1. Smart Grid Research Centre, Institute of Physical Energetics 14 Dzērbenes Str ., Riga , , Latvia
2. Management Information Systems Department , University College Dublin Belfield , Dublin 4, , Ireland
3. Electrical Engineering Department , Eindhoven University of Technology 5600 MB Eindhoven , The Netherlands
4. Energy Systems Department, SINTEF Energy Research Sem Sælands vei 11, 7034 Trondheim , Norway
5. FOSS Research Centre for Sustainable Energy , University of Cyprus Nicosia , Cyprus