Component report performance of solar collector arrays and collector controllers in the National Solar Data Network

The accumulated National Solar Data Network (NSDN) data has been analyzed with regard to collector and collector control performance. The collector data is presented in the ASHRAE format as efficiency vs. operating point, (T/sub inlet/ - T/sub ambient/)/insolation. Collector controls were analyzed by determining the losses caused by control problems common to the NSDN solar systems. This study of collectors and collector controls has several objectives: To compare actual and predicted collector performance; to determine which generic types of components performed well and which performed poorly; to determine why predicted performance was not achieved in the field; to determine the types and causes of failures; to determine the reliability weaknesses; and to determine whether there are any component integration problems. To accomplish these objectives, the work was divided into two parts, the first part was dedicated to the collector component and the second part covered the control component. The report is organized similarly, and also includes a description of each solar system (Appendix A) and a discussion of the interactions between the components.