Review of energy consumption and co<inf>2</inf> emission in school buildings: Case study of the city of kragujevac

© 2019 Published by the Serbian Academic Center. Annual energy consumption in Kragujevac elementary schools is 1.909 MWh of electric energy and 12.510 MWh of heat energy, while the total CO2 emission is 6.406 t. This paper provides an overview of energy consumption and CO2 emissions in 61 elementary school buildings, divided in 12 groups. The goal of this paper is to determine which group of school facilities, depending on the year of construction and area, consumes the most energy and produces the most CO2 emissions. It has been shown that most electrical (36,33%) and heat (41,42%) energy are consumed in the school buildings constructed in the period 1971-1990. Most CO2 emissions (40,39%) come from energy consumed in the school buildings constructed in the same period. It is this group of buildings that represents a significant potential for energy savings and reduction of CO2 emissions, through the implementation of various energy efficiency measures

Optimal position of solar collectors: A review

© 2018, Serbian Academic Center. All rights reserved. Solar energy is the most abundant, inexhaustible and clean of all the renewable energy resources till today. Solar energy has received much more attention in building energy systems in recent years. During the first years of the twenty-first century, extensive efforts have been undertaken to alleviate global warming of the earth caused by emission of CO2 in atmosphere. These emissions are generated by intensive burning of fossil fuels to satisfy the growing energy needs of humanity. The emissions may be mitigated when part of energy needs is satisfied by using non-polluting energy sources such as solar energy, instead of fossil fuels. In households, customary is to use electricity for heating of DHW. Most of electricity is produced by using coal with high greenhouse emission. Accordingly, worldwide, the most rewarding application of solar energy is when it replaces electrical energy for heating of DHW in households. The solar collector has to take the optimal position that will guarantee the highest generation of heat. Optimal positioning must be based on rigorous calculations and not on the basis of experience. Such calculations lead to the improvement of the operation of solar energy systems. This paper gives a review of research with the objective of presenting, classifying and analysing the different criteria by which the authors observed an optimal position of the solar collector. In addition, it is important to have a high efficiency of conversion of solar energy to heat. Then, the highest amount of avoided primary energy, avoided electrical energy, avoided exergy, and decrease in CO2 emissions may be expected