Lifetime performance of semi-transparent building-integrated photovoltaic (BIPV) glazing systems in the tropics

The use of semi-transparent BIPV as a form of on-site renewable energy generation in energy efficient sustainable buildings is increasing. Its popularity is due to its contribution towards zero-(or even plus) energy buildings. In urban cities where the buildings have limited rooftop area but large facade areas, adopting semi-transparent BIPV windows is an alternative for conventional windows. The semi-transparent BIPV windows not only solely generate electricity but also affect the buildings' electricity usage through daylighting and heat gain/loss. In tropical climates where it is hot and humid all year round, the importance of window facade elements is even more pertinent due to high cooling load from the solar heat gains. This paper examines the life cycle environmental and economic performance of commercially available semi-transparent BIPV modules for window application under the tropical conditions of Singapore. Energy simulations, previously performed, were adopted to conduct a life cycle assessment to determine the long term performance in terms of energy and carbon emissions, as well as cost considerations. The EPBT and EROEI for the modules ranged from 0.68 to 1.98 and 11.72 to 34.49 respectively. After considering government subsidies, some modules cost lower than conventional windows, while half of the remaining modules, achieved payback periods of 1.1-13.1 years. These performance indicators were used to form a decision-making tool to assist architects and building designers in the selection of BIPV modules for windows during the early design stages. (C) 2014 Elsevier Ltd. All rights reserved.