The members of the Organizing and the Scientific Committees of ECOS 2003 are pleased to present these Proceedings of the Conference. This is the sixteenth in the series of international conferences that started in Rome in 1987. The slogan chosen for this years conference "Bridge to Our Energy Future" is inspired by the fact that we live in a period of transition: a transition towards deregulated energy markets, towards renewable energy, towards distributed power generation, and towards a CO2-neutral economy. This transition will occur over many years on a human time scale, but almost instantly on a geological time scale. Our natural resources are being consumed at a dizzying speed compared to the time required to accumulate the same resources. This worries many informed observers of both the industrial and the developing worlds. Being here at this time in history and working in the field puts us in an enviable position of privilege and obligation to commit our efforts to the solution of these problems. It should also be mentioned that the choice of slogan of the conference has been inspired by the very extensive construction of bridges that has taken place in the Nordic countries in recent years. ECOS 2003 distinguishes itself through the quality and quantity of the papers submitted for presentation. Without the effort of dedicated researchers and authors from all over the world, this conference could not have taken place. We recognize and appreciate the creativity and work that have gone into the production of the more than 200 papers contained in the Proceedings. The reviewing of this extensive material was carried out by more than one hundred dedicated and highly qualified researchers. We are much indebted to them for their effort, in particular in view of the tight time schedule under which they often worked. Several distinguished and authoritative keynote speakers have contributed to the general theme of the conference, through presentation of their views on central factors that will influence the future in their chosen fields of specialty. The subject matter ranges from overall national planning to technological development, from government-initiated development of market forces to the completely liberalized market, from government-supported development to private investment opportunities, and from centralized generation of electricity from fossil fuels to distributed generation of electricity from renewable energy resources. Summaries of their talks are also included in the Proceedings. We wish to thank our sponsors for removing some of the anxiety of arranging a conference in these turbulent times, all the authors of the papers contained in the Proceedings of this conference, our coworkers, our reviewers, the secretariat, and finally the cooperating institutions and organizations listed in the Proceedings.