CONCETTINI Silvia

We develop an open-source Python software integrating flexibility needs from Variable Renewable Energies (VREs) in the development of regional energy mixes. It provides a flexible and extensible tool to researchers/engineers, and for education/outreach. It aims at evaluating and optimizing energy deployment strategies with high shares of VRE. assessing the impact of new technologies and of climate variability. conducting sensitivity studies. Specifically, to limit the algorithm’s complexity, we avoid solving a full-mix cost-minimization problem by taking the mean and variance of the renewable production-demand ratio as proxies to balance services. Second, observations of VRE technologies being typically too short or nonexistent, the hourly demand and production are estimated from climate time-series and fitted to available observations. We illustrate e4clim’s potential with an optimal recommissioning-study of the 2015 Italian PV-wind mix testing different climate-data sources and strategies and assessing the impact of climate variability and the robustness of the results.

This article empirically investigates the impact of renewable production on congestion using a unique database on the Italian Power Market, where zonal pricing is implemented. We estimate two econometric models: a multinomial logit model, to assess whether renewables increase the occurrence of congestion, and a two stage least squares (2SLS) model to evaluate the impact of wind and photovoltaics on congestion costs. Our analysis suggests that larger renewable supply in importing regions decreases the probability of congestion compared to the no congestion case, while the reverse occurs when renewable production is located in an exporting region. The 2SLS estimations reveal that the same mechanisms explain the level of congestion costs. Our results also highlight that the magnitude of the congestion effects, both in terms of probability and costs, is very sensitive to the location of the historical efficient production, mainly hydro power, and to the geographical configuration of the transmission network.

The literature demonstrates the likely reduction of wholesale electricity prices due to a larger penetration of renewable energy sources (RES). When markets are organized as two or more inter-connected sub-markets within a larger power market the final impact of increasing RES production may be less straightforward given the presence of network constraints. We tests this phenomenon by analyzing the impact of RES production on the probability of congestion and on the size of congestion cost in Italy. Using a database with hourly observations for a five year period we estimate two econometric models on five zonal pairings: a multinomial logit model for the occurrence and direction of congestion and a three stage least square model for the size of congestion costs. The analysis suggests that the e ffect of a larger local wind and solar supply is to decrease the probability of suff ering congestion in entry and to increase the probability of causing a congestion in exit compared to no congestion case. Increasing hydroelectric production has a similar eff ect. These results hold for both importing and exporting regions, but importing regions are less likely to cause congestion in exit, therefore the installation of new RES capacity in these zones may have a positive eff ects in terms of flow balance between regions. Concerning the cost level, a larger local RES supply seems to push the congestion cost towards negative values as it decreases the marginal cost for balancing the system. This is true for all zones in the case of explicit congestion cost, but it is only verified in importing regions in the case of implicit congestion cost. This result suggests that the increase of RES production should be promoted in importing zones, but the overall growth should be controlled in order to avoid congestion in the opposite direction.

The literature demonstrates the likely reduction of wholesale electricity prices due to a larger penetration of renewable energy sources (RES). When markets are organized as two or more inter-connected sub-markets within a larger power market the final impact of increasing RES production may be less straightforward given the presence of network constraints. We tests this phenomenon by analyzing the impact of RES production on the probability of congestion and on the size of congestion cost in Italy. Using a database with hourly observations for a five year period we estimate two econometric models on five zonal pairings: a multinomial logit model for the occurrence and direction of congestion and a three stage least square model for the size of congestion costs. The analysis suggests that the effect of a larger local wind and solar supply is to decrease the probability of suffering congestion in entry and to increase the probability of causing a congestion in exit compared to no congestion case. Increasing hydroelectric production has a similar effect. These results hold for both importing and exporting regions, but importing regions are less likely to cause congestion in exit, therefore the installation of new RES capacity in these zones may have a positive effects in terms of flow balance between regions. Concerning the cost level, a larger local RES supply seems to push the congestion cost towards negative values as it decreases the marginal cost for balancing the system. This is true for all zones in the case of explicit congestion cost, but it is only verified in importing regions in the case of implicit congestion cost. This result suggests that the increase of RES production should be promoted in importing zones, but the overall growth should be controlled in order to avoid congestion in the opposite direction.

This thesis aims to answer three questions raised by the wave of reforms in the electricity sectors: Has the liberalization of electricity supply achieved its objectives in the European Union? How do renewable and non-renewable producers compete in the liberalized market? What is the impact of the increase in electricity generation from renewable sources on grid congestion and zonal price differences in Italy? The first chapter provides a mid-term assessment of the liberalization of electricity supply in Europe. A comprehensive theory of supply liberalization is proposed and its consistency with practice in the European Union is tested. The analysis highlights the persistence of an oligopolistic structure in supply, low customer commitment and asymmetries in the rate and speed of transfer of supply costs into contract prices. Auctioning services by default and as a last resort seems to be the best solution to foster the development of competition. In the second chapter, we study the strategic interactions between a traditional generation technology and a renewable characterized by random capacity. We employ a modified version of Dixit's model of strategic entry deterrence investments with two configurations for post-entry competition: Cournot-style competition in a two-stage game and the dominant firm-competitive fringe framework in a three-stage game. In both cases, the analysis suggests that the renewable producer exploits the merit order to replace the output of its rival. In the third chapter, we analyze the impact of renewable generation on congestion and zonal price differences in Italy. Using a single database, we estimate two econometric models on five pairs of zones: a multinomial logit model for the occurrence and direction of congestion and an OLS model for the size of price differences. The analysis shows that in an importing region the effect of increasing local renewable generation is to decrease (increase) the probability of congestion caused by the bordering region (caused to the bordering region). The increase in renewable energy production seems to have a significant impact on island areas, by decreasing (increasing) the level of positive (negative) price differences.

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The aim of this article is to provide a mid-term evaluation of liberalization of electricity retailing in Europe taking into account some relevant analytic con- straints: di erent and often conflicting theoretical points of view, shortage of routinely collected data, problems in isolating the impact of single reforms in power sector and pervasive regulatory interventions. Theoretical approaches and empirical studies are discussed with the goal of testing the consistency of theory and practice. Our analysis suggests that direct bene ts of retail competition have been often overstated, particularly for small and residential customers. Final market has proven to be less dynamic than forecast and new entry in supply more di cult to sustain in the medium-long run. Regulatory requirements are demonstrated to be more signi cant than suggested in previous papers, due to non-negligible market imperfections. Our main conclusion is that it seems unlikely that \light-handed regulation" may fully substitute for \hard regulation" in this sector, especially for small and residential customers. Moreover, direct regulatory interventions remain essential for arranging and managing Default and Last Resort services and avoiding the risk of excluding \vulnerable customers" from trade. In the light of this limitations, further actions appear to be required to give a thorough organization to this business able to let expected outcomes of other related reforms (e.g. liberalization of generation) a stronger impact on nal customers' welfare.