In clean energy infrastructure, better technology doesn’t always win.
Building physical products for the energy transition comes with a unique set of challenges: manufacturing complexity, supply chain management, long sales cycles, and the constant pressure to lower costs. For Sunfolding, a company that developed innovative pneumatic solar trackers, these hurdles ultimately proved insurmountable.
“I think that the real issue for a lot of climate hardware, hard tech founders is how to get to a point where you can sell things that will pay for your company,” said Leila Madrone, founder and former chief technology officer of Sunfolding, on The Green Blueprint podcast. “It’s very simple.”
Madrone launched Sunfolding in 2012 when the solar market was booming. Her vision for the company centered on making solar tracking systems more manufacturable.
“The basic idea was how do you take the physics of how a solar field works…and then how do you apply high volume manufacturing to it?” Madrone explained.
Unlike conventional solar trackers that used motors connected to steel rods to move panels, Sunfolding’s design used pneumatics — compressed air in industrial airbags — to position the panels. The approach dramatically reduced the amount of steel and the number of components needed.
“Sunfolding had about three to four structural components compared to dozens of structural components that a traditional tracker would have,” Madrone said. This early success, however, wasn’t enough to steel the company against the market turmoil to come.
The early days
Sunfolding’s first notable deployment came in 2015: a 300-kilowatt demonstration at PV Evolution Labs in Davis, California. The owners of the site frequently contracted startups trying to prove their technology in the field.
That first demonstration proved very fruitful for the Sunfolding team; it revealed crucial flaws in the technology that necessitated a redesign.
“We were testing it at the actual product level, which was a field as opposed to the component level,” Madrone explained. “So much about the field is how things interact and so much of the field is how things install…And we realized that we had to do a complete redesign.”
By 2015, the solar industry was experiencing explosive growth, with panel prices steadily falling and installations surging nationwide. So, redesign in hand, Sunfolding spent the next five years in a race against the rapidly falling cost of solar technology. “Bringing up a new technology when it’s part of a new industry was both exhilarating and infuriating because the goalpost kept changing,” said Madrone.
Listen to Leila Madrone’s whole interview on The Green Blueprint:
During this period, Sunfolding was gradually scaling from sub-one megawatt demonstration projects to larger installations of nearly ten megawatts. Each deployment helped build “bankability” — third-party validation that the technology was reliable enough to secure financing.
“We had customers; we had some really big [letters of intent] with big customers signed. We had revenue,” Madrone said. “And I think that’s kind of the right place you want to be as a company to raise Series A,” which Sunfolding did in 2017.
Coming up with solutions
Two years later, the company — faced with investor pressures to continue growing — secured their Series B just as they began noticing issues at some of their sites.
“We realized that a lot of it had to do with possibly not having as many resources to invest in manufacturing and supply chain processes as a bigger company would’ve taken when launching a new product,” Madrone said.
At the start of 2020, Sunfolding decided to take a pause in operations to “implement more best in class processes” and “best in class testing.” It was only supposed to last for six months — but then COVID-19 arrived. Sunfolding’s planned pause stretched into nearly two years as supply chain disruptions and dramatic shifts in material costs — specifically steel — created a perfect storm of challenges.
“There was this historic divergence in the cost of U.S. steel versus Asian steel,” Madrone explained, which hit Sunfolding particularly hard since half of any tracker is steel.
Meanwhile, their U.S.-based manufacturers suddenly faced material costs “three times” higher than their overseas competitors. This price shock forced Sunfolding to quickly develop manufacturing capabilities outside the U.S. “Trying to set up an international supply chain for the first time for a very complex machine during a global pandemic is not fun,” Madrone recalled.
Simultaneously, Sunfolding pivoted its pitch to focus on a unique value proposition: their technology worked exceptionally well on undulating terrain, saving customers from having to grade land flat for solar installations.
“We looked at that and realized that this value proposition we had discounted early on when solar sites were flat was suddenly something that made our technology unique and exceptional,” Madrone said. “Not just value in terms of cost, but value in terms of preserving the land as well as saving money, preserving top soil.”
By 2022, the pause was over and the company was back to working on customer projects. And the investors were back to pressuring for larger scale demonstrations.
“We needed to figure out how to get enough revenue so we would look big enough to get to play at another level if we wanted to prove that we could be one of the top tracker companies,” Madrone explained.
And they had an opportunity to go big — they’d been offered a utility-scale project.
“It was this big project on totally flat land where we’re going to be losing a ton of money and we had to make the decision: is it worth it?” explained Madrone. “I can still remember the day we made the decision…I knew that that decision was going to make or break the company.”
Despite their reservations, Sunfolding decided to commit to the project. But as they began manufacturing, disaster struck half way across the world.
The final blow for Sunfolding
In early 2023, a devastating earthquake in Turkey disrupted the supply chain for a critical polymer that was central to Sunfolding’s technology. “We had been using a material from DuPont that had been used in automotive for 40 or 50 years,” Madrone explained. The earthquake destroyed production of a tiny component essential to this polymer.
Recent corporate changes — DuPont had sold the polymer division to Dow, which then sold it to Celanese — further complicated matters, and Sunfolding found itself at the bottom of priority lists for the limited supply. “For the six months that we were supposed to be deploying product at the utility scale project, our supply chain team was on the phone with all of our customers explaining why we were late,” Madrone said.
By 2023, the accumulated pressures became insurmountable. After exhausting funding options and with investors unable to commit more capital, Sunfolding announced it was shutting down.
“We were trying to raise money for that whole time, and we ultimately came to the conclusion that it wasn’t going to happen,” said Madrone. “Our existing investors were tapped out, and without someone to pass us to take us to the next phase, there just wasn’t enough cash.”
Madrone said the decision to close Sunfolding was heartbreaking: “It was like the worst thing I’d ever imagined happening to this company.”
Madrone sees Sunfolding’s story as part of a broader challenge for climate tech hardware companies. She believes founders need to look beyond traditional venture capital for resources and build coalitions that include corporate partnerships and government support.
“The ecosystem has to stop pushing founders toward VC immediately,” Madrone said. “The current work I’m doing is thinking about what are all these different resources and tools you can use outside of VC.”
And despite Sunfolding’s closure, Madrone remains optimistic about the industry’s trajectory.
“You have these moments where it feels like hope is lost, and then you can’t believe how much progress we’ve made. It is extraordinary,” she said. “You can’t get lost in the waves. You have to see the whole ocean.”
