By Roy L Hales
Originally published on The ECO Report
There was only one problem confronting Borrego Solar, when they built the largest, city-owned solar array on a convention center in North America. The original design was too heavy for the roof.
The installation covers 300,000 square feet on the rooftop of Exhibit Halls A, B and C at the Anaheim Convention Center, in California. There are 7,908 solar panels.
“That’s when the building’s load became a big concern and it was brought to our attention that some of the exhibiting companies that come to the convention center throughout year, might need to hang heavy equipment from the rafters and roof within the exhibit hall. This required a third party structural engineering firm to perform a load analysis before we’d proceed with the installation, and the revised design by Borrego Solar was the best way to proceed.”“The RFP, administered by the consulting group, called for multiple inverters and several points of interconnection to the grid,” a company spokesperson explained. “Borrego Solar’s engineers thought this might be problematic, because it’s usually best to consolidate your connection points given that it is more cost effective, there are fewer logistics and moving parts, and results in a less heavy array. Inverters are heavy, and since these would be on the roof, we’d need to have them ballasted with concrete. This is a lot of weight that wasn’t originally being factored into the load limitations of the convention center itself. The system is already “heavier” than others, because it too is ballasted, and the solar modules are anchored to the roof by weight and not by penetrations, adding more weight to the roof as well.”
The project’s dedication ceremony was held this week. According to the joint press release:
The system will generate an estimated 3.6 million kilowatt-hours of electricity annually — enough energy to power 600 homes for a year. Anaheim Public Utilities is incorporating the project into its renewable energy portfolio. The installation marks the building’s newest sustainability feature; the LEED certified Convention Center maintains a commitment to sustainability through initiatives such as an on-site recycling program, a farm-to-fork culinary program, an on-site composting facility and a rooftop herb garden.
“The City of Anaheim has always sought to take the lead with projects that demonstrate government entrepreneurship and this partnership reflects the success of this effort,” said Tom Morton, executive director of the City of Anaheim’s Convention, Sports & Entertainment Department. “We appreciate the partnership with our Public Utilities and welcomed this opportunity, which benefits not only our residents, but further enhances the Convention Center’s sustainability program.”
“Installing solar on the Convention Center furthers the City’s commitment to renewable energy initiatives,” said Dukku Lee, general manager of Anaheim Public Utilities. “The City was able to add a cost-effective renewable resource that utilizes the abundant sunlight we are fortunate to have in this region.”
“Throughout the contract and construction process, we witnessed firsthand the commitment and enthusiasm of the City, utility and Convention Center leaders to ensure the success and quick development of this project,” said Mike Hall, CEO of Borrego Solar. “It’s communities like Anaheim that will enable California to meet its renewable energy mandates and continue leading the way on clean energy deployment.”
Aside from the original design of the roof, there were no challenges.
Borrego was one of the bidders in January 2013. They were was awarded the contract, the following August, because their proposal was considered “the most advantageous to complete the project for the city.”
They started construction, after all the permits were finalized and approved, in January 2014.
A crew of anywhere from 5-35 Borrego personal were on any given day. There were electricians, the medium voltage workers, trenchers, fencers, temporary fencers, roofers, concrete works and asphalt guys.
“It takes a village,” the company spokesperson said.
A spokesperson for the city added that, “There were no surprises associated with this project—it took just four months to construct and was completed on time and on budget.“