Search

Begin New Search
Proceed to Checkout

Search Results for All:
(Showing results 1 to 10 of 29)

Next 10 >>


Markets in Real Electric Networks Require Reactive Prices

William W. Hogan

Year: 1993
Volume: Volume14
Number: Number 3
DOI: 10.5547/ISSN0195-6574-EJ-Vol14-No3-8
View Abstract

Abstract:
Differences in locational spot prices in an electric network provide the natural measure of the price for transmission. The ubiquitous problem of loop flow requires different economic intuition for interpreting the implications of spot pricing. The DC-Load model is the usual approximation for estimating spot prices, although it ignores reactive power effects. This approximation is best when thermal constraints create congestion in the network. In the presence of voltage constraints, the DC-Load model is insufficient, and the full AC-Model is required to determine both real and reactive power spot prices.



Economic Inefficiency of Passive Transmission Rights in Congested Electricity Systems with Competitive Generation

Shmuel S. Oren

Year: 1997
Volume: Volume18
Number: Number 1
DOI: 10.5547/ISSN0195-6574-EJ-Vol18-No1-3
View Abstract

Abstract:
The main thesis of this paper is that passive transmission rights such as Transmission Congestion Contracts (TCCs) that are compensated ex-post based on nodal prices resulting from optimal dispatch by an Independent System Operator (ISO) will be preempted by the strategic bidding of the generators. Thus, even when generation is competitive, rational expectations of congestion will induce implicit collusion enabling generators to raise their bids above marginal costs and capture the congestion rents, leaving the TCCs uncompensated. These conclusions are based on a Cournot model of competition across congested transmission links where an ISO dispatches generators optimally based on bid prices. We characterize the Cournot equilibrium in congested electricity networks with two and three nodes. We show that absent active transmission rights trading, the resulting equilibrium may be at an inefficient dispatch and congestion rents will be captured by the generators. We also demonstrate how active trading of transmission rights in parallel with 42 competitive energy market can prevent the price distortion and inefficient dispatch associated with passive transmission rights.



Computable Equilibrium Models and the Restructuring of the European Electricity and Gas Markets

Yves Smeers

Year: 1997
Volume: Volume18
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol18-No4-1
View Abstract

Abstract:
More regulation, not less, is temporarily necessary, if effective, competition is to be established in network industries. This paradox places new requirements on computable models: they should provide realistic descriptions of technologies but also of markets and institutions. Industrial economics and computation of economic equilibrium can help achieve this dual requirement. This paper discusses their potential in the context of the deregulation of the European gas and electricity sectors. Some key elements of the European legislative process are first presented in order to point out the diversity of institutions that can emerge and to highlight the need to model institutions. Perfect competition equilibrium models although institutionally poor are argued to be useful for ex post analysis. Applications of the standard Cournot and' Bertrand paradigms in ex ante analysis of gas and electricity markets are reviewed next. Models combining market power and externalities are then discussed with reference to electricity restructuring. Finally multistage equilibrium models are introduced in the context of investment in gas and electricity. Computation remarks conclude the paper.



A Market Power Model with Strategic Interaction in Electricity Networks

William W. Hogan

Year: 1997
Volume: Volume18
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol18-No4-5
View Abstract

Abstract:
When transmission constraints limit the flow of power in an electric network, there are likely to be strong interaction effects across different parts of the system. A model of imperfect competition with strategic interactions in an electricity transmission network illustrates a possible exercise of market power that differs from the usual analysis of imperfect competition in more familiar product markets. Large firms could exercise horizontal market power by increasing their own production, lowering some prices, and exploiting the necessary feasibility constraints in the network to foreclose competition from others. This behavior depends on the special properties of electric networks, and reinforces the need for market analysis with more realistic network models.



Short Term Energy Forecasting with Neural Networks

J. Stuart McMenamin and Frank A. Monforte

Year: 1998
Volume: Volume19
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol19-No4-2
View Abstract

Abstract:
Artificial neural networks are beginning to be used by electric utilities, to forecast hourly system loads on a day ahead basis. This paper discusses the neural network specification in terms of conventional econometric language, providing parallel concepts for terms such as training, learning, and nodes in the, hidden layer. It is shown that these models are flexible nonlinear equations that can be estimated using nonlinear least squares. It is argued that these models are especially well suited to hourly load forecasting, reflecting the presence of important nonlinearities and variable interactions. The paper proceeds to show how conventional statistics, such as the BIC and MAPE statistics can be used to select the number of nodes in the hidden layer. It is concluded that these models provide a powerful, robust and sensible approach to hourly load forecasting that will provide modest improvements in forecast accuracy relative to well-specified regression models.



Forecasting Nonlinear Crude Oil Futures Prices

Saeed Moshiri and Faezeh Foroutan

Year: 2006
Volume: Volume 27
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol27-No4-4
View Abstract

Abstract:
The movements in oil prices are very complex and, therefore, seem to be unpredictable. However, one of the main challenges facing econometric models is to forecast such seemingly unpredictable economic series. Traditional linear structural models have not been promising when used for oil price forecasting. Although linear and nonlinear time series models have performed much better in forecasting oil prices, there is still room for improvement. If the data generating process is nonlinear, applying linear models could result in large forecast errors. Model specification in nonlinear modeling, however, can be very case dependent and time-consuming.In this paper, we model and forecast daily crude oil futures prices from 1983 to 2003, listed in NYMEX, applying ARIMA and GARCH models. We then test for chaos using embedding dimension, BDS(L), Lyapunov exponent, and neural networks tests. Finally, we set up a nonlinear and flexible ANN model to forecast the series. Since the test results indicate that crude oil futures prices follow a complex nonlinear dynamic process, we expect that the ANN model will improve forecasting accuracy. A comparison of the results of the forecasts among different models confirms that this is indeed the case.



Market Power and Network Constraint in a Deregulated Electricity Market

In-Koo Cho and Hyunsook Kim

Year: 2007
Volume: Volume 28
Number: Number 2
DOI: 10.5547/ISSN0195-6574-EJ-Vol28-No2-1
View Abstract

Abstract:
This paper investigates the market power and the welfare performance of the deregulated wholesale electricity market of California between 1998 and 2000 by incorporating the structure of the transmission network. While Wolfram (1999), Borenstein, Bushnell, and Wolak (2002) and Joskow and Kahn (2002) treat the difference between the market price and the marginal production cost of the marginal generator as the indicator for market power, we decompose the difference into the market power and the inefficiency arising from the network constraint. Based on public data for the market from 1998 to 2000, we demonstrate that the welfare loss due to the finite transmission capacity accounts for 29-38% of the total annual welfare loss, while the remaining portion can be explained by the market power exercised by the generators.



A Quantitative Analysis of the Relationship Between Congestion and Reliability in Electric Power Networks

Seth Blumsack, Lester B. Lave and Marija Ilic

Year: 2007
Volume: Volume 28
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol28-No4-4
View Abstract

Abstract:
Restructuring efforts in the U.S. electric power sector have tried to encourage transmission investment by independent (non-utility) transmission companies, and have promoted various levels of market-based transmission investment. Underlying this shift to �merchant� transmission investment is an assumption that new transmission infrastructure can be classified as providing a congestion-relief benefit or a reliability benefit. In this paper, we demonstrate that this assumption is largely incorrect for meshed interconnections such as electric power networks. We focus on a particular network topology known as the Wheatstone network to show how congestion and reliability can represent tradeoffs. Lines that cause congestion may be justified on reliability grounds. We decompose the congestion and reliability effects of a given network alteration, and demonstrate their dependence through simulations on a 118bus test network. The true relationship between congestion and reliability depends critically on identifying the relevant range of demand for evaluating any network externalities.



Modeling Optimal Economic Dispatch and System Effects in Natural Gas Networks

Kjetil T. Midthun, Mette Bjorndal and Asgeir Tomasgard

Year: 2009
Volume: Volume 30
Number: Number 4
DOI: 10.5547/ISSN0195-6574-EJ-Vol30-No4-6
View Abstract

Abstract:
In this paper we present a modeling framework for analyzing natural gas markets, taking into account the specific technological issues of gas transportation. We model the optimal dispatch of supply and demand in natural gas networks, with different objective functions, i.e., maximization of flow, and different economic surpluses. The models take into account the physical structure of the transportation networks, and examine the implications it has for economic analysis. More specifically, pressure constraints create system effects, and thus, changes in one part of the system may require significant changes elsewhere. The proposed network flow model for natural gas takes into account pressure drops and system effects when representing network flows. Pressure drops and pipeline flows are modeled by the Weymouth equation. A linearization of the Weymouth equation makes economic analyses computationally feasible even for large networks. However, in this paper, the importance of combining economics with a model for pressure drops and system effects is illustrated by small numerical examples.



Improving Congestion Management: How to Facilitate the Integration of Renewable Generation in Germany

Friedrich Kunz

Year: 2013
Volume: Volume 34
Number: Number 4
DOI: 10.5547/01956574.34.4.4
View Abstract

Abstract:
In this paper the German congestion management regime is analyzed and future congestion management costs are assessed given a higher share of intermittent renewable generation. In this context, cost-based re-dispatching of power plants and technical flexibility through topology optimization are considered as market-based and technical congestion management methods. To replicate the current market regime in Germany a two-step procedure is chosen consisting of a transactional spot market model and a congestion management model. This uniform pricing model is compared to a nodal pricing regime. The results show that currently congestion can mainly be managed by re-dispatching power plants and optimizing the network topology. However, congestion management costs tend to increase significantly in future years if the developments of transmission as well as generation infrastructure diverge. It is concluded that there is a need for improving the current congestion management regime to achieve an efficient long-term development of the German electricity system.




Next 10 >>

Begin New Search
Proceed to Checkout

 

© 2024 International Association for Energy Economics | Privacy Policy | Return Policy