This paper introduces a novel design of an electric vehicle (EV) fast charging station, consisting of a battery energy storage system (BESS) with reconfigurable cell topology. The BESS comprises two battery strings that decouple the power flow between EV and grid, to enable charging powers above the grid capacity. The reconfigurable design is achieved by equipping the battery cells with semiconductor switches and serves two main purposes. First, it aims at solving cell unbalance issues to increase safety, reliability, and lifetime of the battery. Second, it enables the BESS to actively control the EV charging process by changing its cell configuration in a real-time fashion, making a DC-DC converter redundant. The paper presents a modelling approach that captures the reconfigurable design including the controlling algorithm used for cell engagement. The simulation results show that the BESS is able to fulfil the EV request with sufficient accuracy for most of the fast charging process. However, the switching of cells leads to variations in the charging current that can potentially exceed the tolerance band defined in IEC61851-23. Therefore, complementary measures are suggested to achieve a suitable current control during all phases of the charging process. The estimated BESS efficiency during the EV fast charging process is $93.3$%. The losses caused by the reconfigurable design amount to $1.2$% of the provided energy. It is demonstrated that the proposed design has a competitive efficiency compared to a battery buffered fast charging station with DC-DC converter.

Biogas plants may support the transformation towards renewable-based and integrated energy systems by providing dispatchable co-generation as well as opportunities for biogas upgrading or power-to-X conversion. In this paper, a simulation model that comprises the main dynamics of the internal processes of a biogas plant is developed. Based on first-order kinetics of the anaerobic digestion process, the biogas production of an input feeding schedule of raw material can be estimated. The output of the plant in terms of electrical and thermal energy is validated against empirical data from a 3-MW biogas plant on the Danish island of Bornholm. The results show that the model provides an accurate representation of the processes within a biogas plant. The paper further provides insights on the functioning of the biogas plant on Bornholm as well as discusses upgrading potentials of biogas to biomethane at the plant from an energy perspective.

В работе рассмотрены особенности развития возобновляемой энергетики в Арктической зоне Российской Федерации (АЗРФ).Приведены результаты оценок ресурсов, а также валового и технического потенциала энергии солнца, ветра и отходов лесной и деревообрабатывающей промышленности на территории АЗРФ. Детальные карты распределения ресурсов солнца и ветра позволяют выявить перспективные для внедрения возобновляемой энергетики регионы.Проанализирована структура и диапазоны потребляемой мощности потенциальных потребителей от автономных источников энергии в регионе. Подготовлена база данных действующих и проектируемых объектов на основе ВИЭ в АЗРФ, позволяющая оценить объем введенных мощностей с детализацией по типу используемых ресурсов и степень замещения топливной энергетики на возобновляемую.Построенные по результатам исследований карты введены в состав ГИС ВИЭ РФ и в совокупности представляют собой удобный инструмент для проведения предварительных оценок возможности и необходимости проектирования установок на основе ВИЭ.Приведены требования, предъявляемые к конструктивному исполнению фотоэлектрических установок для надежной работы в регионе. Изложены особенности эксплуатации различных видов накопителей электрической энергии, выявленные в результате экспериментальных исследований, которые должны быть учтены при проектировании установок на основе ВИЭ в условиях Арктики.

Smart integration of different energy sectors on islands could serve as a key to achieve their energy independence and carbon neutrality goals and facilitate the large-scale penetration of renewables. Demonstration projects play a vital role in testing innovative sector-coupling solutions and exploring their synergies in the real-life environment. They also help to build the required market confidence and awareness, verify and enhance the societal acceptance, and identify and prevent unnecessary risks and complications. The aim of this paper is to provide the reader with a comprehensive review of 19 research projects, which concern the demonstration of sector-coupling technologies on European islands. The projects are funded by the European Commission and started between 2010 and 2020. The review focuses on the exploration of various technical aspects of 28 demo pilots. In addition, it addresses objectives, contributions, and novelty of the demonstrations and analyses barriers, challenges, risks, and success factors reported by project stakeholders. The paper intends to support the decision-makers on the identification, adoption, and replication of successful technologies. Moreover, it provides researchers and other interested parties with lessons learnt to ensure the successful project execution and technology demonstration in future projects.