A solar simulator has been designed and built for testing prototype (0.5 ×0.5 m) flat plate thermal collectors. An internally reflecting light tube generates multiple virtual images of the four halogen floodlights to ensure uniform illumination. Ray-tracing simulations were used to choose the tube dimensions and maximum allowable clearance. Illumination measurements agree well with these predictions.The visible & near IR spectrum appears to follow a black body curve. In the absence of a “cold sky” IR filter there is a secondary, long wavelength IR spectral component that causes heating of the cover glass on a solar flat plate collector. The cover glass temperature can be maintained at typical outdoor levels using a cooling fan. The design would be well suited to LED illumination.Simulation of solar collector response to this spectrum shows that an efficiency based on pyranometer readings is approximately 1% higher than would be obtained with an AM1.5 spectrum.
- Black body
Moss, R., Shire, S., Eames, P., Henshall, P., Hyde, T., & Arya, F. (2018). Design and commissioning of a virtual image solar simulator for testing thermal collectors. Solar Energy, 159, 234-242. https://doi.org/10.1016/j.solener.2017.10.044