Danica Pirsl

Energy efficiency of PV solar plant in real climate conditions in Banja Luka

In this paper comparison of experimentally obtained results of energy efficiency of PV solar plant of 2.08 kWp installed on the roof of the Academy of Sciences and Arts (ASARS) in Banja Luka (Republic of Srpska) in the real climate conditions in 2013 and 2014 are given. It was found that energy efficiency of PV solar plant from April till November 2013 was 12.28%, and in same period in 2014 was 13.03%. Also, it was found that the increase in the ambient temperature by 1°C, PV solar plant efficiency decreases by 0.43% from April till November 2013, and by 0.27% in the same period in 2014.

ASSESSMENT OF THE POSSIBILITIES OF BUILDING INTEGRATED PV SYSTEMS OF 1 kW ELECTRICITY GENERATION IN BANJA LUKA

The paper focuses on the analysis and assessment of the possibilities of building integrated PV (BIPV) systems of 1 kW electricity generation in Banja Luka in the Republic of Srpska. Special attention was paid to average monthly sum of global solar irradiation per square meter received by horizontally, optimally and vertically inclined and south-oriented solar modules of 1kW BIPV system and total for year electricity production from 1 kW BIPV system with horizontally, optimally and vertically inclined and south-oriented solar modules of different materials for Banja Luka, obtained by PVGIS. In addition, comparison was made of total for year electricity production of 1kW BIPV system with horizontal, optimal and vertical inclination and south-oriented solar modules of monocrystalline silicon, CdTe and CIS in Banja Luka. The research estimated the proportion of BIPV systems power generation according to different types of PV modules and installation methods. The data could serve as a useful reference for the application of BIPV systems in buildings.

RAZVOJ DINAMICKE SNAGE KOD UCENIKA OSNOVNIH ŠKOLA

Na uzorku od 50 ispitanika muskog pola ucenika osnovnih skola u Nisu, hronoloske starosti 12 god izvrseno je istraživanje sa ciljem da se utvrdi uticaj primene kružnog oblika rada u nastavi fizickog vaspitanja sa težnjom da se poboljsa eksplozivna i repetativna snaga kod ucenika u redovnoj nastavi. Sem toga cilj je bio i da se utvrde razlike u dinamickoj snazi izmedu ucenika eksperimentalne i kontrolne grupe. Eksperiment se sastojao u tome da je ukupan uzorak bio podeljen na dva subuzorka sa po 25 ispitanika u grupi. Eksperimentalna grupa je na redovnim casovima u trajanju od 3 meseca ili 25 casova. Posle vežbi oblikovanja radila specijalne vežbe za razvoj eksplozivne i repetativne snage kružnim oblikom rada u trajanju od 10-12 minuta nakon cega su nastavljali sa normalnim radom u glavnom delu casa. Kontrolna grupa (25 ispitanika) za to isto vreme radila je regularan program nasatve fizickog vaspitanja koje je dalo Ministarstvo prosvete Republike Srbije. Izvrsena su 2 merenja dinamicke snage na pocetku rada i na kraju eksperimenta na celokupnom uzorku i to baterijom od 6 testova (3 za repetativnu snagu i 3 za eksplozivnu snagu). Dobijeni rezultati statisticki su obradeni i prikazani kroz 4 tabele. Analizom reziltata utvrdeno je da je eksperimentalna grupa dobila statisticki znacajno poboljsanje dimanicke snage u odnosu na ispitanike kontrolne grupe koji su takode poboljsali svoju dinamicku snagu ali ti rezultati nemaju statisticki znacaj.