1. Laboratory of Energy Systems Research, Lithuanian Energy Institute, Breslaujos 3, 44403 Kaunas, Lithuania
2. Institute of Environmental Engineering, Kaunas University of Technology, K. Donelaičio 73, 44249 Kaunas, Lithuania
3. School of Economics and Business, Kaunas University of Technology, K. Donelaičio 73, 44249 Kaunas, Lithuania