Optimization-Based Energy Management for Multi-energy Maritime Grids

This open access book discusses the energy management for the multi-energy maritime grid, which is the local energy network installed in harbors, ports, ships, ferries, or vessels. The grid consists of generation, storage, and critical loads. It operates either in grid-connected or in islanding modes, under the constraints of both power system and transportation system. With full electrification, the future maritime grids, such as all-electric ships and seaport microgrids, will become “maritime multi-energy system” with the involvement of multiple energy, i.e., electrical power, fossil fuel, and heating/cooling power. With various practical cases, this book provides a cross-disciplinary view of the green and sustainable shipping via the energy management of maritime grids. In this book, the concepts and definitions of the multi-energy maritime grids are given after a comprehensive literature survey, and then the global and regional energy efficiency policies for the maritime transportation are illustrated. After that, it presents energy management methods under different scenarios for all-electric ships and electrified ports. At last, the future research roadmap are overviewed. The book is intended for graduate students, researchers, and professionals who are interested in the energy management of maritime transportation

Grid-Connected Distributed Wind-Photovoltaic Energy Management: A Review

Energy management comprises of the planning, operation and control of both energy production and its demand. The wind energy availability is site-specific, time-dependent and nondispatchable. As the use of electricity is growing and conventional sources are depleting, the major renewable sources, like wind and photovoltaic (PV), have increased their share in the generation mix. The best possible resource utilization, having a track of load and renewable resource forecast, assures significant reduction of the net cost of the operation. Modular hybrid energy systems with some storage as back up near load center change the scenario of unidirectional power flow to bidirectional with the distributed generation. The performance of such systems can be enhanced by the accomplishment of advanced control schemes in a centralized system controller or distributed control. In grid-connected mode, these can support the grid to tackle power quality issues, which optimize the use of the renewable resource. The chapter aims to bring recent trends with changing requirements due to distributed generation (DG), summarizing the research works done in the last 10 years with some vision of future trends

Microgrids

Integration of renewable energy sources in the electrical power system is key for enabling the decarbonization of that system. The connection of renewable generation to the electrical system is being performed in a centralized form (large renewable power plants like wind or solar power plants connected at the transmission system) and in a decentralized manner (through the connection of dispersed generation connected at the distribution system). The connection of renewable generation at distribution levels, together with other generating sources as well as energy storage systems (the so-called DER, Distributed Energy Resources) close to consumption sites, is promoting the development of microgrids: DER installations that have the capability to operate grid connected and grid isolated. The uncertainty and variability of the renewable energy sources that integrate microgrids, as well as the need for coordination with other energy sources, pose challenges in the operation, protection, control, and planning of microgrids. The five selected papers published in this Special Issue propose solutions to address these challenges.Peer ReviewedObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No ContaminantObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.1 - Per a 2030, garantir l’accés universal a serveis d’energia assequibles, confiables i modernsObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.2 - Per a 2030, augmentar substancialment el percentatge d’energia renovable en el con­junt de fonts d’energiaPostprint (published version

Power Electronics Applications in Renewable Energy Systems

The renewable generation system is currently experiencing rapid growth in various power grids. The stability and dynamic response issues of power grids are receiving attention due to the increase in power electronics-based renewable energy. The main focus of this Special Issue is to provide solutions for power system planning and operation. Power electronics-based devices can offer new ancillary services to several industrial sectors. In order to fully include the capability of power conversion systems in the network integration of renewable generators, several studies should be carried out, including detailed studies of switching circuits, and comprehensive operating strategies for numerous devices, consisting of large-scale renewable generation clusters

Emerging Technologies for the Energy Systems of the Future

Energy systems are transiting from conventional energy systems to modernized and smart energy systems. This Special Issue covers new advances in the emerging technologies for modern energy systems from both technical and management perspectives. In modern energy systems, an integrated and systematic view of different energy systems, from local energy systems and islands to national and multi-national energy hubs, is important. From the customer perspective, a modern energy system is required to have more intelligent appliances and smart customer services. In addition, customers require the provision of more useful information and control options. Another challenge for the energy systems of the future is the increased penetration of renewable energy sources. Hence, new operation and planning tools are required for hosting renewable energy sources as much as possible

Flexibility services for distribution network operation

On the way towards a low carbon electricity system, flexibility has become one of the main sources for achieving it. Flexibility can be understood as the ability of a power system to cope with the variability and uncertainty of demand and supply. Both the generation-side and the demand-side can provide it. This research is focused on the role of the demand-side flexibility for providing a service to the distribution system operator, who manages the medium and low-voltage network. By activating this flexibility from the demand-side to the distribution network operator, the latter can avoid or mitigate congestions in the network and prevent grid reinforcement. This thesis starts with analyzing the current state of the art in the field of local electricity markets, setting the baseline for flexibility products in power systems. As a result of the previous analysis, the definition of flexibility is developed more specifically, considering the flexible assets to be controlled, the final client using this flexibility and the time horizon for this flexibility provision. Following the previous step, an aggregated flexibility forecast model is developed, considering a flexibility portfolio based on different flexible assets such as electric vehicles, water boilers, and electric space heaters. The signal is then modeled under a system-oriented approach for providing a service to the distribution network operator under the operation timeline on a day-ahead basis. The flexibility required by the distribution network operator is then calculated through an optimization problem, considering the flexibility activation costs and the network power flow constraints. Finally, since this scenario aims to lower the environmental impacts of the power system, its sustainability is assessed with the life-cycle assessment, considering the entire life cycle and evaluating it in terms of greenhouse gas emissions. This approach enhances the analysis of the potential role of flexibility in the power system, quantifying whether, in all cases, there is a reduction of emissions when shifting the consumption from peak hours to non-peak hours.En el camí cap a un sistema elèctric amb baixes emissions de carboni, la flexibilitat s'ha convertit en una de les principals fonts per aconseguir-ho. La flexibilitat es pot entendre com la capacitat d'un sistema de reaccionar davant la variabilitat i la incertesa provocades per la demanda i la generació. Tant la part de la generació com el costat de la demanda tenen actius per a poder proporcionar-ho. La recerca presentada en aquest manuscrit està enfocada en el paper de la flexibilitat oferta per la demanda, per a proporcionar un servei a l'operador del sistema de distribució, que gestiona les xarxes de mitja i baixa tensió. Gràcies a l'activació de la flexibilitat de la demanda, l'operador de les xarxes de distribució pot evitar o mitigar la congestió de la xarxa i evitar-ne les inversions per a reforçar-la, així com el seu impacte ambiental. Aquesta tesi comença amb l'anàlisi de l'estat de l'art en el camp dels mercats d'electricitat locals, establint-ne la línia base per a la definició dels productes de flexibilitat en els sistemes elèctrics. Com a resultat de l'estudi anterior, la definició de flexibilitat es desenvolupa més específicament, considerant els actius flexibles que han de controlar-se, el client final que utilitza aquesta flexibilitat i l'horitzó temporal per a aquesta disposició de flexibilitat. A continuació es desenvolupa un model de predicció de flexibilitat agregada, considerant una cartera de flexibilitat basada en diferents actius flexibles, com ara vehicles elèctrics, calderes d'aigua i escalfadors elèctrics, gestionats per la figura de l’agregador. El senyal es modela sota un enfocament orientat al sistema per proporcionar un servei a l'operador de la xarxa de distribució, per un horitzó temporal corresponent a l'operació de la xarxa de mitja i baixa tensió. El resultat és un model de la flexibilitat que pot oferir l’agregador. Una vegada desenvolupat el model de flexibilitat pel costat de l’agregador, la tesi s’enfoca al càlcul de la flexibilitat requerida per l’operador de la xarxa de distribució. Això es desenvolupa mitjançant un problema d'optimització, tenint en compte els costos d'activació de la flexibilitat, la localització dels punts on s’injectarà la flexibilitat i les restriccions de flux de potència de la xarxa de distribució. Finalment, atès que aquest escenari pretén reduir l'impacte mediambiental del sistema elèctric, la seva sostenibilitat s'avalua considerant tot el cicle de vida de les tecnologies que hi participen, i avaluant-la en termes d'emissions de gasos d'efecte d'hivernacle. L'ús d'aquest enfocament millora l'anàlisi del potencial paper de la flexibilitat en el sistema elèctric, quantificant si, en tots els casos, hi ha una reducció de les emissions traslladant el consum de les hores punta a hores vall.Postprint (published version