Portal de Periódicos da CAPES

Design and performance of a novel building integrated PV/thermal system for energy efficiency of buildings

2012; Elsevier BV; Volume: 87; Linguagem: Inglês

10.1016/j.solener.2012.10.022

1471-1257

Huiming Yin, Daiqin Yang, George Kelly, John Garant,

Building Energy and Comfort Optimization

A building integrated multifunctional roofing system has been designed to harvest solar energy through photovoltaics (PVs) and heat utilization while minimizing PV efficiency loss and eliminating the material and labor redundancies of conventional PV systems. Silicon PV modules are embedded between a transparent protective layer and a functionally graded material (FGM) layer that is fabricated from a mixture of heat conducting aluminum and insulating high density polyethylene with water tubes cast within the FGM. Solar energy is collected by the PV modules in the form of PV electricity and heat energy. Due to high thermal conductivity of the upper part of the FGM, the heat in the PV modules is transferred into the FGM and is captured by the water flowing through the embedded tubes, so the modules' temperature can be controlled and, thus, the PV efficiency can be optimized. The warm water can be used as it is gathered for heat supply in a radiant floor systems or it is heat can be extracted into a phase change material (PCM) storage unit, for use in nighttime heating or more efficient ejection during cooler evening hours. Due to the high thermal insulation of the lower part of the FGM and heat collection by water flow, excellent indoor thermal comfort can be achieved and building cooling needs minimized. A thermal resistive structural substrate is integrated into the composite system to provide structural support for FGM and PV elements. This holistic design will fulfill the basic functions of the building envelope: waterproofing, insulation, and structural strength and durability, while simultaneously producing energy and reducing energy consumption to achieve a high degree of energy efficiency and sustainability. A prototype study has proven the concept. The performance analysis indicates that the proposed solar roofing system provides significant advantages over the traditional asphalt shingle roof and PV systems without cooling.