The concept of combining both solar thermal and electric systems is not new yet the limited use and further development needed has been noted by both the Department of Energy in the U.S. [1] and the EU Coordination Action PV-Catapult in Europe [2]. These reports and the university’s solar house entry in the Department of Energy’s 2005 Solar Decathlon provided the opportunity for research and development of a hybrid roof system that combined both photovoltaics with a wet solar thermal system. The main goal of this research was to design and develop a hybrid roof system based on previous research. Once designed then build a prototype model for the purpose of performance analysis with the final stage being the implementation in the university’s solar house entry into the 2005 solar decathlon. This paper discusses the hybrid roof design and performance analysis. The design and development was initialized by a group of students and advisors from both the University of Missouri-Rolla and Crowder College with the intent to use the hybrid system as part of the solar houses in the upcoming solar decathlons. Previous research studies on hybrid roof systems have shown increased performance however the differences in the systems studied vary in their setups and use of materials. In the case of this study a series of copper tubes were integrated into a metal seam roof with an amorphous silicon panel encased in low iron glass. This experiment encompassed almost 160 square feet of hybrid Solar Thermal Electric Panel (STEP) system panels and performance data acquired was used for input to computer simulation software to optimize the system for application. Based on experimental tests the STEP system yielded overall efficiency of 50%. This is compared to a separate thermal and electric system with an estimated 26% for the same roof area. The glazed versus unglazed analysis yielded a glazed panel reducing the PV collection by 23% yet increasing the thermal collection by approximately 200%. In conclusion this paper will discuss experimental performance analysis on the STEP system thermal and overall outcomes.
Optical Design and Performance Analysis of Linear Focusing Solar Thermal Collectors
