Simulação interactiva do mercado de energia eléctrica

A área de comercialização de energia eléctrica conheceu uma profunda mudança após a liberalização do sector eléctrico, que levou à criação de algumas entidades, as quais gerem os mercados de electricidade europeus. Relativamente a Portugal e Espanha, durante esse processo de liberalização, deu-se também um acordo que os levou à criação de um mercado conjunto, um mercado Ibérico (MIBEL). Dentro deste mercado estão contemplados dois operadores, sendo que um deles representa o pólo Português (OMIP) e o outro representa o pólo Espanhol (OMEL). O OMIP contempla os mercados a prazo, ou futuros, normalmente apresenta contratos de energia comercializada com durabilidade de semanas, meses, trimestres, semestres ou mesmo anos. Diariamente estes contratos poderão vencer no OMEL, que engloba os mercados, diário e intradiário. Este, ao contrário do OMIP negoceia para o dia seguinte (mercado diário) ou para uma determinada altura do dia (mercado intra diário). O mercado diário será o exemplo usado para a criação do simulador interactivo do mercado de energia eléctrica. Este será composto por diversos utilizadores (jogadores), que através de uma plataforma HTML irão investir em centrais de energia eléctrica, negociar licitações e analisar o funcionamento e resultados deste mercado. Este jogo subdividir-se-á então em 3 fases: 1. Fase de investimento; 2. Fase de venda (licitações); 3. Fase de mercado. Na fase do investimento, o jogador terá a possibilidade de adquirir unidades de geração de energia eléctrica de seis tipos de tecnologia: 1. Central a Carvão; 2. Central de Ciclo Combinado; 3. Central Hídrica; 4. Central Eólica; 5. Central Solar; 6. Central Nuclear. Com o decorrer das jogadas o jogador poderá aumentar a sua capacidade de investimento, com a venda de energia, sendo o vencedor aquele que mais saldo tiver no fim do número de jogadas previamente definidos, ou aquele que mais depressa atingir o saldo definido como limite pelo administrador do jogo. A nível pedagógico este simulador é muito interessante pois para além de o utilizador ficar a conhecer as tecnologias em causa e as vantagens e desvantagens das centrais de energia renovável e das centrais a combustíveis fósseis, este ganha igualmente uma sensibilidade para questões de nível ambiental, tais como o aumento dos gases de estufa e o degelo resultante do aquecimento global provocado por esses gases. Para além do conhecimento adquirido na parte de energia eléctrica este jogo dará a conhecer ao utilizador o funcionamento do mercado da energia eléctrica, bem como as tácticas que este poderá usar a seu favor neste tipo de mercado.

A simulation study on the abatement of CO2 emissions by de-absorption with monoethanolamine

Because of the adverse effect of CO2 from fossil fuel combustion on the earth's ecosystems, the most cost-effective method for CO2 capture is an important area of research. The predominant process for CO2 capture currently employed by industry is chemical absorption in amine solutions. A dynamic model for the de-absorption process was developed with monoethanolamine (MEA) solution. Henry's law was used for modelling the vapour phase equilibrium of the CO2, and fugacity ratios calculated by the Peng-Robinson equation of state (EOS) were used for H2O, MEA, N-2 and O-2. Chemical reactions between CO2 and MEA were included in the model along with the enhancement factor for chemical absorption. Liquid and vapour energy balances were developed to calculate the liquid and vapour temperature, respectively.

OC/EC ratio observations in Europe: Re-thinking the approach for apportionment between primary and secondary organic carbon

This study explores a large set of OC and EC measurements in PM(10) and PM(2.5) aerosol samples, undertaken with a long term constant analytical methodology, to evaluate the capability of the OC/EC minimum ratio to represent the ratio between the OC and EC aerosol components resulting from fossil fuel combustion (OC(ff)/EC(ff)). The data set covers a wide geographical area in Europe, but with a particular focus upon Portugal, Spain and the United Kingdom, and includes a great variety of sites: urban (background, kerbside and tunnel), industrial, rural and remote. The highest minimum ratios were found in samples from remote and rural sites. Urban background sites have shown spatially and temporally consistent minimum ratios, of around 1.0 for PM(10) and 0.7 for PM(2.5).The consistency of results has suggested that the method could be used as a tool to derive the ratio between OC and EC from fossil fuel combustion and consequently to differentiate OC from primary and secondary sources. To explore this capability, OC and EC measurements were performed in a busy roadway tunnel in central Lisbon. The OC/EC ratio, which reflected the composition of vehicle combustion emissions, was in the range of 03-0.4. Ratios of OC/EC in roadside increment air (roadside minus urban background) in Birmingham, UK also lie within the range 03-0.4. Additional measurements were performed under heavy traffic conditions at two double kerbside sites located in the centre of Lisbon and Madrid. The OC/EC minimum ratios observed at both sites were found to be between those of the tunnel and those of urban background air, suggesting that minimum values commonly obtained for this parameter in open urban atmospheres over-predict the direct emissions of OC(ff) from road transport. Possible reasons for this discrepancy are explored. (C) 2011 Elsevier Ltd. All rights reserved.

Conversão de veículos diesel para tração elétrica

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

The electric vehicles as a mean to reduce Co2 emissions and energy costs in isolated regions: the São Miguel (Azores) case study

Most of small islands around the world today, are dependent on imported fossil fuels for the majority of their energy needs especially for transport activities and electricity production. The use of locally renewable energy resources and the implementation of energy efficiency measures could make a significant contribution to their economic development by reducing fossil fuel imports. An electrification of vehicles has been suggested as a way to both reduce pollutant emissions and increase security of supply of the transportation sector by reducing the dependence on oil products imports and facilitate the accommodation of renewable electricity generation, such as wind and, in the case of volcanic islands like Sao Miguel (Azores) of the geothermal energy whose penetration has been limited by the valley electricity consumption level. In this research, three scenarios of EV penetration were studied and it was verified that, for a 15% LD fleet replacement by EVs with 90% of all energy needs occurring during the night, the accommodation of 10 MW of new geothermal capacity becomes viable. Under this scenario, reductions of 8% in electricity costs, 14% in energy, 23% in fossil fuels use and CO2 emissions for the transportation and electricity production sectors could be expected.

Study on the glycerolysis reaction of high free fatty acid oils for use as biodiesel feedstock

Biodiesel is the main alternative to fossil diesel and it may be produced from different feedstocks such as semi-refined vegetable oils, waste frying oils or animal fats. However, these feedstocks usually contain significant amounts of free fatty acids (FFA) that make them inadequate for the direct base catalyzed transesterification reaction (where the FFA content should be lower than 4%). The present work describes a possible method for the pre-treatment of oils with a high content of FFA (20 to 50%) by esterification with glycerol. In order to reduce the FFA content, the reaction between these FFA and an esterification agent is carried out before the transesterification reaction. The reaction kinetics was studied in terms of its main factors such astemperature, % of glycerin excess, % of catalyst used, stirring velocity and type of catalyst used. The results showed that glycerolysis is a promising pretreatment to acidic oils or fats (> 20%) as they led to the production of an intermediary material with a low content of FFA that can be used directly in thetransesterification reaction for the production of biodiesel. (C) 2011 Elsevier B.V. All rights reserved.

Central de produção de energia eléctrica a partir de energia solar térmica

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Aumento de energia renovável na Ilha da Madeira: proposta integrada para o setor dos transportes e da geração de energia elétrica

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Energia

Impacto económico, energético e ambiental da produção renovável na Ilha Terceira

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Energia

Electric vehicles as a mean to reduce, energy, emissions and electricity costs

Electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs), which obtain their fuel from the grid by charging a battery, are set to be introduced into the mass market and expected to contribute to oil consumption reduction. This research is concerned with studying the potential impacts on the electric utilities of large-scale adoption of plug-in electric vehicles from the perspective of electricity demand, fossil fuels use, CO2 emissions and energy costs. Simulations were applied to the Portuguese case study in order to analyze what would be the optimal recharge profile and EV penetration in an energy-oriented, an emissions-oriented and a cost-oriented objective. The objectives considered were: The leveling of load profiles, minimization of daily emissions and minimization of daily wholesale costs. Almost all solutions point to an off-peak recharge and a 50% reduction in daily wholesale costs can be verified from a peak recharge scenario to an off-peak recharge for a 2 million EVs in 2020. A 15% improvement in the daily total wholesale costs can be verified in the costs minimization objective when compared with the off-peak scenario result.

The impact of driving styles on fuel consumption: a data-warehouse-and-data-mining-based discovery process

This paper discusses the results of applied research on the eco-driving domain based on a huge data set produced from a fleet of Lisbon's public transportation buses for a three-year period. This data set is based on events automatically extracted from the control area network bus and enriched with GPS coordinates, weather conditions, and road information. We apply online analytical processing (OLAP) and knowledge discovery (KD) techniques to deal with the high volume of this data set and to determine the major factors that influence the average fuel consumption, and then classify the drivers involved according to their driving efficiency. Consequently, we identify the most appropriate driving practices and styles. Our findings show that introducing simple practices, such as optimal clutch, engine rotation, and engine running in idle, can reduce fuel consumption on average from 3 to 5l/100 km, meaning a saving of 30 l per bus on one day. These findings have been strongly considered in the drivers' training sessions.

Optimal brake specific fuel consumption trajectory for stand-alone variable speed Diesel Gen-Set

Energy efficiency plays an important role to the CO2 emissions reduction, combating climate change and improving the competitiveness of the economy. The problem presented here is related to the use of stand-alone diesel gen-sets and its high specific fuel consumptions when operates at low loads. The variable speed gen-set concept is explained as an energy-saving solution to improve this system efficiency. This paper details how an optimum fuel consumption trajectory based on experimentally Diesel engine power map is obtained.

Reactores a tório: o futuro da energia nuclear de fissão

Dissertação para a obtenção do grau de mestre em Engenharia Electrotécnica Ramo de Energia

Conversão de um veículo de combustão em veículo elétrico

Trabalho final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica Ramo Manutenção e Produção