Development of an Automatic Heliostat Cleaning System. Final Technical Report

摘要

An automatic washing system was designed consisting of a water treatment system, a pressurized underground water distribution system, an automatic spray washing module for each heliostat, a water collection system, and appropriate controls to operate this equipment. In order to determine the required values for the various washing parameters, a series of washing tests was undertaken in which mirrors were soiled and then cleaned by a high pressure water spray. Reflectivity was measured for the clean, soiled and washed conditions to determine the effectiveness of the cleaning. A heliostat spray module was constructed and operated mainly to obtain information on the mechanical operation of one concept. This testing showed that this system was generally satisfactory, but did show some areas for improvement. Water distribution and waste water systems were designed and evaluated with the main conclusion that conventional waste water collection is complex and the most expensive part of the system. The total system is shown to be cost effective if site meteorological conditions do not supply a large number of cycles of natural cleaning occurrences. Continued development of this concept by constructing a small scale washing system within an existing heliostat field is recommended. (ERA citation 06:007198)