Photovoltaics (PV) are semiconductors that convert sunlight directly to direct-current (DC) electric power. Photovoltaic technology has been used for years in specific applications where conventional utility service is not readily available or practical. For example, PV panels provide a reliable source of needed electric power for orbiting satellites as well as power for terrestrial communication installations in remote areas.
In the past, PV technology has also been experimented with as an alternative or supplement to traditional utility service for residential and commercial buildings. Over the years, a number of building projects have incorporated PV into their design to demonstrate its potential, but these projects usually relied on the owner's commitment to the environment or subsidies to make them economically viable. Today, a number of factors are coming together that could make PV practical for widespread application. For electrical contracting firms, PV could be the next growth market.
Advances in technology and deceasing manufacturing costs are making PV more competitive with traditional power sources. The conversion efficiency of PV materials is increasing due to advances in technology, while manufacturing costs are decreasing due to more efficient processes and increased demand leading to economies of scale. Equally important is the fact that PV is no longer restricted to standalone, ground- or roof-mounted panels. Today, it can be integrated into most exterior building materials, resulting in what is being referred to as building integrated photovoltaics (BIPV). For example, it is possible to get PV integrated into roofing materials such as shingles as well as curtain wall materials such as glass. BIPV reduces installation costs because PV becomes an integral part of the building rather than a standalone system. BIPV also increases the amount of surface area that can be used to generate electricity from the roof to the entire building exterior surface. Finally, when PV is integrated into glass, it not only acts as a tint that shades the building interior but also extracts energy from the light entering the building through the PV conversion process, reducing the air-conditioning load. Improved aesthetics allows designers to integrate PV into building designs in ways that would not be possible with panel-type technology.
Fossil fuel costs continue to increase due to growing worldwide demand. This trend is not likely to reverse as many parts of the world are shifting from agricultural-based to manufacturing- and industrial-based economies. In addition, fossil fuel supplies are being depleted as the growth in energy demand outpaces our ability to find new supplies. Electric power demand continues to increase in the United States despite efforts to conserve and increase efficiency. Environmental and economic constraints are also causing a shift from large coal-fired power plants located away from urban areas near fuel sources to small-scale generating technologies that are more environmentally friendly and located close to the load. This shift is not only the result of concern about impact of the coal-fired plants on the environment but also concern about the construction and upgrading of transmission lines that connect these remote plants with urban load centers.
New generating capacity being planned and built to meet the utilities' increasing demand is almost completely composed of gas turbine units that use natural gas as their fuel. Similarly, both microturbines and fuel cells are promising small-scale generating technologies that can use a variety of fuels, but most often use natural gas because of its ready availability and cost compared to alternate fuels. PV has an advantage over these technologies in that it requires only sunlight and no fossil fuel to produce electricity. As fossil fuel prices and environmental restrictions increase, PV will become increasingly economical.
Interest in PV is also driven by the “green architecture” movement, which is motivated by a greater environmental awareness and sensitivity by building owners, energy codes and certifications, and available technology. Building owners are finding environmentally friendly buildings that incorporate emerging technologies like PV are good business from a life cycle cost standpoint and can also provide a marketing-competitive advantage. Many potential buyers and tenants are also concerned about the environment and would like to be identified with an environmentally friendly building that incorporates “green technologies” such as PV.
The integration of PV into new residential and commercial buildings as well as the retrofit of existing buildings with PV is a potential growth market for electrical contracting firms. Advances in PV technology, improved building aesthetics, increasing energy costs, greater environmental awareness and other factors are all setting the stage for the emerging PV market. EC
GLAVINICH is an associate professor in the Department of Civil, Environmental and Architectural Engineering at The University of Kansas and is a frequent instructor for NECA’s Management Education Institute. He can be reached at 785.864.3435 or firstname.lastname@example.org.