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- Sustainable energy systemsPublication . Caetano, Nídia; Vale, Zita; Jorgensen, Bo Norregaard; Felgueiras, CarlosThis Special Issue, therefore, aims to contribute to the “Sustainable Energy Systems” agenda through advanced scientific and multi-disciplinary knowledge, combined to improve energy security and performance. We therefore invite papers on innovative technical developments, reviews, case studies, analytical, as well as assessments, from different disciplines, which are relevant to “Sustainable Energy Systems”. These include smart grids, renewable energy systems, energy storage systems, life cycle analysis of energy systems, zero energy buildings, electric and hybrid vehicles, financial and economic analysis of energy systems, smart systems, energy management and big data, energy policy, novel energy sources, and renewable-based generation, among others.
- Short-term Price Forecast From Risk Management Point of ViewPublication . Azevedo, Filipe; Vale, ZitaThis paper provides a different approach for electricity price forecast from risk management point of view. Making use of neural networks, the methodology presented here has as main concern finding the maximum and the minimum System Marginal Price (SMP) for a specific programming period, with a certain confidence level. To train the neural network, probabilistic information from past years is used. This approach was developed with the objective of integrating a decisionsupport system that uses Particle Swarm Optimization (PSO) to find the optimal solution. Results from realistic data are presented and discussed in detail.
- Developing the world in 2021 with clean and safe energyPublication . Caetano, Nídia; Vale, Zita; Felgueiras, Carlos; Salvini, Coriolano; Felgueiras, Carlos(Special Issue Information). Dear colleagues, The world’s huge population growth and fast development are putting sustainability issues on the agenda. The COVID-19 pandemic has clearly demonstrated how energy is being used, as well as how dependent on energy we are to work, travel, educate ourselves, or in our daily activities. The ever-growing energy consumption is still mostly relying on fossil fuels, with dramatic impacts on the environment, causing soil, air, and water contamination, that in turn negatively impact on population health and development. To mitigate this situation and try to alleviate the stress on development posed by the uneven distribution of fuel resources, it is mandatory that nations shift away from relying on fossil fuels toward more environmentally sustainable energy sources. The world can only continue to develop sustainably if the effects of fossil fuel extraction, transportation, and combustion are stopped, which can only occur if energy is used more efficiently and produced from renewable sources, produced locally, and made available where needed, using adequate energy distribution networks and storage energy systems. Moreover, empowering energy end users, namely in the scope of citizen energy communities and using effective demand response schemes, is also relevant to ensure sustainable development.
- P.Porto research workshopsPublication . Dias, André; Castro, António Vieira de; Ramos, Carlos; Delerue-Matos, Cristina; Gamboa, Dorabela; Ferreira Sales, Maria Goreti; Baylina, Pilar; Silva, Regina; Pilão, Maria João; Fernandes, Rúben; Vale, ZitaP.PORTO Research Workshops are thematic meetings, to present and discuss R&D activities and outcomes – be it in the form of new knowledge, applied technology, industrial or intellectual property – providing a space for debate, networking and creation of synergies. This volume provides the contributions of the Research Workshop of April 2019, dedicated to the set of R&D projects led by P.PORTO researchers, in collaboration with companies and end-users, in the scope of the national projects call 02/SAICT/2016.
- European Policies Aiming the Penetration of Distributed Energy Resources in the Energy MarketPublication . Borges, Nuno; Spínola, João; Boldt, Diogo; Faria, Pedro; Vale, ZitaEnergy policies have been widely developed in the recent past as sequence of the increasing relevance of distributed energy resources potential in power systems, namely in achieving the reduction of carbon dioxide emissions gaining independence from fossil fuels. Thus, the main factions in the world, as North America and Europe, have been focusing on the implementation of new energy policies capable of managing several types of energy sources considering their decentralized characteristics. In this way, the present work provides an introduction of how the new energy policies, concerning distributed energy resources, are working towards the increase of these resources penetration in the energy mix. Some successful case studies are presented, namely from Europe, to assess the benefits of such policies to consumers, to producers and to energy market as a whole.
- Hybrid fuzzy Monte Carlo technique for reliability assessment in transmission power systemsPublication . Canizes, Bruno; Soares, João; Vale, Zita; Khodr, H. M.This paper proposes a new methodology to reduce the probability of occurring states that cause load curtailment, while minimizing the involved costs to achieve that reduction. The methodology is supported by a hybrid method based on Fuzzy Set and Monte Carlo Simulation to catch both randomness and fuzziness of component outage parameters of transmission power system. The novelty of this research work consists in proposing two fundamentals approaches: 1) a global steady approach which deals with building the model of a faulted transmission power system aiming at minimizing the unavailability corresponding to each faulted component in transmission power system. This, results in the minimal global cost investment for the faulted components in a system states sample of the transmission network; 2) a dynamic iterative approach that checks individually the investment’s effect on the transmission network. A case study using the Reliability Test System (RTS) 1996 IEEE 24 Buses is presented to illustrate in detail the application of the proposed methodology.
- Domestic Consumption Simulation and Management Using a Continuous Consumption Management and Optimization AlgorithmPublication . Gomes, Luis; Faria, Pedro; Fernandes, Filipe; Vale, Zita; Ramos, CarlosThe recent changes concerning the consumers’ active participation in the efficient management of load devices for one’s own interest and for the interest of the network operator, namely in the context of demand response, leads to the need for improved algorithms and tools. A continuous consumption optimization algorithm has been improved in order to better manage the shifted demand. It has been done in a simulation and user-interaction tool capable of being integrated in a multi-agent smart grid simulator already developed, and also capable of integrating several optimization algorithms to manage real and simulated loads. The case study of this paper enhances the advantages of the proposed algorithm and the benefits of using the developed simulation and user interaction tool.
- Large-scale optimization of households with photovoltaic-battery system and demand responsePublication . Lezama, Fernando; Faia, Ricardo; Abrishambaf, Omid; Faria, Pedro; Vale, ZitaThe adoption of distributed resources by households, e.g., storage units and renewables, open the possibility of self-consumption (on-site generation), sell energy to the grid as a small producer, or do both according to the context of operation. In this paper, a framework capturing the interactions between an aggregator and a large number of households is envisaged. We consider households equipped with distributed resources and simple smart technologies that look for the reduction of energy bills and can perform demand response actions. A mixed-integer linear programming formulation that provides optimal scheduling of household devices and minimal operation costs is developed. Results show that the model can be applied considering up to 10000 households. Moreover, households can reduce up to 20% of their energy bill on average using storage units and demand response. Besides, the aggregator can attain profits by offering the resulting flexibility to upper-level players of the energy chain, such as the distribution system operator.
- Simulated Annealing Approach Applied to the Energy Resource Management Considering Demand Response for Electric VehiclePublication . Sousa, Tiago; Vale, Zita; Morais, HugoThe aggregation and management of Distributed Energy Resources (DERs) by an Virtual Power Players (VPP) is an important task in a smart grid context. The Energy Resource Management (ERM) of theses DERs can become a hard and complex optimization problem. The large integration of several DERs, including Electric Vehicles (EVs), may lead to a scenario in which the VPP needs several hours to have a solution for the ERM problem. This is the reason why it is necessary to use metaheuristic methodologies to come up with a good solution with a reasonable amount of time. The presented paper proposes a Simulated Annealing (SA) approach to determine the ERM considering an intensive use of DERs, mainly EVs. In this paper, the possibility to apply Demand Response (DR) programs to the EVs is considered. Moreover, a trip reduce DR program is implemented. The SA methodology is tested on a 32-bus distribution network with 2000 EVs, and the SA results are compared with a deterministic technique and particle swarm optimization results.
- Appliance Shifting for Sequential Processes in Home Management SystemPublication . Spínola, João; Faria, Pedro; Vale, ZitaHome management systems are evolving to enable a more adaptive model to the many consumer’s behaviors, such as, periods of more consumption, habits of appliance use, amongst others. In another perspective, there are processes that require a start-after and sequential operation of multiple appliances, which currently is not a feature that exists in many of the home management systems. The present paper proposes a model to formulate sequential appliances load shifting, such that, the respective processes that the consumer has are maintained implemented correctly. The case study considers multiple appliances that exist in a home, with a sampling of 15 minutes, which is important in order to better observe the appliances consumption cycles.