Serbia is dependent on imports of crude-oil and natural gas, but is endowed by reserves of lignite and the potential of renewable energy sources. Serbia has a strategy to reduce greenhouse gas emissions in the energy sector and to increase the share of renewable in gross final energy production 27% by 2020. Serbia?s total estimated technically usable potential of renewable energy sources is 5.65 Mtoe per year. Biomass has the highest potential for use in Serbia (3.448 Mtoe), followed by hydro power (1.679 Mtoe), solar energy (0.240 Mtoe), geothermal energy (0.180 Mtoe), and wind energy (0.103 Mtoe). This paper presents the potential of renewable energy sources available in Serbia, with current status of their use and prospects for further exploitation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 179013: Sustainability of the Identity of Serbs and National Minorities in the Border Municipalities of Eastern and Southeastern Serbia]

The buildings are among major energy consumers, whose energy efficiency is rather low. Clerestory windows are responsible for a large portion of energy losses from the buildings. The energy efficiency of buildings can greatly be improved by upgrading clerestory and other windows. This paper focuses on the theoretical and experimental investigations on how this can be performed in an old school building in the town of Bor in eastern part of Serbia. For that purpose a modern measuring technique has been applied to identify the existing status, and to compare theoretical and actual conditions.