This proceeding book covers the technical aspects of concentrating photovoltaics (CPV). CPV technology uses optics to concentrate the sunlight onto a solar cell made of semiconductor materials. Silicon solar cells are used at low concentration levels between 2 and 100. At high concentration, typically > 300, the solar cell area is greatly reduced and more expensive technologies like III-V multi-junction solar cells can be used to increase conversion efficiencies. The CPV technology is competitive in arid regions of the world with high solar intensities and will allow to further reduce the cost of solar electricity in the future. The state-of-the art for the technology, but also critical issues are summarized in this proceeding book. Thus, this book is the most up to date and comprehensive summary for the CPV technology written by the most prominent scientist and engineers active in the field.