Qcells, a major solar manufacturer operating in the U.S., says it plans to build a gigawatt-scale factory for tandem solar panels by 2029. Tandem panels layer perovskites onto conventional silicon cells to capture more sunlight, and lab tests have shown efficiencies well above today's standard panels. Qcells says its full-size tandem panels already passed industry quality and safety standards, though the company has not shared details on its perovskite ingredients or early field degradation data.
The move puts Qcells in direct competition with startups like Tandem PV, Oxford PV, and Caelux, which are also trying to commercialize tandem technology. Tandem PV is targeting a gigawatt-scale factory by 2028, and Chinese firm GCL says it opened a 1-GW factory last year. Qcells argues that its experience manufacturing silicon panels at scale gives it an edge over venture-backed startups, noting that it does not need to raise outside money and is focused solely on commercial production.
If tandem panels can be mass-produced with reliable warranties, they could accelerate solar adoption by generating more power in the same footprint, cutting costs on land, wiring, and labor. But the technology still has to prove it can survive decades outdoors, and the industry has yet to see a tandem panel operate for a full commercial lifetime. Qcells' 2029 target leaves time for more testing, but the race to build the first big tandem factory is clearly heating up.