Energy storage systems play an essential role in today’s production, transmission, and distribution networks. In this chapter, the different types of storage, their advantages and disadvantages will be presented. Then the main roles that energy storage systems will play in the context of smart grids will be described. Some information will be given on interactions between energy storage systems and renewables. The emphasis will be on the problems that these storage systems will have to deal with and the possible means that can be used for this purpose. Also the battery management system will be presented as a general concept. The different types of regulation that take place in smart electrical systems (also called smart grids) and the role of energy storage systems will also be discussed. In the end, we will also present one of the biggest weaknesses of storage systems, among others, the degradation of batteries with their use.

In DC microgrids, CLLC topology is commonly applied for battery integration. It provides galvanic separation, the ability to integrate a high-frequency transformer into the resonance circuit, and the ability to operate in a wide range of voltage. Moreover, it assures zero voltage switching conditions for all switches and zero current switching conditions for secondary side switches, which enables obtaining high efficiency. This paper presents a clear and effective approach to design a methodology for a CLLC DC/DC converter, especially a resonant tank. High-frequency transformer is fully integrated in a resonant tank. Its size is minimal and based on area product parameter $A_p$. An equivalent scheme for first harmonic approximation analysis is presented with inclusion of parasitic elements. Based on it, the analytical formulas are provided, which enable graphical determination of working characteristics. It was proved that the model increases the accuracy of the results. The conditions of ZVS and maximal magnetizing inductance are established, including parasitic capacitances of secondary side switches and transformer parasitic capacitances. Based on the proposed design methodology, as the proof of concept, a small-power prototype with a GaN transistor was built operating at 364 kHz. Converter losses were determined through analytical expressions and compared with the experimental and simulation results.

This paper presents a novel literature survey on leveraging electrolysis for grid frequency stabilization in power systems with high penetration of renewable energy sources (RESs), uniquely integrating global research findings with specific insights into the Polish energy context—a region facing acute grid challenges due to rapid RES growth and infrastructure limitations. The intermittent nature of wind and solar power exacerbates frequency fluctuations, necessitating dynamic demand-side management solutions like hydrogen production via electrolysis. By synthesizing over 30 studies, the survey reveals key results: electrolysis systems, particularly PEM and alkaline electrolyzers, can reduce frequency deviations by up to 50% through fast frequency response (FFR) and primary reserve provision, as demonstrated in simulations and real-world pilots (e.g., in France and the Netherlands); however, economic viability requires enhanced compensation schemes, with current models showing unprofitability without subsidies. Technological advancements, such as transistor-based rectifiers, improve efficiency under partial loads, while integration with RES farms mitigates overproduction issues, as evidenced by Polish cases where 44 GWh of solar energy was curtailed in March 2024. The survey contributes actionable insights for policymakers and engineers, including recommendations for deploying electrolyzers to enhance grid resilience, support hydrogen-based transportation, and facilitate Poland’s target of 50.1% RESs by 2030, thereby advancing the green energy transition amid rising instability risks like blackouts in RES-heavy systems.

The functioning of universities during the energy transition can be quite a challenge for them. On one hand, it is necessary to pursue a sensible policy of sustainable development based on the growth of their own renewable energy sources and electricity storage facilities. The aim of such measures is to increase self-consumption and ensure partial energy self-reliance while reducing carbon dioxide emissions into the atmosphere. On the other hand, the current geopolitical situation has indicated significant problems in the energy sectors of European Union countries. From the point of view of decision-makers at universities, the main concern should be ensuring the continuity of the operation of such a facility, including ensuring the energy security of the sites under management. Thus, it is necessary to merge these two areas and consider the development of an energy management strategy on university campuses oriented towards the development of distributed generation resources. For this purpose, one of the methods of multi-criteria decision aiding the ELECTRE I was used. As a result of the analyses, an energy management strategy was established for the main campus of the Warsaw University of Technology, which simultaneously ensures energy security and sustainability efforts.

This paper presents the concept of using electric vehicles (EVs) as a countermeasure to deal with the negative effects of power rationing when electricity demands become difficult to meet due to unfavorable electrical system operating conditions. At present, an energy storage is widely used to maintain the stability of electricity supply in facilities whose main source of energy is renewable energy sources (RESs). However, we must not forget that electric vehicles are also electricity storage facilities, but they are not always available due to their mobility. With properly developed strategies, they can be used in electricity management processes, for example, by reducing their consumption during charging using smart charging technology, or by providing electricity from their batteries using vehicle-to-building (V2B) technology. Thus, this article presents a research methodology that treats electric vehicles as a remedy for eliminating power constraints. It consists of five main steps, including two algorithms for deciding how to deploy EVs during power rationing periods. An efficiency factor for eliminating these constraints was also introduced. The results showed that the use of smart charging or V2B technology in EVs can reduce the number of potential hours in which certain power levels are exceeded by up to several tens of percent. This means that in the future, with the significant development of electromobility, such a way of dealing with power constraints could be an alternative to conventional solutions like diesel generators.

This study presents the analysis of voltage and frequency dynamics in a smart microgrid through the dynamic model developed on the experimental microgrid situated within the PrInCE laboratory at the Polytechnic University of Bari. The main aim of this work is to investigate the network responses to substantial perturbations, such as short-circuits, that systems can experience. Through a preliminary offline analysis, various operational conditions are considered to provide a comprehensive overview of voltage and frequency variations caused by these events across network nodes. The feasibility of an operational condition could be analyzed simply comparing these nodal trends with the settings of the corresponding protection relays, giving a wide practical comprehension of the system dynamical behavior. Applying this method to a large number of operating points, it is possible to explore and analyze in a practical manner the operating hyperspace of the entire system. From this knowledge it will be possible to study proactive control methodologies to uphold the dynamic integrity of the microgrid.