Search Results (20)

With the rapid increase in photovoltaic (PV) micro-installations in Europe, ensuring the stability and safety of the power grid has become a critical challenge. A key aspect in this context is the reliable detection of unintentional islanding by distributed energy resources. This paper presents the results of metrological tests on seven commercially available three-phase and single-phase PV inverters, conducted in accordance with the requirements of the EN 50549-1 and EN 62116 standards. A dedicated test setup was developed to enable measurements following standardized procedures. The tests assessed both the response time and the effectiveness of islanding detection mechanisms under various fault scenarios, including simulations of autonomous operation of multiple inverters. The main findings indicate that while all inverters with active islanding protection successfully detected islanding within the mandated 2-s limit, their individual response times varied significantly. Parallel operation further influenced this behavior: when one inverter operated with its islanding protection intentionally disabled, the remaining units exhibited notably increased detection times, though still within regulatory thresholds. Moreover, the inverter with disabled protection was capable of sustaining stable islanded operation indefinitely under balanced load conditions. Repeated multi-inverter tests also revealed significant variability in detection time within the same scenario, demonstrating that detection dynamics are sensitive to subtle changes in operating conditions. These findings highlight important limitations of existing certification procedures, which focus primarily on single-inverter testing. Real-world interactions between simultaneously operating inverters can substantially affect detection performance. The results therefore support the need to revise and extend test standards to include controlled multi-inverter parallel-operation conditions, ensuring the safe integration of prosumer PV systems into distribution networks. Full article

Energy storage facilities serve as flexible resources that comprehensively support grid operations; they are also essential, especially when the thermal power plants that previously served as regulators run out. Electricity is becoming the dominant carrier through which the bulk of consumers’ energy needs are met. The efficiency of long-distance transmission and the ease of conversion to other forms of energy in Poland are attributed to the national grid. Thanks to the development of new technologies and distribution channels, energy is changing its supply network system. The purpose of this article is to discuss the economic viability of energy storage systems and their strategic role in the energy transition. The research methods used are data analysis, and the dependence on capital expenditures ($CAPEX$) and operating costs ($OPEX$) of energy storage in distribution channels. Energy storage facilities operated by grid companies account for 90% of the installed capacity, but there is a noticeable increase in the number of prosumer installations, with an energy storage of up to 50 KWh at microinstallations. Full article

Photovoltaic (PV) micro-installations producing renewable electricity and automatic pellet boilers producing renewable heat energy are promising solutions for single-family houses. A single-family house equipped with a prosumer 7.56 kWp PV micro-installation and a 26 kW pellet boiler was analyzed. This study aimed to analyze the production and use of electricity and heat over three successive years (from 1 January 2021 to 31 December 2023) and to identify opportunities for securing renewable energy supply for the house. Electricity production by the PV was, on average, 6481 kWh year⁻¹; the amount of energy fed into the grid was 4907 kWh year⁻¹; and the electricity consumption by the house was 4606 kWh year⁻¹. The electricity supply for the house was secured by drawing an average of 34.2% of energy directly from the PV and 85.2% from the grid. Based on mathematical modeling, it was determined that if the PV installation had been located to the south (azimuth 180°) in the analyzed period, the maximum average production would have been 6897 kWh. Total annual heat and electricity consumption by the house over three years amounted, on average, to 39,059 kWh year⁻¹. Heat energy accounted for a dominant proportion of 88.2%. From a year-round perspective, a properly selected small multi-energy installation can ensure energy self-sufficiency and provide renewable energy to a single-family house. Full article

This article aimed to assess the use of renewable energy sources (RES) in households in Poland in the context of the Statistics Poland (GUS) research and our survey research. In addition, plans for using renewable energy sources and the willingness of respondents to spend money for this purpose were examined. At the beginning of this article, a theoretical approach to the household as an energy prosumer was presented, and the structure of obtaining energy from RES in Poland was shown. Then, the survey research methodology was presented, including the selection of the sample and the purpose of the survey. The next part of this article concerns the characteristics of the respondents and the buildings they inhabit, as well as statistics on RES used in the surveyed households. The research shows that 12% of the surveyed population was an energy prosumer, and 22% were interested in and planning to invest in RES. Only half of the respondents were ready to spend their money on micro-installations. The results were presented using the documentary and comparative methods. This article uses data from Statistics Poland (GUS) and our survey research conducted among 1112 representatives of households in Poland. Full article

Photovoltaic (PV) systems are becoming increasingly popular, especially in residential buildings. However, the high penetration of prosumer PV micro-installations can have a negative impact on the operation of distribution networks due to the low self-consumption of the energy produced. One way to mitigate this problem is to use a residential energy storage system (RESS) and load shifting under a demand-side management (DSM) scheme. Energy management systems (EMSs) are used to control the operation of RESSs and to implement DSM. There are two main categories of EMSs: rule-based and optimization-based. Optimization-based EMSs provide better results than rule-based EMSs but can be computationally expensive. This article proposes an optimization-based EMS that is designed specifically for residential buildings. The proposed home energy management system (HEMS) uses a particle swarm optimization method to maximize the prosumer’s financial neutrality, which is calculated based on dynamic energy prices. Simulation-based evaluation using the measurements taken in a building equipped with a PV source, RESS, and shiftable loads shows the improved performance of the proposed HEMS compared to rule-based RESS control. The results show that the designed HEMS increases self-consumption, thus reducing the impact of the prosumer’s PV micro-installations on the distribution grid. Full article

This article presents examples of cogeneration systems, which are standard equipment for biogas installations, based on the production of heat and electricity. It has been shown that in the case of microgeneration, ease of servicing and low installation costs are crucial. Characteristic aspects of developing concepts for mobile installations (small scale) that produce biogas, often with a simple container structure that is ready to be located in the economic infrastructure of the agricultural industry, were indicated. Recommendations for the operation of micro-biogas models are presented, which have the greatest impact on the advisability of using agricultural waste for energy purposes. A characteristic farm was selected, which has a substrate necessary for the process of methane fermentation of slurry from pig farming. The cogenerator, which constitutes a potential energy demand from the point of view of Polish agriculture in the context of renewable energy production, was analyzed. The research goal was to adapt the cogenerator to the conditions existing on a farm, which should meet the technical and technological expectations for the process of managing the produced methane with a value of 80% in agricultural biogas. The assessment of the impact of the amount of biogas on the level of CO, NO, NO₂ and PM emissions was carried out at a constant engine speed for various load levels; the percentage of biogas was changed from 40 to approximately 70–80%, i.e., until significant knocking combustion was detected in the tested engines. As a result, the existing control and control system for the operation of the cogeneration unit prevents the most effective mode of operation of the research installation as a prosumer micro-installation. When the AG20P biogas unit operated in parallel with the grid with an active power of up to 11.7 kW, the electricity produced by the unit met the adopted assumptions and requirements. What is new in this article is the use of a cogeneration unit that has been adapted to its functionality, taking into account the assessment of the prospects for optimizing the cogeneration system in the context of the use of renewable energy sources as agricultural biogas. The best method was to attempt to determine the operating conditions of the cogenerator to develop the optimization of a biogas cogeneration unit producing electricity and heat in a micro-installation for the needs of an individual farm. Full article

The integration of renewable energy systems in buildings leads to a reduction in energy bills for end users and a reduction in the carbon footprint of such buildings, usually referred to as prosumers. In addition, the installation of charging points for the electric vehicles of people working or living in these buildings can further improve the energy efficiency of the whole system if innovative technologies, such as vehicle-to-building (V2B) technologies, are implemented. The aim of this paper is to present an Energy Management System (EMS) based on mathematical programming that has been developed to optimally manage a prosumer building equipped with photovoltaics, a micro wind turbine and several charging points for electric vehicles. Capabilities curves of renewable power plant inverters are modelled within the EMS, as well as the possibility to apply power curtailment and V2B. The use of V2B technology reduces the amount of electricity purchased from the public grid, while the use of smart inverters for the power plants allows zero reactive power to be drawn from the grid. Levelized cost of electricity (LCOE) is used to quantify curtailment costs, while penalties on reactive power absorption from the distribution network are evaluated in accordance with the current regulatory framework. Specifically, the model is applied to a prosumer building owned by the postal service in a large city in Italy. The paper reports the main results of the study and proposes a sensitivity analysis on the number of charging stations and vehicles, as well as on the consideration of different typical days characterized by different load and generation profiles. This paper also investigates how errors in forecasting energy production from renewable sources impact the optimal operation of the whole system. Full article

In recent years, the issue of energy security has been the subject of many studies, debates, and discussions. Undoubtedly, geopolitical crises in Eastern Europe and the actions of the EU as part of the continuous development of the EU’s climate and energy policy have contributed to the advancement of discussions in this area. Due to the growing role and importance of energy in the economic systems of individual countries, the need to guarantee energy security is commencing to be regarded as an element of the economic security of the state and therefore, national security. The legal solutions adopted in Poland in recent years and the launch of government support programs for the development of micro-installations and prosumer energy have led to the rapid development of this sector. The aim of this article is therefore to assess the conditions of renewable energy sources development in Poland on the example of photovoltaics in the line of energy security concept. The empirical results emphasize that the development of photovoltaic is so dynamic for several reasons, primarily due to lower technological costs, stakeholder cooperation, confidence in the regulatory environment, as well as the high interest of the Polish public in this issue. Full article

It is indisputable that power systems are being transformed around the world to increase the use of RES and reduce the use of fossil fuels in overall electricity production. This year, the EU Parliament adopted the Fit for 55 package, which should significantly reduce the use of fossil fuels in the energy balance of EU countries while increasing the use of RES. At the end of 2022, the total number of prosumer installations in Poland amounted to about one million two hundred thousand. Such a high saturation of prosumer micro-installations in the power system causes many threats resulting from their operation. These threats result, among others, from the fact that photovoltaics are classified as unstable sources and the expected production of electricity from such installations is primarily associated with highly variable weather conditions and is only dependent on people to a minor extent. Currently, there is a rapid development of topics related to forecasting the volume of energy production from unstable sources such as wind and photovoltaic power plants. This issue is being actively developed by research units around the world. Scientists use a whole range of tools and models related to forecasting techniques, from physical models to artificial intelligence. According to our findings, the use of machine learning models has the greatest chance of obtaining positive prognostic effects for small, widely distributed prosumer installations. The present paper presents the research results of two energy balance prediction algorithms based on machine learning models. For forecasting, we proposed two regression models, i.e., regularized LASSO regression and random forests. The work analyzed scenarios taking into account both endogenous and exogenous variables as well as direct multi-step forecasting and recursive multi-step forecasting. The training was carried out on real data obtained from a prosumer micro-installation. Finally, it was found that the best forecasting results are obtained with the use of a random forest model trained using a recursive multi-step method and an exogenous scenario. Full article

This article overviews Poland’s current electric vehicle infrastructure development. It discusses market segmentation and the analysis of charging standards, connectors, and types of charging. The paper focuses on Poland’s charging infrastructure, including costs and charging times for popular electric vehicle models in 2022. It highlights the challenges faced by charging operators and the barriers to infrastructure development. The article also presents the outlook for the electric vehicle market in Poland until 2025 and 2030. Furthermore, it examines private charger development, particularly in prosumer households with renewable energy sources. The implementation of smart charging and the potential for vehicle-to-grid technology in Poland are addressed. Lastly, a comparative analysis of incentives for electric vehicle users in Poland and Norway is discussed in the context of achieving 100% zero-emission vehicle sales by 31 December 2035, in Poland. Full article

The implemented climate policy and the current geopolitical situation make us pay special attention to energy independence, both in the household and in the national dimension. One way to obtain inexpensive and environmentally friendly energy is the development of photovoltaic micro-installations. For positive changes to occur, correct state regulation and an appropriate set of administrative and economic instruments are necessary. The purpose of this article is to discuss changes in the accounting system for renewable energy prosumers and their consequences for the further development of renewable energy. The financial settlement methods favorable to prosumers were recently replaced with new solutions. According to the authors, this slows down the energy transformation. Full article

Renewable Energy Sources (RES) have been gaining popularity on a continuous basis and the current global political situation is only accelerating energy transformation in many countries. Objectives related to environmental protection and use of RES set by different countries all over the world as well as the European Union (EU) are becoming priorities. In Poland, after years of a boom in photovoltaic (PV) installations, the Renewable Energy Sources Act has been amended, resulting in a change to the billing system for electricity produced by individual prosumers. The change in the billing method, also in pursuance to the provisions of EU laws, has contributed to the inhibition of the PV installation market for fear of energy prices and investment payback time. In this paper, by using the Net Present Value (NPV) method, three mechanisms of billing of electricity from prosumer micro-installations—based on the net-metering principle and net-billing principle (using monthly and hourly prices)—have been analysed. Particular attention has also been paid to the aspects of electricity self-consumption and energy storages, which play a significant role in the economy of PV installations in the net-billing system. Full article

Renewable energy sources are intended to support the decarbonisation process of the Polish economy. Since 2005, the share of renewable energy in total electricity in Poland has been increasing. The number of photovoltaic panels installed by prosumers as part of micro-installations increased particularly strongly. The aim of this research is an assessment of the impact of government programmes on the development of RES micro-installations in Poland. A regression discontinuity design was used in the analysis. It is a model from the group of average impact effect models used in evaluation studies. The added value of the presented study is its application in the assessment of the impact of implemented programmes on the number and output of micro-installations in Poland. In the study, it is shown that there had been no increase in the number and output of micro-installations at the adopted threshold (2019Q4). On the other hand, there was a sharp increase in them over the whole period starting from 2019Q4. Full article

From 2010 in Europe and from 2019 in Poland, the development of a significant number of photovoltaic (PV) microinstallations have been observed; for example, 1 million PV installations were built in Poland, September 2019–May 2022. A PV microinstallation is typically designed for a household (single-family house). Their capacity and energy productivity should be aligned with energy consumption in a given period, for example, a year (prosumer rules in Poland). The aim of this study is to verify the possibilities and accuracy of the use of PV energy production calculation methods in Polish conditions. The existing methods of calculating the energy produced may be inaccurate due to non-adaptation to terrain conditions, place, wind conditions, representativeness of PV panels in the installation, and many other factors. In the study, the HDKR (Hay, Davies, Klucher, Reindl) method was used based on data from the 0.25-degree (both longitude and latitude) mesh of ERA5 weather conditions. Then, the theoretical energy productivity from PV panels was calculated based on broadly used methods like those used in HOMER software. Statistical verification was done to compare the obtained energy production results from 10 PV panels with real results from microinstallations (energy productivity from each panel measured). The representativeness of the analysis period (one year) over the years was also checked using statistical methods. This is the first study to evaluate energy production from a microinverter installation in real conditions in Central Eastern Europe. Full article

In Poland, electricity production is based on nonrenewable energy sources. The energy market is dominated by corporations. Rising electricity prices and threats of power shortages have become, among others, prerequisites for the development of distributed sources based on renewable sources, primarily using photovoltaic panels. The development of the renewable energy market is slow due to the lack of legal solutions and insufficient state support. Polish farmers, especially fruit growers, whose electricity consumption costs are a significant item in production costs, may become part of the energy sector by building a local energy system. In 2022, Poland introduced two new legal regulations, which currently provide three options for obtaining electricity using renewable micro-installations. The conducted study aimed at indicating which of the legally permitted option is the most advantageous for fruit farms in Poland. Growers can produce energy by being a prosumer who settles accounts in the net-metering and net-billing system and by participating in an energy cooperative. The direction of changes was ascertained by conducting a pilot study among fruit growers. The study used real quantitative and valuable data on the consumption and costs of electricity in 2012–2022 and the production of photovoltaic panels in a fruit farm in 2021. The study consisted of comparing three models of settling accounts for electricity with two comparative models in two scenarios. The analysis of prosumers’ functioning showed that the situation in Poland is favorable for the development of civic energy. However, participation in an energy cooperative with new legal solutions will not always be the more advantageous solution in terms of economy and energy. In particular, the study showed that the support mechanism needs further changes. The results of the research confirm the existing potential of fruit farms, which can be developed in the area of securing energy needs. The results of this research can be used as the premise for introducing changes to the legal conditions for the establishment and operation of energy cooperatives in Poland. Full article