Designers have the flexibility of purchasing BIPV systems as a “Plans and Specifications” package as well as having the system installed. In certain cases, the manufacturer will provide an expert on BIPV curtain-wall installations to coordinate the complete installation. For mid- and high-rise products, the most advanced pre-wired curtain-wall options come as complete packages that combine four usually separate trades: photovoltaic design, electrical engineering, curtain-wall manufacturing and waterproofing. The photovoltaic design component calculates system size and determines PV module selection, DC wiring, UL-rated harnesses, inverter size, life-cycle replacement, and the monitoring solution for the project. The UL-rated wiring harness is shop installed, which reduces field labor by 85 percent. The final curtain-wall design and installation includes energy modeling and AAMA water testing procedures.

Curtain-wall retrofit systems also exist. A curtain-wall retrofit system for SMUD (Sacramento Municipal Utility District) Corporate Headquarters that was AAMA tested and UL approved demonstrates the benefits that can be expected. The retrofit eliminated the problem of harsh direct sunlight and dramatic solar heat gain. The installation retrofitted opaque PV panels in front of the existing curtain wall, without interrupting the original glazing and warranty. This solution dramatically improves SHGC and harvests electricity in an area that was unavailable before. The opaque PV panels generate electricity to run the DC-powered HVAC systems, so the brighter the sun shines, the harder the air-conditioning runs.

Glass for Net Zero

When it comes to windows, architects have numerous tools to achieve solar control while increasing occupant comfort, improving building aesthetics and reducing building energy costs both up front and in energy-related costs for typical commercial buildings. Building integrated photovoltaic units and pre-wired curtain walls have the potential to turn entire buildings into power producers. The reality of ubiquitous net-zero buildings may still be a way off, but today's glass solutions are making a clear contribution to achieving that goal for motivated architects and owners.

 

A pre-wired curtain-wall retrofit system and waterproof outriggers for SMUD (Sacramento Municipal Utility District) Corporate Headquarters. Photo by David Bush, courtesy of BISEM USA

 

 

Guardian Industries is a diversified global manufacturing company headquartered in Michigan, with leading positions in float glass, coatings and fabricated glass products. Guardian’s most recognizable products are its energy-saving architectural glass products SunGuard® for commercial and ClimaGuard® for residential applications. www.guardian.com