Search results for "Insolation"
showing 8 items of 8 documents
A Finite Difference Model of a PV-PCM System
2012
Abstract The performances of a photovoltaic panel (PV) are defined according to the “peak power” that identifies the maximum electric power supplied by the panel when it receives an insolation of 1 kW/m2 and the temperature of the cell is maintained at 25 °C. These conditions are only nominal since the solar radiation has a variable intensity and also the panel is subjected to thermal excursions; due to these reasons the real power efficiency of the panel is considerably lower than that obtainable in the nominal conditions. The study focused on assessing a method to reduce the peak temperatures of PV systems using Phase Change Materials (PCM). To this aim it was created a numerical model ca…
Application of the reduced I-V Blaesser’s characteristics in predicting PV modules and cells conversion efficiency in medium and high insolation cond…
2017
Abstract The article presents theoretical foundations of application of the reduced I-V Blaesser’s characteristics in predicting a photovoltaic cell/module (PV) efficiency, together with calculation procedures. A detailed analysis of the error of this transformation method of characteristics was carried out. Its practical application in predicting efficiency of operation of various PV cells and modules in medium and high insulation conditions was demonstrated. The practical suitability of the presented method in early detection of ageing phenomena, such as, for example, absorber degradation taking place in PV modules, was demonstrated. The article was prepared on the basis of the results of…
Scientific and methodical foundations of heat saving of rural territories on the basis of use of local biomass
2018
W ostatnich latach gaz ziemny na Ukrainie, a w szczególności w regionie połtawskim,wykorzystywany jest najczęściej do ogrzewania prywatnych domów. Niestety co roku państwo podnosi cenę gazu. Koszty ogrzewania stają się dla mieszkańców wsi dużym obciążeniem. Wcześniej na wsi tradycyjnie budowano domy o dużej powierzchni. Dlatego obecnie wspólnoty terytorialne szukają alternatywnych sposobów ogrzewania. W celu oszczędzania ciepła ważnymi dla nich stają się zagadnienia związane z izolacją budynków mieszkalnych, zakładów produkcyjnych. Głównym celem artykułu jest analiza możliwości wykorzystania biomasy jako materiału termoizolacyjnego oraz źródła energii alternatywnej. Przedstawiono doświadcze…
Analysis of Solar Energy Resources in Southern Poland for Photovoltaic Applications / Analiza Struktury Zasobów Energii Słonecznej Obszaru Polski Poł…
2013
Abstract The article presents an analysis of the resources and the structure of the solar energy in the area of Southern Poland on the basis of complete meteorological data from the AGH University of Science and Technology in Krakow in 2009. An analysis attempt of its use for photovoltaic conversion using different modules with different spectral characteristics of absorbers was made. These latest methods for characterizing the structure of solar energy resources such as: distributions throughout the year: sky clearness or cloudiness indexes, the average values of photon energy (APE) and the contents of the useful fraction (UF) of the solar spectrum, are not yet widely known and used as in …
Comparison of quantitative Holocene temperature reconstructions using multiple proxies from a northern boreal lake
2017
Four biotic proxies (plant macrofossils, pollen, chironomids and diatoms) are employed to quantitatively reconstruct variations in mean July air temperatures ( Tjul) at Lake Loitsana (northern Finland) during the Holocene. The aim is to evaluate the robustness and biases in these temperature reconstructions and to compare the timing of highest Tjul in the individual reconstructions. The reconstructed Tjul values are evaluated in relation to local-scale/site-specific processes associated with the Holocene lake development at Loitsana as these factors have been shown to significantly influence the fossil assemblages found in the Lake Loitsana sediments. While pollen-based temperatures follow…
Correlation between relative sunshine and state of the sky
1981
Abstract It is possible to construct a sunshine map referring to a large zone, lacking in a widespread network of recording stations, correlating the relative sunshine with the “state of the sky”, defined by the monthly mean number of the clear, mixed and overcast days, whose data are more largely available. In the correlation here proposed climatological and meteorological factors are introduced in order to express the helioclimatic characteristics of every location. The application to Italy, using the data of the period 1973–1977 provided by the 31 stations of ITAV, has suggested the classification of these stations in seven “helioclimatic groups” characterized by different values of the …
The mean daily insolation
1953
Cheap Sensor Made of Multicrystalline Silicon for Insolation and Temperature Measurements
2016
Abstract In the paper some results on measurement of insolation and „real” cell’s temperature carried out with use of standard silicon solar cells are presented. Two identical cells are applied in such a sensor. Short circuit current of one cell is a direct indication of insolation value and open circuit voltage of the other cell is indirect indication of actual sensor’s temperature but in this case more complex formula must be used for temperature calculation.