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Session
Session 01: Network Congestion Management
Time: Wednesday, 25/May/2011: 11:30am - 1:00pm
Session Chair: Laurens James de Vries
Location: Casino

Presentations

Congestion Management in the European Electricity Sector: Lessons from the European Air Transport Sector

Christof Duthaler, Matthias Finger

Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland

The electricity sector and the air transport sector are two network industries of crucial pan-European importance. Driven by liberalization and the increasing usage of their networks, they are both faced with the challenge of network congestion and its efficient management at national and European scale. Given the head-start of liberalization in the air transport sector, the development of congestion management mechanisms began about a decade earlier than in the electricity sector and achieved significant performance improvements. This paper compares the approaches to congestion management in the two sectors from a technical and institutional point of view. It concludes that congestion management in the European electricity sector could be improved by applying coordination and optimization mechanisms established in the European air transport sector.


Congestion Management in the Deregulated Electricity Market: An Assessment of Locational Pricing, Redispatch and Regulation

Ralph Hermans1, Paul van den Bosch1, Andrej Jokić1, Paul Giesbertz2, Paul Boonekamp3, Ana Virag1

1Eindhoven University of Technology; 2Statkraft Markets B.V.; 3APX-ENDEX

We analyze the fundamental differences between locational pricing and redispatch-based congestion management, followed by an assessment of their effects on grid operation and market efficiency. It is indicated that although optimal nodal pricing and congestion redispatch can provide equal results in terms of power injections, they are not equivalent in terms of short-run social welfare. Moreover, a modeling framework is presented to decouple and analyze the effects of transmission system operator/regulator and prosumer behavior on energy market efficiency in a transparent fashion. All results are illustrated on the basis of case studies for the IEEE 39-bus New England test network.


Transmission Congestion Cost Allocation Using Congestion Severity Index Considering Load Participation in Transmission Line Flows

Mehrdad Hojjat, Javidi Hossein, Hadi Aliabadi

Ferdowsi University, Iran, Islamic Republic of

Transmission congestion is a challenging problem in power system operation. Independent system operators (ISO) usually have to re-dispatch generation units to alleviate congestion. This results in significant additional costs for customers. In this paper, a new method for equitable allocation of congestion costs, especially when more than one line is congested, is proposed. The method is based on a new index, referred to as severity index. This index is used for allocating the cost of congestion to different congested lines, in cases where more than one line is congested. The index considers both technical and economical effects of congestion on power system and it is very useful to allocate load contribution in transmission costs. Therefore, it can be easily used for allocating congestion costs to different loads.

The proposed method is implemented and evaluated on IEEE 14-bus system by calculating the cost allocated to each customer. The proposed method has been compared with nodal pricing approach. Simulation results show that the equity and accuracy parameters are observed in the proposed approach.


Congestion Pricing in Electricity Markets: Infeasibility, Sub-optimality and Degeneracy

Ricardo Rios-Zalapa, Jie Wan, Eugene Zak, Kwok W Cheung

Alstom, United States of America

Infeasible, sub-optimal and/or degenerate solutions of the economic dispatch problem cause undesirable effects on the ex-ante and ex-post market price calculations. To determine market prices, this paper explores a scheme that relies on a dual formulation of the economic dispatch problem, stated in terms of prices, i.e. prices become variables. With such a dual perspective, direct control of the prices is achieved, e.g. minimizing the side payments needed to comply with a revenue sufficiency guarantee to market participants. The proposed method combines a primal formulation to find the dispatch (MW), and a dual formulation to determine Locational (nodal) Marginal Prices (LMPs) into a single primal-dual model. Having both, dispatch levels (MW) and nodal prices ($/MWh), as variables, opens possibilities not explored before, e.g. constraints and objective functions that combine both, MW and prices. Computational experiments demonstrate the benefits of the alternative proposal.


Proposed Data Set for Monitoring the 8th Congestion Management Region

Lahorko Wagmann, Srdjan Zutobradic

HERA

Recent development of the congestion management monitoring in the European 8th Congestion Management (CM) region has been carried out at three levels. In the article the proposed data model for the regional CM monitoring which would fulfill all three monitoring levels is presented. In addition, the activities and role of the Croatian Energy Regulatory Agency – HERA and the Energy Community Regulatory Board– ECRB in monitoring of the cross border capacity allocation on the level of the Energy Community are presented.


Technical and Economic Comparison of Joint Cross-Border and National Curative Congestion Management Application

Christopher Breuer, David Echternacht, Christian Linnemann, Albert Moser

IAEW

Due to an increasing penetration of renewable energies, planning and operation of the European transmission grid is facing new requirements. Whereas the volatility of feed-in and the amount of transmitted power is rising rapidly inducing needs for additional transmission lines, grid enhancement is not keeping pace with this development. Therefore efficient congestion management methods are becoming essential in the short- and mid-term. This paper presents an approach to compare the technical and economic effects of a national redispatch regime, which is currently common practice in most of the European countries, to a joint cross-border redispatch regime, which might become common practice in the future.

To demonstrate the effectiveness of the developed method, an investigation of the redispatch volumes and costs is carried out for the Central-Western-European (CWE) energy system expected in 2020.