Christopher Breuer

Modeling optimal redispatch for the European Transmission grid

The European Electricity System is undergoing fundamental changes in the next decades. Among other reasons the massive increase of electricity generation from renewable energy sources as well as the increasing cross-border power flows can be identified as the main drivers. This development leads to new challenges for the operation of the transmission grid as bulk power transfers over wide distances will increase rather than remain the exception. The current transmission grid on the other hand has not been designed to allow massive wide area power transfers resulting in overloadings and congestions.

Determination of alternative bidding areas based on a full nodal pricing approach

Congestion management and capacity allocation have turned out to be some of the major challenges in the European electricity system. Although it is known that nodal prices, or often called locational marginal prices, would, in theory and from a static efficiency point of view, lead to an optimal congestion management, due to various reasons (e.g. market power and liquidity) this is no feasible solution in the mid-term; therefore, adjusting the current shape of bidding areas based on the physical transmission constraints could provide a preferable interim solution. Consequently, an algorithm to determine bidding areas based on a full nodal pricing simulation is developed and applied to a model of the European electricity system. The results show that the developed method is capable of investigating large power systems including impacts from uncertainties like grid extension or future development of Renewable Energies Sources (RES).

Scenario-based evaluation on the impacts of electric vehicle on the municipal energy supply systems

By improving the ecological situation in the congested urban areas and reducing the dependence on fossil oil imports, a high penetration of electric vehicles (EV) in the automobile market is expected within the next years. Integration of area-wide charging infrastructures rises the challenge for the municipal energy supply systems to fulfill the demand of an increasing number of EV in the near future. Versatile technologies and integration strategies may be implemented in the charging regime, which might have significant impacts on the electrical distribution network. This paper presents the results of a comprehensive investigation in order to evaluate different charging concepts and strategies. Furthermore the resulting consequences on the battery management of the EVs are discussed by means of scenario-based evaluation and demand side management possibilities. The possible impacts on the charging behavior of EV-customers, driven by structurally changed prices for electrical energy due to a rising share of renewables will be also demonstrated.

Optimized bidding area delimitations and their impact on electricity markets and congestion management

The delimitation of bidding areas and the overall European congestion management have been heavily discussed in the recent years. Although main evaluation criteria are defined in the network code on congestion management, the question of adequate or optimized bidding area delimitations remains open. Thus, this paper presents an approach for an optimized delimitation of bidding areas based on a clustering of security-constraint nodal prices. Relevant evaluation criteria, like the level of generation and redispatch costs or the level of network security, are derived via a multi-step optimization approach. Results show, that optimized bidding area delimitations differ significantly from the current ones. However, these optimized delimitations yield only small cost savings compared to the current bidding area delimitation.

Expectation-based reserve capacity dimensioning in power systems with an increasing intermittent feed-in

The ongoing transition process of the European electricity sector to an increasing share of renewable electricity generation is in full swing. Unavoidable forecast errors of non-dispatchable energy sources (e.g. wind and solar power) have to be balanced out by reserve capacity power plants. This is normally organized in markets for ancillary services. Whereas the necessary reserve capacity, calculated by the transmission system operator (TSO), was historically dimensioned on a monthly basis, not considering information on the forecasted feed-in of the fluctuating generation from RES, this will change in future. Consequently this paper intents to present a methodology for an expectation-based reserve capacity dimensioning, based on a method currently applied by many of the European TSO. The results show, that by application of the methodology in an exemplary European case study for the year 2022, the necessary average reserve capacity decreases. However, the hourly demand for tertiary reserve capacity is subjected to significant fluctuations, due to volatile wind and solar generation.

Operational optimization of municipal energy supply systems

Supplying a reliable, efficient, economic electrical service to all customers is the basic responsibility of utilities. However, increasing penetration of new customers in distribution grids as dispersed generation (DG), electric heating systems and electric vehicles (EV), makes conventional operation of energy supply systems difficult while meeting the aforementioned responsibility. Therefore, the question arises if these new customers can be used as standalone energy sources or mobile storage devices to counter aforementioned development and relieve increasing stress on distribution grids. To answer that question a method is developed to optimize the operation of DG units, EV and electric heating systems to prevent extension of existing distribution grids and to achieve minimum operational costs. This paper presents the results of an investigation of an comprehensive supply task in order to demonstrate the functionality of the developed method and to determine the profit of an operational optimization.

Technical and economic comparison of national and joint cross-border curative congestion management application

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.