End-use Electricity Research Articles

A bottom-up approach to residential load modeling

A model of electric residential end-use is proposed for establishing the load diagram of an area by a process of synthesis. The model follows a "bottom-up" approach, allowing construction of the relative load shape of the area, starting from knowledge of its most relevant socioeconomic and demographic characteristics, unitary energy consumption and the load profiles of individual household appliances. Several probability functions have been introduced in order to cover the close relationship existing between the demand of residential customers and the psychological and behavioral factors typical of the household; the model makes frequent use of the latter through a Monte Carlo extraction process. The model has been applied for the simulation of a residential area where field measurements of power demand had been made at 15-minute intervals and a combined mail survey had been conducted to investigate household energy usage. The paper reports the results of a comparison between recorded and predicted load profiles.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Efficient Electricity in Stockholm

Abstract In 1987 Stockholm Energi began to build a marketing department with the intention of focusing on the customer. A program for efficient electricity end use was formulated, but a gap has now appeared between the original grand plan and its inferior implementation. First, ambitions were too high. A utility recommends measures, but the customer decides which to undertake. Second, the operative level in the organizational hierarchy interpreted intentions differently from the strategic level. Efforts were rather business related than societal. Third, conditions in the Swedish electricity market were announced as about to change in favor of competition. A political organization is susceptible to modem topics. Stockholm Energi reoriented its efforts, and a desire to be businesslike has taken the place of electricity efficiency.

The potential for energy efficiency in electric end use technologies

The authors summarize a recent study conducted by the Electric Power research Institute (EPRI) that contains estimates of potential energy savings that will result if the most efficient electricity technologies readily available immediately attain complete market saturation in the year 2000. They first define and contrast various efficiency scenarios and then summarize the energy savings forecast associated with demand-side management measured by sector. These estimates have been developed through discussions with a wide range of experts both inside and outside the utility industry, review of the trade and technical literature, and simulations and forecasts using several end-use models. The main results for efficient technologies that reduce electric usage are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The Potential for Reducing Carbon Dioxide Emissions with Modern Energy Technology: An Illustrative Scenario for the Power Sector in China

As development and environmental goals become increasingly inte grated in international discourse, practical efforts to generate economic and environmental benefits simultaneously deserve increased attention. The electricity scenario for China presented here suggests thatan expansion of the power sector in China consistent with achieving a high living standard could be brought about over the next half century in ways that offer major environmental benefits, including no increase in CO, emissions from the power sector, at competitive costs. Accomplishing this goal requires that the following six elements be integrated: efficient electricity end-use, hydroelectric power, nuclear power, efficient gas turbine technologies fired with naturalgas, use ofcoal-derived hydrogen in fuel cells,and biomass-integrated gasifier/gas turbine technologies. While modern technology is emphasized, the scenario involves only systems that could be commercialized in the 1990s-no long-term technological possibilities are taken into account.

The potential for reducing CO2emissions with modern energy technology: An illustrative scenario for the power sector in China

The case study developed here is a scenario for the power sector of China looking 50 years into the future. The scenario is constructed in such a way that total CO[sub 2] emissions from the power sector are the same in 2039 as in 1989. As the scenario represents a radical departure from present plans, some assumptions may be unrealistic. The exercise is intended, however, not to forecast the future but to explore whether such a goal might be plausibly achievable at acceptable cost. To the extent that the assumptions are plausible and the indicated costs attractive, the analysis can suggest strategies that should be pursued further, both in China, and in the international community that is seeking a basis for cooperative approaches for coping with greenhouse warming and other environmental issues. The scenario combines the following elements: efficient electricity end-use; hydroelectric power; nuclear power; efficient gas turbine technologies fired with natural gas; use of coal-derived hydrogen in fuel cells; and biomass-integrated gasifier/gas turbine technologies. While modern technology is emphasized, the scenario involves only systems that could be commercialized in the 1990s - no long-term technological possibilities are taken into account.

Hydrogen and electricity as carriers of solar and wind energy for the 1990s and beyond

This study compares the costs of possible future large-scale and long-distance solar and wind energy delivery systems for electric, thermal, and automotive end-uses. Solar and wind resources are intermittent, and the best sites are often remote from the energy end-use. Electricity is presently the dominant secondary carrier of renewable energy to end-use markets. However, electricity is relatively expensive to store in large quantities and to deliver over long distances. Hydrogen systems potentially offer storage and long-distance delivery advantages. The analysis indicated that hydrogen systems could be competitive with electricity as an energy carrier for thermal end-uses, particularly over longer distances. Development of cheaper bulk electric storage technologies, e.g. superconducting magnetic energy storage, could erode this advantage. Hydrogen energy systems do not appear to be competitive when the end-use is electric or automotive. The increased cost of the larger solar and wind capture and generation requirements, due to the overall lower efficiency of the hydrogen systems, more than offsets the energy storage and delivery savings. The economics of hydrogen as an energy carrier would significantly improve in electric end-use applications if cogeneration value were considered or if fuel cell and other efficiencies were improved beyond expected levels. The wind energy systems examined had overall lower cost than solar energy systems for hydrogen production. Further comparisons of hydrogen and electric systems would benefit from site-specific analyses. Sensitivity studies for transportation distance, electric transmission costs, capacity factor, storage time, cogeneration, time-dependent end-use value, hydrogen water requirements and costs, and aerospace applications would be valuable areas for further investigation.

The structure of electricity demand in the Brazilian household sector

The present structure of residential electricity demand is analysed by electricity consumption classes and end-uses. Nearly 70% of households consume less than 150 kWh/month and are responsible for 35% of total residential demand. Other determinants of electricity-use, such as income and place of residence, are also discussed. It is found that electricity demand is increasing faster than income as the country reaches appliances saturation in upper consumption levels. Water heating and refrigeration account for the major part of residential consumption. Residential conservation efforts have started introducing more efficient lighting equipment and refrigerators, but further work will have to be done to speed up the diffusion of efficient technology at costs that can be paid by consumers.

A PC-based simulation package for supporting end-user demand side energy management strategies

A simulation package designated at SIMCA-E/sup 2/ (simulation for management, control and analysis of electricity end-use) is described. The package covers a wide area of applications-namely, the testing and performance evaluation of demand controllers and demand control algorithms, computer-aided analysis of data from energy audits, generation of alternative scenarios according to different consumption patterns and/or different contractual terms with the utility, and computer-aided teaching of demand-side management techniques and strategies. The package is written in Pascal and runs on IBM PC-AT, XT, or compatible computers. It may be used with different graphic cards.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

China's Changing Development Strategy: The Case of Rural Electrification

ABSTRACT Rural electrification is necessary if rural incomes are to keep pace with those of urban dwellers as an economy develops. The recent changes in China's development strategies have altered both the emphasis and form of electrification strategies. The move away from small local power generation to an emphasis on large projects and extension of the electrical grid are likely to have two effects. First, as the extension of the grid to rural consumers is likely to be prohibitively expensive the pace of rural electrification is likely to slow. Second, as the central government will have more control on the end use of electricity, less of the benefits from electrification are likely to remain in rural areas. The end result is that urban-rural income differences will increase. As the Chinese revolution has historically had a rural base, the recent changes may lead to less consensus on the appropriate development strategy.

Determinants of electricity use for residential water heating: The hood river conservation project

Because 85% of the homes in the Pacific Northwest have electric water heaters, water heating is the second most important residential electricity end-use in the region (second to space heating). This paper analyses the determinants of water-heating electricity use, using end-use load data and responses to a detailed home interview. These data are available for 142 homes in Hood River, Oregon. On average, these homes used 5000 kWh/yr for water heating. Almost 60% of the household-to-household variation in electricity use was explained with eight variables in a simple regression model. The number and ages of household members are the strongest determinants of electricity use: use increases by roughly 1000 kWh/yr with each additional household member. Other statistically significant determinants of water-heating electricity use are hot-water temperature, water-heater location, number of showers in the home and house type. Electricity use varies considerably throughout the year (as well as across households). Weekly usage was 50% higher in mid-winter than in summer. About half of this temporal variation is due to changes in outdoor temperatures and half is due to seasonal changes in behavior (i.e. increased use of hot water in winter).

Commercial sector energy efficiency improvements: An economic and statistical analysis of empirical data

In this article a statistical and economic analysis of programmes that audited almost 6000 California commercial buildings is presented. Potential and installed efficiency improvements for four customer sizes and eight major end users are included. Lighting represented the electrical end use with the greatest potential for improvement followed by air conditioning, refrigeration, and motors. With regard to gas improvements, space heating had the greatest potential, followed by water heating and boiler process heat. Economic analyses showed that for each customer size the energy audit programme was cost-effective from the perspective of the participant, non-participant, the utility and society.

Forecasting of electricity demand by end-use characteristics

Effective forecasting requires that efficient use be made of the information contained in the available data so that essential data properties can be extracted and projected into the future. As an alternative to econometric methods for electricity demand forecasting, which are subject to errors and uncertainties in model specification and knowledge of causal variables, time series analysis has the advantage of being statistically adaptive to data characteristics. Through a comparative study with data from more than six years, it is demonstrated that good forecasting results can be obtained with an approach based on stochastic time series modelling of homogeneous sectors of electricity end users. This refined approach outperforms both conventional data smoothing techniques and time series modelling of aggregate demands.

Radiation cured coatings - Some commercial successes

I have been asked by the organizers to discuss some commercially successful applications of radiation cured coatings with reference to both technical and commercial factors. This paper will cover three such applications, Case A in the graphic arts field, Case B in vacuum metallizing and Case C in a specialist electrical end use. In each of the three cases to be considered, there were different economic and technical arguments for use of radiation cured coatings. In all three cases, the general advantages of radiation cured coatings, such as no solvent emission, low energy usage and high operating speeds were considered to be important factors, and, as such, will be dealt with in this paper. However, each case had unique problems to which radiation technology presented equally unique solutions. These solutions, and the ways in which they differ from those offered by conventional solvent or water based coatings, will be considered in detail in this paper. During the last five years, industry in general has searched for technologies which would enable it to reduce or eliminate its dependence on organic solvents and which would also be less wasteful of energy. This search was allotted high priority after the 1973 oil embargo and the rapid increase in solvent prices which resulted. Since reduction in the use of organic solvents would also ease the problems of emission control, the recent EPA initiatives, aimed at a very big reduction in the usage of organic solvents in coatings and adhesives, have given a further impetus to this search. Finally, many of you will still have vivid memories of the natural gas shortage experienced over much of the United States during January and February of 1977 and of the problems, shutdowns and dislocations that followed. Because of the factors described above, many users of solvent based coatings have become much more interested in radiation cured coatings because these would: 1. 1) Eliminate concerns about availability of solvents, 2. 2) Reduce material inventory, 3. 3) Reduce in-plant fire hazard (and insurance premiums), 4. 4) Reduce energy usage, 5. 5) For all practical purposes, eliminate problems related to compliance with EPA emission controls. Furthermore, the use of solventless radiation cured coatings would enable the user to dispense with hot air tunnels on all new equipment. (With certain types of radiation cured coating, ventilation with large volumes of cold air is still desirable in order to reduce or eliminate residual odor.)