Paper Conference

Proceedings of BSA Conference 2013: 1st Conference of IBPSA-Italy


Integrated BIPV performance assessment for tropical regions: a case study for Bangalore

Gayathri Aaditya, Rohitkumar Pillai, Monto Mani

Abstract: Building Integrated Photovoltaic (BIPV) are Photovoltaics (PVs) integrated as a building envelope. In addition to effectively generating energy, BIPV need to be energy efficient. They would need to passively regulate the responsiveness of the building envelope to the external environment to provide (natural) indoor thermal comfort, thus accomplishing the prime function of a building. Thermal comfort is an important parameter in building design as it contributes to overall health and productivity. Tropical regions, such as India, are generally characterized by high temperatures and humidity where passive designs need to integrate a combination of both, appropriate thermal massing and space orientation for adequate ventilation. BIPV poses unique considerations (and opportunities) as the inherent thermal mass is low and the radiative transmittance is high. Consequently, the BIPV also permits rapid heat-loss at night from the indoors through radiation, particularly when integrated as a roof. Regulating indoor thermal comfort in tropical regions poses a particular challenge under such conditions, as the Mean Radiant Temperature is likely to be high. Thermal comfort is also a key factor in assessing the energy efficiency of a building envelope as it determines the dependence on active (power-intensive) regulation for providing thermal comfort. Thus, building design strategies for optimizing BIPV performance would require an integrated consideration of three interdependencies, viz., maximizing PV performance, passive climate-responsive environment and natural thermal comfort. The paper investigates the performance of a 5.25 kWp roof integrated BIPV lab at the Indian Institute of Science, Bangalore (India) and is based on a year-long systematic study of parameters determining PV performance, indoor thermal comfort and building climate response. Regulating indoor thermal comfort is of particular concern as temperature stratification has been noted under BIPV roof. The current paper investigates the influence of thermal comfort on building climate response and BIPV performance and suitable strategies have also been evaluated through a simulation model.
Pages: 181 - 190