On top of the Orange County Convention Center (OCCC), there's a 1-megawatt array that covers an area equivalent to five football fields. The system is the largest rooftop solar array in the Southeast. Johnston Controls developed the system, which features almost 6,000 SolarWorld panels that were installed by Florida-based Solar Source.

Solar Power International (SPI) brought attendees up to the roof daily during the show to tromp through the electrical workings of the OCCC and check out the array, the four Satcon 250-kW inverters, and the Fat Spaniel monitoring technology. Fat Spaniel was acquired by Power-One in 2010, but the boxes still bear the Fat Spaniel name.

According to tour guide Brian Kennedy, who works for the convention center, the system offsets about 10 percent of the buildings’ electrical use, which he pointed out, doesn’t seem like a lot. However, when you consider that the convention center’s electric bill is $1 million per month, it’s a pretty significant chunk of electricity, he said.  At one point during the tour, Kennedy checked the monitors and announced the panels were making about 428 kW at the moment.  “Not bad for 9:49 in the morning,” he said.

Since it’s in Florida, Solar Source installed the panels to withstand hurricanes, which wreak havoc on the nation during hurricane season each year. “This was really a pioneering system,” said Rick Gilbert, a VP at Solar Source who was also serving as a tour guide. “It was the first ballasted system of its kind in this part of the country,” he said.  Gilbert said Florida has the highest wind codes to meet in the entire country.  Arrays need to withstand wind speeds of up to 150 milers per hour, he said. 

In all, there are five solar PV systems in various locations around the Convention Center facilities. The small hybrid PV/thermal array offers solar air conditioning through dehumidification, but it’s mostly a demonstration project, as is the small thin-film laminate array, and two other ground-mounted arrays near the parking lot. One of the ground-mounted arrays is bi-facing uses Enphase micro-inverters, which Gilbert pointed out were just emerging as a new technology when the system was installed.  The demonstration arrays are used for educational purposes.

Kennedy said the convention center is going to add about 400 kW more to bump up its total installed capacity to near 1.5 MW.

When it was placed in service nearly four years ago, the total project cost was $8.8 million. Today, due to lower modules costs and BOS advances, the price would be less than half of that, said Gilbert.