Heterojunction has been a part of the solar industry for several years now. It’s still a clear minority compared to TOPCon, which is more easily switched to from existing PERC production lines, and which is less challenging considering heterojunction’s relatively more high-tech nature and cost reduction challenges. TOPCon is expected to reach around 500 GW of cell production capacity by the end of this year, while heterojunction is at around 20 GW as of mid-2023 and will more than double by December – with over 100 GW of production capacity under planning from a variety of companies. Both N-type technologies, TOPCon and heterojunction, use much more silver paste than PERC does, posing a serious cost challenge for heterojunction. Now an…