1. Department of Renewable Energy Engineering, West Pomeranian University of Technology in Szczecin, 71-459 Szczecin, Poland
2. Institute of Automation and Electronics and Electrical Engineering, University of Zielona Góra, 65-417 Zielona Góra, Poland
3. Institute of Management, University of Szczecin, 70-453 Szczecin, Poland
4. Faculty of Economics and Management, Opole University of Technology, 45-758 Opole, Poland
5. Institute of Management, University of Social Sciences, 9 Sienkiewicza Str., 90-113 Lodz, Poland
6. Institute of Economics and Finance, University of Szczecin, 70-453 Szczecin, Poland
7. Faculty of Economics, The Jacob of Paradies University in Gorzów Wielkopolski, 66-400 Gorzów Wielkopolski, Poland