A barrier to the widespread application of building integrated photovoltaics (BIPV) is the

lack of validated predictive performance tools. Architects and building owners need these

tools in order to determine if the potential energy savings realized from building integrated

photovoltaics justifies the additional capital expenditure. The National Institute of

Standards and Technology (NIST) seeks to provide high quality experimental data that

can be used to develop and validate these predictive performance tools. The temperature

of a photovoltaic module affects its electrical output characteristics and efficiency. Traditionally,

the temperature of solar cells has been characterized using the nominal operating

cell temperature (NOCT), which can be used in conjunction with a calculation

procedure to predict the moduleˇŻs temperature for various environmental conditions. The

NOCT procedure provides a representative prediction of the cell temperature, specifically

for the ubiquitous rack-mounted installation. The procedure estimates the cell temperature

based on the ambient temperature and the solar irradiance. It makes the approximation

that the overall heat loss coefficient is constant. In other words, the temperature

difference between the panel and the environment is linearly related to the heat flux on the

panels (solar irradiance). The heat transfer characteristics of a rack-mounted PV module

and a BIPV module can be quite different. The manner in which the module is installed

within the building envelope influences the cellˇŻs operating temperature. Unlike rackmounted

modules, the two sides of the modules may be subjected to significantly different

environmental conditions. This paper presents a new technique to compute the operating

temperature of cells within building integrated photovoltaic modules using a onedimensional

transient heat transfer model. The resulting predictions are compared to

measured BIPV cell temperatures for two single crystalline BIPV panels (one insulated

panel and one uninsulated panel). Finally, the results are compared to predictions using

the NOCT technique. @DOI: 10.1115/1.1385825#

1. Evaluating building integrated photovoltaic performance models
2. Evaluation of methods to extract ergosterol for quantitation of soil fungal biomass  

1. Evaluating building integrated photovoltaic performance models
2. Experimental verification of a moisture and heat transfer model in the hygroscopic regime
3. Heat and moisture transfer in wood-based wall construction: measured versus predicted
4. Test procedures for advanced insulation panels
5. Water vapor permeability measurements of common building materials  

1. Evaluating building integrated photovoltaic performance models