Natural Gas Distribution Companies Research Articles

Forecasting risks of natural gas consumption in Slovenia

Efficient operation of modern energy distribution systems often requires forecasting future energy demand. This paper proposes a strategy to estimate forecasting risk. The objective of the proposed method is to improve knowledge about expected forecasting risk and to estimate the expected cash flow in advance, based on the risk model. The strategy combines an energy demand forecasting model, an economic incentive model and a risk model. Basic guidelines are given for the construction of a forecasting model that combines past energy consumption data, weather data and weather forecast. The forecasting model is required to estimate expected forecasting errors that are the basis for forecasting risk estimation. The risk estimation strategy also requires an economic incentive model that describes the influence of forecasting accuracy on the energy distribution systems’ cash flow. The economic model defines the critical forecasting error levels that most strongly influence cash flow. Based on the forecasting model and the economic model, the development of a risk model is proposed. The risk model is associated with critical forecasting error levels in the context of various influential parameters such as seasonal data, month, day of the week and temperature. The risk model is applicable to estimating the daily forecasting risk based on the influential parameters. The proposed approach is illustrated by a case study of a Slovenian natural gas distribution company.

Mass customization: A method for market segmentation and choice menu design

This paper proposes a method for designing choice menus for mass customization (MC). The method is based on the analysis of stated preferences (SP) on product or service attributes obtained through panel studies. The method is first presented, and then illustrated with a real world case application in a natural gas (NG) distribution company. The case application indicated the method was able to elicit stated preferences on a broad range of attributes enabling the design of choice menus of different sizes and content for alternative customer segments, thus balancing the trade-off between flexibility and complexity that is at the core of choice menu design.

Enbridge Inc

AbstractOil and Gas (MIC: 14.2 SIC: 4619 NAIC: 486990)Enbridge provides energy transportation and distribution in North America and internationally. As a transporter of energy, Co. operates, in Canada and the United States, a crude oil and liquids pipeline system. Co. also has international operations and involvement in the natural gas transmission and midstream businesses. As a distributor of energy, Co. owns and operates a Canadian natural gas distribution company, and provides distribution services in Ontario, Quebec, New Brunswick and New York State.

Enbridge Inc

AbstractOil and Gas (MIC: 14.2 SIC: 4619 NAIC: 486990)Enbridge provides energy transportation and distribution in North America and internationally. As a transporter of energy, Co. operates, in Canada and the United States, a crude oil and liquids pipeline system. Co. also has international operations and involvement in the natural gas transmission and midstream businesses. As a distributor of energy, Co. owns and operates a Canadian natural gas distribution company, and provides distribution services in Ontario, Quebec, New Brunswick and New York State.

Performance evaluation and case studies of microturbines fuelled with natural gas and diesel

The high reliability and simple design of microturbines make them an attractive prime mover in the generation and distribution of electricity in the low capacity range. This paper gives an overview of microturbines in the Brazilian environment and provides a performance assessment and an economic analysis of these machines fuelled by natural gas and diesel and also an indication of their emission levels. This work was based on data that were obtained from experimental tests on microturbines operating at full and part load. The performance assessment indicated that it is possible to obtain up to 27 per cent microturbine efficiency at full load under local conditions. The nitrogen oxides (NOx) and carbon monoxide (CO) emissions level of the machines tested are less than 7 ppmv@15%O2 at full load when natural gas is the fuel. The units are therefore clean enough to be sited among residential and commercial establishments. The results of the economic analysis show that with the natural gas microturbine used in cogeneration, it is possible to achieve a payback time on capital equipment of less than 4 years. The return on the investment has improved with the favourable pricing policies of some of the natural gas distribution companies and with the rise in electricity prices in Brazil.

Development of a systematic observation protocol of physical exposure of the back: a preliminary study.

At present there is no systematic observation protocol for the assessment of the multi-factorial aspects of physical exposure related to the back used within the constraints of occupational epidemiological research. In this context, a new preliminary systematic observation protocol is proposed to assess exposure to physical loading of the back using nine categories of physical risk factors: the SOPE back protocol. The objective of this study was to investigate whether the new protocol can correctly identify the level of exposure related to measured physical loading of the back. The subjects of this closed cohort study were 451 manual workers at a natural gas distribution company. The assessment of exposure was made with the protocol using groups with different job titles. The workers were followed for a 2 yr period to establish the risk of a new occurrence of complete disability related to the back (NOCD back injury) in each job grouping. Based on the median of the total scores derived from the protocol, two levels of exposure were identified (high and low). Taking into account the limitations of this study, the protocol in development may be a good tool to establish two levels of exposure to physical loading of the back in large epidemiological studies of occupational low back pain. Further research is needed to replicate these results with larger samples and to test the reliability and predictive validity of the protocol.

On field characterisation of static domestic gas flowmeters

Different solutions to the metering of natural gas consumption can be adopted according to whether the distribution is domestic or industrial. In the domestic field, almost all the flow meters used by natural gas distribution companies are conventional diaphragm meters, whereas greater flow rates justify metrologically better performing measurement systems. The requirement for new safety and remote-reading related functions and the availability of new technologies is now encouraging the use of static innovative flow meters. In the present study, after a short analysis of metering principles and of static ultrasonic flow meter characteristics, the authors report the results of the field tests carried out on two different types of static ultrasonic flow meter for 2 years.

Gas Utility Prices in a Restructured Industry

The natural gas industry has witnessed significant policy changes since 1978. The Federal Energy Regulatory Commission has undertaken a number of policy initiatives designed to promote competition in the natural gas industry. These initiatives have affected both natural gas pipeline and local gas distribution companies. This study provides an empirical examination of the impact of restructuring on local gas distribution utilities' residential, commercial, and industrial prices.

Weather Normalization and Natural Gas Regulation

The residential demand for natural gas is the subject of two recent articles in this journal.' Each used pooled time-series/cross-section data to estimate price and income elasticities as well as other relationships that determine the quantity of natural gas consumed by individual households or groups of households. Not surprisingly, among relationships other than price or income, the most important links consumption to weather conditions .2 Regulating natural gas distribution companies requires that this dependence of consumption on weather conditions be recognized and reflected in ratemaking. If it is not (or if it is recognized incorrectly) the regulator will approve prices and revenues that make expected return on utility investment either greater or smaller than allowed return.

Retirement disability among workers in a natural gas distribution company.

Epidemiological investigations of occupational disability are severely limited because of the inherent difficulties in standardizing definitions of disability and because of the lack of appropriate comparison data. Nevertheless, occupational disability is of great concern to workers. An investigation of disability, defined as permanent retirement due to medical disability, among hourly employees of a natural gas distribution company was undertaken in response to a request by the employees' union. Because of the above limitations, a hypothesis-generating rather than hypothesis-testing approach was taken, utilizing both disability retirement incidence rates and a prevalence survey of the living disabled retirees. It was hypothesized from the analysis that this group of workers did experience an excess of retirement disability for the period 1971-1980 when compared to estimated disability incidence rates of the general Social Security insured population, and that this excess may have been due in part to an excess of musculoskeletal disabilities associated with occupational physical stresses and strains.

Simulating the Operation of ANatural Gas Distribution System With Linear Flow Models

Abstract The energy crisis has created a need for more efficient operation of every sector of the energy industry. Shortages of natural gas, federal regulations and increasing demand have imposed special hardships on natural gas distribution (NGD) companies. Management personnel and engineers are in search of economical and practical methods to simulate the operation of gas distribution 8YStem s to allow economic studies to be made of alternative operating policies. This paper presents research conducted to refine a previous attempt at simulating NGD systems with linear flow models (LFM). A new method of constructing the transaction matric of an NGD system LFM is presented. The new method allows the calculation of storage field leakage volumes and compressor fuel requirements for steady-state operation. Application of the model to an existing system is described. The validity of the model is verified through comparison of metered and predicted gas flows and pressures. A comparison of historic economic data with model-predicted data is presented to further substantiate model validity. A discussion of model uses is presented, including an example compressor fuel reduction problem. A general compressor fuel minimization procedure is proposed. Introduction THE BELATED RECOGNITION of an "energy crisis" throughout the world has focused attention on the energy production and transportation industry. Efficient operation of every sector of the energy industry has become a necessity as a consequence of impending raw material (i.e. oil and gas in particular) shortages and cost increases. NGD companies form one sector of the energy industry which is especially aware of increased difficulties brought about by the energy crisis. Natural gas is in short supply and increased wellhead prices are inevitable. Federal regulations in the United States do not permit gas distribution companies to pass along increased costs to customers without lengthy and costly court hearings before the Federal Power Commission. As a result of increased operating costs and restrictive governmental regulation, gas distribution company management personnel are in search of economical and practical techniques which will enable them to simulate the operation of gas delivery systems to permit the study of alternative operating policies. Literature Review Early work on gas flow simulation concentrated on the study of steady-state flow in single line segments(1,2,3,4,5,6). In the early fifties, the study of transient flow in single lines was initiated by Olds and Sage(7). Many others have since studied transient gas flow(8,9,10,11). Stoner"" published one of the first papers on the steady-state analysis of integrated gas networks. The n-dimensional Newton-Raphson iterative procedure was used to solve the nonlinear equations which result from the problem formulation. A refinement of Stoner's work was published by Evrenos et al.(13). Transient analysis of complex pipeline systems has been studied recently by several authors(14,15,16,17) Rachford et al.(18) described a gas pipeline system transient flow model utilizing variational methods. LFM's, as described by Rosenblatt(9), were first used to describe the American economy by Leontief(20). Extensions of this original work continue today.

Economics of Underground Gas Storage

The economic advantages of using underground gas storage to balance variations in gas load are illustrated here by comparing it with various other approaches: increasing pipeline flow gas purchases, increasing interruptible sales, and installing LNG or LPG peak-shaving facilities. All other methods run a poor race for a return on the investment dollar. Introduction Most natural gas distribution companies have been faced with the problem of obtaining gas supplies to meet increased winter peak loads. There are several possible alternatives that companies may take to aid possible alternatives that companies may take to aid in meeting the peak demands: Contract for additional pipeline flow gas. Contract for peak-shaving service. Develop storage or peak-shaving facilities. Do nothing and quit growing. If companies clearly understand their sales load and the availability and economics of the various peak-shaving methods, then the choice of alternatives peak-shaving methods, then the choice of alternatives should be easy. The current short supply of gas is a factor that exerts great pressure for more efficient use of fuel. At the same time, it may be the factor that limits the development of peak-shaving facilities or of underground storage of gas. This paper does not attempt to solve the supply problem, but it does review the need for load problem, but it does review the need for load balancing or peak shaving by use of underground storage of natural gas. It compares the economics of underground storage with other methods of peak shaving and with pipeline gas costs. pipeline gas costs. Need for Underground Storage of Natural Gas The storage of gas is needed to increase the efficiency of the gas distribution business. This need for storage is triggered by the variations in weather (daily, monthly, or seasonal) and the volume of gas required to satisfy space-heating customers, Space heating constitutes a large segment of the distribution company's market; consequently, the variation in weather causes a variation in load or sales. The greater the change in weather, the more difficult the problem of operating the company (system) at high efficiency. This efficiency is commonly referred to as load factor, which is the annual volume of gas purchased by the distribution company divided by the annual volume that the pipeline company has contracted to deliver. Table I shows the load factors for the different sales loads for Northern Illinois Gas Co. Since the company is located in the northern Illinois area these load factors should be typical of those of a distribution company located in the midwest climate region. The general load is the segment of the company's sales with the highest load factor and the lowest volume of gas sold. The load factor ranges from 76.8 percent for residential use to 137 percent for percent for residential use to 137 percent for industrial sales. The general sales load factor is high because it is independent of variations in weather. The space-heating load is the segment of the company's sales with the lowest load factor but the highest volume of gas sold. Note that the space-heating load factor ranges from 34.3 percent for residential heating to 43.7 percent for commercial heating. JPT P. 1221