Solar options are evaluated as a potential source for meeting future energy supply requirements. Emphasis is on contemporary concepts in the solar-thermal and photovoltaic systems and their space, as well as economic constraints. The range of uncertainties during this formative stage of solar technology is shown in typical examples of performance and cost estimates. The broad spectrum of assessed information is synthesized and condensed for general information as an interim report. The fundamental trends of the continuing efforts in the subject field are identified.