The demand for photovoltaic (PV) systems in commercial, institutional and residential buildings continues to grow. Over the past decade, the PV industry has experienced phenomenal growth driven by environmental concerns. Actual PV growth is nowhere near its potential because production has not kept pace with demand, due to shortages of both raw materials and manufacturing capacity. This situation will soon change as more manufacturing facilities are brought online worldwide to address growing PV demand. In addition, the conversion efficiency of PV materials is increasing, and manufacturing costs are decreasing thanks to advances in PV manufacturing technology and economies of scale. All this is setting the stage for explosive PV growth in the building market. In order to take advantage of the emerging PV market, the electrical contracting firm needs to understand where the PV market is going and have an effective strategy for profitably participating in it.
PV systems for commercial, institutional and residential buildings are evolving from the stand-alone roof- or ground-mounted PV panels to building-integrated photovoltaic (BIPV) systems. With BIPV crystalline and thin-film PV, materials are integrated with other conventional building materials. The advantage of BIPV over conventional stand-alone panels is that the PV system becomes an integral part of the building, which reduces installation costs, eliminates the need for special support systems and improves the aesthetics of the building. In addition, with BIPV, the entire skin of the building can incorporate PV, which greatly increases the area available to generate electricity, as opposed to traditional roof-mounted panels. As a result, the electrical contractor may not find PV system requirements included in the electrical drawings and specifications in the future.
Both the 1995 and 2004 editions of the MasterFormat—published by the Construction Specifications Institute (CSI)—provide framework for construction specifications in building construction and address PV as a separate stand-alone system. In the 1995 edition—still widely used in the construction industry—PV systems are covered only in Section 13650/Photovoltaic Collectors, part of Division 13/Special Construction.
In the 2004 MasterFormat, PV is moved to the new Division 23/Electrical and specifically addressed in Section 26 31 00/Photovoltaic Collectors. However, the 2004 MasterFormat also included Section 07 31 00, which addresses solar collector roof shingles as part of Division 07/Thermal and Moisture Protection. Where Section 26 31 00 addresses stand-alone PV panels for buildings, Section 07 31 00 recognizes the trend toward BIPV and the need for the electrical contractor to think differently about PV in the future.
For the most part, the addition of PV to existing buildings, even during a major renovation, will be limited to installing a stand-alone PV system on the roof. This is a potential growth market because the electrical contracting firm can perform all the work itself and work directly for the owner in many cases. To participate, the electrical contractor needs to understand these systems and how to install them, the local economics of PV and available utility and government incentives, and how to market PV to building owners. The electrical contractor also needs to be aware of the latest framing and anchoring systems, including self-ballasted panels that can reduce both installation cost and roof penetrations.
BIPV is the trend in new building construction, which probably will result in a new role for the electrical contracting firm involved in solar installations. Since the PV material is integrated into other building materials, such as curtain wall glass, other specialty contractors probably will install the BIPV material as they have traditionally. The electrical contractor will make the electrical connections; install the balance of the systems (BOS), which includes DC interconnections, inverters and other required equipment; and interconnect the PV with the building electrical distribution system. Having other specialty contractors with expertise in installing the base BIPV material, such as roofing, eliminates the risk and liability associated with the installation, including water penetration for the electrical contractor.
BIPV systems probably will not be included in CSI Division 23/Electrical, but in the section addressing the base building material, such as Division 07/Thermal and Moisture Protection for roofing or Division 08/Openings. If the BOS for a BIPV system is specified in Division 23 and shown on the electrical drawings, then the EC can bid the work directly as part of its electrical scope of work.
On the other hand, if the BIPV system is specified totally in the base building material section, then the electrical contracting firm may need to subcontract to the specialty contractor installing the base building material for the electrical work associated with the BIPV system. Depending on the market and managerial capabilities, the electrical contractor also could bid the installation of the entire BIPV base building material and subcontract or joint venture with another specialty contractor specializing in the base building material work.
This article is the result of a research project investigating the emerging photovoltaic market sponsored by ELECTRI International Inc. The author would like to thank EI for its support.
GLAVINICH is an associate professor of the Department of Civil, Environmental and Architectural Engineering at the University of Kansas. He can be reached at 785.864.3435 or email@example.com.