A comparison of actual and simulated conditions on the performance of solar collectors

One of the problems in solar energy education is providing the opportunity for students to get hands-on experience. Conducting a solar energy laboratory outdoors is not always conducive nor practical for obvious disadvantages such as limited daylight and inclement weather. Furthermore, the many uncontrollable variables encountered during outdoor testing, such as intermittent cloud cover, variable wind speeds, etc., can lead to difficulties when analyzing solar collector performances. Many of these problems can be circumvented by testing collectors under controlled conditions using a solar simulator. However, since exact duplication of the solar spectrum by artificial means is unaffordable to many university lab facilities, a trade-off is often introduced between cost and accuracy. At the University of Toledo, a low-cost solar simulator was designed and constructed allowing for the testing of various collectors. The tests under simulated conditions were compared to the outdoor performance under actual conditions. Therefore, this paper addresses the educational aspects of solar energy by means of studying what influence a low-cost simulated test condition has on the actual performance of a solar collector.