Fuel cost uncertainty,capacity investment and price in a competitive electricity market

This paper studies the effect of natural-gas fuel cost uncertainty on capacity investment and price in a competitive electricity market. Our model has a two-stage decision process. In the first stage, an independent power producer (IPP) builds its optimal capacity, conditional on its perceived uncertainties in fuel cost and electricity demand. In the second stage, equilibrium prices and quantities are determined by IPPs competing in a Cournot market. Under the empirically reasonable assumption that per MWh fuel costs are log-normally distributed, we find that a profit-maximizing IPP increases its capacity in response to rising fuel cost volatility. Consequently, the expected profit of the IPP and expected consumer surplus increase with volatility, rejecting the hypothesis that rising fuel cost uncertainty tends to adversely affect producers and consumers. Expected consumer surplus further increases if the IPP hedges the fuel cost risk. However, the IPP's optimal strategy is not to do so. The policy implication of these results is that the government should not intervene to reduce the price volatility of a well-functioning spot market for natural gas, chiefly because such intervention can have the unintended consequence of discouraging generation investment, raising electricity prices, and harming consumers.     

The plunge in German electricity futures prices – Analysis using a parsimonious fundamental model

The German market has seen a plunge in wholesale electricity prices from 2007 until 2014, with base futures prices dropping by more than 40%. This is frequently attributed to the unexpected high increase in renewable power generation. Using a parsimonious fundamental model, we determine the respective impact of supply and demand shocks on electricity futures prices. The used methodology is based on a piecewise linear approximation of the supply stack and time-varying price-inelastic demand. This parsimonious model is able to replicate electricity futures prices and discover non-linear dependencies in futures price formation. We show that emission prices have a higher impact on power prices than renewable penetration. Changes in renewables, demand and installed capacities turn out to be similarly important for explaining the decrease in operation margins of conventional power plants. We thus argue for the establishment of an independent authority to stabilize emission prices.     

High penetration wind generation impacts on spot prices in the Australian national electricity market

This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations.     

Cross-border effects in interconnected electricity markets - an analysis of the Swiss electricity prices

Electricity markets in Europe become increasingly interconnected due to new grid connections and market coupling regulations. This paper examines the interdependencies between the Swiss electricity market and those of neighbouring countries. The Swiss market serves as a good example for a smaller electricity market which is increasingly affected by developments in the large neighbouring countries. To study these cross-border effects, especially those on Swiss electricity prices, we apply two different methodologies, an econometric and a Nash-Cournot equilibrium model.The analyses show that the Swiss electricity price correlates strongly with the German electricity price in the summer, but tends to follow the French electricity price in the winter. Another finding is that gas prices and the electricity load of neighbouring countries have a significant influence on prices. In particular, the load of France and Italy is driving up Swiss prices in the winter, while the German electricity demand and renewable energy generation have a larger influence on Swiss prices in the summer.     

Abuse of dominance and antitrust enforcement in the German electricity market

In 2008, the European Commission investigated E.ON, a large and vertically integrated electricity company, for the alleged abuse of a joint dominant position by strategically withholding generation capacity in the German wholesale electricity market. The case was settled after E.ON agreed to divest 5 GW generation capacity as well as its extra-high voltage network. We analyze the effect of these divestitures on wholesale electricity prices. Our identification strategy is based on the observation that energy suppliers have more market power during peak periods when demand is high. Therefore, a decrease in market power should lead to convergence between peak and off-peak prices, after controlling for different demand and supply conditions as well as the change in generation mix due to the expansion of renewable technologies. Using daily electricity prices for the 2006–2012 period, we find economically and statistically significant convergence effects after the settlement of the case. In a richer specification, we show that the price reductions appear to be mostly due to the divestiture of gas and coal plants, which is consistent with merit-order considerations. Additional cross-country analyses support our results.     

Measuring the competitiveness benefits of a transmission investment policy: The case of the Alberta electricity market

Transmission expansions can increase the extent of competition faced by wholesale electricity suppliers with the ability to exercise unilateral market power. This can cause them to submit offer curves closer to their marginal cost curves, which sets market-clearing prices closer to competitive benchmark price levels. These lower wholesale market-clearing prices are the competitiveness benefit consumers realize from the transmission expansion. This paper quantifies empirically the competitiveness benefits of a transmission expansion policy that causes strategic suppliers to expect no transmission congestion. Using hourly generation-unit level offer, output, market-clearing price and congestion data from the Alberta wholesale electricity market from January 1, 2009 to July 31, 2013, an upper and lower bound on the hourly consumer competitiveness benefits of this transmission policy is computed. Both of these competitiveness benefits measures are economically significant, which argues for including them in transmission planning processes for wholesale electricity markets to ensure that all transmission expansions with positive net benefits to electricity consumers are undertaken.     

Market power in the Nordic electricity wholesale market: A survey of the empirical evidence

We review the recent empirical research assessing market power on the Nordic wholesale market for electricity, Nord Pool. The studies find no evidence of systematic exploitation of system level market power on Nord Pool. Local market power arising from transmission constraints seems to be more problematic in some price areas across the Nordic countries. Market power can manifest itself in a number of ways that have so far escaped empirical scrutiny. We discuss investment incentives, vertical integration and buyer power, as well as withholding of base-load (nuclear) capacity.     

An ex-post analysis of the effect of renewables and cogeneration on Spanish electricity prices

Growing concerns about climate change and energy dependence are driving specific policies to support renewable or more efficient energy sources such as cogeneration in many regions, particularly in the production of electricity. These policies have a non-negligible cost, and therefore a careful assessment of their impacts seems necessary. In particular, one of the most-debated impacts is their effect on electricity prices, for which there have been some ex-ante studies, but few ex-post studies. This article presents a full ex-post empirical analysis, by looking at use of technologies and hourly electricity prices for 2005–2009 in Spain, to study the effects that the introduction of renewable electricity and cogeneration has had on wholesale electricity prices. It is particularly interesting to perform this study in Spain where an active system of public support to renewables and cogeneration has led to a considerable expansion of these energy sources and electricity pricing is at the center of intense debate. The paper reports that a marginal increase of 1 GWh of electricity production using renewables and cogeneration is associated with a reduction of almost 2 € per MWh in electricity prices (around 4% of the average price for the analyzed period).     

Area price and demand response in a market with 25% wind power

Denmark, east and west of the Great Belt are bidding areas with separate hourly area prices for the Nord Pool power exchange, covering four Nordic countries and parts of Germany. The share of wind power has now increased to 25% on an annual basis in western Denmark. This has a significant impact not only on the electricity wholesale prices, but also on the development of the market. Hourly market data are available from the website of Danish TSO from 1999. In this paper these data are analysed for the period 2004–2010. Electricity generators and customers may respond to hourly price variations, which can improve market efficiency, and a welfare gain is obtained. An important limitation for demand response is events of several consecutive hours with extreme values. The analysis in this paper is a summary and update of some of the issues covered by the EU RESPOND project. It shows that extreme events were few, and the current infrastructure and market organisation have been able to handle the amount of wind power installed so far. This recommends that geographical bidding area for the wholesale electricity market reflects external transmission constraints caused by wind power.     

Price formation and market power in the German wholesale electricity market in 2006

From 2002 to 2006, German wholesale electricity prices more than doubled. The purpose of this paper is to estimate the price components in 2006 in order to identify the factors responsible for the increase. We develop a competitive benchmark model, taking into account power plant characteristics, fuel and CO₂-allowance prices, wind generation, cross-border flows, unit commitment, and startup conditions, to estimate the difference between generation costs and observed market prices for every hour in 2006. We find that prices at the German wholesale market (European Energy Exchange—EEX) are above competitive levels for a large fraction of the observations. We verify the robustness of the results by carrying out sensitivity analyses. We also address the issue of revenue adequacy.     

Impacts of day-ahead versus real-time market prices on wholesale electricity demand in Texas

The somewhat recent nodal market structure in Texas impacts wholesale day-ahead market (DAM) and real-time market (RTM) prices. However, comparative insights on consumer responses to both these prices have not received attention. This paper attempts to fill this void by developing a system-wide demand response model to better understand price elasticities under DAM and RTM pricing. These insights may also assist grid operators to develop improved short-term forecasts of electricity demand. Using a large dataset from the Electric Reliability Council of Texas and a hierarchical Bayesian population model, we offer new insights on how DAM and RTM pricing shapes demand for electricity, and the related consequences for maintaining a reliable electricity market.     

Market integration among electricity markets and their major fuel source markets

Dynamic price information flows among U.S. electricity wholesale spot prices and the prices of the major electricity generation fuel sources, natural gas, uranium, coal, and crude oil, are studied. Multivariate time series methods applied to weekly price data show that in contemporaneous time peak electricity prices move natural gas prices, which in turn influence crude oil. In the long run, price is discovered in the fuel sources market (except uranium), as these prices are weakly exogenous in a reduced rank regression representation of these energy prices.     

Transmission-constrained oligopoly in the Japanese electricity market

We simulate the Japanese wholesale electricity market as a transmission-constrained Cournot market using a linear complementarity approach. First, we investigate the effects of upgrading the bottleneck transmission line between the eastern and western regions, focusing on the mitigation of transmission congestion. Although increasing the bottleneck capacity would lead to welfare gains, they might not be substantial particularly when transmission capacity costs are taken into account. Second, we examine the effects of splitting the largest electric power company, which is located in the eastern region, focusing on the mitigation of market power. Splitting the largest company into two companies would lead to a 25% reduction in the eastern price, and a 50% reduction in deadweight loss. The divestiture of the largest company would have a significant effect of mitigating market power in the Japanese electricity market.     

Short-term optimal wind power generation capacity in liberalized electricity markets

Mainly because of environmental concerns and fuel price uncertainties, considerable amounts of wind-based generation capacity are being added to some deregulated power systems. The rapid wind development registered in some countries has essentially been driven by strong subsidizing programs. Since wind investments are commonly isolated from market signals, installed wind capacity can be higher than optimal, leading to distortions of the power prices with a consequent loss of social welfare. In this work, the influence of wind generation on power prices in the framework of a liberalized electricity market has been assessed by means of stochastic simulation techniques. The developed methodology allows investigating the maximal wind capacity that would be profitably deployed if wind investments were subject to market conditions only. For this purpose, stochastic variables determining power prices are accurately modeled. A test system resembling the size and characteristics of the German power system has been selected for this study. The expected value of the optimal, short-term wind capacity is evaluated for a considerable number of random realizations of power prices. The impact of dispersing the wind capacity over statistical independent wind sites has also been evaluated. The simulation results reveal that fuel prices, installation and financing costs of wind investments are very influential parameters on the maximal wind capacity that might be accommodated in a market-based manner.     

Market power in the European electricity market—The impacts of dry weather and additional transmission capacity

This paper uses a static computational game theoretic model of a fully opened European electricity market and can take strategic interaction among electricity-producing firms into account. The model is run for a number of scenarios: first, in the baseline under perfect competition, the prices differ due to the presence of various generation technologies and a limited ability to exchange electricity among countries. In addition, when large firms exercise market power, the model runs indicate that prices are the highest in countries where the number of firms is low. Second, dry weather would increase the prices in the hydro-rich Nordic countries followed by the Alpine countries. The price response would be about 20% higher with market power. Third, more transmission capacity would lower the prices in countries with high prices and it also reduces the impact of market power. Hence, more transmission capacity can improve market competitiveness.     

Integration of multiple national markets for electricity: The case of Norway and Sweden

During the second part of the 1990s the Nordic (Denmark, Finland, Norway and Sweden) countries have created a unique multinational market for electricity. This paper aims to analyse the degree of integration of the different national markets that constitute the Nordic electricity market. In particular the Norwegian and Swedish wholesale and retail electricity markets are analysed. The results suggest that the wholesale markets are well integrated. Thus prices differ significantly only during periods with unusually high or low supply of hydropower. However, the retail markets are not integrated to the same degree. Thus retail prices and trade margins differ significantly. Differences in the national electricity market legislation seem to be a key factor behind these differences.     

Impacts of a common green certificate market on electricity and CO2-emission markets in the Nordic countries

The purpose of this study is to analyze the effects of introducing a common Nordic system for tradable green certificates (TGCs) on the electricity market and a future market for tradable CO₂-emission permits (TEPs). In the analysis, the energy-system model generator MARKAL was used to model the electricity and district-heating supply systems in the four Nordic countries Sweden, Norway, Finland and Denmark. It is shown that the introduction of TGC quotas reduces wholesale electricity and TEP prices. The impact on the latter is very pronounced. Retail electricity prices may become lower or higher, depending on the TGC quota, than if obligations to fulfill TGC quotas were absent. The TGC scheme's efficiency in reducing a specific amount of CO₂ emissions is also compared to the corresponding efficiency of a TEP scheme involving a broader range of technologies. Furthermore, obligations to fulfill TGC quotas affect investment incentives for new non-renewable electricity supply. This seems especially true for gas-fired power plants. Finally, it is indicated that electricity supply based on biomass combustion dominates the TGC scheme, at least in the short run.     

美国加州电力市场电价的分形特征

以美国加州电力市场长期电价序列为研究对象，并由此引入了分数布朗运动模型和R／S分析法，计算出了不同时间区间内电价的赫斯特指数，发现加州电力市场符合分形市场假设，电价遵循有偏的随机游走．具有长期相关性和统计自相关性等性质。这些发现为描述市场环境下的电价分布提供了一种新模式。     

Efficient pricing and investment in electricity markets with intermittent resources

Facing growing technological and environmental challenges, the electricity industry needs effective pricing mechanism to promote efficient risk management and investment decisions. In a restructured electricity market with competitive wholesale prices and traditionally regulated retail rates, however, there are technical and institutional barriers that prevent dynamic pricing with price responsive demand. In regions with limited energy storage capacity, intermittent renewable resources present special challenges. This could adversely affect the effectiveness of public policies causing inefficient investments in energy technologies. In this paper, we present an updated economic model of pricing and investment in restructured electricity market and use the model in a simulation study for an initial assessment of renewable energy strategy and alternative pricing mechanisms. A key objective of the study is to shed light on the policy issues so that effective decisions can be made to improve efficiency.     

A stochastic fuel switching model for electricity prices

This paper develops and applies a novel electricity price model. We reproduce the merit order of a thermal-dominated electricity system by establishing a non-linear dependency of wholesale electricity prices on the prices of fuels (coal and natural gas) and of CO₂ emission allowances. The coefficients are estimated using a Markov Switching Regression.This approach might prove valuable for cross-hedging positions in the fuel, electricity and emission spot markets. It is also of use for studying the degree to which electricity prices in different countries reflect fuel and emission cost. Applying the model to the electricity markets of the UK and Germany, we find that British electricity prices are quite well-explained by short-run cost factors while the German ones are less well-explained.