading model for smart homes in the smart grid

This research addresses a demand side management (DSM) system coordinated with Peer-to-Peer (P2P) energy trading among the households in the smart grid. It considers the components which have significant impact on cost optimization, e.g., storage, renewables, and microgrid. The model utilizes load and source scheduling, and energy trading strategies for cost optimization. It also addresses the inconvenience created to the users by delaying certain tasks. The contributions of the research are threefold. First, to our knowledge, this is the first optimal model which integrates DSM with P2P energy trading. The solutions of the proposed model determine optimal microgrid energy and price for P2P trading, which was not considered previously. Second, P2P energy trading in the microgrid potentially results in an unfair cost distribution among the participating households. We address this unfair cost distribution problem by employing Pareto optimality, ensuring that no households will be worse off to improve the cost of others. Third, our proposed trading strategy considers total cost optimization in a microgrid. The model utilizes all available energy to minimize energy cost. Therefore, there is a very low risk of energy waste, which is typically neglected in other energy trading strategies.     

Ventilated facades energy performance in summer cooling of buildings

The use of ventilated facades and roofs can help to reduce summer thermal loads and, therefore, the energy consumption due to air-conditioning systems. This paper discusses a simple analytical method for the calculation of the energy saving achievable by using ventilated facades in which the air flow inside the air duct is due to stack effect. Two particular cases of outstanding importance are investigated. The first in which the inner masonry wall is given, and the air duct and the outer facing have to be optimized. The second in which the outer facing is given, and the inner masonry wall and the air duct have to be optimized. The first case can occur in existing buildings renovation, while the second case can occur during the design process. Finally, the influence of the variation of some quantities necessary for calculation on the energy performance of ventilated facades is investigated. In particular, the energy performance of such facades results to be strongly influenced by the air duct width, the insulating material distribution, the solar radiation intensity, the wall outer surface thermal resistance and the roughness of the slabs delimiting the air duct.