Abstract
The restructuring of power systems with the introduction of electricity markets and decentralized structures increased the number of participating entities. This is particularly true in generation and retailing which are now provided under competition. Accordingly, it is important to develop models to simulate the behavior of these agents and to optimize their participation in electricity markets. Among them, it is essential to adequately model generation agents namely in countries having a large share of hydro stations. This paper describes an agent-based approach to model the day-ahead electricity market having a particular emphasis on hydro generation. Apart from the characterization of the agents, the paper details the introduction of the Q-Learning algorithm in the model as a way to enhance the performance of generation agents. This paper also presents some preliminary results taking the Portuguese generation system as an example.

Abstract
This paper analyzes the impact of storage installations on grid electricity demand. Storage systems allow the decoupling of consumption from electricity generation and therefore have the potential to change the daily demand profile seen by the network in a significant way. This has far reaching consequences for many stakeholders, as changes in the net demand would for example impact electricity prices or change the requirements for peak generation. The developed approach considers the installation of storage devices to increase self-consumption of locally generated electricity in a residential and small commercial end users context as well as its application for electricity arbitrage. Assumptions about their implementation on a system level are described and their impact on overall electricity demand is determined considering the German case.

Abstract
In this paper we describe the models and the simulations that were conducted in order to access the impact of feed-in subsidized generation in the market price in Portugal in the context of the Iberian Electricity Market. In Portugal and Spain feed-in generation (namely wind power) has a large share both in terms of installed capacity and generated energy and the presence of this energy in the hourly balance originates the reduction of the market price and of the number of hours during which traditional generation (namely coal and CCGT stations) are scheduled. This paper aims at evaluating this impact both in the short term (using the real market curves) and in the long term (using a long term generation expansion planning model). The paper includes results for the Iberian power system currently having a total installed capacity above 120 GW and a total demand of 310 TWh by the end of 2013. © 2014 IEEE.

Abstract
This paper describes a long term generation expansion model that uses system dynamics to capture the interrelations between different variables and parameters. Using this model, it is possible to estimate the long term evolution of the demand and of the electricity price that are then used by generation agents to prepare individual expansion plans. These plans are submitted to a coordination analysis to check some global indicators, as the reserve margin and the LOLE. The developed approach is illustrated using a realistic generation system based on the Portuguese/Spanish system with an installed capacity of nearly 120 GW and an yearly demand of 312 TWh in 2010. Large investments were directed in the last 20 years to the Iberian generation system both regarding traditional technologies and dispersed generation (namely wind parks and solar systems). Today, the excess of installed capacity together with the demand reduction poses a number of questions that should be addressed carefully namely to investigate the impact of several options. The planning exercise aims at identifying the most adequate expansion plans in view of the increased renewable generation (namely wind parks). For illustration purposes, we also conducted a sensitivity analysis to evaluate the impact of increasing the installed capacity in wind parks, of internalizing CO2 emission costs and of incorporating a capacity payment. These analyses are relevant in order to get more insight on the possible long term evolution of the system and to allow generation companies to take more sounded decisions.

Abstract
In this paper we describe the models and the simulations that were conducted in order to access the impact of feed-in subsidized generation in the market price in Portugal in the context of the Iberian Electricity Market. In Portugal and Spain feed-in generation (namely wind power) has a large share both in terms of installed capacity and generated energy and the presence of this energy in the hourly balance originates the reduction of the market price and of the number of hours during which traditional generation (namely coal and CCGT stations) are scheduled. This paper aims at evaluating this impact both in the short term (using the real market curves) and in the long term (using a long term generation expansion planning model). The paper includes results for the Iberian power system currently having a total installed capacity above 120 GW and a total demand of 310 TWh by the end of 2013.

Abstract
Power industry has been deeply restructured in recent decades. Along this period vertically integrated structures evolved to more disaggregated models in which some activities are now provided under competition as generation and retailing while some others are provided under regulated monopolies as network transmission and distribution. Simultaneously, most countries started to encourage the use of renewable sources, namely to cope with environmental issues and to enlarge the energy independency. Having in mind these ideas and given the development of the Iberian Electricity Market and the increase of the installed capacity in units paid by feed-in tariffs, it becomes important to estimate the impact of this feed-in generation in the market prices. This paper describes the approach that was developed to estimate this impact and the implemented software application. This application was then used to evaluate the impact on prices on all trading hours of 2013 of the Portuguese photovoltaic generation, the Portuguese wind generation, all the Portuguese feed-in generation and also all the Iberian feed-in generation.