Qcells aims to build a giant factory for next-gen tandem solar

Solar panel maker Qcells is working on a new kind of panel that could make rooftop and ground-mounted solar more efficient. The technology layers perovskites, a crystal material, on top of standard silicon solar cells. This "tandem" design has set efficiency records in labs, but until now no one has mass-produced and sold these panels with a standard warranty, because the perovskite layer tends to break down faster than regular solar panels.

Qcells says it plans to open a large factory to build these tandem panels by 2029. The company has already tested full-size tandem panels in the field and says one version passed industry-standard quality testing, including simulated hail and years of accelerated wear, run by independent labs. Current top-performing panels convert about 24 percent of sunlight into electricity; Qcells has already hit 28.6 percent with a tandem cell in testing, though that number came from a lab, not a mass-produced panel on a roof. The location of the planned factory has not been finalized.

For homeowners, this matters down the road more than today. If tandem panels reach the market with a normal warranty, they would produce more electricity in the same amount of roof space as current panels, or let installers use a smaller array to get the same output, which could lower costs for mounting hardware and wiring. But that is still a few years off, and Qcells is one of several companies, including some in China, racing toward the same goal. Nothing changes yet for anyone considering solar now.