A Panel Discussion
As companies like Johnson & Johnson look to install solar panels as part of their larger sustainability efforts, FM Global helps them also measure the risk involved with going green
It's high noon and the powerful June sun is baking the roof of the parking garage at Johnson & Johnson's New Brunswick, New Jersey, USA headquarters. Michael Newman, the company's manager of loss prevention and property claims, walks slowly under the galvanized steel framework supporting 33,000 square feet (3,066 square meters) of solar panels on sun-tracking mounts. The panel arrays tilt slowly overhead, following the sun's path.
In a sort of modern alchemy, solar or photovoltaic cells (from the Greek phos, meaning "light," and "voltaic," from the name of the Italian physicist Alessandro Volta, meaning "electric") convert the sun's rays directly into electricity. Rooftop solar-panel systems are also known as photovoltaic (PV) systems or building-integrated photovoltaics (BIPV).
The 234 kilowatts of power generated by these semiconductor devices are used directly by Johnson & Johnson's headquarters to meet up to 20 percent of the facility's electricity needs. Johnson & Johnson, founded in 1886, is a large global medical devices, biologics, pharmaceutical
and consumer health company. In the United States, its operating companies produce 4.1 megawatts of electricity from 10 solar installations—enough to power nearly 4,000 homes.
Solar power—along with other on-site renewable energy sources, such as wind, solar hot water, biomass co-generation and geothermal—
is a key element in Johnson & Johnson's Climate Friendly Energy Policy, approved by the company's executive committee in 2003. Since 1999, when Johnson & Johnson first announced its ambitious commitment
to reduce its carbon footprint worldwide, through 2007, it has achieved a decrease in CO2 emissions of 12.7 percent. (This figure exceeds the firm's original goal of a 7 percent reduction from its 1990 baseline.) Sales, during the same period, have increased nearly 400 percent.
With 2007 sales of more than US$61 billion and 119,000 employees, Johnson & Johnson is the second-largest corporation in the United States to use on-site solar power. Except for two stand-alone solar "farms," the company's solar-panel systems are roof-mounted on office or research facilities, predominantly in the (U.S.) states California,
New Jersey and Pennsylvania.
Rooftop development requires expert advice
When it comes to harnessing solar energy, commercial rooftops represent an untapped resource for "green" initiatives; there is still great opportunity for development. It is estimated that there is approximately 30 billion square feet (nearly 2.8 billion square meters) of commercial roof space that could potentially be outfitted with photovoltaic technology. According to one estimate, the average size of a distribution warehouse in the United States in 2007 was more than 300,000 square feet (27,871 square meters), or large enough to hold a one-megawatt solar power system.
In 2001, when Johnson & Johnson was planning its first solar installation, a 546-kilowatt rooftop installation at its Neutrogena headquarters, in Los Angeles, Calif., USA, the company turned to engineers from FM Global for advice. (Neutrogena makes an extensive variety of cosmetic products.) An insured client since 1888—it is FM Global account number 27—Johnson & Johnson relies on FM Global and its field engineers worldwide for advice on a wide range of property loss prevention issues.
"When our own engineering folks first began talking about rooftop solar projects, they asked me what I thought some of the risks might be," said Johnson & Johnson's Newman. "One of the first people I contacted was our FM Global account engineer, Sal Sorrentino. We're typically in contact daily, so it wasn't a big deal to bring up new issues—they're a critical part of our loss prevention efforts." Sorrentino, a senior account engineer in FM Global's New York office, worked closely with colleague and senior engineering specialist Bob Tarnecki to assess the potential risks associated with Johnson & Johnson's solar projects.
"When I first heard about their plans for solar energy, it was an unfamiliar area to me—we were basically starting from scratch when it came to PV power generation," said Sorrentino. "But we know roof systems, so that gave us a firm foundation to work from. And Johnson & Johnson recognizes that, when it comes to property loss issues relating to any project, we're going to dig in and get them good advice."
The hazards associated with solar panels
Sorrentino and Tarnecki teamed with FM Global senior engineering technical specialist Richard Davis, who is based in Norwood, Mass., to review site plans for Johnson & Johnson's PV arrays planned for California and New Jersey. Tarnecki, who works out of FM Global's Parsippany, N.J., office and has worked with Johnson & Johnson since 1980, is an expert at evaluating the property risks unique to pharmaceutical and medical-device manufacturers—a major industry in New Jersey.
FM Global clients, particularly those with sites located in states that provide tax incentives or grants for renewable energy development—such as New Jersey, California and Pennsylvania—are increasingly looking to their rooftops to find ways to reduce greenhouse gas (GHG) emissions, save on energy costs and demonstrate their commitment to improving the environment.
"For many companies, the roof or top level of a corporate parking garage is a popular first choice for a PV site," said Tarnecki. "This is because the structure is typically reinforced concrete. Keep in mind that the greatest risk is not in the loss of the solar panels themselves, but in how that solar installation may affect the building it's installed on. When you look beyond parking garages to research-and-development or drug-manufacturing facilities, the loss prevention stakes obviously go way up."
According to Tarnecki, there are several important risk factors FM Global considers in its evaluation of rooftop solar-panel systems, including combustibility, wind uplift and securement, roof loading, drainage and natural-hazards resistance. How will the panel and its mounting system affect the combustibility of the overall roof system? What are the maximum expected winds in the building's location? How much weight is the roof designed to hold, and how much does the solar system weigh? How will the accumulation of snow and ice, for instance, add to this loading?
Sorrentino, meanwhile, finds the drainage issue especially troubling. "It's surprising how many solar installation proposals fail to adequately consider roof drainage," he said. "Ponding can result and drastically increase loading. If we see the potential for this to happen, we'll make a recommendation for risk improvement." Tarnecki, for his part, wondered whether the solar panels had been tested for hail and wind-borne debris resistance. "What test did the manufacturer use for hail testing?" he asked. "Did they drop a steel ball on it? A golf ball? What diameter was it? We try to take a hard look at the test data from the manufacturers or their representatives."
PV growth expected to shine on
Solar power is one of today's fastest-growing energy sources. According to a report in Professional Roofing magazine, since 2002, PV system use has been growing at an average of 50 percent per year. While PV roofing currently accounts for only 2 percent of the commercial roofing market, this percentage is likely to increase in the coming years as PV prices fall, tax incentives increase and energy costs escalate.
One major financial incentive that has driven the adoption of PV systems is the U.S. federal solar investment tax credit (ITC), which was renewed at the end of 2008 for an additional eight years. The ITC provides up to a 30 percent credit for both residential and commercial solar installations. The new version of the ITC now allows regulated electric utilities to take advantage of the tax credit. This is expected to dramatically increase the development of PV and solar thermal power generating systems nationwide.
Cell Talk
Shedding some light on photovoltaic technology
As energy costs rise and pressure mounts to offset or reduce greenhouse-gas emissions, a growing number of corporations, utilities and municipalities are turning to photovoltaic (PV) systems—solar panels—to turn sunshine directly into electricity. Typically, the power generated by PV systems is used directly on site, and any extra is fed into the electrical grid for use by the general public; the PV system owner often receives a credit for any power that is sent to the grid.
PV systems convert sunlight into direct current electricity through an interconnected series of tiny semiconductor devices called solar cells. These specially treated (doped) silicon sandwiches have a positive and negative side and allow electrons, dislodged by the sun's rays, to flow through wire contacts. Solar cells are often grouped or referred to by the form of silicon used in their production: monocrystalline, or sliced from a single silicon crystal; polycrystalline, or cut from multiple crystals; or amorphous, in which a thin, generally flexible layer of silicon is deposited on a substrate.
PV panels come in many forms, colors and mounting configurations. Increasingly, amorphous PV panels are being incorporated directly into roof membrane material to form an integrated roof covering. The most efficient solar arrays use a sun-tracking system that rotates them on one or two axes, following the sun throughout the day. While effective, tracking systems require greater spacing between panels, to allow for shadows cast by the panels as they are tilted. Large sun-tracking solar arrays are most often used in large solar "farms" or on concrete structures such as parking garages.
Along with rigid solar cells and flexible films, there are many other types of PV systems on the market or in development, including tubular solar cells, which absorb direct and reflected sunlight; concentrated solar cells, which amplify the sun's rays; screen-printed or mass-produced cells on very thin substrates; and experimental three-dimensional solar cells that promise to capture nearly all available sunlight.
A Solar Array of Questions
When evaluating rooftop solar-panel systems, FM Global engineers consider the following five risk factors
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1
Combustibility. How will the panel and its mounting system impact the combustibility of the overall roof system? For
instance, some early solar systems included a backing of polystyrene plastic, which can be highly combustible.
-
2
Wind uplift and securement. How much wind force can the assembly withstand,
and what are the maximum expected winds in this location? Is simple ballast enough, or should the installation be connected to the underlying
roof structure?
-
3
Roof loading.
How much weight is the roof designed to hold and how much does the solar system weigh? How will the accumulation of snow and ice, for instance, add to this loading?
-
4
Drainage. How do solar panels affect roof drainage? Is there ponding, which can drastically increase loading?
-
5
Other natural hazards resistance. Have the solar panels
been tested for hail and wind-borne debris resistance? What test did the manufacturer use for hail testing? Was
a steel ball dropped onto the panel? A golf ball? What size was it?
Many utilities see commercial rooftops as the ideal location for their PV projects. In California, in particular, open land in urban areas is prohibitively expensive for solar installations alone. However, commercial rooftops are generally
located near high demand areas, appropriately zoned, and offer abundant sunshine for maximum output.
FM Approvals looks to develop Approval Standard for photovoltaics
To meet the increasing demand from clients for support in developing solar energy resources and from manufacturers
who seek to provide FM Approved products, FM Approvals is formalizing its knowledge of PV systems by developing a new Approval Standard.
"We're building on the knowledge we have already gathered in helping our clients evaluate these installations over the past few years," said Jill Norcott, a technical team manager in the FM Approvals Materials
Group. "We're working to make sure we consider not only PV systems that are currently on the market, but also, as much as possible, potential future systems."
According to Norcott, one of the newest and perhaps most promising PV systems her team plans to evaluate are those that combine roofing membranes with semi-flexible PV panels in a self-adhering system. "We believe this type of system will become increasingly popular because it is easier to install and may be less susceptible to wind uplift concerns," she noted. "The new Approval Standard will likely include tests or criteria for evaluating
PV systems' wind uplift as well as other risk factors, including fire resistance and hail."
Sky's the limit
Harnessing the natural elements for man's benefit is nothing new. In fact, civilizations
have been tapping into our abundant renewable resources for thousands of years. Many renewable or alternative energy and conservation technologies that were previously either marginally viable or technically immature are now ready to take center stage in a perfect storm of technological advances, economic renewal and environmental awareness.
The sky's the limit for solar energy around the world. As efficiencies continue to increase and energy costs climb, the point is rapidly approaching when solar power will be cost-competitive with other forms of electricity, without subsidies or other incentives.
"FM Global has worked with us to evaluate each of our projects with an eye toward helping us reduce the potential for property loss—losses that would come out of our pocket," concluded Johnson & Johnson's Michael Newman. "Whenever
possible, we try to comply with FM Global's recommendations. The global resources that it can apply to any challenge we may propose makes them a critical
part of our loss prevention team."
This story originally appeared in the #1/2009 issue of FM Global's [reason] magazine.
www.fmglobal.com/reason
©2009 FM Global.
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