Maverick pneumatic solar tracker maker Sunfolding has amassed a pipeline of 60 megawatts for the first quarter of 2019, following its 2018 commercial rollout, says Matthew Schneider, the vice president of product at the San Francisco-based company. Sunfolding also is supplying its first delivery contract for a utility-scale photovoltaic array, a 39 MW project in California, using the company’s motor-less T29 single-axis design.
The company has previously sold into the commercial and industrial segment, ranging from 1 MW to 10 MW, but this year, with multiple component manufacturing partners in place, it is poised to roll out far more projects based on its T29, says Schneider. Apart from eliminating motors, the tracker design eliminates multiple parts that are typically used by Tier 1 tracker suppliers— requiring only 3 versus 29, the company claims. The unique bellows positioning design of the T29 generation 3 eliminates motors, batteries, cylinder actuators, and gear plates.
The bellows are based on a DuPont High Performance polymer, blow-injected in Tennessee by automotive manufacturer Martinrea. Perhaps the most noticeable aspect of the tracker design after the bellows is the lack of a torque tube, instead supporting and rotating the panels on a set of off-the-shelf purlins. The bellows assembly attaches to the mast with two bolts, and to each purlin with another two bolts. Given the low elevation of the design, no stepladder is required in the field, Schneider says.
Because the tracker has fewer parts and because the bellows is pre-assembled, installation time is cut by as much as 50%, one installer told Sunfolding. “We are pleased to see that word is spreading quickly about our installation speed, which is at least two times faster than traditional trackers,” noted Sunfolding’s CEO, Jurgen Krehnke, at the time of the contract announcement
“As time is literally money in this case, installation speed makes a huge difference for our customers’ financial calculations,” said Krehnke. “With simplicity and durability hand in hand, Sunfolding’s next-to-zero maintenance requirements will continue to create value during the lifetime of the plant. It is this level of systemic advantages that really sets our technology apart and drives fast adoption,” he suggested.
The pneumatic system has a pressure about the same as a soccer ball, says Schneider. Each 300 kW of array requires a pressure tank, regulated with high-grade valves.
The company has filed for three patents on fluidic actuators for use in solar arrays, and has pioneered the bellows application of the material provided by Dupont Performance Polymers. Dupont became a strategic partner in 2015, advising on material selection and manufacturing, utilizing its expertise in long-lifetime, harsh environment applications like automotive and marine, the company says.
Sunfolding won a SunShot award from the U.S. Department of Energy that amounted to $2 million in 2016, aimed at component cost reduction of the bellows technology. The company was able to attract $1 million in funding from the California Energy Commission to allow the deployment of 300 kW of tracked PV in 50 kW phases at the DNV GL solar test center at Davis, CA. “We continuously provide updated data to DNV which can utilize it in bankability reports,” says Schneider.
Sunfolding hired DNV-GL to perform a bankability study on the T29, and a first draft was produced in August 2016. Field tests show that “the T29’s motor-free, wear-free tracker rows require minimal maintenance during the system’s operational lifetime and the tracker is showing a 99.9% uptime,” Sunfolding claims. The company also hired another independent engineer to perform an in-depth technical analysis of the T29, which is offered to prospective clients, notes Schneider.
Sunfolding also reassures prospective clients of its durability claims — up to 35 years on many components — through a self-insurance fund that takes the place of a third-party warranty. The fund is legally “bankruptcy remote” meaning even in bankruptcy, the warranty money is protected for the use for which the fund was established.
“We are the only solar company in the industry with this kind of fund,” Schneider says. The Sunfolding warranty fund is administered by Bay4 Energy, the Harbor, FL-based energy asset manager, which facilitates any repair requirement, he notes.
Among venture capitalists supporting Sunfolding are Y Combinator Incubator/Accelerator, based in Mountain View, CA, Alumni Ventures Group Venture Capital, based in Manchester, NH, and Castor Ventures Angel Investor Group based in Waltham, Mass.