Closer look: Who should install solar panels?
As the solar market takes off and the building integrated photovoltaic market gains traction, solar panel installation opens up a big business opportunity for glass and glazing professionals. However, the question regarding who should install these solar panels remains undecided.
There are two major types of photovoltaic module construction: standard, pre-framed modules and custom laminates (see "Harnessing the sun"). While standard, pre-framed PV modules are typically installed by "solar integrators"—small- to medium-sized companies specializing in solar work—industry professionals question if they are best equipped to handle these types of installations.
Recently, electrical contractors have been handling some standard, pre-framed PV module installations, says Steve Coonen, BIPV consultant, Grass Valley, Calif. Steelworkers and electrical contractors, working under a general contractor, often install larger-scale, ground-mounted, central station solar projects. "It is interesting when you think that each 1 megawatt installation is five acres and involves 100,000 square feet of tempered glass, and no glazier to install it," he says.
Standard pre-framed PV modules are constructed in high-volume production lines, often using robotics, says Eddie Bugg, director, Sustainable Solutions, Kawneer/Alcoa Building & Construction Systems, Norcross, Ga. The PV cells are sandwiched in between a thin layer of glass and a polyvinyl fluoride film, and mounted in an aluminum frame. Typically, they are used in ground-mount or rooftop arrays with a low-cost mounting system. Manufacturers produce them in standard sizes that optimize efficiency. They are not typically used in building envelopes, he says.
These modules have been—and probably will continue to be—installed by solar integrators because they are designed primarily to make solar power, or electricity, Bugg says. "Unlike [custom laminates, aka,] BIPV fenestration systems that provide protection between conditioned indoor space and the elements, these arrays are not air/water tight, insulated, structural or architectural. In fact, they are typically mounted out of sight. So, the trade skills of the contract glazier are not generally required."
Rob Jorden, director of training, Glazier Local 2001 JATC, District Council 15 IUPAT, Las Vegas, offers a different perspective.
The reason the glazing industry is not performing more PV installation, "is [because of] a misunderstanding by building designers, developers and general contractors of who has the necessary skills and qualifications required for the installation of these photovoltaic systems," Jorden says. "We are talking about essentially a glass product and its supporting structure, so who better but the glazing community [to install it]?"
"Glass—while a very tough and durable building product—does require special training to ensure it is safely and properly installed to perform in the manner intended," Jorden says. "Our industry needs to start promoting ourselves as the only qualified entity to perform the installation of not only standard PV panels, but also the BIPV systems. Our failure to actively pursue this has already placed us behind in the race, and we can no longer idly sit by and watch as other trades lay claim to this new and valuable portion of our industry. Our trade associations must all partner together to ensure our continued growth in the field. Remember, we are glaziers and glazing contractors, and we are the only ones qualified to fabricate and install all glazing products and their supporting systems."
Coonen brings the two views together: Given that standard solar panels or custom solar panels for glazing applications are both electricity generating devices under architectural flat glass, "the solar modules should be installed within the scope of a glass and glazing subcontractor with an electrician following behind to electrically connect them to an inverter, and the inverter to the utility grid."
Who should install custom laminates?
There are at least two schools of thought when it comes to installing custom glass laminates, Bugg says. "No. 1: Only an experienced contract glazier is qualified to properly and safely install commercial glass units, even if there happens to be some PV cells laminated in the unit. No. 2: Only an experienced electrical contractor is qualified to properly and safely install PV panels, even if the panels happen to be commercial glass units. Of course, there are flaws in both arguments."
Custom PV laminates are usually built in specified sizes to fit the requirements of the framing system — window, curtain wall, skylight, etc.—and the building envelope opening, Bugg explains. Some call this application BIPV. "The PV cells are laminated between two layers of glass; and, can be part of an insulating, or insulating-laminated glass unit. These units are engineered to order and can be much more expensive than standard, pre-framed modules. Other than the care that must be given to managing the wire leads that must be ultimately connected to make a PV array, these units can be glazed like typical commercial glass. But, other considerations must be given to proper grounding, especially when the wiring is designed to be concealed in the framing."
Unlike ground-mount and rooftop arrays that use standard, pre-framed PV modules, BIPV installations serve multiple purposes. In addition to generating energy, these systems must protect conditioned space from air/water infiltration, wind/snow loads, and exterior temperatures. And, in contrast to hiding these systems on rooftops, they showcase PV technology architecturally, within the building envelope.
The installation of custom laminates "cries out for coordination of trades," Bugg says. "It won't be easy; but, it's not the first time our industry has seen similar challenges. Contract glaziers, ironworkers and sealers have found a way to coordinate their trade skills when erecting a complex curtain wall. To be successful at integrating PV into the building envelope, a similar approach will have to be taken."