[en] This Risoe Energy Report, the ninth in a series that began in 2002, analyses the long-term outlook for energy technologies in 2050 in a perspective where the dominating role of fossil fuels has been taken over by non-fossil fuels, and CO₂ emissions have been reduced to a minimum. Against this background, the report addresses issues like: 1) How much will today's non-fossil energy technologies have evolved up to 2050? 2) Which non-fossil energy technologies can we bring into play in 2050, including emerging technologies? 3) What are the implications for the energy system? Further, Volume 9 analyses other central issues for the future energy supply: 4) The role of non-fossil energy technologies in relation to security of supply and sustainability 5) System aspects in 2050 6) Examples of global and Danish energy scenarios in 2050 The report is based on the latest research results from Risoe DTU, together with available international literature and reports. (Author)