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2003, Journal of Futures Markets
https://doi.org/10.1002/FUT.10093…
25 pages
1 file
In this article we investigate the statistical properties of wholesale electricity spot and futures prices traded on the New York Mercantile Exchange for delivery at the California–Oregon Border. Using daily data for the years 1998 and 1999, we find that many of the characteristics of the electricity market can be viewed to be broadly consistent with efficient markets. The futures risk premium for 6‐month futures contracts is estimated to be 0.1328% per day or about 4% per month. Using a GARCH specification, we estimate minimum variance hedge ratios for electricity futures. Finally, we study the dynamic relation between spot and futures prices using an Exponential GARCH model and between the spot and futures returns series using a vector autoregression. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:931–955, 2003
In the last few decades European electricity markets have been subject to a broad deregulation process. Since spot electricity prices are characterized by high volatility most markets started to quote futures as long as spot contracts in order to allow market players to hedge their positions. This paper investigates how electricity futures can be used to hedge spot position. We compare the performance of the hedge ratio estimated with traditional naïve and OLS (Ordinary least squares) method with more elaborated GARCH models. We focus on correlation GARCH models and we test if correlations models perform better than traditional models in a context of high time varying volatility as the case of electricity markets. Our results shows that futures hedging reduce the variance of the portfolio depending on the model chosen to estimate the hedge ratio. In some cases traditional hedging lead to an increase in the variance of the hedged portfolio due to the change in correlation between the in sample and the out of sample estimation period. This explain why the correlation structure should be taken into consideration.
Journal of International Financial Markets, Institutions and Money, 2010
European electricity markets have been subject to a broad deregulation process in the last few decades. We analyse hedging policies implemented through different hedge ratios estimation. More specifically we compare naïve, ordinary least squares, and GARCH conditional variance and correlations models to test if GARCH models lead to higher variance reduction in a context of high time varying volatility as the case of electricity markets. Our results show that the choice of the hedge ratio estimation model is central on determining the effectiveness of futures hedging to reduce the portfolio volatility.
2004
This paper examines the relationship between futures and spot electricity prices for two of the Australian electricity regions in the National Electricity Market (NEM): namely, New South Wales and Victoria. A generalized autoregressive conditional heteroskedasticity (GARCH) model is used to identify the magnitude and significance of mean and volatility spillovers from the futures market to the spot market. The results indicate the presence of positive mean spillovers in the NSW market for peak and off-peak (base load) futures contracts and mean spillovers for the off-peak Victorian futures market. The large number of significant innovation and volatility spillovers between the futures and spot markets indicates the presence of strong ARCH and GARCH effects. Contrary to evidence from studies in North American electricity markets, the results also indicate that Australian electricity spot and futures prices are stationary.
European electricity markets have been subject to a broad deregulation process in the last few decades. We analyse hedging policies implemented through different hedge ratios estimation. More specifically we compare naïve, ordinary least squares, and GARCH conditional variance and correlations models to test if GARCH models lead to higher variance reduction in a context of high time varying volatility as the case of electricity markets. Our results show that the choice of the hedge ratio estimation model is central on determining the effectiveness of futures hedging to reduce the portfolio volatility.
Energy Economics, 2013
This paper examines the impact of the introduction of electricity futures on the spot-price volatility of the French (Powernext) and German (EEX) electricity markets, as well as the degree of their price correlation over the period 2002-2011. Our working hypotheses were tested based on a bivariate VECM-GARCH model. The results indicate that the introduction of futures contracts in the French electricity market, as well as the launch of the joint futures market in these countries in 2009, has decreased spot price volatility. However, this effect was not as explicit for the German market, due to data specificities. Other interesting results are: the German market dominates and leads the long run price relationship; the impact of cooling needs on demand is greater than the impact of heating needs; there is a substantial systematic pattern of electricity prices and their respective volatilities during weekdays and holidays. Overall, results are supportive of policy making at the European Commission regarding electricity market integration.
Energy Economics, 2014
This work discusses potential pitfalls of applying linear regression models for explaining the relationship between spot and futures prices in electricity markets, in particular, the bias coming from the simultaneity problem, the effect of correlated measurement errors and the impact of seasonality on the regression results. Studying a 13-year long (1998-2010) price series of spot and futures prices at Nord Pool and employing regression models with GARCH residuals, we show that the impact of the water reservoir level on the risk premium is positive, which is to be expected, but contradicts the results of . We also show that after taking into account the seasonality of the water level, the storage cost theory proposed by to explain the behavior of convenience yield has only limited support in the data.
Pizhūhishnāmah-i Iqtiṣād-i Inirzhī-i Īrān, 2015
Iran Energy Exchange started to work on 03/09/2013. Electricity trading is carried out within the framework of forward contracts in this exchange. This paper examines the impact of trading in the electricity forward market on the volatility of electricity spot market. Using daily data of electricity market prices between 03/21/2011 to 06/21/2015, we employed GARCH technique to investigate the impact of forward trading on the volatility of the spot market in Iran. Our two main findings are as follows: (1) forward trading has led to increased volatility in Iran electricity spot market, (2) there is an increase in sensitivity to new information while sensitivity to historical information decreases after introduction of the electricity forward contracts.
In the last few decades European electricity markets have been subject to a broad deregulation process. Since spot electricity prices are characterized by high volatility most markets started to quote futures as long as spot contracts in order to allow market players to hedge their positions. This paper investigates how electricity futures can be used to hedge spot position. We compare the performance of the hedge ratio estimated with traditional naïve and OLS (Ordinary least squares) method with more elaborated GARCH models. We focus on correlation GARCH models and we test if correlations models perform better than traditional models in a context of high time varying volatility as the case of electricity markets. Our results shows that futures hedging reduce the variance of the portfolio depending on the model chosen to estimate the hedge ratio. In some cases traditional hedging lead to an increase in the variance of the hedged portfolio due to the change in correlation between the in sample and the out of sample estimation period. This explain why the correlation structure should be taken into consideration.
Electricity spot market price is notoriously difficult to predict because of the high variability of its volatility that results in prominent price spikes, interlaced with more Gaussian behavior. Such varying volatility has prompted researchers to use GARCH modeling to forecast spot prices. In this article, we study the reliability of an optimally chosen GARCH and its accompanying ARMA model of two electricity spot market price time series using a Markov Chain Monte Carlo (MCMC) method. The MCMC method is used to estimate the parameters of the ARMA-GARCH model. It appears based on this analysis that even an optimally chosen ARMA-GARCH model is not sufficient to explain the behavior of electricity spot market price.
Energy Economics, 2020
This paper compares the in-sample and out-of-sample performance of several models for computing the tail risk of one-month and one-year electricity futures contracts traded in the NordPool, French, German, and Spanish markets in 2008-2017. As measures of tail risk, we use the one-day-ahead Value-at-Risk (VaR) and the Expected Shortfall (ES). With VaR, the AR (1)-GARCH (1,1) model with Student-t distribution is the best-performing specification with 88% cases in which the Fisher test accepts the model, with a success rate of 94% in the left tail and of 81% in the right tail. The model passes the test of model adequacy in the 100% of the cases in the NordPool and German markets, but only in the 88% and 63% of the cases in the Spanish and French markets. With ES, this model passes the test of model adequacy in 100% of cases in all markets. Historical Simulation and Quantile Regressionbased approaches misestimate tail risks. The right-hand tail of the returns is more difficult to model than the left-hand tail and therefore financial regulators and the administrators of futures markets should take these results into account when setting additional regulatory capital requirements and margin account regulations to short positions.
Energy Economics, 2012
The goal of this paper is to examine to what extent electricity futures prices contain expected risk premiums or have power to forecast spot prices and whether this might be dependent on the type of electricity supply. We analyse futures prices from the Dutch market, a market in which power is produced with storable fossil fuels, and futures prices from the NordPool market, where electricity is mostly produced by hydropower. We show that futures prices from markets in which electricity is predominantly produced by imperfectly storable fuels such as hydro, wind and solar contain information about expected changes in the spot price of electricity, whereas futures prices from markets in which electricity is predominantly produced with perfectly storable fuels contain information about both expected price changes and time-varying risk premiums. These findings provide insight in the applicability of forward price models; one cannot apply the same model to all electricity markets. Forward models for markets with imperfect indirect storability should depend heavily on price expectations and models should include time-varying risk premiums for markets with perfect indirect storability.
International Journal of Finance & Economics
This paper estimates and applies a risk management strategy for electricity spot exposures using futures hedging. We apply our approach to three of the most actively traded European electricity markets, Nordpool, APXUK and Phelix. We compare both optimal hedging strategies and the hedging effectiveness of these markets for two hedging horizons, weekly and monthly using both Variance and Value at Risk (VaR). Our key finding is that electricity futures can effectively manage risk only for specific time periods when using hedging strategies that have been very successful in financial and other commodity markets. More generally they are ineffective as a risk management tool when compared with other energy assets. This is especially true at the weekly frequency. We also find significant differences in both the Optimal Hedge Ratios (OHR's) and the hedging effectiveness of the different electricity markets. Better performance is found for the Nordpool market, while the poorest performer in hedging terms is the Phelix market.
SSRN Electronic Journal, 2017
We model the impact of supply and demand on risk premiums in electricity futures, using daily data for 2003-2014. The model provides a satisfactory fit and allows for unspanned economic risk not embedded in the futures price. The spot risk premium and forward bias implied by the model are on average large and negative but highly time-varying. Risk premiums display strong seasonal patterns, are related to the variance and skewness of the electricity spot price, and help predict future returns. The risk premium associated with supply constitutes the largest component of the total risk premium embedded in electricity futures.
2003
This paper examines the transmission of spot electricity prices and price volatility among the five Australian electricity markets in the National Electricity Market (NEM): namely, New South Wales (NSW), Queensland (QLD), South Australia (SA), Snowy Mountains Hydroelectric Scheme (SNO) and Victoria (VIC). A multivariate generalised autoregressive conditional heteroskedasticity (MGARCH) model is used to identify the source and magnitude of innovations
E3S Web of Conferences, 2020
This paper presents an original trading strategy for electricity buyers in futures markets. The strategy applies a medium-term electricity price forecasting model to predict the monthly average spot price which is used to evaluate the Risk Premium for a physical delivery under a monthly electricity futures contract. The proposed trading strategy aims to provide an advantage relatively to the traditional strategy of electricity buyers (used as benchmark), anticipating the good/wrong decision of buying electricity in the futures market instead in the day-ahead market. The mid-term monthly average spot price forecasting model, which supports the trading strategy, uses only information available from futures and spot markets at the decision moment. Both the new trading strategy and the monthly average spot price forecasting model, proposed in this paper, have been successfully tested with historical data of the Iberian Electricity Market (MIBEL), although they could be applied to other ...
Energy Policy, 2019
Against the backdrop of numerous evidence that variable renewable generation decreases electricity prices and increases price volatility, this paper assesses the drivers of electricity prices in spot and futures markets, focusing on the German electricity markets. We take into account nonlinearities in electricity prices by means of structural breaks and threshold regressions. We find that short-run and medium/long-run price drivers differ and, more importantly, that they vary over time. In the case of the spot market, the determinants of prices are renewable infeed and electricity demand, while in the futures market the main drivers are natural gas, coal and carbon prices. Our results give relevant insights for market participants who seek to optimize procurement/ selling strategies in the spot market, and use the futures market to hedge against spot price volatility, which has increased due to a higher renewable generation.
2010
Electricity markets have several interesting features. For example, electricity spot markets are not free markets, but oligopoly; and due to the low elasticity in the demand, the spot prices have large spikes, which may lead to infinite expectation in the spot prices, although the futures prices have much less spikes and tend to have finite expectations. We propose a two-factor model for on-peak electricity spot and futures prices, starting from the electricity demand. More specifically, we first model the the peak demand as a two-factor mean reverting affine jump diffusion process, attempting to describe two different mean reversion features related to the normal peak demand and abnormal spikes in the demand separately. Then we derive the on-peak spot price based on a minimum Nash equilibrium for the demand-and-price function in oligopoly markets, using the existing game theory results. After constructing a risk-adjusted measure via an equilibrium argument, we obtain analytical solutions for futures prices and call and put options on futures prices. Not only can our model capture some intrinsic features of electricity spot prices, such as mean reversion, spikes, and seasonality, but it is also consistent with the empirical observation that under the physical measure, the on-peak spot prices may have either finite or infinite expectations, while the futures prices tend to have finite means under the physical measure. Numerical examples indicate that our model seems to more reasonable than the existing one-factor models.
2002
We conduct an empirical analysis of electricity forward prices using a high-frequency data set of hourly spot and day-ahead forward prices. We find that there are significant risk premia in electricity forward prices. These premia vary systematically throughout the day and are directly related to economic risk factors such as the volatility of unexpected changes in prices and demand as well as the risk of price spikes. In contrast to the popular post-Enron view that electricity markets are easily manipulated, these results support the hypothesis that electricity forward prices are determined rationally by risk-averse economic agents. . We are grateful for helpful discussions with David Hirshleifer, Mitz Igarashi, and Scott Benner. All errors are our responsibility.
IEEE Transactions on Power Systems, 2005
Price forecasting is becoming increasingly relevant to producers and consumers in the new competitive electric power markets. Both for spot markets and long-term contracts, price forecasts are necessary to develop bidding strategies or negotiation skills in order to maximize profits. This paper provides an approach to predict next-day electricity prices based on the Generalized Autoregressive Conditional Heteroskedastic (GARCH) methodology that is already being used to analyze time series data in general. A detailed explanation of GARCH models is presented and empirical results from the mainland Spain and California deregulated electricity-markets are discussed.

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