Market Power Mitigation Research Articles

Market Power Under Nodal and Zonal Congestion Management Techniques

Contrary to the common thought that nodal pricing provides more opportunities for a strategic player to exert market power than the zonal model, we show that in the latter one because of the need for re-dispatch or counter-trading, another extra place is created letting more gaming possibilities. Therefore, if proper market power mitigation approaches are not utilized in both day-ahead and re-dispatch markets, then zonal pricing may be more susceptible to market power, especially in zonal model which is based on available transfer capacity (ATC), strategic player’s profit and social welfare can be very volatile. In general, the more network constraints are incorporated in day-ahead market (100% in nodal and almost zero in ATC), the more social welfare is attainable. Hence, nodal model is acquitted from the more market power denunciation.

High-level design for the compliance of the Greek wholesale electricity market with the Target Model provisions in Europe

The stated aim of the European Commission has been the unbounded flow of energy across Europe and the effective functioning of a single European power market so as to achieve secure, sustainable and affordable energy supplies, as well as to foster competition and increase the utilization of electricity networks and generation capacity. Most countries have already adapted or are gradually adapting their wholesale markets to the provisions of the so called Target Model for the internal electricity market in Europe, however Greece still lies behind in this binding target. In this paper, the basic design variables and respective options for the integration of the Greek wholesale electricity market with the other European markets under the Target Model paradigm are presented. The design variables refer to all market instances and mechanisms. The proposed choices are justified in terms of effectiveness and market power mitigation, considering the current market structure in Greece. A transitional phase for the full integration of the Greek Intraday and Balancing Markets is proposed, considering the relevant evolutions in the wholesale markets of Greece’s neighboring countries. Finally, a simulation analysis is performed in order to highlight the implications on schedules of utilizing European-based order formats in the restructured Greek electricity market.

Network Expansion to Mitigate Market Power

Constrained transmission capacity in electricity networks may give generators the possibility to game the market by specifically causing congestion and thereby appropriating excessive rents. Investment in network capacity can ameliorate such behavior by reducing the potential for strategic behavior. However, modeling Nash equilibria between generators, which explicitly account for their impact on the network, is mathematically and computationally challenging. We propose a three-stage model to describe how network investment can reduce market power exertion: a benevolent planner decides on network upgrades for existing lines anticipating the gaming opportunities by strategic generators. These firms, in turn, anticipate their impact on market-clearing prices and grid congestion. In this respect, we provide the first model endogenizing the trade-off between the costs of grid investment and benefits from reduced market power potential in short-run market clearing. In a numerical example using a three-node network, we illustrate three distinct effects: firstly, by reducing market power exertion, network expansion can yield welfare gains beyond pure efficiency increases. Anticipating gaming possibilities when planning network expansion can push welfare close to a first-best competitive benchmark. Secondly, network upgrades entail a relative shift of rents from producers to consumers when congestion rents were excessive. Thirdly, investment may yield suboptimal or even disequilibrium outcomes when strategic behavior of certain market participants is neglected in network planning.

Generation flexibility in ramp rates: Strategic behavior and lessons for electricity market design

A ramp rate usually defines the speed at which an electric power producer can decrease or increase its production in limited time. The availability of fast-ramping generators significantly affects the economic dispatch, especially in the systems with high penetration of intermittent energy sources, e.g. wind power, since the fluctuations in supply are common and sometimes unpredictable. One of the regulatory practices of how to impel generators to provide their true ramp rates is to separate the stages of submitting the bids on ramp rate and production. In this paper we distinguish two types of market structures: one-stage – when electric power producers are deciding their production and ramp rate at the same time, or two-stage – when generators decide their ramp rate first, and choose their production levels at the second stage. We employ one-stage and two-stage equilibrium models respectively to represent these market setups and use a conjectured price response parameter ranging from perfect competition to the Cournot oligopoly to investigate the effect of the market competition structure on the strategic decisions of the generators. We compare these two market setups in a symmetric duopoly case with two time periods and prove that in the two-stage market setup the level of ramp rate is independent of the strategic behavior in the spot market and generally lower than the one offered in the one-stage setup. We also show that the ramp-rate levels in one- and two-stage models coincide at the Cournot oligopoly. We extend the model to asymmetry, several load periods, portfolio bidding, and uncertainty, and show that withholding the ramp rate still occurs in both models. Our findings prove that market regulators cannot rely on only separating the decision stages as an effective measure to mitigate market power and in certain cases it may lead to an adverse effect.

Ex‐ante evaluation and optimal mitigation of market power in electricity markets including renewable energy resources

In this study, a new framework is proposed to evaluate the market power in electricity markets including renewable energy resources. To this end, a virtual electricity market (VEM) model is proposed based on multi-agent systems to investigate the behaviour of market players from the regulator's viewpoint. In addition to the tacit collusive behaviour of market players, the potential of explicit collusions is also considered. Moreover, three indices are proposed for ex-ante assessment of the market power. The proposed indices not only recognise the market power potential but also express the reasons for the market power. Furthermore, an algorithm is proposed based on the VEM to select the optimal rule, regulation and market structure, in order to maximise the market efficiency. In order to represent the effectiveness of the proposed method, several case studies are considered and the impacts of various market rules on market behaviour are simulated and discussed.

Does wind energy mitigate market power in deregulated electricity markets?

A rich body of literature suggests that there is an inverse relationship between wind power penetration rate into the electricity market and electricity prices, but it is unclear whether these observations can be generalized. Therefore, in this paper we seek to analytically characterize market conditions that give rise to this inverse relationship. For this purpose, we expand a recently developed theoretical framework to facilitate flexibility in modeling the structure of the electric industry with respect to the degree of market concentration and diversification in the ownership of wind power capacity. The analytical results and their attendant numerical illustrations indicate that the introduction of wind energy into the market does not always depress electricity prices. Such a drop in electricity prices is likely to occur when the number of firms is large enough or the ownership of wind energy is sufficiently diversified, or most often a combination of the two. Importantly, our study defines the circumstances in which the question of which type of firm invests in wind power capacity is crucial for market prices.

Incentive-based demand response programs designed by asset-light retail electricity providers for the day-ahead market

Following the deregulation experience of retail electricity markets in most countries, the majority of the new entrants of the liberalized retail market were pure REP (retail electricity providers). These entities were subject to financial risks because of the unexpected price variations, price spikes, volatile loads and the potential for market power exertion by GENCO (generation companies). A REP can manage the market risks by employing the DR (demand response) programs and using its' generation and storage assets at the distribution network to serve the customers. The proposed model suggests how a REP with light physical assets, such as DG (distributed generation) units and ESS (energy storage systems), can survive in a competitive retail market. The paper discusses the effective risk management strategies for the REPs to deal with the uncertainties of the DAM (day-ahead market) and how to hedge the financial losses in the market. A two-stage stochastic programming problem is formulated. It aims to establish the financial incentive-based DR programs and the optimal dispatch of the DG units and ESSs. The uncertainty of the forecasted day-ahead load demand and electricity price is also taken into account with a scenario-based approach. The principal advantage of this model for REPs is reducing the risk of financial losses in DAMs, and the main benefit for the whole system is market power mitigation by virtually increasing the price elasticity of demand and reducing the peak demand.

Network Expansion to Mitigate Market Power: How Increased Integration Fosters Welfare

Lack of transmission capacity hampers the integration of the European electricity market, and thereby precludes reaping the full benefits of competition. We investigate the extent to which transmission grid expansion promotes competition, efficiency and welfare. This work proposes a three-stage model for grid investment: a benevolent planner decides on network upgrades, considering welfare benefits of investments through a reduction of market power exertion by strategic generators. These firms anticipate their impact on market clearing, in particular when lines are congested. To this end, we provide the first model effectively endogenizing the trade-off between costs of grid investment and benefits by reduced market power potential. In a three-node network, we illustrate three distinct strategic effects: firstly, by reducing market power exertion, network expansion can promote welfare beyond pure efficiency gains: optimally accounting for strategic generator behavior can push welfare close to a first-best competitive benchmark. Secondly, network upgrades entail a relative shift of rents from producers to consumers, and thirdly, they may yield suboptimal or even disequilibrium outcomes when strategic behavior is neglected.

New indices of capacity withholding in power markets

Summary Market power evaluation and mitigation influence the efficiency of the electricity markets. The traditional indices cannot analyze market power, which caused by capacity withholding of generation companies. This paper describes a new approach to assess capacity withholding. The method is an improvement of a strategy previously proposed by the authors. The contributions of the new approach can be summarized as the following. First, the supply function equilibrium model and Cournot model are used to develop the concept of capacity withholding in electricity markets. Then, distortion–withheld index is calculated according to capacity constraints, reliability, and demand elasticity. Based on distortion–withheld index, the value of capacity withholding index, which shows the cost that independent system operator could spend for market power mitigation, can be obtained. It has been proved that the new approach is able to assess capacity withholding exactly and identify the proper market power mitigation program. The finding in this paper is helpful for market designers and regulators. Copyright © 2013 John Wiley & Sons, Ltd.

Market power in renewable portfolio standards

Renewable portfolio standard (RPS), which requires a certain percentage of electricity production from renewables, has received considerable attention. One emerging issue is the possibility of strategic behavior in the renewable energy certificate/credit (REC) market, and its spillover effects on the electricity market. This paper develops dominant firm-competitive fringe models that account for market power. We show that market power could have significant impacts on the REC and power prices. In particular, when a nonrenewable generator is a dominant firm and a renewable generator is a competitive fringe, the nonrenewable firm has a strong incentive to lower the REC price, even to zero for avoiding REC costs. The zero REC price would negate price impacts in the power market, thereby mitigating market power of the dominant firm. However, this could lead to an underinvestment in renewables in the long run as subsidies received by renewables in form of RECs vanish. Therefore, regulatory agencies need to carefully oversee the market performance to ensure a healthy development of renewable industries under the RPS policies.

Optimal asset divestments with homogeneous products

We study alternative market power mitigation measures in a homogeneous goods industry where productive assets have asymmetric costs. We characterise the asset divestment by a dominant firm which achieves the greatest reduction in prices (taking the size of the divestment as given). The optimal divestment entails the sale of assets whose costs are close to the post-divestment price (i.e. they are price-setting). A divestment of this type can be several times more effective in reducing prices than divestments of low-cost assets. We also establish that virtual divestments (often employed in the power industry) are at best equivalent to low-cost divestments in terms of their impact on consumer welfare, and cannot replicate the optimal divestment.

Effective monitoring and mitigation in the organized wholesale electric power markets

The organized wholesale electric power markets in the United States are characterized by structural market power, and would not produce competitive results absent administrative intervention. Market power mitigation is a fundamental and permanent part of the market design for the organized wholesale electricity markets. Market power mitigation is essential to FERC’s policy of relying on competition to regulate electric wholesale power prices, consistent with its mandate under the Federal Power Act. Controversy has arisen about how to ensure that the markets clear on the basis of offers that have been determined to be competitive. Specifically, the issue is what institution and function is best situated to provide the initial critical determination about whether a participant’s offer is competitive. Despite recent clarification of FERC policies on the market monitoring function, the roles of market administrators and market monitors are a potential source of confusion and counterproductive institutional conflict. The FERC should refine and clarify its policy in this area by according exclusive responsibility to institutional, independent market monitors to monitor participants’ conduct and the potential for the exercise of market power through ex ante review of cost-based offers used in market power mitigation, subject to review by FERC.

Mitigating Market Power under Tradeable Permits

As shown by R. Hahn [6], free allocation equal to the amount of permits a firm with market power uses in equilibrium, can prevent welfare losses. If the necessary amount of free allocation is not provided to the firm with market power, a second best solution is obtained where marginal batement costs of regulated firms are not equated. In this paper, it is proposed that the government may change the economy wide emissions constraint (cap) as a response to market power, e.g. when free allocation cannot be adjusted. Changing the cap can lead to a situation where marginal abatement costs are equated in the presence of market power. Because changing the cap will lead to changes of social welfare, both effects must be balanced. It is shown that there exists a second best social optimum by balancing the positive effect of limiting market power and the negative effect of changing the cap.

Gaming-Based Reserve Constraint Penalty Factor Analysis

To ensure secure real-time power system operations, the system operator must schedule sufficient resources to meet energy demand and operating reserve requirements simultaneously. Under a joint real-time energy-reserve market regime, a dominant market participant can exercise pricing power by withholding reserve capability or by marking up energy offers. This paper examines the short-term impact of the choice of reserve price cap on participant behavior and market outcomes. A Stackelberg game is utilized to analyze the strategic bidding behaviors of the dominant participants assuming a range of reserve price caps and market conditions. The market participants play the role of the leaders, while the independent system operator is treated as a follower. The proposed model is applied to the New England electricity market. The computed solutions show that although the reserve price cap is unable to eliminate physical withholding behaviors, it disciplines the participants and limits incentives to withhold economically. Also, it limits prices to a reasonable level during reserve shortage events when only supply-side market power mitigation options are available. Absent any transmission improvements or effective demand response participation, the reserve price cap remains an effective tool to mitigate the impact of the exercise of supplier market power.

Pivotal Suppliers and Market Power in Experimental Supply Function Competition

In the process of regulatory reform in the electric power industry, the mitigation of market power is one of the basic problems regulators have to deal with. We use experimental data to study the sources of market power with supply function competition, akin to the competition in wholesale electricity markets. An acute form of market power may arise if a supplier is pivotal; that is, if the supplier's capacity is required in order to meet demand. To be able to isolate the impact of demand and capacity conditions on market power, our treatments vary the distribution of demand levels as well as the amount and symmetry of the allocation of production capacity between different suppliers. We relate our results to a descriptive power index and to the predictions of two alternative models: a supply function equilibrium (SFE) model and a multi-unit auction (MUA) model. We find that pivotal suppliers do indeed exercise their market power in the experiments. We also find that observed behavior is consistent with the range of equilibria of the unrestricted SFE model and inconsistent with the unique equilibria of two refinements of the SFE model and of the MUA model.

Large-Scale Market Power Modeling: Analysis of the U.S. Eastern Interconnection and Regulatory Applications

This paper presents results from a large-scale Cournot model of the U.S. Eastern Interconnection using a DC load flow network. There are 100 network locations (at the level of control areas) along with 2725 generators owned by 99 Cournot firms and 200 competitive fringe suppliers. These results demonstrate that this modeling approach can analyze potential generation market power with a reasonable approximation of the actual transmission network over a large integrated region. While such models have been used to analyze market design alternatives, their application to regulatory decision-making concerning generation market power mitigation has been more controversial. We suggest that such large-scale market price simulations could improve upon aspects of the existing generation market power screening methods used in the United States for mergers and market-based rates, illustrating such applications using this model.

Using forward markets to improve electricity market design

Forward markets, both medium term and long term, complement the spot market for wholesale electricity. The forward markets reduce risk, mitigate market power, and coordinate new investment. In the medium term, a forward energy market lets suppliers and demanders lock in energy prices and quantities for one to three years. In the long term, a forward reliability market assures adequate resources are available when they are needed most. The forward markets reduce risk for both sides of the market, since they reduce the quantity of energy that trades at the more volatile spot price. Spot market power is mitigated by putting suppliers and demanders in a more balanced position at the time of the spot market. The markets also reduce transaction costs and improve liquidity and transparency. Recent innovations to the Colombia market illustrate the basic elements of the forward markets and their beneficial role.

Market power analysis for the Iranian electricity market

The market power problem in Iranian electricity market is addressed in this study. This paper by using various structural indices of market power and reviewing market results analyzes the intensity of competition in Iran’s electricity market and examines whether this market is functioning at an appropriate level of efficiency. In this article the most well-known indices of market power are calculated in two approaches for two different scenarios (current situation and future outlook of generation sector’s ownership in Iran’s power industry). Comparing the results of these scenarios promises more competitive market for the second scenario. Calculating Residual Supply Index for Iran’s power market shows despite admissible values of concentration ratios, due to supply scarcity during periods when the demand is close to the total available capacity, some suppliers can exercise market power even with a relatively small market share. The most important price and load indices like weighted average prices and load/price duration curves of Iranian electricity market during March 2007–March 2008 are also analyzed in this paper. These results imply the existence of economic withholding. The main limiting factors of competition and significant implemented countermeasures for market power mitigation in Iran’s electricity market are also mentioned.

Evaluation of Market Rules Using a Multi-Agent System Method

The California energy crisis in 2000-2001 showed what could happen to an electricity market if it did not go through a comprehensive and rigorous testing before its implementation. Due to the complexity of the market structure, strategic interaction between the participants, and the underlying physics, it is difficult to fully evaluate the implications of potential changes to market rules. This paper presents a flexible and integrative method to assess market designs through agent-based modeling. Realistic simulation scenarios are constructed for evaluation of the proposed PJM-like market power mitigation rules of the California electricity market. Simulation results show that in the absence of market power mitigation, generation company (GENCO) agents facilitated by Q-learning are able to exploit the market flaws and make significantly higher profits relative to the competitive benchmark. The incorporation of PJM-like local market power mitigation rules is shown to be effective in suppressing the exercise of market power.

Demand response resources: Who is responsible for implementation in a deregulated market?

Demand response resources (DRR) have potential to offer substantial benefits in the form of improved economic efficiency in wholesale electricity markets. Those benefits include better capacity factors for existing capacity, reductions in requirements for new capacity, enhanced reliability, relief of congestion and transmission constraints, reductions in price volatility, mitigation of market power and lower electricity prices for consumers. However, DRR has been slow to penetrate. There has been substantial disagreement as to which entities in a restructured market should promote the expanded implementation of DRR. This paper contends that no single entity can perform this function. But rather, wider implementation will need to accrue from coordinated actions along the electricity supply chain.