Portugal

In the past decades, Portugal has had little development of wind power plant installations, mainly due to the low tariffs practised. However, at the end of 2001, the scenario changed with the publication of new legislation and tariffs. By 2003, that change became reflected in the implementation of new wind park projects and a strong increase in the development rate of capacity installed. In the following sections, a synthesis of the past as well as a summary of the current situation is presented with a main focus on the Portuguese current state of development and trends

The Future Energy Mix Paradigm: How to Embed Large Amounts of Wind Generation While Preserving the Robustness and Quality of the Power Systems?

The 2001/77/CE Renewable Energies European Directive together with Kyoto Protocol ratification by many countries, supported by some Governments vision and strong objectives on the reduction of external oil dependence, put Europe and other developed economies in the front line to achieve a remarkable wind energy penetration within ten years time. These goals will not be achieved without technical costs and risks, but mainly,without a careful planning and assessment of the power system behaviour with large amounts of wind generation (SRA, 2008; IEAWind, 2008).These days, one of the most relevant difficulties the wind sector faces was caused by this technology own extreme success. The high capacity installed in the last decade introduced a brand new set of power system technological concerns that recently became one of the more referenced subjects among developers, network planners and system operators. These concerns are not anymore a negligible distribution grid integration issue that some years ago the experts tended not to give too much relevance since they were easily solved and even more easily avoided through good design and planning, but this is a real power system operation and planning challenge (Holttinen et al, 2009): will the power systems be capable to cope with the specificities of the wind power production in large quantities (aka “high penetration”) without requiring new wind park models, system operation tools,increased performance of the wind turbines or even a change in the Transmission System Operators (TSOs) conventional mode of operation? The recent concern of the TSOs is very legitimate, since it is their responsibility to design and manage the power system global production and its adjustment to the consumer loads as well as to assure the technical quality of the overall service, both in steady-state and under transient occurrences

A cyclic time-dependent Markov process to model daily patterns in wind turbine power production

Wind energy is becoming a top contributor to the renewable energy mix, which raises potential reliability issues for the grid due to the fluctuating nature of its source. To achieve adequate reserve commitment and to promote market participation, it is necessary to provide models that can capture daily patterns in wind power production. This paper presents a cyclic inhomogeneous Markov process, which is based on a three-dimensional state-space (wind power, speed and direction). Each time-dependent transition probability is expressed as a Bernstein polynomial. The model parameters are estimated by solving a constrained optimization problem: The objective function combines two maximum likelihood estimators, one to ensure that the Markov process long-term behavior reproduces the data accurately and another to capture daily fluctuations. A convex formulation for the overall optimization problem is presented and its applicability demonstrated through the analysis of a case-study. The proposed model is capable of reproducing the diurnal patterns of a three-year dataset collected from a wind turbine located in a mountainous region in Portugal. In addition, it is shown how to compute persistence statistics directly from the Markov process transition matrices. Based on the case-study, the power production persistence through the daily cycle is analysed and discussed

Portugal

During 2005, Portugal reinforced the tendency shown during 2004 of high growth rate of wind capacity installation. Also visible was some simplification of critical administrative processes concerning the implementation of renewable energy projects and, for the second year in a row, Portugal almost doubled the installed wind power capacity. In the following sections, a synthesis of the actual situation is presented with a main focus on the Portuguese current state of development and trends

Impact of Wind Generation Fluctuations in the Design and Operation of Power Systems

In this paper, the impact of the wind time variability and the spatial smoothing effect in mountainous complex terrains, usually taken as 1/sqrt(N) for fast fluctuations, is studied. The dimension of the regions, the type of electrical clustering of large numbers of wind turbines and the local meteorological effects are addressed and conclusions drawn on selected experimental case studies

Portugal

During 2004, Portugal reversed the tendency of slow wind capacity growth observed in previous years. The publication of legislation and tariffs at the end of 2001 and subsequent government simplifi cation of administrative processes concerning the implementation of renewable energy projects resulted in nearly doubled capacity in Portugal during 2004. In the following sections, a summary of the events of the year is presented with a main focus on the current state of development and trends

Impact of weather conditions on the windows of opportunity for operation of offshore wind farms in portugal

The deployment of offshore wind parks face several challenges. Among them are the difficulties introduced by the atmospheric and sea conditions in accessing those wind parks. A window of opportunity is a timeframe when weather and sea conditions are acceptable and enable to perform specific tasks in the installation and operation/maintenance of the offshore wind park. This study identifies typical time periods of windows of opportunity to access three offshore Portuguese maritime regions. The accessibility conditions also take into account the system type transportation method for local access, namely, rubber boat, boat with OAS or helicopter. It was concluded that Portugal has adequate conditions for offshore site maintenance strategies, with a large number of windows of opportunity, but they are relatively short, therefore the installation of offshore wind parks must be carefully planned. This is an important factor in favor of the offshore wind farm deployments on the country

From Wind to Hybrid: A Contribution to the Optimal Design of Utility-Scale Hybrid Power Plants

ABSTRACT: When a substantial number of wind parks are approaching the end of their lifespan, and developers of renewables are facing decisions about what to do with their assets, concepts such as hybrid power plants are emerging as a promising solution to enable renewable integration in a cost-effective and robust manner. This work proposes a decision-aid algorithm to perform a comprehensive analysis of hybrid power plants, focusing on the energetic contribution and economic feasibility of converting existing wind power plants into hybrid power plants (i.e., installing photovoltaic panels and a storage system). The analysis was performed by comparing the option of converting existing wind plants into hybrid plants with a pure repowering exercise or overplanting using wind technology only. The obtained results unequivocally demonstrate the added value of hybrid power plants as they promote: (i) a higher installed capacity and yearly capacity factor (up to 50%); (ii) an increased efficiency of existing electric infrastructures; and (iii) a positive contribution to a sustainable energy system with the ability to generate economic value.info:eu-repo/semantics/publishedVersio

Portugal

Portugal has few indigenous energy resources, such as those that satisfy the majority of the energy needs of the economically developed countries, such as oil, gas, and coal. This situation leads to a large dependence on foreign economies for fossil primary resources. In this context, the contribution of renewable energies and the need to improve their penetration becomes of strategic relevance for the country’s development. In 2006, the total renewable sources installed capacity was 6,961 MW. The total electric energy production from renewables has shown an impressive 86% growth rate with respect to the end of 2005, its final value being reported as 16,120 GWh. This growth was strongly correlated with the variation in hydropower production, about 124%. In what concerns to wind energy, as will be shown in the next paragraphs, there was a moderate growth in the installed capacity when compared to previous years. In 2006, the 2005 policy continuance was verified, with special relevance to the ending of the first phase of the 1,500 MW public call for wind park grid connection opened in July 2005