Suchergebnisse

The variable electricity output of the renewable energy sources (RES) power plants, such as wind and hydro power technologies, is seen as an important challenge for the electricity system managers. This paper addresses the problem of an electricity system supported mainly on hydro, thermal and wind power plants, presenting a short-term model planning. A binary mixed integer non-linear optimization model for one year planning with hourly time step is described and applied to a system close to the expected Portuguese electricity scenario for the year 2020. The main objective of this paper was to analyze the impact that different levels of installed wind power and hydropower have in the operation of thermal power units. Besides that, the analysis of results demonstrate the influence that the characteristics of the seasons of the year has on the renewable power units electricity generation and by this way on the total production cost of the system. ; This work was financed by: the QREN – Operational Programme for Competitiveness Factors, the European Union – European Regional Development Fund and National Funds- Portuguese Foundation for Science and Technology, under Project FCOMP-01-0124-FEDER-011377 and Project ...

Over the last decades, models and concepts related to sustainable electricity planning decisions have been changed according to the society, energy policy objectives and concerns. New and clean energy technologies are emerging as major contributors for the achievement of a set of imposed goals, being the energy efficiency combined with renewable energy sources (RES) a key strategy for a sustainable future. Power planning based on optimization models plays an important role for, not only electricity industry decision making process, but also for all processes where complex decision must be made. Following the idea of sustainability combined with the emergence of RES, this study aims to present an on-going research project that involves the development of a set of mathematical models to be used on the electricity planning. Assuming a time period of 10 years and through scenario analysis, the expected impacts in terms of costs and CO2 emissions were evaluated. The behaviour of system when coal and gas fuel price varies is observed. The results put evidence the significant wind power and hydro power impacts on the electricity sector performance and demonstrate importance of these technologies to achieve the European Union goals for the sector. ; This work was financed by: the QREN – Operational Programme for Competitiveness Factors, the European Union – European Regional Development Fund and National Funds- Portuguese Foundation for Science and Technology, under Project FCOMP-01- 0124-FEDER-011377 and Project ...

Sustainable electricity power planning involves trade-offs between multiple goals. The different attributes of each technology or generation portfolio in terms of the attainment of society goals must be assessed and included in the planning models. Optimization models always played an important role for supporting complex planning decision making, from which the particular case of the electricity industry stands out. This study addresses energy policy and strategic central decisions, presenting a long-term model for electricity planning. A MILP problem is described, which addresses a mixed hydro-thermal-wind power system close to the Portuguese electricity case. Through scenario analysis, the expected impacts in terms of costs, CO2 emissions and external energy dependence are evaluated for a 10 years planning period. Based on the assumed cost information and on the imposed technical restrictions, the obtained results put in evidence the importance of coal power plants combined with new hydro power investments for minimum cost scenarios. ; This work was financed by: the QREN – Operational Programme for Competitiveness Factors, the European Union – European Regional Development Fund and National Funds- Portuguese Foundation for Science and Technology, under Project FCOMP-01-0124-FEDER-011377 and Project ...

The electric power market is changing - it has passed from a regulated market, where the government of each country had the control of prices, to a deregulated market economy. Each company competes in order to get more clients and maximize its profits. This market is represented by a Stackelberg game with two firms, leader and follower, and the leader anticipates the reaction of the follower. The problem is formulated as a Mathematical Program with Complementarity Constraints (MPCC). It is shown that the constraint qualifications usually assumed to prove convergence of standard algorithms fail to hold for MPCC. To circumvent this, a reformulation for a nonlinear problem (NLP) is proposed. Numerical tests using the NEOS server platform are ...