Foresight is a vital prerequisite in order to bring our current energy system onto the path of sustainable development. Which technologies may be available in 25 years from now? Which technologies will be needed in the future? The European Energy Delphi project - EurEnDel aimed at bri- ing orienting knowledge to these two questions. Trying to show a glimpse of European Energy Futures in the year 2030. This book contains the main results of the EurEnDel project. It includes the findings of the European Energy Delphi survey and the resulting recommendations for R&D policy. In comparison to other industry sectors, energy has two very remarkable features: For one, transformations are very slow. Life-times of power plants are 30 years and longer. Thus the decisions we take today will still have impacts 30 to 50 years from now - which makes sound foresight so important. On the other hand, the energy system is strongly dependent on national political decisions. Priority setting may change quite drastically with new parties coming to power, at least for individual country. This is one of the reasons, why predictions in the energy field can be extremely difficult. Combining these two characteristics it becomes evident why foresight in the energy field must not be restricted to an analysis of what the future could be like, but must always assess what the future should be like. This book tries to weave together these two traces which were inh- ent in the EurEnDel project.