4 Times Square

This 48-storey building, developed by the Durst Organisation in New York City in the 1990s, demonstrates the use of BIPV technology in way of a curtain wall. Kiss + Cathcart architects were the consultants for the building tower’s state-of-the art, thin-film BIPV system, working in collaboration with Fox and Fowle architects for the base building.

Kiss + Cathcart designed the BIPV system to function as an integral part of the tower's curtain wall. Energy Photovoltaics of Princeton, New Jersey, developed the custom PV modules to meet the aesthetic, structural, and electrical criteria.

The south and east facades of the 37^th through the 43rd floor were designated as the sites for the photovoltaic skin. BIPV was incorporated into the design after the tower’s general appearance had already been decided upon, so the design briefs: 4 Times Square five BIPV panels have been integrated into the curtain wall instead of conventional glass spandrel panels on the 37th through the 43^rd floor.

The custom-made BIPV panels are visible in this sidewalk view from Broadway. Kiss + Cathcart, Architects/PIX08460 Kiss + Cathcart, Architects/PIX06457 installation was made to harmonize with the established design concept.

The PV modules replace conventional spandrel glass in the south and east facades. There are four different sizes of modules, corresponding to the spandrel sizes established earlier in the design process. The modules are attached to the building structure in exactly the same way that standard glass is attached.

There is a separate electrical system for each facade. Each system consists of two subsystems, feeding two 6kW inverters and one 4kW inverter. The larger inverters serve the two large-sized PV modules, which have electrical characteristics that are different from those of the smaller ones. Using multiple inverters enables the system to perform more efficiently.