“Solar is so adaptable, it’s unbelievable. You can pretty much put it anywhere,” says Phil Cavallo, president and CEO of Massachusetts-based installer Beaumont Solar. Nonetheless, that doesn’t mean solar projects are without their challenges, and some installs are undoubtedly more difficult than others.
In fact, as sustainability and clean energy grow more popular among homeowners, corporations, governments and utilities, solar companies are already being tasked with getting creative and figuring out how to best meet the needs of a diverse group of customers. That is especially true for a number of rooftop solar installers, which have relied not only on their own experience and adaptability, but also on the vast capabilities of current racking and mounting solutions, in order to complete some of their most unique projects.
A project with teeth
Beaumont Solar recently tackled an installation on a saw-tooth roof at the New Bedford, Mass., plant of men’s suit maker Joseph Abboud Mfg Corp. Built back in the 1900s, the manufacturing facility had a roof that needed repair, so Joseph Abboud thought it a good opportunity to add on-site solar at the same time. Beaumont Solar coordinated with the roofing contractor and installed a 1.3 MW solar array, which Cavallo calls a “beautiful marriage of old and new.”
As Joseph Abboud President Anthony Sapienza pointed out in a recent announcement, “When you look at our facility, you immediately see a big, tall smokestack across the street. This is how our facility used to get powered, first with coal and then with oil. Now we are almost completely self-sufficient, producing our own clean energy, without emissions, and significantly reducing our energy costs.”
The building has over 40 saw-tooth roof sections with windows on their north-facing sides – a design Cavallo notes was popular with older factories in order to provide ventilation and light for workers down below. On the sections’ south sides, though, are 22-degree ramps that face 180 degrees due south. In other words, Cavallo says, the saw-tooth roof was surprisingly “perfect for solar.”
That’s right: The odd-shaped roof required no panel or racking tilting, and the modules were mounted flat along each saw-tooth section’s surface.
Because the roof’s wooden decking wasn’t quite strong enough to support the load of the solar panels, Beaumont Solar installed stanchions and opted for heavy-duty, long-span rails from DPW Solar that could stretch far from one beam to the next. Furthermore, the saw-tooth sections weren’t perfectly flat, so the company had to adjust the L-foot attachments a bit to account for a small curvature where necessary.
“The rest was pretty standard solar installation, meaning we just clipped the panels down, installed the inverters and wired up,” says Cavallo. However, he emphasizes that although the saw-tooth design was ideal for solar production, the unique roof created some major logistical challenges.
For instance, the saw-tooth sections were like “little mountains” the installation team had to maneuver around. Cavallo says, “When you have a flat roof, you can basically walk anywhere you want, but a saw-tooth design requires you to walk all the way down to the end of one section, then walk all the way up from the other, just to get to where you need to be.” That could get tiring, considering the Joseph Abboud plant has a 272,000-square-foot roof.
Staging the project proved to be another issue. The saw-tooth design left little space to store all of the materials, including the project’s 4,127 solar panels, so Beaumont Solar had to leave the majority of its inventory across the street. At night, the company would get a police detail that allowed the crew to resupply the roof with more gear and new materials for the next day. “That’s not typical. You’d usually get a crane, load everything up and have everything right at your fingertips from the beginning. Then you’d just rock and roll,” says Cavallo.
Solar as architecture
California-based Baker Electric Solar doesn’t see many houses with standing seam metal roofs, but that didn’t stop the company from installing a solar array for a customer’s modern-style home in Carlsbad, Calif. As of this writing, Baker has completed the 14.72 kW installation and is waiting for the customer to finish the construction process on the brand-new home before commissioning the array.
Jay Miller, director of operations, says the vast majority of houses Baker works on have tile roofs, and the company most often uses Quick Mount PV’s Tile Replacement Mount. “We’ve been using them for about a year now, and they’ve been saving us a lot of labor and tile costs because the mounts basically generate spare tiles in case some break,” he says.
For the Carlsbad project, however, Baker turned to S-5! clamps, which Miller deems “perfect for this type of application.”
“It’s kind of like how brakes work on your car,” says Miller. “It basically squeezes the standing seam securely enough to where it’s considered a structural attachment point. You’re not penetrating the roof. That’s the beauty of it. The only holes we had to cut for this project were for conduits to get down into the building for electrical wiring.”
In order to meet an interesting request from the customer, Baker also added L-feet and tilt legs from Unirac to lift the panels up from the five-degree roof pitch and make the solar modules stand out. Although this helped maximize the array’s energy production, the decision was driven mostly by aesthetics.
“During a typical install, we’re in parallel with the roof and mount straight to it for a low-profile look. On this project, the back stanchions are adjustable legs, which all had to be adjusted to the same length so the whole row would cover the same angle. It’s like a mini ground-mount project, but on a roof,” explains Keith Randhahn, Baker’s director of engineering, products, services and policy.
“This particular home is very modern looking,” he adds. “The customer had specific architectural details he wanted to highlight on his property, including wanting to see his PV system on the roof and not just have it blend in.”
Randhahn and Miller both suggest Baker likely could have gotten the same amount of energy production if the company kept the project flat and just added a few more solar modules, but Randhahn says, “It’s cool to see homeowners recognize that solar is not necessarily ugly, not something that needs to be hidden, and that it can add to the aesthetic appeal of a building.”
“We’re really starting to see customers proud of their solar,” concludes Miller.
A barrel of hurdles
Although California-based Vista Solar completed an installation at DPR Construction’s San Francisco office in 2014, Sam Kim, asset performance manager of Vista Solar, says it remains one of the company’s most unique installs to date. In part, it was due to the tough logistics of working in a major city, but mostly, it was because the building has what Kim calls a “highly constrained” rooftop that was primarily barrel shaped.
“Imagine a ship upside down – that’s what the roof looks like,” explains Kim. “It wasn’t a regular pitch, and every penetration attachment needed to pivot and swivel. In addition, we had to custom-make blocks for every footing.” Although Vista Solar tried to come up with an in-house racking and mounting solution, which Kim says often saves the company on overall costs, the company had to “switch gears” after it became apparent that option wouldn’t work for the barrel roof.
“We had to re-engineer the plan and work with Silverback Solar, which had a solution for us that met the need for the attachment points every 20 feet in terms of our span. Normally, we’d do about an eight-foot span,” says Kim. “That was pretty tricky, but it all came together quickly after that.”
Vista Solar built the 118 kW solar array as part of a full retrofit in order to help DPR Construction’s San Francisco location become among the first buildings in the city to reach net zero energy status.
“You’re always going to find a new challenge no matter how long you’ve been in this industry,” comments Kim. “Of course, you might have some cookie-cutter roofs you’ve done plenty of times before where you can get in and out pretty quickly – but you’ve never seen it all.”
District-wide rollout
As of this writing, Maryland-based Standard Solar Inc. has completed 28 of 30 rooftop solar projects in Washington, D.C., for the D.C. Department of General Services (DGS). The majority of the installations are located at schools, with the remaining arrays built at educational buildings and police and fire facilities. Ranging from 108 kW to 560 kW, the commissioned solar projects total about 7 MW.
The rooftop arrays are the result of a power purchase agreement (PPA) with DGS signed at the end of 2015. In partnership with local energy technology company Nextility and solar finance and development firm Sol Systems, Standard Solar started building the arrays in the first few months of 2016.
In a 2015 announcement, D.C. Mayor Muriel Bowser said, “This PPA doubles down on my administration’s commitment to renewable energy and sustainability – using district government assets as staging grounds to capture the sun’s energy and power our building portfolio.”
Though successful, Standard Solar had to devise some innovative designs and overcome logistical issues for the projects. Tony Clifford, the company’s chief development officer, says, “It’s not only 30 different buildings; it’s 30 different buildings in a high-density urban area. That was a major challenge.”
In addition, C.J. Colavito, Standard Solar’s director of engineering, says the company set a “very aggressive goal” to maximize the system size on every rooftop possible because the renewable energy credits (RECs) in D.C. are especially valuable compared to some other regions.
“In order to take advantage of the RECs, we needed to shoehorn as much PV in and produce as much power as we could,” he says, adding that’s why Standard Solar decided to use the Ten K Solar DUO system on most of the D.C. projects. According to Colavito, the Ten K Solar solution is a fully integrated, dual-tilt system that includes two back-to-back modules, built-in ballasted racking and electronics.
“I kid you not: It has north-facing modules, and it actually makes sense financially and from a technical perspective,” says Colavito. “Half of the modules are pointed south, and the other half are facing north. We have a lower tilt on the north side and a higher tilt on the south side, and it enables us to get very high energy density.”
In some cases, Colavito adds, the Ten K system allowed Standard Solar to install panels “unusually close” to HVAC or other equipment on the rooftops, “even though we knew it was going to shade most hours during the winter before noon.”
He explains, “One of the reasons we chose Ten K is that they have a unique module that has built-in module-level power electronics, and every cell within the module is wired in parallel. So, if you shade one cell, only that cell is affected and the rest of the cells in the module operate optimally. We wouldn’t typically be as aggressive with the layout in other regions, but because the production-based incentives were so valuable in D.C., it was well worth it to get those extra five or so panels on the roof.”
On a few of the projects, however, Standard Solar used a variety of other racking and mounting solutions, including a five-degree tilt, ballasted mounting system from PanelClaw; S-5! clamps; and an extruded aluminum, rail-based system from Mounting Systems Inc. All told, Standard Solar avoided making any roof penetrations, save for on four projects.
Colavito says the company also didn’t need to customize any of the racking and mounting solutions it used: “They all did what we expect from our racking and mounting providers. These systems are carefully engineered and designed, so making significant modifications is not advisable.”
In addition to the design details, the company had to figure out how to pull off a district-wide endeavor in such a dense, urban area. As Colavito explains, “These installations were simultaneously engineered, managed and built into one big, complicated construction schedule. Just permitting cranes, managing access to the buildings and finding parking – all of that was very complicated logistically and from a project-management standpoint.” He adds that doing a project in D.C. required meeting a lot of rules and permitting regulations, and the company had to secure approvals from a wide variety of organizations before even getting started.
Nonetheless, Standard Solar’s Clifford suggests such challenges can be “readily overcome” through “careful planning and innovative installation approaches.” He asserts that the D.C. project demonstrates “how transferable this type of success can be throughout cities in the U.S.”
Panel-mounted exoskeleton
Last year, New England solar installer ReVision Energy completed a 60 kW project atop the Keene, N.H., manufacturing facility of Tree-Free Greetings.
As an environmentally friendly greeting card company, Tree-Free Greetings had wanted to go solar; however, although standing seam metal roofs are common in the commercial and industrial space, the company’s existing metal roof was already underbuilt and couldn’t support the additional weight of a solar array, according to ReVision Energy project manager Chris Lee.
The solution? A steel exoskeleton.
Travis Genatossio, operations specialist at ReVision, says, “The customer reached out to structural engineering outfits to look for a fix. We provided a ballpark estimate of what the additional load for a solar project would be, and the architectural firm came up with a solution by building and attaching a steel exoskeleton through the roof to the structural support steel framing in the facility, as opposed to the roof deck.” The exoskeleton consists of steel I-beams outside and above the roof, and Genatossio says the solution was more efficient and likely less expensive than if Tree-Free Greetings had built a completely new roof.
After the architectural firm installed the structure, Lee says, “The racking and mounting we used was very similar to a residential job, where we put in aluminum L-feet and rails and modules on top of that. But what we did do is bolt to the I-beams, which acted essentially as rafters would on a normal roof.”
ReVision opted for IronRidge’s XR1000 rail solution, whose strength Lee says allowed for wider spans per attachment point and, thus, reduced the number of steel I-beams necessary for the exoskeleton. “We didn’t need to modify the IronRidge racking, itself, and used standard components,” he says. “The custom part of the job was putting in the I-beams and fastening to them in a way that would be structurally sound.”
Given the steel exoskeleton, one laborious challenge for ReVision was the need to through-bolt each L-foot into the I-beams. The installation team had to drill each hole, by hand, in the field, and Lee notes, “The crew probably went through 30 or 40 drill bits and a lot of oil.”
Despite the drilling issue, the exoskeleton actually provided some inherent benefits due to the excess room available underneath the new structure. For example, Lee says the crew was able to prepare racking with pre-wired optimizers on the ground, lift it onto the roof, square it up with the holes in the beams and secure the bolts.
“Then we were able to land modules very quickly because we didn’t even need to clip them,” he says. “We had techs underneath the array doing the wiring, and this created a kind of manufacturing mode. It worked tremendously well and efficiently to wire the array after the modules were placed down. It was kind of like a ground-mount project.”
“It’s not every rooftop job that you can literally climb underneath the entire solar array with comfortable working clearances,” adds Genatossio. “Usually, these installations are only a few inches high off the roof deck.”
Furthermore, Genatossio says the extra space will be “great for any necessary maintenance in the future,” and the raised structure will allow the array to “run a little cooler and better with the additional airflow, especially during the summer months.”
The exoskeleton also allowed ReVision to try a new safety solution. “We need to tie off and stay safe the entire time, and this array went right to the edge of the roof,” explains Lee. “So, we ended up buying some I-beam clamps for safety – typically used by steelworkers when welding together substructures – and fastened them to the beams. It worked out tremendously well and allowed us to walk up and down the outside perimeter of the array.”
All that said, Lee and Genatossio wouldn’t necessarily recommend using an exoskeleton unless absolutely necessary, as the solution took additional time, design and materials. If necessary, though, and if the aesthetics of steel beams are not a big concern to the customer, an exoskeleton could be an odd, but viable, option.
New challenges ahead
As mentioned, solar power is attracting new customers every day, and with the increasing mix of adopters comes a demand for solar companies to meet a variety of customer needs. That includes solar installers and equipment providers, both of which appear ready to take on any future challenges.
“In general, there’s probably a racking and mounting solution for just about anything you want to do on an installation,” says Standard Solar’s Colavito. “It’s really a function of what the right product is for your application.”
And as for installers, their project portfolios will undoubtedly keep expanding and become more diverse. The solar industry is not only growing; it is adapting.
