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

• Published in: Solar energy Vol. 87; pp. 184 - 195
• Main Authors: Yin, H.M., Yang, D.J., Kelly, G., Garant, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2013; Elsevier; Pergamon Press Inc
• Subjects: Applied sciences; Building integrated photovoltaic/thermal system; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Energy; Energy consumption; Energy efficiency; Equipments, installations and applications; Exact sciences and technology; Functionally graded materials; Heat conductivity; Hybrid solar roofing panel; Materials; Modular design; Natural energy; Phase change materials; Photoelectric conversion; Photovoltaic cells; Photovoltaic conversion; Solar cells. Photoelectrochemical cells; Solar energy; Solar heat collector; Thermal energy; Phase change materials; Modular design; Hybrid solar roofing panel; Functionally graded materials; Building integrated photovoltaic/thermal system; Solar heat collector; Water; Performance evaluation; High density ethylene polymer; Water flow; Composite material; Optimization; Indoor installation; Energetic efficiency; Functionnally graded material; Photovoltaic array; Thermal conductivity; Integrated system; Silicon; Roofing; PCM material; Thermal conductor; Thermal comfort; Cooling; Thermal insulation; Photovoltaic system; System design; Aluminium; Solar heating; Solar hybrid technology; Thermal energy; Cooler; Protective layer; Solar energy
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2012.10.022

► We designed a BIPVT system for multi-functions in energy efficient building. ► The hybrid solar panel provides synergistic benefits for energy harvesting and saving. ► The functionally graded material with water tubes enhances structural integrity. ► The performance and cost analysis show great potential and economic viability. ► The holistic design is applicable to various PV and thermoelectric cells. 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.