1. USDE, United States Department of Energy, A national version for electricity’s second 100 years (Office of Electric Transmission and Distribution, 2003), p. 89
2. ESGTP, European Smart Grids Technology Platform, Vision and Strategy for Europe’s Electricity (2006), p. 44
3. SRA, Strategic Research Agenda Update of the Smart Grids, SRA 2007 for the needs by the year 2035 (2012), p. 72