Tandem PV opened a 65,000‑square‑foot automated perovskite line in Fremont, California, the same Bay Area site that Tesla used for its electric‑vehicle plant. The new factory can produce panels that reach 30% efficiency, up from the 22% conversion rate of conventional silicon cells, a jump that could deliver one‑third more power per square foot. Perovskite crystals have long been touted as the next leap in solar technology, but scaling the laboratory process to commercial production has proven difficult. The Fremont line is the first large‑scale commercial plant to apply the material, moving beyond the 10‑centimeter test cells that have dominated the field. First Solar has been producing thin‑film panels in the U.S. for years, yet few other companies have succeeded at the same scale. The facility covers 65,000 square feet and is designed to produce 40 megawatts of solar capacity each year, a modest output compared with gigawatt‑scale U.S. plants. During the learning phase it runs 10 to 20 panels a day, with plans to ramp to full‑scale production by June. The panels are 60 times larger than those produced in the R&D lab, yet still only a quarter of the size of typical utility‑scale modules. The company’s Series A round, led by Eclipse Ventures , raised $50 million, and the technology’s theoretical efficiency ceiling sits at about 45%. “We’re at 30%,” Scott Wharton , the CEO, said, noting that the goal is to “get thousands of panels out there to show that we can replicate the process.” He added that the automated line should eventually churn out panels that perform as well as or better than the lab specimens. Greg Reichow of Eclipse Ventures said the company had “never seen somebody that can do both a big jump forward on efficiency, and do it at a demonstrated panel size that was relevant for an actual product, and demonstrate the durability that you need.” If Tandem’s approach proves scalable, U.S. solar could leapfrog silicon’s efficiency ceiling, reduce reliance on the Chinese supply chain, and provide the U.S. with an advantage in clean energy production without additional dependence on the silicon supply chain that China has dominated. The company plans to launch full‑size panels in 2028 from a still‑unannounced larger factory, positioning it to meet the growing demand for clean energy.