Global energy demand has grown steadily since the industrial revolution. During the two decades from 1991 to 2012, total primary energy demand (TPED) grew from 91,200 to 155,400 TWhth, or by 70%, and projections expect this number to increase by a further 40% by 2040. Although greenhouse gas emissions in the energy sector have to be reduced to zero by mid-century or earlier to avoid an ecologic disaster, less than 15% of this energy demand is supplied by renewable resources nowadays. The International Energy Agency (IEA) has a significant impact on both political and economic decisions of governments and stakeholders regarding energy. The World Energy Outlook (WEO) report published annually by the IEA projects for the decades to come how TPED and electricity generation, amongst others, will evolve for all major technologies. Since the WEO is often used as a basis for policy making on renewable and conventional energy, a comprehensive analysis of past WEO projections is crucial. Such analysis will ensure well-grounded and realistic energy policy making and can contribute to efforts to fight climate change and to achieve energy security.