ELECTRICITY SUPPLY INDUSTRY IN USA

Electricity Supply Industry in USA

Petroleum

Electricity Supply Industry in USA

Introduction

Recent years have seen an upsurge of interest in life-cycle inventories; that is, calculating the energy and raw materials requirements of extended industrial systems as well as the solid, liquid and gaseous emissions from these systems. In this context, an extended system is one in which all inputs are traced back to the extraction of raw materials from the earth and all outputs are followed through to final waste disposal. A significant contributor to the inputs and outputs of all industrial systems is the electricity supply industry, because of the relatively low conversion efficiency from primary thermal energy to delivered power. This low conversion efficiency arises not because the electricity supply industry is operated in an inefficient manner but because of the thermodynamic limitations imposed when thermal energy is converted to work (electricity). If the results of life-cycle inventories are to be accurate, it is therefore important to ensure that the efficiency of the electricity supply industry is calculated as accurately as the available data will allow.

Discussion

Traditionally, the public electricity supply in the United States has been treated in the literature as a single super-grid covering the whole country with all generators feeding into it and all consumers drawing from it. [ 1-5] In such a scenario, the performance of this system can be described as a national average and the data needed to evaluate this average performance can be obtained from the annual statistics published by Government Agencies such as the Department of Energy. A similar type of treatment is frequently applied to Canada. The need to consider possible regional variations in electricity supply has been recognized [6] but there appears, as yet, to be no complete analysis of the North American electricity system.

In practice, however, the simplified super-grid treatment can only be regarded as an approximation, for two main reasons. First, the electricity production and distribution systems of the USA and Canada are interlinked and cannot sensibly be separated from one another. Secondly, the North American electricity supply is composed of four major interconnections, which allow power to be transferred between them in order to achieve a reliable, stable supply over the whole area.

Within these major interconnections are a set of about 150 smaller control areas, which are primarily concerned with the base supply to their immediate area. However, they also buy power from and sell power to neighbouring control areas. Ideally, a complete analysis of the North America electricity supply industry would require a detailed analysis of all of the individual control areas together with the interchanges of electricity between them. However, the information needed to accomplish such an analysis is not readily available and it is doubtful whether such a detailed analysis would be readily usable given that much of the data available for manufacturing industry is not yet available on a site by site basis. From an institutional viewpoint, each control area belongs to one of the Reliability Councils which ...