Integração de Sistemas de Energia - ISE
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- Acciones para el desarrollo de las energias renovablesPublication . Pinto, Filomena; Rodrigues, Carlos; Viana, Susana; Marques, Isabel PaulaO parque experimental de energias renováveis da Herdade da Mitra, em Évora integra um sistema de microgeração de abastecimento eléctrico em Portugal, através da integração de diferentes unidades utilizadoras de fontes renováveis: fotovoltaica, eólica, gasificação e digestão anaeróbica. Neste capítulo serão abordadas estas diversas tenologias referindo os princípais conceitos teóricos que suportam cada uma delas, antes de descrever cada uma das instalações projectadas no âmbito do projecto PETER. Na instalação de gasificação a biomassa florestal existenet na Zona do Parque é utilizada para a produção de um gàs. O gasificador de leito fluidizado tem uma capacidade térmica de 350 kW e um consumo de cerca de 80 kg/h de biomassa. Após as operações de limpeza do gás obtido para melhorar as respecivas características, este é convertido em enrgia através de um grupo gerador, que é constituído por um motor de combustão interna "dual-fuel" acoplado a um gerador eléctrico de 70kWe. A instalação de digestão anaeróbica do parque destna-se à conversão da matéria orgânica da biomassa húmida em biogás, tendo como fonte os efluentes agro-pecuários e industriais que são produzidos na herdade e/ou na região Alentejana. A unidade de digestão anaeróbia é um protótipo de demonstração que corresponde a um digestor híbrido de fluxo ascendente com 15 m3 de capacidade. As unidades de digestão anaeróbica e de gasificação partilham os sitemas de colecta e de tratamento do gás produzido e da sua conversão em energia eléctrica e térmica. A energia eléctrica é, por seu turno injectada no circuito de microgerção e a energia térmica é valorizada através da manutenção da temperatura de digestão da unidade anaeróbica. Assim, a gestão integrada de diversas tecnologias, vocacionadas para a remoção da carga poluente contida nos efluentes agro-pecuários e para a reutilzação dos fluxos obtidos, apresenta-se como um sistema de valorização energética e agrícola de recursos endógenos da região onde são produzidos. O sistema fotovoltaico tem uma potência de pico de 10 kW, permitindo a demonstração de diferentes tecnologias de conversão. O sistema fotovoltaico encontra-se ligado à rede eléctrica da herdade da Mitra.
- Agent-based model of citizen energy communities used to negotiate bilateral contracts in electricity marketsPublication . Algarvio, HugoABSTRACT: The worldwide targets for carbon-neutral societies increased the penetration of distributed generation and storage. Smart cities now play a key role in achieving these targets by considering the alliances of their demand and supply assets as local citizen energy communities. These communities need to have enough weight to trade electricity in wholesale markets. Trading of electricity can be done in spot markets or by bilateral contracts involving customers and suppliers. This paper is devoted to bilateral contracting, which is modeled as a negotiation process involving an iterative exchange of offers and counter-offers. This article focuses on local citizen energy communities. Specifically, it presents team and single-agent negotiation models, where each member has its sets of strategies and tactics and also its decision model. Community agents are equipped with intra-team strategies and decision protocols. To evaluate the benefits of CECs, models of both coalition formation and management have been adapted. This paper also describes a case study on forward bilateral contracts, involving a retailer agent and three different types of citizen energy communities. The results demonstrate the benefits of CECs during the negotiation of private bilateral contracts of electricity. Furthermore, they also demonstrate that in the case of using a representative strategy, the selection of the mediator may be critical for achieving a good deal.
- Agent-based retail competition and portfolio optimization in liberalized electricity markets: A study involving real-world consumersPublication . Algarvio, Hugo; Lopes, FernandoABSTRACT: The liberalization of energy markets brought full competition to the electric power industry. In the wholesale sector, producers and retailers submit bids to day-ahead markets, where prices are uncertain, or alternatively, they sign bilateral contracts to hedge against pool price volatility. In the retail sector, retailers compete to sign bilateral contracts with end-use customers. Typically, such contracts are subject to a high-risk premium—that is, retailers request a high premium to consumers to cover their potential risk of trading energy in wholesale markets. Accordingly, consumers pay a price for energy typically higher than the wholesale market price. This article addresses the optimization of the portfolios of retailers, which are composed of end-use customers. To this end, it makes use of a risk-return optimization model based on the Markowitz theory. The article presents a simulation-based study conducted with the help of the MATREM system, involving 6 retailer agents, with different risk preferences, and 312 real-world consumers. The retailers select a pricing strategy and compute a tariff to offer to target consumers, optimize their portfolio of consumers using data from the Iberian market, sign bilateral contracts with consumers, and compute their target return during contract duration. The results support the conclusion that retail markets are more favourable to risk-seeking retailers, since substantial variations in return lead to small variations in risk. However, for a given target return, risk-averse retailers consider lower risk portfolios, meaning that they may obtain higher returns in both favourable and unfavourable situations.
- Agent-based simulation of retail electricity markets: Bilateral contracting with demand responsePublication . Lopes, Fernando; Algarvio, Hugo; Ilco, Cristina; Sousa, JorgeThe novelty of the evolving electric power industry implies that researchers lack insight into numerous open problems. There is a growing need for advanced modeling approaches that simulate the behavior of electricity markets over time. Accordingly, this article looks at using software agents to help manage the complexity of electricity markets, particularly retail markets, towards ensuring long-term capacity sustainability. The article focuses on bilateral trading and describes some important features of an agent-based system for bilateral contracting with demand response. Special attention is devoted to two strategies for promoting demand response: a “volume management” strategy, for Buyer agents, and a “price management” strategy, for Seller agents.
- Agent-based simulation of retail electricity markets: Bilateral trading playersPublication . Lopes, Fernando; Algarvio, Hugo; Coelho, HelderThe electricity industry throughout the world, which has long been dominated by vertically integrated utilities, has experienced major changes. Deregulation, unbundling, wholesale and retail wheeling, and real-time pricing were abstract concepts a few years ago. Today market forces drive the price of electricity and reduce the net cost through increased competition. As power markets continue to evolve, there is a growing need for advanced modeling approaches. Accordingly, this article looks at using software agents to help manage the complexity of electricity markets, particularly retail markets. The article focuses on bilateral trading and describes some important features of an agent-based system for bilateral contracting. Special attention is devoted to the characteristics and negotiation behaviour of Buyer and Seller agents.
- Análise técnica do impacto da mudança de hora legal na penetração da geração de energia renovável não controlável no consumo em Portugal continentalPublication . Silva, João M. Henriques da; Couto, António; Duque, JoaquimRESUMO: A análise técnica do impacto da alteração do regime de hora legal no consumo de energia em Portugal Continental, suprido pela geração de energia renovável não despachável (VRE) e, por isso, não regulável em função do consumo, procurou averiguar a presença de eventuais benefícios que poderiam decorrer dessa alteração. Contudo, neste domínio de análise, não foi detetada a existência de qualquer vantagem significativa decorrente da alteração do regime de hora legal vigente para quaisquer outros regimes de hora legal analisados.
- Analysis of processing systems involving reaction and distillation : the synthesis of ethyl acetatePublication . Filipe, Rui M.; Castro, Pedro; Matos, Henrique A.; Novais, Augusto Q.The integration of reaction and separation into a single process unit, i. e., reactive destillation, may offer several advantages over conventional systems that use a reactor followed by a distillation column. In this paper we explore the operational characteristics of reactive distillation and highlight some of this potential benefits, using the production of ethyl acetate as an illustrative example. With this aim, the two types of system are compared employing different reactor types and a number of performance indicators, such as yield, conversion, purity, specific energy consumption and residence time. A sensitivity analysis is carried out on some variables and parameters, in order to explore and define the distillation columns operating conditions. As expected, results point to a clear advantage of reactive distillation allowing for the azeotrope to be surpassed and for the overcoming of chemical equilibrium, favouring an increase in conversion and product purity, along with reduced operating costs.
- Assessing micro-generation’s and non-linear loads’ impact in the power quality of low voltage distribution networksPublication . Bonifácio, Paulo; Viana, Susana; Rodrigues, L.; Estanqueiro, AnaDistribution networks face an increasing penetration of solar PV (photovoltaic) and small WTG (wind turbine generator) as well as other forms of micro-generation. To this scenario, one must add the dissemination of non-linear loads such as EV (electric vehicles). There is something in common between those loads and sources: the extensive use of power electronic converters with commutated switches. These devices may be a source of medium-to-high frequency harmonic distortion and their impact on the local distribution grid must be carefully assessed in order to evaluate their negative impacts on the network, on the existing conventional loads and also on other active devices. In this paper, methodologies to characterize effects such as: harmonics, network unbalances, damaging power line resonance conditions, and over/under voltages are described and applied to a real local grid configuration.
- Assessing the industrial effects of the deployment of renewable energy technologies: when product identity mattersPublication . Barbosa, Juliana; Fontes, Margarida; Bento, NunoABSTRACT: Investment in renewable energy technologies (RET) produces impacts on economic activity and job creation that are fundamental to increase the social acceptability of those technologies. Previous research that attempted to measure the impacts of RET has mainly focused on its effects in energy production and climate mitigation, but surprisingly little is known about the potential of RET to transform the industrial structure of an economy. This paper proposes a methodology to understand and measure the industrial transformative impact of RET. The paper draws on contributions from the sustainability transitions literature and from the economic literature that analyses the socioeconomic impacts of RET, and combine them with the economic complexity literature in order to address two main gaps: the lack of measurement of industrial transformative effects in the first; and the assumption of product homogeneity in the second that precludes an assessment of more structural impacts. We develop a conceptual approach to the way technology deployment can lead to changes in the industrial structure, centered on the notion of product heterogeneity intrinsic to the economic complexity literature. We advance three main dimensions along which to measure the changes in the industrial structure driven by modifications in the basket of products being produced due to the development of the technology value chain: sophistication, connectivity, and competitiveness. We also propose a more precise delineation of the industrial value chain of the technology, by considering the actual weights of each sector to the technology and the technology to each sector. This approach is applied to the case of wind energy in Portugal (a successful fast follower), compared with three other main wind energy producers (Spain, Denmark, Germany). The results show a strong relationship between the deployment of the technology and the sophistication and the competitiveness of the Æcloud of productsÆ composing the industrial value chain. The paper proposes a novel analytical framework and measurement tools that can support a timely assessment of the effects of sustainable energy technologies in the industrial structure, with relevance for policy.
- Aumentar os impactos transformadores das inovações sustentáveis: evidência das tecnologias de energia renovável marinhaPublication . Fontes, Margarida; Bento, Nuno; Sousa, Cristina; Barbosa, Juliana; Santos, Hélder; Sá Marques, TeresaRESUMO: Tanto as empresas como os decisores políticos procuram aproveitar as oportunidades para criar atividade e emprego na transição para uma economia de baixo carbono. Os co-benefícios da transição sustentável são cada vez mais investigados pelos ganhos potenciais que proporcionam aos países e pela sua contribuição para a aceitação social da transição sustentável. Em particular, o desenvolvimento e a experimentação de novas tecnologias energéticas deverão criar efeitos de aprendizagem localizados que melhorem os custos e o desempenho dessas tecnologias, permitindo, ao mesmo tempo, que os atores criem capacidade e diversifi quem para novas atividades necessárias à cadeia de valor emergente. Este Policy brief esclarece como a política tecnológica e a estratégia industrial se podem complementar, de modo a criar recursos coletivos para acelerar o progresso de tecnologias emergentes, obtendo vantagens competitivas, e transformando os sectores existentes.