Study and optimization of a novel asymmetric photovoltaic/thermal hybrid solar collector

Abstract

Solarus is one company in Sweden which is developing solar collectors. The type of collector that is developed at the moment is an asymmetrical low-concentrating PV/T Collector that can produce both electrical and thermal power. This collector consists of two similar troughs where each trough has one absorber and PV cells at the top and the bottom of the absorber. The main purpose of this thesis work is to investigate the performance of PV/T collector from Solarus with two different sides, transparent and reflective end gables. Temperature dependency is also interesting to be analyzed in order to see the difference power output in various temperatures. Doing literature study, preparing the test rig, installing PV/T collectors into test stand, and solving the problems are the way how this thesis works. Finding proper control valves, removing air bubbles, making new fitting, and building new support stands are the parts of troubleshooting that has already been done. When all the systems are ready, measurement can be performed. The first task was to figure out the I-V curve for the PV cells. After that, daily performance was done for both troughs with transparent and reflective end gables. During that measurement, the flow rate was set constant of 25 l/h. The last experiment is varying the flow rate to get different temperature for PV cells. There is no significant difference in electrical output between the trough which is using transparent and reflective end gables. Solarus should review of these end gables again especially for economic issue. The other experiments such as incident angle modifier (IAM) and trajectory movement should be performed and analyzed to improve the performance of the collector. For example, by modifying the IAM, the maximum angle can be found for this type of collector because in this thesis work, only fixed angle or 36° was used. Both transversal and longitudinal IAM should be performed and analyzed for optimizing this collector. Moving the collector could not be performed because of the limitation of the test stand. By turning out the collector to the sun means the collector will receive more direct than beam radiation. The direct radiation is much more important for this low concentrating collector than beam radiation