An important aspect of the off-grid utilization of hybrid generation systems is the integration of energy storage facilities into their structures, which allows for improved power supply reliability. However, this results in a significant increase in the cost of such systems. Therefore, it is justified to use optimization resulting in the minimization of the selected economic indicator taking into account the most important technical constraints. For this reason, this work proposes an algorithm to optimize the structure of a hybrid off-grid power distribution system (with electrochemical energy storage), designed to supply a load with known daily energy demand. The authors recommend genetic algorithm utilization as well as a modified criterion for evaluating the quality of solutions based on the Levelized Cost of Energy (LCOE) index. Several technical and economic analyses were presented, including unit costs, power distribution of the wind and solar sections, nominal battery capacity, SSSI index (System Self-Sufficiency Index), etc. The model of the system includes durability of the elements which have a significant impact on the periodic battery replacement. The tests were carried out for two types of loads and two types of electrochemical batteries (NMC—Lithium Nickel Manganese Cobalt Oxide; and PbO₂—Lead-Acid Battery), taking into account the forecast of an increased lifetime of NMC type batteries and decreasing their price within five years. The proposed synthesis method of photovoltaic-wind (PV-wind) hybrid off-line systems leads to limiting the energy capacity of electrochemical storages. Based on the analyses, the authors proposed recommended methods to improve (reduce) the value of the criterion index (LCOE) for PV-wind off-grid systems while maintaining the assumed level of power supply reliability.

The development and advantages of renewable energy technologies mean that their areas of application are constantly expanding. The development of roads, transport systems, and electromobility also increases the demand for electricity. Roads occupy a certain area that could be used to install wind turbines or photovoltaic systems that could be used to power, among others, electric vehicle charging stations and road technical infrastructure facilities (travel service areas, tunnel lighting, road signs). There are many examples around the world where such solutions have been used. This critical review of existing solutions and the possibilities of their application in new places may contribute to further development and research in this area. Particular attention was paid to the possibility of using renewable energy systems in Poland, which can be successfully transferred to other countries with a similar climate.

This article describes the problems associated with distributed electrical power generation and the most frequent interruptions occurring in power grids. The most common methods of improving the quality of the power supply were analyzed and the possibilities offered by energy storages in this respect were considered. The operating parameters of an exemplary PV system connected to the power grid were analyzed. For this purpose, the model implemented in the Matlab/Simulink environment was used. Based on the conducted analysis and a review of the literature, conclusions were drawn and solutions were presented which could improve the quality and the reliability of power supply. The simulations conducted focused on the co-operation of individual photovoltaic, micro-installations, with rated powers of 12.2, 19.825, and 39.65 Kw in the power grid, which also corresponds to the co-operation of several, smaller micro-installations with low density.

This paper presents a proposal for a new type of regulator for switched reluctance motor (SRM) drives. The proposed regulator enables a significant extension of the rotational speed range and drive output power. This regulator is characterized by a complex structure, including two regulation modules: voltage and phase supply switch-on angle. The voltage module includes a proportional integral derivative (PID) voltage regulator. During its operation, the value of the phase supply switch-on angle and the width of the phase supply range are determined as a result of interpolation of the data previously determined in the simulation program. The other module contains the PID controller of the phase supply switch-on angle. The values of the angles included in the tables have been determined so as to ensure that the drive works with the greatest possible efficiency. The control method is determined based on the current operating parameters of the drive, i.e., torque and speed. The operation of the regulator was simulated in the MATLAB Simulink program. The regulator presented here was implemented in a field programmable gate array (FPGA). Tests of the regulator’s operation in the prototype system were carried out in the field of control of commutation angles.

The paper presents an original method underlying an efficient tool for assessing the condition of photovoltaic (PV) modules, in particular, those made of amorphous cells. Significantly random changes in operational parameters characterize amorphous cell operation and cause them to be challenging to test, especially in working conditions. To develop the method, the authors modified the residual method with incorporated histograms. The proposed method has been verified through experiments that show the usefulness of the proposed approach. It significantly minimizes the risk of false diagnostic information in assessing the condition of photovoltaic modules. Based on the proposed methods, the inference results confirm the effectiveness of the concept for evaluating the degree of failure of the photovoltaic module described in the paper.

The growing global demand for food and energy requires land-use strategies that support agricultural production and renewable energy generation. Agrivoltaic (APV) systems allow farmland to be used for both agriculture and solar power generation. The aim of this study is to critically synthesize the interactions between the key dimensions of APV implementation—technical, agronomic, legal, and economic—in order to create a multidimensional framework for designing an APV optimization model. The analysis covers APV system topologies, appropriate types of photovoltaic modules, installation geometry, shading conditions, and micro-environmental impacts. The paper categorizes quantitative indicators and critical thresholds that define trade-offs between energy production and crop yields, including a discussion of shade-tolerant crops (such as lettuce, clover, grapevines, and hops) that are most compatible with APV. Quantitative aspects were integrated in detail through a review of mathematical approaches used to predict yields (including exponential-linear, logistic, Gompertz, and GENECROP models). These models are key to quantitatively assessing the impact of photovoltaic modules on the light balance, thus enabling the simultaneous estimation of energy efficiency and yields. Technical solutions that enhance synthesis, such as dynamic tracking systems, which can increase energy production by up to 25–30% while optimizing light availability for crops, are also discussed. Additionally, the study examines regional legal frameworks and the economic factors influencing APV deployment, highlighting key challenges such as land use classification, grid connection limitations, investment costs and the absence of harmonised APV policies in many countries. It has been shown that APV systems can increase water retention, mitigate wind erosion, strengthen crop resilience to extreme weather conditions, and reduce the levelized cost of electricity (LCOE) compared to small rooftop PV systems. A key contribution of the work is the creation of a coherent analytical design framework that integrates technical, agronomic, legal and economic requirements as the most important input parameters for the APV system optimization model. This indicates that wider implementation of APV requires clear regulatory definitions, standardized design criteria, and dedicated support mechanisms.