A Message From the Guest Editors

This special issue of JSEE is devoted to concentrating solar thermal technologies and applications, usually known by the acronym CSP for Concentrating Solar Power. 18 research papers and 7 technical briefs have been selected from the 13th SOLARPACES International Symposium on Concentrated Solar Power and Chemical Energy Technologies held in Seville, Spain, in June 2006. Additional selected papers from the symposium are scheduled for forthcoming issues of JSEE. The focus on CSP is justified by the recent revival of solar thermal power markets. This issue compiles recent works dedicated to develop new technological solutions for advanced solar thermal power plants, solar fuels production, and solar detoxification.

Direct Steam Generation (DSG) in parabolic troughs has sufficiently matured to begin scaling-up and may become an efficient and cost-effective alternative to current technologies. The design and testing of a water separator—a key DSG collector-field component for operating in recirculation mode—is presented here. Another challenging aspect pertinent to DSG technologies is heat storage via phase change materials, which are investigated in the framework of the European project DISTOR. New schemes for solar tower power plants are on the verge of commercialization, offering better dispatchability and energy conversion efficiencies. Examples include the projects: SOLAR TRES—which uses molten salt as thermal fluid—and PEGASE—which uses pressurized air solar receivers. In addition, correlations are provided for the main design parameters of large scale beam-down solar concentrating systems. Selected papers are included on the latest developments in heliostats and receivers. Dish Stirling systems need improved availability through extended testing campaigns. Several 10-kW EURODISH units are subject to comparative testing, and thermal modelling of two units tested in Seville and Odeillo are also presented. A new methodology based on high-resolution slope measurement was developed for the optical characterization of parabolic dish concentrators. Solar thermochemical production of hydrogen is experiencing increased research activities worldwide. Solar routes presented in this issue are based on redox reactions of zinc, boron, and iron-containing YSZ. Uncertainties regarding high-temperature materials, products separation, and recyclability still need to be addressed, but life cycle assessments for solar thermal hydrogen reveal the potential of reducing greenhouse gas emissions by at least 75%.

We would like to thank the authors, the reviewers, and the JSEE Editor who helped us assemble this thematic special issue on CSP technologies and applications.

Organizing Committee of the13th SOLARPACES International SymposiumSeville, Spain, 2006