Browsing by Issue Date, starting with "2013-09-26"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Electricity spot prices structural changes in the Iberian electricity marketPublication . Bolas, João; Sousa, Jorge A. M.; Martins, Ana Alexandra; Lagarto, JoãoIn recent years, the power sector has undergone a restructuring process in many economies in the world. This movement towards liberalization led to the establishment of electricity markets that promote the competitiveness of the production and trading segments of the power sector. In these markets, the agents have to deal with frequent electricity price changes leading to different strategies in their daily bidding behavior. There are a set of variables that can have an impact in the electricity price definition, such as: fuel prices, CO 2 emissions prices, electricity production and demand. This paper proposes to analyze structural changes in the Iberian electricity market price between two periods of time: 2007/2008 and 2010/2011. For this purpose, three quantitative analysis methods were used: correlation, causality and Principal Components. Results suggest that the electricity price had a structural change between the analyzed periods, in particular the increasing importance of special regime production.
- Optimal renewable generation mix of hydro, wind and photovoltaic for integration into the Portuguese power systemPublication . Sousa, Jorge A. M.; Martins, Ana AlexandraIn spite of the advantages of renewable energy sources (RES), their variability and uncertainty raises important issues in power systems operation, such as the need to balance demand with a highly variable and uncertain power generation. In this context, is of utmost importance the choice of the optimal renewable generation mix to be integrated in the power system in order to accomplish the established renewable energy targets with the lowest technical impacts. With this aim, this paper presents a methodology that supports decision making on the renewable energy policy by deriving the optimal renewable generation mix from different available technologies - hydro, wind and photovoltaic - that integrates a given amount of electricity from renewable sources, taking into account the variability of the renewable generation mix and the target share of renewable generation. This methodology is applied to a case study of one month using renewable generation data of the Portuguese power system.
- Modeling the strategic behavior of the iberian electricity market producers using time series analysisPublication . Faria, Ricardo; Sousa, Jorge A. M.; Martins, Ana Alexandra; Lagarto, JoãoThe Iberian Electricity Market (MIBEL) emerges in the context of the integration and cooperation between the Portuguese and Spanish electricity markets, in response to the European Union incentive for regional electricity markets creation. The present study, focus on the modeling and forecasting of the hourly competitive strategies of the electricity producers in the MIBEL. For this analysis, the studied variable was the MIBEL's conjectural variation, which estimates the level of competitiveness of the electricity producers on the day-ahead electricity market. The methodology adopted for forecasting was time series analysis, using ARIMA and exponential smoothing models. The results obtained show that the estimated models that best suit the hourly MIBEL conjectural variation forecast were mainly of the ARIMA seasonal type with daily seasonality, followed by ARIMA non-seasonal type models. It was also observed, that the selected models were mainly estimated with a time series of 5 working days.