Breakthrough solar project

The solar power project that PermaCity completed earlier this year on the Los Angeles Convention Center continued to add to LA's considerable success with renewable energy-and was also a breakthrough for PermaCity and its patented SolarStrap attachment sy

By Paul MacDonald

The solar power project that PermaCity developed and completed earlier this year on the Los Angeles Convention Center (LACC), owned by the City of Los Angeles, was a breakthrough for the company—and continued to add to the city's considerable investment in, and success with, renewable energy.

LA Mayor Eric Garcetti unveiled LACC's 2.21-megawatt solar array at a ceremony in April and celebrated that Los Angeles once again was the largest solar powered city in the United States. Garcetti has been a strong advocate for Los Angeles moving to solar power through a Feed-In Tariff (FiT) program and net metered projects, such as the LACC project.

Located on the roof of South Hall, this addition brings the facility's total solar power to 2.58 megawatts, making it the largest solar array on a municipality-owned convention center in the U.S.

Starting in October 2017, the six-month project included the installation of 6,228 355-watt panels. The new array is projected to generate 3.4 million kilowatt hours per year that equates to 17 percent of the LACC's annual energy usage. This amount of produced electricity can power 565 homes in Los Angeles.

"I'm proud to celebrate the completion of the convention center's solar project," said Jon Vein, chair of the City of Los Angeles Department of Convention and Tourism Development Commission, at the ceremony. "This project has set a precedent for other facilities to follow and is key to keeping Los Angeles the number one solar city in America."

PermaCity and its employees are also proud of the project for an additional reason.

"This project was a big breakthrough for us," says PermaCity CEO Jonathan Port. "This is the first major project we've done using our patented attachment system with SolarStrap that is both non-ballasted and non-penetrating on a PVC roof sitting only on three feet of foam. It really took the PermaCity technology to another level.

"It took a lot to orchestrate the project with our team—we had to be very careful of the roof and meticulous not to damage it," Port added.

When you come down to it, you could probably not take on a more high profile project in Los Angeles, since the LACC is one of the largest convention centers in the U.S., with 720,000 square feet of exhibit hall space and 147,000 square feet of meeting room space. It is located in the cultural, business, and entertainment center of the city's downtown and hosts more than 350 events and two million visitors annually.

With the LACC being such an active place, the solar project required careful planning to avoid impacting the events held at the center.

"One of the challenging aspects of the solar project involved planning and designing the installation of the rooftop solar array in a manner that did not disrupt the numerous events we host in the exhibit halls below," said Thomas Fields, chief operating officer, LA Department of Convention and Tourism Development.

"PermaCity's design solution and execution of the project was terrific, allowing us full continuity of business without a hitch."

During construction of the solar project, the LACC hosted everything from the city's Auto Show, with thousands of attendees, to the Jurassic Tour Dinosaur Adventure.

The solar installation designed and constructed by PermaCity was selected by the convention center as a result of public bid.

In advance of the bid, Promise Energy, in partnership with Brooks + Scarpa Architects, was hired by the City of LA's Department of Public Works Bureau of Engineering, the convention center, and the Bureau of Tourism and Development to prepare complete bid scoping documents for the design/build installation of the solar array on the roof of the South Hall.

PermaCity's Jonathan Port says the 2.21-MW size of the project was a good fit for PermaCity. "It's right in our core expertise of large rooftop solar projects."

The project, as awarded, would not have been possible if not for PermaCity's patented, UL and ICC certified SolarStrap technology, which Port says is a game changer for commercial rooftop installation. The system works seamlessly with leading roof products, yielding high performance, with up to 60 percent more power over the system's life, and it is very labor friendly, he says.

Port stressed the importance of the company's SolarStrap technology. "We're able to build differently than any other rooftop technology."

The SolarStrap roof attachment system is said to be a revolutionary advancement in mounting technology for PV systems on flat roofs It requires neither penetrations nor ballasts, while being both easy to install and attractively priced, says the company.

A proprietary design employs heat sealing technology to secure SolarStrap's simple framework to the roof with only a few tools, allowing for rapid installation and zero waste. The system hardware is also available coupled with PermaCity's design and installation services.

In carrying out the LA Convention Center solar power project, PermaCity and its workers and contractors did not require much of a laydown area, a particular advantage considering the busy convention center and its location in downtown Los Angeles.

The LACC posed a unique challenge, says Port, in that it has a fragile roof that can't take any point load or significant wind stress—it is only a foam roof with a PVC overlay.

"Our technology allowed us to install solar power over that fragile roof-with our system, we don't have to cut into the roof at all. And the roof is too lightly supported for ballast. SolarStrap is a perfect fit, being a non-ballasted system that evenly distributes solar weight. Without it, it would have meant gouging the roof, welding, and bolting to the structural frame, and it would have been very time consuming, more disruptive, and more expensive."

He notes that the SolarStrap system is pre-fabricated, with a limited number of parts, and there is very little in the way of waste materials on the job site.

In carrying out the project, Perma-City and its workers and contractors did not require much of a laydown area, a particular advantage considering the busy convention center, and it being located in downtown Los Angeles.

"Our construction teams are very efficient and highly experienced in doing these jobs," says Port. "We were the general contractor, and we put together a great team. Our system is very efficient—we took deliveries of the solar modules and then steadily mounted them."

Carrying out construction were workers from IBEW Local 18 and Local 11, Roofers Local 36, and Labor Local 300. "We work closely with the unions and are grateful for the job training their members receive," says Port. The electrical subcontractor on the solar project was CSI Electrical Contractors, a full-service firm with offices in Los Angeles, Palmdale, and San Jose.

Port says that since they were working with a fragile roof, they carefully rolled out construction. "There were a lot of logistics involved, but we all thought it through carefully and had everyone organized accordingly."

	The convention center solar power project included the installation of 6,228 355-watt panels. The new array is projected to generate 3.4 million kilowatt hours per year that equates to 17 percent of the convention center's annual energy usage.

Due to the light foam roof, they used a number of 100-pound mats for protection. "The roof was much more fragile than we had thought. But we managed that with a very systematic implementation of construction in a way that protected the roof. I'm very pleased with our entire team, and I would repeat any major job like this again with them."

Port noted that the project was completed on schedule, and there was never an interruption of any of the events at the convention center. The former was especially important because there were penalties in the contract if construction had run late.

In terms of materials, they used Hyundai solar panels. "They are one of our preferred suppliers," said Port. He noted that the solar panel tariff announcement caused major problems for this project—the original solar panel manufacturer could not supply them. But Hyundai was able to deliver for the project.

On the inverter side, they used Chint 60-kW inverters. "The Chint 60 is a nice piece of equipment—it carries 15 strings, and it works very efficiently with our racking system. It fits right on top of our racks."

The 60-kW medium-power CPS three-phase string inverters are designed for ground mount, large rooftop, and carport applications. The Chint inverters are said to be feature rich—with integrated and separable wire-box and integrated AC switch. They have vertical or lay-flat flexibility for NEC code in-array compliance and low-shadow orientation. The company says they are also cost-effective.

With the construction schedule, PermaCity and its crews started work on the project in the fall, and went through the early winter, so there were really no weather-related heat issues. "We had some warm days, but our team is really experienced and we set up shade and break areas," says Port. "We are careful for the safety of our workers on hot days. In some parts of California, like the Valley and the Desert, you have to adjust your work schedule."

PermaCity is said to be the largest commercial rooftop solar developer and installer in Los Angeles. Since 2003, they have worked with public facilities, real estate portfolio owners, and business owners to convert unused roof assets into revenue while contributing to a sustainable climate, reducing heat islands, and reducing local air pollution. LA now has more than nine million square feet of commercial solar roofs and 100 megawatts of installed solar capacity. Its projects include Westmont which, at 16.4 megawatts, is said to be one of the largest and most powerful solar roof arrays in the world, generating enough renewable energy to power nearly 5,000 homes. PermaCity has also done solar projects for Anheuser Busch, Forever 21, 20th Century Fox Studios, AmeriCold, Costco, and Cathay Bank.

And more is on the way. Earlier this year, PermaCity launched two new enterprises with a mission to grow solar and jobs: a $250 million fund dedicated to solar projects and new roofs and PermaCity Empower Corp., which offers solar jobs to veterans and careers through the unions.