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Detalhes

Detalhes

  • Nome

    José Villar
  • Cluster

    Energia
  • Cargo

    Responsável de Área
  • Desde

    01 setembro 2016
006
Publicações

2018

Flexibility products and markets: Literature review

Autores
Villar, J; Bessa, R; Matos, M;

Publicação
ELECTRIC POWER SYSTEMS RESEARCH

Abstract
This paper reviews flexibility products and flexibility markets, currently being discussed or designed to help in the operation of power systems under their evolving environment. This evolution is characterized by the increase of renewable generation and distributed energy resources (including distributed generation, self-consumption, demand response and electric vehicles). The paper is an attempt to review and classify flexibility products considering its main attributes such as scope, purpose, location or provider, and to summarize some of the main approaches to flexibility markets designs and implementations. Main current literature gaps and most promising research lines for future work are also identified.

2018

Advanced scoring method of eco-efficiency in European cities

Autores
Moutinho, V; Madaleno, M; Robaina, M; Villar, J;

Publicação
Environmental Science and Pollution Research

Abstract
This paper analyzes a set of selected German and French cities’ performance in terms of the relative behavior of their eco-efficiencies, computed as the ratio of their gross domestic product (GDP) over their CO2 emissions. For this analysis, eco-efficiency scores of the selected cities are computed using the data envelopment analysis (DEA) technique, taking the eco-efficiencies as outputs, and the inputs being the energy consumption, the population density, the labor productivity, the resource productivity, and the patents per inhabitant. Once DEA results are analyzed, the Malmquist productivity indexes (MPI) are used to assess the time evolution of the technical efficiency, technological efficiency, and productivity of the cities over the window periods 2000 to 2005 and 2005 to 2008. Some of the main conclusions are that (1) most of the analyzed cities seem to have suboptimal scales, being one of the causes of their inefficiency; (2) there is evidence that high GDP over CO2 emissions does not imply high eco-efficiency scores, meaning that DEA like approaches are useful to complement more simplistic ranking procedures, pointing out potential inefficiencies at the input levels; (3) efficiencies performed worse during the period 2000–2005 than during the period 2005–2008, suggesting the possibility of corrective actions taken during or at the end of the first period but impacting only on the second period, probably due to an increasing environmental awareness of policymakers and governors; and (4) MPI analysis shows a positive technological evolution of all cities, according to the general technological evolution of the reference cities, reflecting a generalized convergence of most cities to their technological frontier and therefore an evolution in the right direction. © 2017 Springer-Verlag GmbH Germany

2018

An electricity generation expansion model with ICEV and PEV investments

Autores
Castanon, R; Campos Fernandez, FAC; Domenech Martinez, SD; Collado, JV;

Publicação
International Conference on the European Energy Market, EEM

Abstract
Environmental policies could accelerate the replacement of Internal Combustion Engine Vehicles (ICEV) by Plug-in-Electric Vehicles (PEV) in many countries. However, in countries where these policies are still not implemented (for example those with no significant PEV subsidies like Spain), technical and economic criteria can also be relevant to assess the future PEV penetration. This work develops a new long-term expansion model that computes the share of PEV and ICEV based on economic criteria, including the impact of PEV on the electricity price and generation mix. The model minimizes the power and transport system costs (investment, operation and maintenance costs, etc.) considering electricity and private transportation needs. Results provide insight on the combined evolution of the renewable generation and of the PEV and ICEV future fleets in Spain, considering environmental constraints such as those imposed by the European Commission. © 2018 IEEE.

2018

Synthetizing representative periods for chronological hourly electricity generation expansion models

Autores
Domenech, S; Campos, FA; Villar, J;

Publicação
International Conference on the European Energy Market, EEM

Abstract
Capacity generation expansion problems have traditionally been represented with low time resolution models due to their high computational cost, very often using blocks of hours with similar demand. However, the current transformation of the power system with the new generation and consumption technologies, the flexibility and reserve requirements, and the expected new behavioral consumption patterns, requires more complex and detailed models with higher time resolution to provide accurate investment decisions and allow for closer analyses. In particular, these challenges require chronological hourly models with constraints linking all the years of the planning horizon, compromising in most cases the computational feasibility. This paper presents a new approach to synthetize a reduced representative time period for capacity expansion problems, for being used in detailed chronological hourly models, while keeping them computationally feasible. The representative period is synthetized by selecting, with a genetic algorithm, those real days that minimizes the distance between the duration curves of a set of relevant variables (such as demand, renewable generation, ramps, etc.) computed for the original and for the representative periods. Results show that investments decisions with the representative period are very similar to those obtained with the full planning horizon, while computational times are strongly reduced. © 2018 IEEE.

2018

The contribution of renewable energy to European decarbonization

Autores
Madaleno, M; Robaina, M; Villar, J;

Publicação
Focus on Renewable Energy Sources

Abstract
The European Union (EU) is adopting proactive strategies toward global decarbonization, proposing ambitious climate objectives to the international community, and adopting by itself ambitious energy and climate change objectives, as can be checked in its strategic packages for 2020, 2030 and 2050. As can be seen in these packages and in global climate and energy agreements, renewable generation is a key aspect to reach the global decarbonizing objectives. This chapter starts with a review of the very basic concepts of greenhouse gases emissions and its impact on climate change and summarizes the main objectives of the strategic EU energy packages and of the Paris agreement. It then focuses on methodologies for estimating the impact of renewable energies on greenhouse gases emissions reduction and reviews the reported EU related achievements. It also proposes a classification of EU countries in terms of Tapio decoupling states by analyzing and classifying the countries emissions intensities and its variation for a considered time period and analyzes the impact renewable energies had in that greenhouse gases emissions variations, in relation with other possibly relevant factors. The chapter ends with a summary of the expected evolution of renewable energies in the EU, and with the final conclusions.

Teses
supervisionadas

2017

Energy management in smart cities

Autor
Christian Francisco Calvillo Muñoz

Instituição
Outra