Sun-tracking solar panels invade rooftop market
Californian start-up Edisun Microgrids could bring solar trackers to the commercial rooftop sector, following the successful installation of a 1 MW solar array using the technology in Oxnard. Solar trackers, which follow the sun as it moves across the sky, are traditionally deployed in utility-scale projects on the ground, but Edisun developed a dual-axis rooftop system ideal for warehouses, retail outlets and hospitals. The company said its trackers can improve a solar project's energy output by between 30% and 40%, compared to fixed-tilt and non-tracking arrays.

A startup has installed close to 3,000 solar trackers on top of an industrial rooftop in Southern California, earning the title of “world’s largest rooftop solar tracker installation.”

That’s a solar industry equivalent to being "the world’s tallest leprechaun." Trackers -- which allow solar panels to move with the sun throughout the day -- aren’t commonly used on the tops of roofs.

Strong winds, small roof spaces and heavy tracking gear mean that much of the tracker hardware doesn’t make economic sense on top of a roof. Instead, tracking systems are being used in the majority of the large ground-mounted solar systems that are found in remote regions. Trackers boost the amount of energy a solar system generates and can lower the overall cost.

But startup Edisun Microgrids, which was founded by tech entrepreneur Bill Gross and emerged a year ago, has developed a dual-axis rooftop tracking system specifically designed for the roofs of commercial and industrial building owners. Its distributed trackers pivot from the bottom edge of a panel (instead of from the center in most tracker systems) and can also retract to lie flat against the roof.

The company says its rooftop tracking gear can boost the energy output of a solar project by 30 percent compared to fixed-tilt trackers and 40 percent compared to solar panels without trackers. The hardware adds 10 percent onto a budget of a solar project, and can improve the economics of a solar installation by 20 percent, says founder and CEO Gross.

“We’re hoping to show tracking is just as valuable on the roof compared to the ground," he said. "We hope this will be a big sea change and make a big impact."

The company’s big solar-tracker project was installed on an industrial rooftop in Oxnard, Calif., which is being used by produce distributor Chiquita Brands International. The 1-megawatt solar array is using 2,900 trackers across 368,000 square feet. West Hills Construction developed the project, and it’s financed and owned by building owner Harry Ross Industries.

The project is the first larger one by Edisun Microgrids, but Gross said that the company has a pipeline of 20 megawatts-worth of projects to be built on the roofs of commercial and industrial buildings. The company says ideal customers include warehouse owners, retail outlets, college campuses and hospitals.

While the Chiquita roof is a big step for Edisun Microgrids, it could face an uphill climb. The industry is notoriously hard for solar hardware startups to break into.

“The solar industry is quite conservative and price-sensitive. They’re producing electricity, which is a commodity,” noted Scott Moskowitz, a solar analyst at GTM Research.

When it comes to Edisun Microgrid’s prospects, Moskowitz pointed out that adding an individual tracker to each module adds equipment, complexity and cost.

“Proving that their technology adds enough value (via increased performance) and reliability will be an extremely difficult thing to do,” said Moskowitz.

However, Moskowitz also noted that the commercial sector is more willing to invest in the premium that the new tracking gear would require. If Edisun can prove that the performance and economics work, there could be an opportunity in certain areas like California or Arizona, said Moskowitz.

Gross said that the majority of the company’s customers are in California. “Whenever I fly into the San Jose airport, I can see all those white warehouse roofs that would be perfect,” said Gross.

Edisun Microgrids has grown to 16 employees, and Gross says the company is looking for funding to expand.