Proceedings of a symposium jointly organized by the EC, ESCAP, IAEA, IIASA, OECD/NEA, OPEC, UNEP, UNIDO, IBRD and WMO, Vienna, 16-19 October 1995. The symposium was convened as part of the inter-agency joint project on databases and methodologies for comparative assessment of different energy sources for electricity generation (DECADES). Its objective was to enhance and strengthen information sharing and co-operation between interested and affected parties in the field of electricity demand analysis and supply planning, aiming at implementing sustainable policies in the power sector, taking into account economic, social, health and environmental aspects.