Innovations are driving the development and production of increasingly powerful and cost-effective solar cells and modules, as is evident in the trajectory from multi-busbar technology to half-cut cell modules to solar tiles and shingles.
Meanwhile, both module wattage and wafer size have increased over time. Wafers with a diameter of 182 mm2 (M10) or 210 mm2 (M12) have become the new standard. Leading manufacturers have begun mass producing modules with capacities exceeding 500 or even 600 watts. Highly efficient monocrystalline solar modules now have a larger share of the global market than multicrystalline modules. According to a report by the International Energy Agency (IEA), the share of crystalline solar cells using PERC (Passivated Emitter and Rear Cell) technology already topped 65 percent back in 2019. In the first half of 2020, multicrystalline PERC cells achieved an average efficiency of 20.6 percent, with monocrystalline PERC cells at 22.4 to 22.5 percent. Another important step toward even greater efficiency is heterojunction technology (HJT), which boasts cell efficiencies of over 25 percent; this technology earned REC Solar EMEA GmbH the Intersolar Award in 2020. Bifacial modules, which additionally exploit solar radiation on the backsheet, are also growing in popularity, leading to even higher solar power yields. When used in combination with single-axis tracking systems in large free-standing installations, bifacial modules have an especially high potential to further lower the costs of producing electricity. Bifacial modules are also experiencing strong growth in applications for agrivoltaics and floating PV. The IEA expects bifacial modules to reach a 50 percent market share by the end of 2023.
The development and manufacturing of perovskite cells, typically in conjunction with silicon cells, is also making huge strides. In December 2020, Oxford PV achieved a conversion efficiency of 29.52 percent with a perovskite cell (silicon, with a thin perovskite coating) The cells are expected to be market-ready by 2022.