Dariusz Kurz

Bio: Dariusz Kurz is an academic researcher from Poznań University of Technology. The author has contributed to research in topics: Photovoltaic system & Roof. The author has an hindex of 6, co-authored 39 publications receiving 102 citations.

Analysis of power and energy losses in power systems of electric bus battery charging stations

Abstract: Two variants of electricity transmission from the Transfer-Switching Station (TSS) to the battery charging station were analysed in the paper. The first variant under analysis referred to the transmission of electricity via a three phase a.c. line with rated voltage of 15 kV. In the second variant of electricity transmission, the d.c. line with the working voltage of 1500 V was used. For both variants, lines and other equipment such as transformers, rectifier system and voltage stabilisation system in the battery charging station were modelled. For both solutions, analysis of energy per annum was conducted depending on the distance of the charging station from the TSS. On top of this, the simultaneous operation of several chargers was taken into account, which would correspond to the case of charging many buses at the same time from a single power line. The paper demonstrates that in the case of the analysed electricity transmission systems in the electric bus battery charging systems it is possible to use a more advantageous solution, which is characterised by reduced power and energy losses.

Analysis of the Impact of Building Integrated Photovoltaics (BIPV) on Reducing the Demand for Electricity and Heat in Buildings Located in Poland

Abstract: Based on a method to reduce energy consumption suggested in a real energy audit carried out in an industrial plant located in Poznan (city in Poland), the potential of using photovoltaic (PV) panels as wall cladding was analyzed, in order to reduce energy (electric and thermal) consumption and financial expenditure. The authors’ concept of using building integrated photovoltaic installation (BIPV) was presented and tested. This study checked whether the presence of PV modules would also affect heat transfer through the external wall of the building on which the installation is located. The analysis consisted of determining, for two variants, the heat transfer coefficients across the partition, in order to estimate the potential thermal energy savings. The first variant concerned the existing state, i.e., heat transfer through the external wall of the building, while the second included an additional partition layer in the form of photovoltaic panels. As a result, the use of panels as wall cladding allowed the improvement of the thermal parameters of the building wall (by increasing the thermal resistance of the wall), and the reduction of gas consumption for heating. The panels also generate electricity for the factory’s own needs. Payback time, compared to calculations which do not include changes in thermal parameters, was shortened from 14 to 11 years. The main reason for this is that gas consumption is reduced due to the improved heat transfer coefficient of the wall and the reduction of the heat loss of the facility. This aspect is usually overlooked when considering photovoltaic installations and, as argued by this paper, can be important.

Analysis of the influence of shading by horizon of PV cells on the operational parameters of a photovoltaic system

Abstract: The work presents the components of solar radiation that reaches the horizontal plane and a method of determining the energy value of the radiation that reaches the surface of a photovoltaic receiver inclined to the ground line at a certain angle. A shading assessment diagram and a methodology for determining the vertical angles and the influence of the horizon on the shading of a PV receiver were provided. A method of determining the direct radiation correction factor depending on the horizon line was presented. The influence of light shading on the current and voltage characteristics of a solar module was determined. Streszczenie. W pracy przedstawiono skladowe promieniowania slonecznego docierającego do powierzchni horyzontalnej oraz sposob wyznaczenia wartości energii promieniowania padającej na powierzchnie odbiornika fotowoltaicznego nachylonego pod pewnym kątem do ziemi. Zamieszczono diagram oceny cieniowania oraz metodyke wyznaczenia kątow pionowych i wplywu horyzontu na cieniowanie odbiornika PV. Przedstawiono sposob wyznaczania wspolczynnika korekcyjnego promieniowania bezpośredniego wywolanego linią horyzontu. Określono wplyw slabego cienia na charakterystyke prądowo-napieciową modulu solarnego. (Analiza wplywu cieniowania ogniw PV przez horyzont na parametry pracy systemu fotowoltaicznego).

Thermal Time Constant of PV Roof Tiles Working under Different Conditions

Abstract: This paper presents different types of photovoltaic (PV) roof tiles integrating PV cells with roof covering. Selected elastic photovoltaic roof tiles were characterised for their material and electrical characteristics. Practical aspects of using PV roof tiles are discussed, alongside the benefits and drawbacks of their installation on the roof. Thermal resistance, heat transfer coefficient and thermal capacity were identified for elastic PV roof tiles and roof construction built of boards and PV roof tiles, according to valid standards and legal regulations. The resistance–capacity (RC) models of PV roof tiles and roofs are proposed according to the time constants identified for the analysed systems. The energy balance of the studied systems (PV roof tiles alone and the roof as a whole) is presented, based on which temperature changes in the PV cells of the roof tiles working under different environmental conditions were identified. The timing of PV cells’ temperature change obtained by material data and energy balance analyses were compared. The relationship between the temperature change times of PV cells and the thermal resistance and heat capacity of the whole system are demonstrated, alongside environmental parameters.

Analysis and Evaluation of the Photovoltaic Market in Poland and the Baltic States

Abstract: : The household, industrial, and service sectors in Poland and the Baltic States have been facing ever-higher bills for their electricity consumption at a time when a number of them have been hit hard financially by the pandemic. Rising inflation, the border crisis—with its set of restrictions, or the spread of the fourth wave of the COVID-19 coronavirus pandemic, is causing strong concerns in the social and economic sphere, with significant increases in electricity prices. Many countries are implementing measures to reduce the adverse effects of rising electricity prices in response to this complex situation. The main orientation is towards obtaining energy from renewable sources, such as the sun. The current situation in the energy market determines the price per 1 KW. Among the countries under study, the price of electricity has increased the most in Poland. On the other hand, the development of the photovoltaic segment in Poland is undergoing a strong, upward trend. The above inspired the authors to explore the energy market situation in Poland and the Baltic States in the current economic conditions, along with an analysis of its development potential in light of the coronavirus pandemic. The main research problem of this study is an attempt to answer the question of what should be changed in the development of the renewable energy market in Poland, with particular emphasis on photovoltaics, to accelerate the process of reducing CO 2 emissions, leading to a reduction in dramatically rising electricity prices. Which solutions implemented in the Baltic countries can inspire strengthening Poland’s energy market development?

Analysis and Evaluation of the Photovoltaic Market in Poland and the Baltic States

Abstract: The household, industrial, and service sectors in Poland and the Baltic States have been facing ever-higher bills for their electricity consumption at a time when a number of them have been hit hard financially by the pandemic. Rising inflation, the border crisis—with its set of restrictions, or the spread of the fourth wave of the COVID-19 coronavirus pandemic, is causing strong concerns in the social and economic sphere, with significant increases in electricity prices. Many countries are implementing measures to reduce the adverse effects of rising electricity prices in response to this complex situation. The main orientation is towards obtaining energy from renewable sources, such as the sun. The current situation in the energy market determines the price per 1 KW. Among the countries under study, the price of electricity has increased the most in Poland. On the other hand, the development of the photovoltaic segment in Poland is undergoing a strong, upward trend. The above inspired the authors to explore the energy market situation in Poland and the Baltic States in the current economic conditions, along with an analysis of its development potential in light of the coronavirus pandemic. The main research problem of this study is an attempt to answer the question of what should be changed in the development of the renewable energy market in Poland, with particular emphasis on photovoltaics, to accelerate the process of reducing CO2 emissions, leading to a reduction in dramatically rising electricity prices. Which solutions implemented in the Baltic countries can inspire strengthening Poland’s energy market development?