Solar photovoltaic (PV) modules are approaching the limits of physical efficiency improvements using current technology, but manufacturers are now looking toward the next generation of dual-layer cells — with additional cost gains likely to result. Emerging "tandem" cells will extend the limits by using two layers, instead of one at present, although they are not expected to be available in fully commercial volumes until around 2030. The most promising forms of this technology involve using perovskite crystals, a synthetic material, in addition to silicon. Each layer of a tandem cell is optimized for converting a certain portion of the solar spectrum, so the combination can achieve better efficiency than a single layer.
Solar cells are the building blocks of solar panels, and their efficiency refers to the amount of sunlight they convert into electricity. The best commercial single-layer silicon panels — today's main technology — currently convert 26% of incoming sunlight into electricity, or 90% of the 29% theoretical maximum. Gradual technological improvements have steadily pushed that ratio higher over years, but further progress is intrinsically limited by the cap.
From Lab to Factory
