1. IREC—Catalonia Institute for Energy Research, 08930 Sant Adrià de Besòs, Spain
2. Departament d’Enginyeria Electrònica i Biomèdica, IN2UB, Universitat de Barcelona, 08028 Barcelona, Spain
3. University of Oslo, P.O. Box 1048
Blindern, 0316 Oslo, Norway
4. Photovoltaic Group, Electronic Engineering Department, Universitat Polytècnica de Catalunya (UPC), 08034 Barcelona, Spain
5. Martin-Luther-University Halle-Wittenberg, 06099 Halle (Saale), Germany
6. DTU—Technical University of Denmark, 2800 Kgs. Lyngby, Denmark