Photovoltaic cells have been used for a long time to supply the electrical devices of small power in areas without access to the electricity networks (or other sources of electric energy). The ecological aspect of the use of the renewable energy sources, together with the technology development and increasingly lower costs of production the photovoltaic cells, cause the increase of their application. The solar power plants are built in several places in the world, not necessarily in the areas of high light intensity. Nowadays, such developments mostly depend on the wealth of a particular country. The largest photovoltaic power stations have power of a several dozen of MW. The major disadvantage of the photovoltaic cells is that the energy production is possible only during the day. This causes a necessity of energy accumulation in large photovoltaic systems. One possibility of storing large amounts of energy gives a hydrogen fuel, generated in the electrolysers powered directly from photovoltaic cells. Hydrogen, stored in pressure tanks or in tanks with synthetic porous materials, can be again used to produce electricity in fuel cells. This paper introduces selected issues and test results associated with the use of photovoltaic cells to power the hydrogen generators. The possible connections of photovoltaic modules integrated with electrolysers were analyzed. In this article the results of the electricity daily production by polycrystalline photovoltaic cells, collected in the course of the entire year were also presented.

This article introduces a laboratory-scale concept and research on photovoltaic (PV) modules designed for building integrated photovoltaics (BIPV) market, with enhanced architectural aesthetics and no protective glass. The proposed concept involves replacing a typical glass protective and load-bearing element of PV modules with an ethylene tetrafluoroethylene (ETFE) foil while using an aluminium sheet as a load-bearing element in the system. To further enhance the visual appeal of the solution, special modifications were proposed to the geometry of the front security foil. To confirm the feasibility of the proposed concept for mass production, critical tests were conducted on the material system and the process of modifying the surface of the ETFE foil. These tests included evaluating adhesion strength between layers, optical transmission coefficients, and electrical parameters of the developed PV modules. Additionally, the effect of the ETFE film modification on the formation of micro-cracks in solar cells was also investigated.

The microgrid (MG) technology integrates distributed generations, energy storage elements and loads. In this paper, dynamic performance enhancement of an MG consisting of wind turbine was investigated using permanent magnet synchronous generation (PMSG), photovoltaic (PV), microturbine generation (MTG) systems and flywheel under different circumstances. In order to maximize the output of solar arrays, maximum power point tracking (MPPT) technique was used by an adaptive neuro-fuzzy inference system (ANFIS); also, control of turbine output power in high speed winds was achieved using pitch angle control technic by fuzzy logic. For tracking the maximum point, the proposed ANFIS was trained by the optimum values. The simulation results showed that the ANFIS controller of grid-connected mode could easily meet the load demand with less fluctuation around the maximum power point. Moreover, pitch angle controller, which was based on fuzzy logic with wind speed and active power as the inputs, could have faster responses, thereby leading to flatter power curves, enhancement of the dynamic performance of wind turbine and prevention of both frazzle and mechanical damages to PMSG. The thorough wind power generation system, PV system, MTG, flywheel and power electronic converter interface were proposed by Rusing Mat-lab/Simulink.

The proper designing of PV systems requires the use of advanced building energy simulation techniques. It allows to design the best position of the PV array, as well as the right quantity of produced energy in different cases. On the other hand the PV efficiency is not only a constant value but changes according to temperature and solar radiation. This paper is devoted to estimate the simultaneous effect of both weather factors on PV efficiency. The task was achieved by numerical simulation and ESP-r software. Computer simulations have been carried out with the use of the Typical Meteorological Year data for Warsaw (52°N 21°E). The greatest influence of temperature on the efficiency of solar energy conversion was observed for crystalline silicon cells. The influence of the boundary conditions assumed in the study is ignored for amorphous silicon cells in the summer period and regardless of the material type in the winter period.

The article presents a water-cooling system for photovoltaic (PV) modules using a two-axis tracking system that tracks the apparent position of the Sun on the celestial sphere. The cooling system consists of 150 adjustable spray nozzles that cool the bottom layer of PV modules. The refrigerant is water taken from a tank with a capacity of 7 m ³. A water recovery system reduces its consumption with efficiency of approximately 90%. The experimental setup consists of a full-size photovoltaic installation made of 10 modules with an output power of 3.5 kWp combined with a tracking system. The article presents an analysis of the cooling system efficiency in various meteorological conditions. Measurements of energy production were performed in the annual cycle using three different types of photovoltaic installations: stationary, two-axis tracking system and two-axis tracking system combined with the cooling system.

This article considers designing of a renewable electrical power generation system for self-contained homes away from conventional grids. A model based on a technique for the analysis and evaluation of two solar and wind energy sources, electrochemical storage and charging of a housing area is introduced into a simulation and calculation program that aims to decide, based on the optimized results, on electrical energy production system coupled or separated from the two sources mentioned above that must be able to ensure a continuous energy balance at any time of the day. Such system is the most cost-effective among the systems found. The wind system adopted in the study is of the low starting speed that meets the criteria of low winds in the selected region under study unlike the adequate solar resource, which will lead to an examination of its feasibility and profitability to compensate for the inactivity of photovoltaic panels in periods of no sunlight. That is a system with fewer photovoltaic panels and storage batteries whereby these should return a full day of autonomy. Two configurations are selected and discussed. The first is composed of photovoltaic panels and storage batteries and the other includes the addition of a wind system in combination with the photovoltaic system with storage but at a higher investment cost than the first. Consequently, this result proves that is preferable to opt for a purely photovoltaic system supported by the storage in this type of site and invalidates the interest of adding micro wind turbines adapted to sites with low wind resources.

This article presents an investigation of solar power plants’ economic efficiency in the case of energy prosumers. The economic effect of the development of solar energy, the environmental effect of the transition to green energy and the social effect due to lower electricity costs and investment growth from the use of photovoltaic installations (PVI) have been proven. The level of annual savings in PVI due to changes in production and own consumption of electricity are determined. Through use of factor analysis, the grouping method, the method of generalizing indicators, quantitative data collection for solar PV systems and the matrix method, the two main hypotheses were proven: (i) solar energy production should be stimulated by a sound state tariff policy; (ii) prosumers as players of the electricity market should be considered in the tariff policy. It is revealed that at current interest rates, PVI operational activity is subject to more complex factors, and the main one becomes economic, namely considering the economy of consumers, the level of taxation or grants of PVI activities, as well as productivity and the real state of technical condition of devices. The provided research develops the theoretical and empirical basis for the state policy of solar electricity usage with consideration to the peculiarities of its production and consumption. The process of production and consumption of electricity in PVI is not characterized by uniformity, which is derived from a number of factors, primarily from natural and climatic conditions. It also depends on the technical characteristics of the devices.

Perovskite solar cells represent the biggest breakthrough in photovoltaics in decades, bringing a chance for affordable and widely available green energy. They are suitable in areas where silicon cells have fallen short.

In this work, two thermal- and air-stable, hole transporting materials (HTM) in perovskite solar cells are analyzed. Those obtained and investigated materials were two polyazomethines: the first one with three thiophene rings and 3,3′-dimethoxybenzidine moieties (S9) and the second one with three thiophene rings and fluorene moieties (S7). Furthermore, presented polyazomethines were characterized by Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy, atomic force microscopy (AFM) and thermogravimetric analysis (TGA) experiments. Both polyazomethines (S7 and S9) possessed good thermal stability with a 5% weight loss at 406 and 377°C, respectively. The conductivity of S7 was two orders of magnitude higher than for S9 polymer (2.7 × 10⁻⁸ S/cm, and 2.6 × 10⁻¹⁰ S/cm, respectively). Moreover, polyazomethine S9 exhibited 31 nm bathochromic shift of the absorption band maximum compared to S7.

Obtained perovskite was investigated by UV–vis and XRD. Electrical parameters of perovskite solar cells (PSC) were investigated at Standard Test Conditions (STC). It was found that both polyazomethines protect perovskite which is confirmed by ageing test where Voc did not decrease significantly for solar cells with HTM in contrast to solar cell without hole conductor, where V_oc decrease was substantial. The best photoconversion efficiency (PCE = 6.9%), among two investigated in this work polyazomethines, was obtained for device with the following architectures FTO/TiO₂/TiO₂ + perovskite/S7/Au. Stability test proved the procreative effects of polyazomethines on perovskite absorber.

Effects of temperature variation on the performance of silicon heterojunction solar cells are studied using opto-electrical simulations. It is shown that the low-temperature cell efficiency is determined by the fill factor, while at high temperatures it depends on the open-circuit voltage. Simulations revealed that the low-temperature drop in the fill factor is caused by poor tunnelling, in particular at the ITO/p-a-Si:H heterojunction. The authors link this drop in fill factor to a low maximum-power-point voltage and show how poor tunnelling is reflected in the charge redistribution determining the device voltage. The effect of the contact work function on temperature behaviour of efficiency by varying the electron affinity of ITO layers has been demonstrated. It was also demonstrated that increasing the electron affinity of ITO on the p-side minimises the work function mismatch, leading to significant improvements in efficiency, especially at low temperatures, while optimisation on the n-side results in marginal improvements over the entire temperature range. In addition to the cumulative effects of the temperature-dependent parameters, their individual contributions to the efficiency were also investigated. Moreover, it was presented that the thermal energy (kT) determines the efficiency temperature behaviour, while other parameters play only a minor role. This paper shows how temperature variations affect device performance parameters.

A solar photovoltaic (PV) system has been emerging out as one of the greatest potential renewable energy sources and is contributing significantly in the energy sector. The PV system depends upon the solar irradiation and any changes in the incoming solar irradiation will affect badly on the output of the PV system. The solar irradiation is location specific and also the atmospheric conditions in the surroundings of the PV system contribute significantly to its performance. This paper presents the cumulative assessment of the four MPPT techniques during the partial shading conditions (PSCs) for different configurations of the PV array. The partial shading configurations like series-parallel, bridge link, total cross tied and honeycomb structure for an 8×4 PV array has been simulated to compare the maximum power point tracking (MPPT) techniques. The MPPT techniques like perturb and observe, incremental conductance, extremum seeking control and a fuzzy logic controller were implemented for different shading patterns. The results related to the maximum power tracked, tracking efficiency of each of the MPPT techniques were presented in order to assess the best MPPT technique and the best configuration of the PV array for yielding the maximum power during the PSCs.

In this paper, dynamic response improvement of the grid connected hybrid system comprising of the wind power generation system (WPGS) and the photovoltaic (PV) are investigated under some critical circumstances. In order to maximize the output of solar arrays, a maximum power point tracking (MPPT) technique is presented. In this paper, an intelligent control technique using the artificial neural network (ANN) and the genetic algorithm (GA) are proposed to control the MPPT for a PV system under varying irradiation and temperature conditions. The ANN-GA control method is compared with the perturb and observe (P&O), the incremental conductance (IC) and the fuzzy logic methods. In other words, the data is optimized by GA and then, these optimum values are used in ANN. The results are indicated the ANN-GA is better and more reliable method in comparison with the conventional algorithms. The allocation of a pitch angle strategy based on the fuzzy logic controller (FLC) and comparison with conventional PI controller in high rated wind speed areas are carried out. Moreover, the pitch angle based on FLC with the wind speed and active power as the inputs can have faster response that lead to smoother power curves, improving the dynamic performance of the wind turbine and prevent the mechanical fatigues of the generator.

Fast and accurate grid signal frequency estimation is a very important issue in the control of renewable energy systems. Important factors that influence the estimation accuracy include the A/D converter parameters in the inverter control system. This paper presents the influence of the number of A/D converter bits b, the phase shift of the grid signal relative to the time window, the width of the time window relative to the grid signal period (expressed as a cycle in range (CiR) parameter) and the number of N samples obtained in this window with the A/D converter on the developed estimation method results. An increase in the number b by 8 decreases the estimation error by approximately 256 times. The largest estimation error occurs when the signal module maximum is in the time window center (for small values of CiR) or when the signal value is zero in the time window center (for large values of CiR). In practical applications, the dominant component of the frequency estimation error is the error caused by the quantization noise, and its range is from approximately 8×10-10 to 6×10-4.

Photovoltaic (PV) power optimizers are introduced in PV systems to improve their energetic productivity in presence of mismatching phenomena and not uniform operating conditions. Commercially available converters are characterized by different DC-DC topologies. A promising one is the boost topology with its different versions. It is characterized by its circuital simplicity, few devices and high efficiency values - necessary features for a Distributed Maximum Power Point Tracking (DMPPT) converter. PV power optimizer designs represent a challenging task since they operate in continuously changing operating conditions which strongly influence electronic component properties and thus the performance of complete converters. An aspect to carefully analyze in such applications is the thermal factor. In this paper, a necessity to have a suitable temperature monitoring system to avoid dangerous conditions is underlined In addition, another important requirement for a PV power optimizer is its reliability, since it can suggest a useful information on its diagnostic aspects, maintenance and investments. In fact, a reliable device requires less maintenance services, also improving the economic aspect. The evaluation of the electronic system reliability can be carried out using different reliability prediction models. In this paper, reliability indices, such as the Mean Time Between Failure (MTBF) or the Failure Rate of a Diode Rectification (DR) boost, are calculated using the evaluation of the Military Handbook 217F and Siemens SN29500 prediction models. With the reliability prediction results it has been possible to identify the most critical components of a DMPPT converter and a measurement setup has been developed in order to monitor the component stress level on the temperature, power, voltage, current, and energy in the DMPPT design phase avoiding the occurrence of a failure that might decrease the service life of the equipment.

A sliding mode controller for the photovoltaic pumping system has been proposed in this paper. This system is composed of a photovoltaic generator supplying a three-phase permanent magnet synchronous motor coupled to a centrifugal pump through a three-phase voltage inverter. The objective of this study is to minimise the number of regulators and apply the sliding mode control by exploiting the specification of the field oriented control scheme (FOC). The first regulator is used to force the photovoltaic generator to operate at the maximum power point, while the second is used to provide the field oriented control to improve the system performance.The whole system is analysed and its mathematical model is done. Matlab is used to validate the performance and robustness of the proposed control strategy.

An integrated Z-source inverter for the single-phase single-stage grid-connected photovoltaic system is proposed in this paper. The inverter integrates three functional blocks including maximum-power-point-tracking, step-up/down DC-side voltage and output grid-connected current. According to the non-minimum-phase characteristic presented in DC-side and the functional demands of the system, two constant-frequency sliding-mode controllers with integral compensation are proposed to guarantee the system robustness. By using two controllers, the effects caused by the non-minimum-phase characteristic are mitigated. Under the circumstance of that the input voltage or the grid-connected current changes suddenly, the notches/protrusions following the over-shoot/ under-shoot of the DC-bus voltage are eliminated. The quality of grid-connected current is ensured. Also, a small-signal modelling method is employed to analyze the close-loop system. A 300W prototype is built in the laboratory. A solar-array simulator (SAS) is used to verify the systematic responses in the experiment. The correctness and validity of the inverter and proposed control algorithm are proved by simulation and experimental results.

The energy efficiency of photovoltaic modules is one of the most important aspects in energetic and economic aspects of the project related to system installations. The efficiency of modules and the electricity produced by photovoltaic conversion in solar modules is affected by many factors, both internal, related to the module structure itself and its technical and external factors related to the energy infrastructure, which includes: cabling, inverters, climate conditions prevailing at the micro-installation location and the orientation and angle of inclination of the solar modules. The installation of photovoltaic modules should be preceded by an energy efficiency analysis, which will help to indicate the optimal solution adapted to the given conditions. The article presents a comparative analysis of the amount of energy produced under real and simulated conditions. Analyzes were made on the basis of research carried out in the Wind and Solar Energy Laboratory located at the AGH University of Science and Technology, data from solar irradiation data-bases and computer software for estimating energy resources. The study examined the correlation of the solar irradiation on the modules and the amount of electricity generated in the photovoltaic module. The electricity produced by the module was compared under real conditions and simulated based on two sources of data. The comparison and analysis of the amount of energy of the module were also made, taking simulated different angles of the module’s inclination into account.

The paper presents the results of the energy analysis of the conversion of solar radiation energy into electrical energy in Polish weather conditions. The effect of sunlight and working temperature on the photovoltaic module on its power curve P = f(U) is shown. STC and NOCT conditions are described for which the manufacturers specify the parameters of the photovoltaic modules. The manufacturers of photovoltaic panels should give the PPV = f(E) characteristic for the different values of the operating temperature of the modules. An analysis of the economic efficiency of a photovoltaic power plant investment of 1 MWp taking the current legal regulations for the three variants into account was presented. Variant I – the investor benefits from the support of public aid of operational only, Variant II – the investor benefits from the support of public aid for investment in the amount of PLN 1 million, Variant III – the investor benefits from the support of public aid for investment in the amount of PLN 2 million. For all variants, indicators for assessing the economic effectiveness of the investment and the value of the auction price from the maximum price to the price at which the project loses its profitability are determined.

The energy sector, particularly that related to renewable energy, is growing rapidly. The analysis of factors influencing the production of electricity from solar radiation is important in terms of the ever-increasing number of photovoltaic (PV) installations. In Poland, the vast majority of installed PV capacity belongs to prosumers, so a comparative analysis was conducted for two domestic installations, one in southern Poland and the other located in central Poland. Operating conditions were compared, specifically with regard to irradiance, outdoor temperature and the calculated temperature of photovoltaic cells. The specific yield was then compared in daily, monthly and annual statements. The effects of the previously mentioned parameters on the energy yields of the two installations were considered. The installation in southern Poland in 2022 produced 5,136.6 kWh, which corresponds to a specific yield of 1,019.17 kWh/kWp, while the energy production of the installation in central Poland was 4,248.9 kWh, which corresponds to a specific yield of 965.67 kWh/kWp.

Photovoltaic (PV) technologies which play a role in PV market are divided into basic two types: wafer-based (1st generation PV) and thin-film cell (2nd generation PV). To the first category belong mainly crystalline silicon (c-Si) cells (both mono- and multi-crystalline). In 2015 around 90% of the solar market belonged to crystalline silicon. To the 2nd generation solar cells belongs thin film amorphous silicon (a-Si) or a combination of amorphous and microcrystalline silicon (a-Si/μc-Si), compound semiconductor cadmium telluride (CdTe), compound semiconductor made of copper, indium, gallium and selenium (CIS or CIGS) and III–V materials. The PV market for thin film technology is dominated by CdTe and CIGS solar cells. Thin film solar cells’ share for all thin film technologies was only 10% in 2015. New emerging technologies, called 3rd generation solar cells, remain the subject of extensive R&D studies but have not been used in the PV market, so far.

In this review the best laboratory 1st and 2nd generation solar cells that were recently achieved are described. The scheme of the layer structure and energy band diagrams will be analyzed in order to explain the boost of their efficiency with reference to the earlier standard designs.

The presented distributed photovoltaic system is made of divided into individual modules photovoltaic panel, consisting of several photovoltaic cells properly connected and coupling them with low-power DC / DC converters. The essence of the research is to increase the reliability of the system and the resultant efficiency of the entire system, so that it is possible to convert solar radiation energy into electricity with the greatest efficiency. The article focuses on the presentation of the implementation and tests of the overriding control algorithm, the task of which is to provide full functionality for a distributed photovoltaic system. The control is designed to minimize the negative effects of shadows on the operation of the photovoltaic system and conduct self-diagnostics. The conclusion for the carried out work is the formulation of hardware and interface requirements for the further development of the project.

Research related to photovoltaic panels comprises different topics starting with modelling solar cells, finding new maximum power point tracking (MPPT) algorithms, testing existing ones or designing of DC/DC converters for MPPT systems and microgrids that incorporate photovoltaic energy sources. In each of the examples above a deep knowledge of photovoltaic panels is required, as well as a reliable measurement system that can deliver continuous, stable light with enough power to meet standard test conditions (STC) and that can ensure repeatable results. Therefore this paper presents a low-cost solar simulator with a microcontroller-based measurement system, that can be used for various measurements of low-power photovoltaic panels.

In less than a decade, the photovoltaic sector has transformed into a global business. The dynamics of its development vary depending on the country. According to estimates, the value of the photovoltaic micro-installations market in Poland at the end of 2019 exceeded PLN 2.8 billion. In the first half of 2020, the PV sector recorded dynamic growth with a total capacity of the micro-installations of 2.5 GWp. Government subsidies were among the factors contributing to the expansion of the PV sector. In Poland, there are many financial ways to intensify the construction of new renewable energy source installations, among others: feed-in tariff, grants, and loans. An example of photovoltaic grant support in Poland is the “Mój Prąd” [My Electricity] program created in 2019 with a budget of PLN 1.1 billion. The interest in the “My Electricity” program in individual provinces may vary, depending on socio-economic factors, technological and environmental resources, and the level of innovation. The research motivation of this article is a comparison of provinces in Poland according to selected energy, environmental, innovation, and socio-economic indicators and to show how these factors affect individual interest in the “My Electricity” photovoltaic development program in provinces. The highest correlation is for the total installation power under the “My Electricity” program and Gross Domestic Product and Human Developed Index. The highest correlation coefficient from RIS indicators and photovoltaic data programs was achieved for “R&D expenditure in the business sector”. The population was closely correlated with the total installation power and the grant value of the “My Electricity” program.

The large variability and unpredictability of energy production from photovoltaic power microinstallations results from the dependence on the current weather conditions. These conditions depend on a number of factors and are variable over the time. Despite this specificity, photovoltaic micro-installations are becoming more and more popular in the world and in Poland. This is mainly due to the fact that the generation of energy from renewable sources has numerous advantages, the energy is free, renewable in time and ecological, and its production on its own gives partial independence from energy supplies from the power grid. In addition, the observed significant prices decrease of solar modules has further accelerated the development of the use of this energy source. Concern for this method of energy production among households has increased significantly in Poland after introducing the prosumer in the legal framework and the use of administrative and financial support. The implemented prosumer mechanisms allowed, for example, the net balancing of the energy consumed and produced by the micro-installation through storage in the power grid. The article describes the problem of balancing sources using solar energy, based on micro-installation used in the household (the so-called prosumer installation). The conducted analyses compared the load profile of a typical household and the energy generation profile from a photovoltaic installation, determining the real balancing formation level of such a system.