Maxwell Electrical Load-Curve Coverage

Proceedings of the Symposium on Load-Curve Coverage in Future Electric Power Generating Systems, Organized by the Committee on Electric Power, United Nations Economic Commission for Europe, Rome, Italy, 24 - 28 October 1977
1. Auflage 2013
ISBN: 978-1-4832-8093-6
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 564 Seiten

Electrical Load-Curve Coverage covers the proceedings of the Symposium on Load-Curve Coverage in Future Electric Power Generating Systems, organized by the Committee on Electric Power, United Nations Economic Commission for Europe, Rome, Italy, on October 24-28, 1977. This symposium considers the opportunity for an international exchange of economic and technical information on problems connected with the coverage of the full load curve. This book is composed of five parts encompassing 48 chapters, and begins with the optimum composition of the generating system. The first part considers the use of mathematical models for optimization of energy sources in some countries. The succeeding parts deal with the means of electricity generation for the variable part of the load curve. This part examines the electric consumption of steam and gas turbines and the concept of peak-power load. Other parts discuss the means of storage at user level. The final parts consider natural characteristics of the energy demand (load curves). This book will prove useful electrical engineers and researchers.

Autoren/Hrsg.

Maxwell, Robert

Leseproben

Introduction

The Symposium on Load-Curve Coverage in Future Electric Power Generating Systems provided the opportunity for an international exchange of economic and technical information on problems connected with the coverage of the full load curve. In their recommendations, the participants in the symposium made proposals for the strengthening of international exchanges of information and studies on load curve coverage.

Twenty-two countries* were represented at the symposium with, in addition, the International Atomic Energy Agency (IAEA), the European Economic Community (EEC), the International Union of Producers and Distributors of Electrical Energy (UNIPEDE) and the Union for Coordinating Production and Distribution of Electricity (UCPTE).

The symposium was organised by the Committee on Electric Power of the United Nations Economic Commission for Europe (ECE); at the invitation of the Italian Government, it was held in Rome, at the headquarters of the Italian National Electricity Board (Ente Nazionale per l’energia elettrica - ENEL) from 24 to 28 October, 1977.

The subject matter of the symposium was dealt with under five main topics:

1. Optimum composition of the generating system

2. Means of electricity generation for the variable part of the load curve

3. Means of storage at producer level

4. Means of storage at user level

5. Natural characteristics of energy demand (load curves)

Forty-two expert papers were contributed to the symposium. In the consolidated report prepared by a general rapporteur for each subject-group, papers are referred to by numbers which are provided in the table of contents of these proceedings.

The chairman of the symposium was Mr. A. Angelini, President of ENEL. Five vice-chairmen - Mr. A. Loeffler (German Democratic Republic), Mr. E. Sovary (Hungary), Mr. A. di Perna (Italy), Mr. F. Willekens (Netherlands), and Mr. A. Plumpton (United Kingdom) - were elected as vice-chairmen. Each vice-chairman presided over the discussions on a subject-group. Mr. M. Penel (France) and Mr. J. Tuma (Czechoslovakia) were appointed as rapporteurs.

Mr. G. Colamarino, of Italy, chairman of the ECE Committee on Electric Power, declared the symposium open. Participants were welcomed on behalf of the Italian Government by the Under-Secretary of State for Industry, Commerce and Small Business, Mr. E. Erminero, and on behalf of ENEL by Mr. Angelini. Mr. Edmond Janssens, Director of the Energy Division of the ECE secretariat, spoke at the opening ceremony on behalf of the Executive Secretary of ECE.

The chairman of the organising committee was Mr. P. Peiser, of ENEL.

CONCLUSIONS AND RECOMMENDATIONS

Optimum Composition of the Generating System

Comparison of present methods. It appeared that, with regard to static characters, a number of methods of investigation and calculation were available to planners and operators who were concerned with the optimum composition of the generating system with a view to determining capacity, including the reserve required to ensure reliable and economic supplies. In particular, methods were available for studying the introduction of new units in an existing system within the context of short-term planning. Those methods were at present applied in decision-making processes. A set of models supplying mutually relevant information was often used. There were different approaches to the problem, but the experience of planners and operators who used them certainly permitted the best possible application of results of their particular power generating systems. An exchange of different experiences would be desirable in order to be able to make comprehensive appraisal.

Methodological improvements to be considered. An important aspect of the optimization of the generating system, namely optimization of the ability to follow the continuously variable load (generating system flexibility), would require more detailed consideration, but there were insufficient data and completely developed models to be able to simulate the operating conditions of a power system in respect of flexibility requirements. The data collected did not seem to be either coherent or complete. They must therefore be arranged on a common clearly-defined basis and efforts made continuously to keep them up to date. The consideration of the load curve as a reference model seemed to be the simplest approach to a study of the coverage of energy demand by different types of generating units. When peak plant structure had to be defined (such plant accounts for a substantial proportion of total installed capacity), the contribution of this plant to peak load coverage and to reserve capacity must be considered. This joint function had assumed greater relevance and importance with the increasing size of generating units.

Means of electricity generation for the variable part of the load curve. At present, two methods were widely favoured as means of peak generation: pumped storage hydroelectric stations and gas turbine stations. Neither system offered clear-cut advantages since their economic performance depended to a large extent on various local conditions. A technical or economic evaluation should always be considered.

Coverage of the intermediate power levels between base-load and peak-load was at present provided by base-load stations whose capacity was reduced during off-peak hours. Would it not thus be preferable to develop conventional equipment specifically adapted for such a function and to consider questions relating to the use of base-load nuclear stations to cover the peaks ?

Means of Storage at Producer Level

Storage means in use and prospects. Pumping was at present the only energy storage method used by electricity producers. Experience in this technique was of long standing, and advanced technology had been developed. Prospects in the field of storage means in general seemed to suggest that the other options mentioned in the consolidated report should be studied very closely, since none of them could be dismissed out of hand: thermal storage, elastic (compressed air) storage, inertia storage, electrochemical storage and electromagnetic storage. Prototypes were being developed in the fields of elastic, thermal and inertia storage. Hydrogen, touched upon during the discussions, deserved special mention since the research to be undertaken in that area required cooperation between widely differing disciplines (chemistry, fuels, etc.).

Methodology. A broad exchange of views enabled the group to compare methods, some of which were extremely elaborate and others purposely simplified. The range of methods available was therefore extremely wide.

The Symposium nevertheless considered that pumping stations could not always be justified from an economic point of view, under present conditions, exclusively on the basis of their “static” advantages, i.e. essentially the advantage offered by the difference in energy costs between the pumping and generating operations. Those kinetic advantages - load variation flexibility, frequency regulation, rapid intervention possibilities - today substantially enhanced the value of pumping stations. New methods which had made it possible for that type of advantage to be appreciated in quantitative terms were considered to be of interest, and it was felt that extensions and improvements in that methodological field would be very useful.

In that connexion, a certain contradiction was found in the development of multistage reversible hydraulic units in which the non-existence of a distributor eliminated any possibility of finely regulating their capacity.

Development of storage methods from now until the end of the century. The prospects for the widespread development of nuclear energy and increases in the size of individual sets left little room for doubt as to the increasingly important role that storage would be called on to play in the future. Other reasons, including the long-term need to regularize non-conventional fluctuating energy sources such as the sun or the wind, and a number of environmental constraints, would seem to confirm that view.

That impression was further confirmed by the extent of the programmes described by various countries for the period 1985-1990. An average estimate of the pumping power needed until then represented some 10 per cent of the generating systems’ installed capacity.

In the long run, pumping would be restored to its former economically advantageous position from the standpoint of energy transfer, and the development of its “kinetic” qualities would undoubtedly continue.

Exchange of experiences. In addition to a number of excellent reports, various statements provided a wealth of valuable information on the operating criteria of pumped storage power stations.

In view of the interest shown in this type of hydroelectric scheme, the Symposium noted that it would be useful to take measures to encourage exchanges of ideas or experience in that field between member countries.

Means of Storage at User Level

The role of storage in the optimization of the energy system. Certain uses of electricity, such as heating or...