Integral energy performance characterization of semi-transparent photovoltaic elements for building integration under real operation conditions

• Published in: Energy and buildings Vol. 68; pp. 280 - 291
• Main Authors: Olivieri, L., Caamaño-Martin, E., .Olivieri, F, Neila, J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.01.2014; Elsevier
• Subjects: Applied sciences; BIPV modules; Building integrated photovoltaics; Building technical equipments; Buildings; Buildings. Public works; Energy efficiency; Energy management and energy conservation in building; Environmental engineering; Exact sciences and technology; Experimental study; Semi-transparent photovoltaics; Spain, Castilla, Madrid; Energy efficiency; Experimental study; Building integrated photovoltaics; Semi-transparent photovoltaics; BIPV modules; Performance evaluation; Energy analysis; Buildings; Semitransparent medium; Photovoltaic system; Experimental device; Climatic engineering; Characterization; Daylight; Energetic efficiency; Integrated system; Thermal analysis
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2013.09.035

•Design development and construction of an outdoor testing facility for STPV modules.•Global performance assessment of STPV modules in real operation conditions.•STPV solar gains and heat losses exceed the values achieved by a reference glass.•STPV daylight factor ranges between 1% (10S) and 8% (40S).•Transparency degree is not the most determining factor for the STPV electrical performance. In this paper, a methodology for the integral energy performance characterization (thermal, daylighting and electrical behavior) of semi-transparent photovoltaic modules (STPV) under real operation conditions is presented. An outdoor testing facility to analyze simultaneously thermal, luminous and electrical performance of the devices has been designed, constructed and validated. The system, composed of three independent measurement subsystems, has been operated in Madrid with four prototypes of a-Si STPV modules, each one corresponding to a specific degree of transparency. The extensive experimental campaign, continued for a whole year rotating the modules under test, has validated the reliability of the testing facility under varying environmental conditions. The thermal analyses show that both the solar protection and insulating properties of the laminated prototypes are lower than those achieved by a reference glazing whose characteristics are in accordance with the Spanish Technical Building Code. Daylighting analysis shows that STPV elements have an important lighting energy saving potential that could be exploited through their integration with strategies focused to reduce illuminance values in sunny conditions. Finally, the electrical tests show that the degree of transparency is not the most determining factor that affects the conversion efficiency.