Five-Man Crew Installs Solar System in Little Over a Day in Tooele, Utah
by Mike Russo, freelance writer
Roofing contractors who perceive solar installations as being too complex and time consuming should think again. If a five-man crew – three of whom never installed solar before – can put down more than 6,000-sq.ft. of photovoltaic (PV) panels, capable of generating 50,000 watts, in just over a day, think about what an experienced professional roofing crew could accomplish.
The Proof is on the Roof
The unique solar panels are made up of cylindrical solar cells, a design that allows them to always be at the optimal “sun-catching” angle. Solyndra, is the Fremont, Calif.-based manufacturer of these unique solar panels.
Carlisle and Solyndra wasted no time in putting their new solar system to the test. In the fall of 2008 the roofing manufacturer selected its Tooele, Utah, TPO manufacturing facility as a trial site for the system. It was there that the company’s five-man crew installed its first PV system so quickly and easily.
“We selected the Tooele site because of its middle latitude location and sunny climate,” says Dick Gillenwater, Carlisle’s manager of advanced products. “In addition, the Tooele facility already has a white, reflective TPO roof that will help enhance the performance of the Spectro360 PV system. And, because it is a Carlisle plant, the roof can be easily accessed and monitored.”
Gillenwater oversaw the installation by the five-man, in-house crew, which included Dave Thomas, who manages Carlisle’s Asia/Pacific division. Thomas’ team quickly laid out the two, 150-panel solar arrays that make up the 50kw system. “We put the panels down in less than two days,” recalls Gillenwater. “Actually, the project was almost completed in one day, but the crew ran out of sunlight. On the second morning, there were only 60 panels left, and they were installed in 45 minutes.”
According to Kelly Truman, vice president of marketing, sales, and business development for Solyndra, the system – which includes both panels and mounting hardware – is typically installed in half the time and with one third the labor required for a conventional photovoltaic system. “We designed the panels for easy installation, but what this crew accomplished is simply remarkable,” said Truman.
Licensed electricians then installed the inverter, which converts DC current to AC current at the service meter. Carlisle worked with the local utility company in Tooele on a net-metering concept that feeds the new-found power generated on the roof into the electrical grid. The company estimates that the 50kw system can generate enough electricity to supply 14 homes with power. Up to 20% of that power is attributed to the reflective TPO roof membrane.
Carlisle provides a packaged system comprised of the panels and mounting hardware required for assembling standard-sized arrays. “We realize that it’s the roofing crew that gets the job done,” says Gillenwater. “Our job is to make life easier for them. One example is the ground straps we supply to ground each panel. Each strap requires two screws. The crew is supplied with a bag of 100 screws and 50 straps, so they go back to the bin together. It’s an orchestrated system.”
Carlisle’s system enables its customers to realize significant savings on installation costs. The panels and mounts are quickly attached together, enabling installations to be completed in one third of the time required by conventional PV systems. After the installation is complete, these same attributes enable Carlisle’s Spectro360 systems to be easily moved for relocation or roof servicing, a benefit that is not possible with traditional systems that are either adhered to the rooftop or bolted in place.
Because wind naturally flows through the gaps between the modules in the Spectro360 panels, it greatly simplifies the system’s mounting requirements. Even in areas with high winds, there is no need for roof-penetrating mounts or ballast to hold the PV panels in place. According to Truman, the panels have been tested and are certified for use in winds of up to 130 mph. Further, having a distributed rooftop load of 3.3 lbs/ft2, the self-ballasting systems can be used on buildings that would otherwise require structural reinforcement to harvest solar power.
Natural air-flow between the cylindrical modules also results in lower operating temperatures compared to those required by conventional flat-plate PV panels. Reduced operating temperatures provide higher energy output, improved reliability, and less heat transfer to the roof membrane and building envelope below.
Carlisle Energy Services’ Spectro360 PV system was designed with the roofing contractor in mind. The unique solar panels are made up of cylindrical solar cells, a design that allows them to always be at the optimal “sun-catching” angle. The Spectro360 panels are also self-ballasting, so they require no rooftop penetrations. They simply lock together and sit on the roof.
“We spent three years consulting with leading solar installers and roofing manufacturers before introducing our PV solution for low-slope rooftops,” says Truman. “We introduced a solar product that allows roofing crews with minimal training to install the system quickly and easily.”
Solyndra focused specifically on improving the ease and speed of installation, addressing the common misconception that PV system installation requires extensive training and a highly specialized skill set. In contrast, its system is designed so a two-man crew can handle the panel installation and low-voltage DC wiring, while an electrician attaches the system to the inverter. “A licensed electrician is still needed to connect the arrays to the inverter and install the AC power, but most roofing contractors already have existing relationships with such resources,” says Truman.
Last November, Solyndra’s research and development efforts paid off when it signed a long-term sales contract with Carlisle Energy Services, a newly formed division of Carlisle SynTec Incorporated, Carlisle, Penn.
“The Solyndra PV system is a natural fit for our ENERGY STAR®-qualified, cool roof systems,” said John Altmeyer, CEO of Carlisle SynTec Inc.’s parent, Carlisle Construction Materials. “When installed on Carlisle’s white reflective TPO roofing membrane, the output of the Solyndra PV system increases by up to 20%. Further, the installation of a Solyndra system is exceptionally quick and economical to install, and can be easily accomplished by a roofing contractor along with the installation of an insulated cool roof. Together with Carlisle’s large network of roofing installers, we can rapidly deploy systems that provide both energy conservation and low-cost solar electricity generation.”
Although some solar systems are easy to install, most are at least ten times more expensive per-square-foot than a TPO roof alone. This makes the sales process more complex and often requires that the person proposing the solar system to the architect or building owner be knowledgeable about PV technology.
“The salesperson also needs to understand the nuances of state and local incentives and how they interact with federal tax credits,” said Gillenwater. “Not all roofing contractors have invested in salespeople with this skill set, but they will need to in order to succeed in the solar PV market.”
Some roofing contractors have moved quickly to partner with solar integrators. When it comes time to close the sale, the roofing contractor brings in the solar expert to structure the sale, explain it, and then sell it.
“We may see a massive rush to install solar systems, but it’s going to take collaboration between roofers and regional electricians, along with some added learning on how to execute the project,” said Gillenwater. “With federal tax credits now locked in for the next eight years, the U.S. is the largest untapped, and potentially fastest growing solar market in the world.”