1. Energy Department, Politecnico di Milano, Via La Masa 34, 20126 Milano, Italy
2. Chair on System Science and Energetic Challenge, Fondation EDF, Centrale Supélec, Chatenay-Malabry Cedex, 92295 Paris, France
3. Idaho National Laboratory, Idaho Falls, ID 83415, USA
4. EDF R&D, 92141 Clamart Cedex, France