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The increasing global penetration of photovoltaic (PV) technology creates not only enormous opportunities for clean energy production but also poses challenges that put energy systems to the test. Although there are many ways of dealing with the rising share of PV energy, most of these solutions require substantial funding, time, and effort to implement, which highlights the importance of solving some of the issues at their source, i.e., through the direct use of the electricity generated at PV power plants, many of which are owned and operated by households. In recent decades, PV technology has experienced an unprecedented growth in Europe due to a range of reasons, including the nations' policies and supporting schemes. The goal of the present research was to determine the annual consumption of electricity per capita in the households of certain European countries and how much of this can be covered by the direct use of PV energy in the case of an on-grid PV system and to show what the annual potential of the direct use of PV energy is compared to the annual energy production of the PV systems. The significance and novelty of this research is justified by the lack of comparative scientific studies related to the annual potential of the direct household use of PV energy, which could alleviate some of the problems facing electricity networks with high shares of PV energy. The novel practical benefit of the study was determining, for the examined European countries, the extent to which direct household PV energy use could lower annual electricity consumption from the grid, in the case of on-grid PV systems of different capacities. In addition, these findings also provide information related to the grid's macro-energy systems in terms of local network load effects related to given investment sizes. [ABSTRACT FROM AUTHOR]

In the context of the ever-growing demand for energy, especially electric energy, from renewable sources, there has been great interest in photovoltaic energy generation. The speed at which the penetration of photovoltaic technology can grow, however, does not simply depend on supply and demand but also on the various policies and schemes adopted by countries around the world. These, in turn, play decisive roles in investment decisions and determine how projects are approached. Investors in photovoltaic (PV) systems need to be aware of the country-specific risk factors for investments and the regulatory environment. The aim of this research was to explore which managerial, economic and technical aspects should be considered in a causal approach when designing PV power plants with over 50 kW of capacity in the Hungarian regulatory environment for the success of the project. The innovative significance of the study is that it presents a validated, practically usable model for the realization of PV power plant projects in Hungary, which provides an in-depth description of the causal steps of their planning and establishment, based on real-life experience. The novel, practical benefit of the research is that it updates and clarifies the steps necessary for the design of PV power plants, since nowadays there are no current scientific works that provide knowledge of a sufficient depth regarding such projects, so these characteristics need to be investigated. [ABSTRACT FROM AUTHOR]

Despite the rapid spread of the use of wind energy to generate electricity, harnessing this energy source remains a great challenge due to its stochastic nature. One way of dealing with this is to prepare accurate wind power forecasts. This paper explored the accuracy of day-ahead and intraday scheduling of energy generation of the onshore and offshore wind farms of the member countries of the European Network of Transmission System Operators (ENTSO-E) in the period from 2013 to 2021. The precision of the scheduling activities showed a varying picture: the onshore wind farms of Germany, Spain, France, and Sweden produced more precise forecasts than others, with annual downward and upward regulatory needs between 0.8% and 14.4%, and from 0.8% to 6.5%, of the yearly energy generation, respectively. In certain countries, however, the forecasts were less accurate, with discrepancies exceeding 41% for downward and 132% for upward regulation. As for offshore wind farms, the annual downward and upward regulatory needs ranged between 0.9% and 61.7%, and from 1.3% to 44.1%, respectively, with Germany and Denmark producing the most accurate schedules. The innovative novelty and practical contributions of this study are that it determines and presents information related to the accuracy of the day-ahead and intraday wind power generation forecasting of the ENTSO-E countries, which is of practical relevance to the transmission system operators (TSOs), the main actors in the energy market and the decision-makers, too. This information may also help investors who invest in onshore and offshore wind farms with the economic aspects, and it may also greatly contribute to the market-related development of the management systems of energy storage solutions related to these technologies. [ABSTRACT FROM AUTHOR]

What basically determines how much energy is generated by a photovoltaic (PV) system is the amount of solar irradiation that is absorbed by its PV modules. One of the technical solutions to boost this quantity, and thusly also maximize the return on PV investments, is solar tracking, which makes the following of the sun on its daily and annual journey in the sky possible and also takes changes in cloud conditions into consideration. The solar-tracking solutions that PV systems are most frequently equipped with deploy active sensor technologies, while passive ones are less common in present-day practice. However, even the popular solutions of today have their limitations. Their active sensor-tracking algorithms leave room for improvement for at least three major reasons, as they do not prevent the unnecessary operation of the motors in cloudy weather, they do not make the modules assume an appropriate position after nightfall, and they do not make sure that the structure and the electronics of the PV systems are protected from rain and the strong winds in the event of storms. This paper introduces a new active sensor-tracking algorithm, which has not only been tested but it is also in the process of patenting (patent ID: p2100209). By their contribution, the authors endeavor to propose a solution that can solve all three of the issues mentioned above. The concept is based on two fundamental findings. According to the first one, periodic movement can not only considerably decrease motor movement but also increase system lifetime, while the second one simply suggests that moving the modules into an almost horizontal position facing the equator at low light levels is conducive to the prevention of damages caused by storms and fast reaction to the increase in the amount of light at daybreak. A positive feature of the new system for PV power plant operators is that it performs the tracking of the sun practically without any decrease in power compared to the focal point position, since it works with an average inaccuracy of 1.9°. [ABSTRACT FROM AUTHOR]

With the dynamic growth in both the global hunger for electrical energy and the share of variable renewable energy sources in the energy mix, distribution networks are facing new challenges where conventional solutions may not be the best ones. The increase in load in distribution grids is routinely countered by network development and expansion, in a great part to supply for on-peak load demand, which could also be done by utilizing supplementary technologies to lessen the need for or defer such expansion. Vehicle-to-grid technology could efficiently contribute to handling this issue, as electric vehicles can potentially function as storage capacities to mitigate the fluctuations of power generation. The battery energy storage systems of hybrid or completely electric watercraft, which are becoming increasingly popular, are no exception, either. These vehicles represent a considerable potential to create more complex vehicle-to-grid solutions for countries with significant inland or seaport networks, for example, Hungary, with the largest lake of Central Europe. Since there is only deficient information on the topic, the main goal of this study was to explore the energy storage capacities of small electric boats in the context of Lake Balaton, Hungary. By this example, the paper presents the potential utilization of Europe's significant network of sea and inland recreational ports for the purpose of energy storage. Similarly to other European countries, Hungary's energy strategy for 2030 also includes the promotion of virtual production integration, local energy communities and micro-grid solutions. At the beginning of 2021, the small electric boats in the sailing marinas of Lake Balaton represented a cumulative energy storage capacity of 4.8 MWh, which may reach even 15.6 MWh by 2030, by the promotion of micro-grid solutions. The innovative novelty of this study is that it regards small fully electric boats not just as vehicles, but also explores their energy storage potentials. The novel goal of these examinations is to explore the volume of the energy storage potentials of the small fully electric boats around Lake Balaton, the knowledge of which may facilitate the creation of new types of flexibility services related to energy storage. [ABSTRACT FROM AUTHOR]

This article examines the positioning features of polycrystalline, monocrystalline, and amorphous silicon modules relative to the focus points of concentrator photovoltaic modules under real meteorological conditions using a dual tracking system. The performance of the photovoltaic modules mounted on a dual-axis tracking system was regarded as a function of module orientation where the modules were moved step by step up to a point where their inclination differed by 30° compared to the ideal focus point position of the reference concentrator photovoltaic module. The inclination difference relative to the ideal focus point position was determined by the perfect perpendicularity to the rays of the sun. Technology-specific results show the accuracy of a sun tracking photovoltaic system that is required to keep the loss in power yield below a defined level. The loss in power yield, determined as a function of the measurement results, also showed that the performance insensitivity thresholds of the monocrystalline, polycrystalline, and amorphous silicon modules depended on the direction of the alignment changes. The performance deviations showed clear azimuth dependence. Changing the tilt of the modules towards north and south showed little changes in results, but inclination changes towards northwest, southwest, southeast, and northeast produced results diverging more markedly from each other. These results may make the planning of solar tracking sensor investments easier and help with the estimate calculations of the total investment and operational costs and their return concerning monocrystalline, polycrystalline, and amorphous silicon photovoltaic systems. The results also provide guidance for the tracking error values of the solar tracking sensor. [ABSTRACT FROM AUTHOR]

In today's photovoltaic (PV) power plants, traditional crystalline PV modules are the prevalent technology, which is highly susceptible to partial shading due to the risk of irreversible damage. Therefore, it is advisable to explore potential construction sites for objects that might cause shading, including high-voltage transmission towers, whose shading effects can be significant due to their height. By means of innovative simulation, using a model, validated with actual data, this study endeavored to deliver novel information related to the problems of shading by high-voltage transmission lines. In the context of Hungary, it examined the risk factors, technical and economic aspects, and possible solutions important for PV projects. It provides new insight, much needed also at the international level, considering the fact that the extent of the shadows cast by conductors on the surface at low Sun elevations is not known at present and neither are the shading characteristics of conductors between two transmission towers, depending on their height, in winter, when the Sun is low. An added practical benefit of the study is that its technical and economic approaches and the software solutions are all based on the practice of PV system design and construction. Related to the investigated issues, this can facilitate the formulation of the technical and economic aspects of suitable PV power plant building strategies in Hungary. [ABSTRACT FROM AUTHOR]

As efforts are made worldwide to meet the growing energy needs of the population in a more sustainable way, harnessing weather-dependent renewable energy sources is becoming more and more important. One of the available technologies is photovoltaic energy production. In the last decade, there has been a growing need among households, institutions, and businesses to reduce the use of fossil-fuel-based electricity from the public grid. In order to meet their electricity demand in Hungary, investors prefer using household-sized photovoltaic power plant (HMKE) systems. The novelty of this study is that it examines the number and total power of photovoltaic HMKEs at the district level in the service areas of different electricity distributors, taking into account the social, economic, infrastructural, and welfare dimensions of these districts as well. The study seeks to uncover whether there is a correlation between the number and total power of these types of power plants and the indicators of the districts, and if so, how strong these relationships are. The examination of the relationships also involved, in addition to correlations by pairs, the relationships of the ranking of the districts according to the complex indicators created from the district indicators and the ranking of the districts based on the number and power of photovoltaic HMKEs per 1000 members of the population. By exploring correlations, the paper seeks to establish a regression model for the number of photovoltaic HMKEs and the territorial (district) indicators. [ABSTRACT FROM AUTHOR]

In the global transformation of energy systems, solar energy plays a prominent role, since the energy from our star is a limitless and clean resource, which is available practically almost everywhere. In spite of the immense advancements of photovoltaic systems, which utilize this source of energy, no in-depth research has been carried out regarding the present Hungarian status of the small-scale photovoltaic power plants, the most common type of solar power plant in Hungary. The novelty of this study is that it examines the number and power of these small-scale power plants at the settlement level within the service areas of the various distribution companies, by also considering the economic and infrastructural dimensions of the settlements. The paper seeks answers to the questions whether there are any significant relationships between the number and the power of power plants of this type and the indicators of the settlements, and if so, how strong they are. Besides pairwise correlations, the study also involved the analysis of the relationship between the ranking of the settlements based on the settlements' complex indicators that were created from the settlements' indicators and the ranking of the settlements according to the number and power of household-sized photovoltaic power plants per 1000 people. In the course of exploring the relationships, a regression model was also devised concerning the number of household-sized photovoltaic power plants and the settlement indicators. [ABSTRACT FROM AUTHOR]

The accuracy and reliability of solar tracking greatly impacts the performance of concentrator photovoltaic modules (CPV). Thus, it is of utmost significance to know how deviations in tracking influence CPV module power. In this work, the positioning characteristics of CPV modules compared to the focus points were investigated. The performance of CPV modules mounted on a dual-axis tracking system was analysed as a function of their orientation and inclination. The actual experiment was carried out with CPV cells of 3 mm in diameter. By using a dual tracking system under real weather conditions, the module's position was gradually modified until the inclination differed by 5° relative to the optimal position of the focus point of the CPV module. The difference in inclination was established by the perfect perpendicularity to the Sun's rays. The results obtained specifically for CPV technology help determine the level of accuracy that solar tracking photovoltaic systems are required to have to keep the loss in power yield under a certain level. Moreover, this power yield loss also demonstrated that the performance insensitivity thresholds of the CPV modules did not depend on the directions of the alterations in azimuthal alignment. The novelty of the research lies in the fact that earlier, no information had been found regarding the tracking insensitivity point in CPV technologies. A further analysis was carried out to compare the yield of CPV to other, conventional photovoltaic technologies under real Central European climate conditions. It was shown that CPV needs a sun tracking accuracy of at least 0.5° in order to surpass the yield of other PV technologies. Besides providing an insight into the tracking error values of solar tracking sensors, it is believed that the results might facilitate the planning of solar tracking sensor investments as well as the economic calculations related to 3 mm cell diameter CPV system investments. [ABSTRACT FROM AUTHOR]

The use of solar energy is an obvious choice; the energy of the sun is not only indispensable for most processes in nature but it is also a clean, abundant, sustainable, and—most importantly—universally available resource. Although the further spread of photovoltaic systems, which make use of this source of energy, is expected in the future all around the world, no comprehensive investigation has been conducted into the current situation of the small-scale photovoltaic power plants in Hungary, where this type of photovoltaic system is the most popular. By means of a case study, whose novelty lies in its focus on small-scale power plants and their complex examination, including economic and geographic indicators, this paper analyzes their status in Hungary. The study endeavors to establish the reasons for the popularity of this type of power plant and to identify some typical geographical locations with well-illustrated photovoltaic density. Residential, as well as business prosumers, were examined with the aim of learning more about the density of the small-scale photovoltaic systems and their geographical locations. Another goal was to calculate the average size of small-scale photovoltaic power plants and to gain more understanding of their economic aspects. The outcomes of this research include maps displaying the density of the small-scale photovoltaic power plants in Hungary and the results of the economic calculations for such investments. [ABSTRACT FROM AUTHOR]

For implementing renewable energy policies it is necessary to convince the population of the appropriateness and usefulness of the ideas. The information provision needed for that requires the communication to be accessible and understandable to the target audience. This research examined the national renewable energy action plans of the member states of the European Union. The online accessibility of these documents and their readability were examined using a simple accessibility test and the Flesch and Flesch–Kincaid readability tests. The paper also addresses the relationship between the culturally-determined power distance indices and the economic and developmental characteristics of the countries and the readability values of their samples. The results showed that the examined documents could be easily accessed, but the action plans of all the member states were difficult to read. The emerging pattern suggested that the text samples of the countries with higher power distances were harder to interpret. Nevertheless, no significant relationship was detected by the correlation analyses between the power distance indices and the Flesch and Flesch–Kincaid readability scores, while strong relationships were detected between the Human Development Index (HDI) data and the results of both readability tests in the group of countries with the highest power distance values. [ABSTRACT FROM AUTHOR]

We tested the usefulness of exuviae as an environmentally friendly method for exploring the variability of the trace element contents of protected insect populations without killing specimens. It is a notable characteristic of dragonflies that they are good ecological indicators for both aquatic and terrestrial habitat quality. Thus, we investigated the trace element accumulation in different stages of dragonflies: larva, exuvia, and adult. Using microwave plasma atomic emission spectrometry (MP-AES), we analysed the concentrations of Al, Ba, Cr, Cu, Fe, Mn, Pb, Sr and Zn. We found that the trace element contents of exuviae are a good proxy of the trace element contents of both the larvae and the adults. We conclude that exuvia is useful for assessing the environmental health of aquatic ecosystems. It is an environmentally friendly method and it can be used even in the case of protected dragonfly species. [ABSTRACT FROM AUTHOR]

Global electricity demand is constantly growing, making the utilization of solar and wind energy sources, which also reduces negative environmental effects, more and more important. These variable energy sources have an increasing role in the global energy mix, including generating capacity. Therefore, the need for energy storage in electricity networks is becoming increasingly important. This paper presents the challenges of European variable renewable energy integration in terms of the power capacity and energy capacity of stationary storage technologies. In this research, the sustainable transition, distributed generation, and global climate action scenarios of the European Network of Transmission System Operators for 2040 were examined. The article introduces and explains the feasibility of the European variable renewable energy electricity generation targets and the theoretical maximum related to the 2040 scenarios. It also explains the determination of the storage fractions and power capacity in a new context. The aim is to clarify whether it is possible to achieve the European variable renewable energy integration targets considering the technology-specific storage aspects. According to the results, energy storage market developments and regulations which motivate the increased use of stationary energy storage systems are of great importance for a successful European solar and wind energy integration. The paper also proves that not only the energy capacity but also the power capacity of storage systems is a key factor for the effective integration of variable renewable energy sources. [ABSTRACT FROM AUTHOR]

The energy demand of mankind is constantly growing, thus the utilization of various renewable energy sources, which also reduces negative environmental effects, is becoming more and more important. Because of the achievement of climate protection targets, photovoltaic (PV) energy has an increasing role in the global energy mix. This paper presents the technical and economic aspects of different photovoltaic system configurations designed to suit the Hungarian renewable energy regulations. In this study, five alternative PV configurations were examined for systems with a capacity from 50 kW to 500 kW, related to low- and medium-voltage installations. This article also introduces and explains the Hungarian economic PV and Feed-in-Tariff (FiT) regulations, where three different investment alternatives are analyzed with the help of economic indicators. This study could help stakeholders in the market (e.g., the Hungarian industry sector and local governments) understand the possible directions of technical and economic PV development. According to the results, the payback periods in all the studied economic-technical cases were below 10 years. The experimental results show that each investment option may be a good decision from an economic and technical point of view under the Hungarian regulations in force in 2019. [ABSTRACT FROM AUTHOR]