Case Studies


Building a Net-zero Energy Skyline

Energy prices are estimated to continue rising in the years to come, but a new generation of green building materials has emerged to dispel the notion that rising costs will be forced onto the shoulders of building owners and occupants. BISEM Inc. (BISEM) was officially incorporated in 2011, while the company itself was born a few years earlier as the result of its founder’s personal passion for building-integrated photovoltaic (BiPV) panels.

BISEM stands for Building Integrated Skin Electrical Mechanical, and powered envelope components remain the company’s core product. Ever the paragon of sustainable technologies, the company is based out of a net-zero energy facility in Sacramento, Calif. In fact, it was the construction of what became BISEM’s facility that led to the company’s founding. “About five years ago we bought an old building and decided to remodel it to be as energy efficient as possible,” explains Nick Bagatelos, founder and president of BISEM.

The building was purchased to house manufacturing operations for Bagatelos’ other venture, Bagatelos Architectural Glass Systems Inc. (BAGS), a Sacramento-based, union-affiliated glass and aluminum panel contracting company. During the remodel the facility was equipped with a rainwater harvesting system, high-efficiency electric heat pump HVAC systems, low-energy light controls, and a string of 40 skylights to provide ample indoor light. The remodeled facility was proven to use 60-percent less energy than comparable buildings. After reaching this already dramatic improvement, solar panels were added to the roof and vertical walls to make the facility a net-zero energy building.

Bagatelos stumbled across the technology for BISEM’s building-integrated photovoltaic panels while traveling back and forth to meet with the German company manufacturing all of BAGS’ production machinery. “I stumbled across a German curtain wall manufacturer that was doing things I assumed were years away from being possible,” reflects Bagatelos. “When I came back from Germany, I was determined to meet with that company and sell their photovoltaic systems here in the U.S.”

Never Say Never, Especially to a Bagatelos

That German company is Schüco, a global market leader in innovative building envelopes, especially products for solar power and solar heating. BAGS became Schüco’s West Coast manufacturer, but despite Bagatelos’ enthusiasm and the photovoltaic curtain wall system’s potential, American markets simply weren’t biting because the product wasn’t cost competitive. More specifically Bagatelos estimates the average Schüco system cost as much as 10 times the cost of a non-photovoltaic curtain wall system. The systems were still too costly even after Bagatelos tried to work with the German company’s engineers to produce a cost-effective system that the U.S. market would embrace.

But Bagatelos was determined and set out to build his own energy-generating systems by retrofitting BAGS systems with photovoltaic panels. It took the fine-tuning of three prototypes before a viable solution was established that could be specifically engineered for use with photovoltaic panels, and Bagatelos’ work wasn’t quite done yet. “Glaziers don’t do wiring and electricians don’t do waterproofing, so we set out to find a multitrade solution so contractors wouldn’t have to hire a set of electricians and a separate set of glaziers just to install the product,” expands Bagatelos.

BISEM worked with consultants in nearby Silicon Valley, Calif., to develop a method of prefabricating the systems in-house, complete with all required electrical wiring and waterproofing. This allows BISEM products to be shipped to site ready to install. “We also had the product tested and certified for safety by UL [Underwriters Laboratories Inc.], so it’s basically built like a chassis that can add multiple energy-efficient products,” adds Bagatelos. The beauty of the BISEM system is that it can accommodate or change out photovoltaic panels from any manufacturer, so long as the product is also UL-approved.

BISEM’s products meet AAMA [American Architectural Manufacturer’s Association] standards for constructability, and can contribute greatly to new or retrofitted LEED Platinum-oriented construction projects. Beyond the curtain wall, BISEM has innovated systems that can be incorporated onto pre-existing walls or attached as sunshades, contributing to aesthetics and comfort while adding the benefit of energy generation.

Fit for the Future

BISEM’s design provides greater flexibility for clients, ensuring that if one product becomes more cost-effective to use, the BISEM system will be able to accommodate the change without much of a hassle. This inherently makes the system perfect for retrofit applications as well, since the BISEM curtain wall retrofit system is engineered to anchor directly to all standard pressure plate curtain wall systems. BISEM even went as far as to develop structural calculations and water testing to prove its compatibility with systems from manufacturers such as Kawneer, Vistawall, US Aluminum and YKK.

BISEM also became a member of the Advanced Technologies Group organized by Guardian Industries Corp. (Guardian). As one of the leading manufacturers of high-performance glass products, Guardian aims to also lead the industry with the next generation of energy-efficient glass products and net-zero energy building envelopes. BISEM joins members such as Pythgoras Solar, whose photovoltaic glass product incorporates small photovoltaic units between two layers of insulated glass, and Soladigm Inc., which produces a dynamic electrochromic glass product that tints in response to the amount of light and heat entering a building.

Building Momentum

Through the Guardian connection BISEM landed a contract with the Department of Defense, installing a wired curtain wall system to one of the facilities at the Marine Corps Air Station Miramar in San Diego, Calif. The pilot project will see one of the base’s existing facilities outfitted with a net-zero building envelope, which will be closely monitored to test the system’s viability at other bases. Other recent projects include the installation of a BiPV curtain wall retrofit system for the Sacramento Municipal Utility District and at the BART station in Freemont, Calif.

Enthusiasm for BISEM products is high and likely to continue building as the country continues to search for even greater energy savings through net-zero energy designs. The hiccup for net-zero energy designs, though, is that the net-zero concept is by definition tailored to meet that specific facility’s needs in that precise location, making a universal and off-the-shelf solution unlikely. “It’s the last 30 percent that’s the hardest,” admits Bagatelos. “So the next step for BISEM is developing a product that fits into a net-zero envelope solution and can be easily tuned to the needs of different climate zones.”

As BISEM’s talented engineers sink their teeth into this next project, the company will continue its efforts to prove building integrated photovoltaic curtain wall systems are viable, affordable and incredibly energy efficient. With every completed installation BISEM Inc. moves closer to a world with cost-efficient, net-zero energy skylines.

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Spring 2018



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