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I've been curious about the modules ever since I read the announcement.
LONGi didn't provide much in the way of technical details, so I did some research. I'm impressed with the technology, and think they will dominate the DG market once they ramp production into the 10s of GW.
The "BC" in "HPBC" stands for back contact. PERC and TOPCon cells have positive traces on one side and negative on the other, blocking some of the incoming radiation. HPBC cells use Interdigitated Back Contacts (IBC), with alternating fingers for positive and negative. One contact is aluminum, and one is silver, which reduces costs compared to TOPCon where silver is typically used for both.
The meaning of hybrid passivation took more research to figure out. The LONGi cells are a heterojunction cell (HJT), which benefit from passivation of both the positive and negative-doped areas. Passivation is done by coating hydrogenated amorphous silicon on the cell. It results in lower surface recombination and therefore more power. LONGi's HBPC cells only passivate one polarity area, not both. I'm not sure why, but I'd guess it is either for mass production efficiency, or due to chemistry (compatibility of Al or Ag contacts).
LONGi's HPBC cells use p-type mono silicon, whereas most TOPCon cells use n-type, which is about 20% more expensive. With polysilicon prices approaching $15/kg, I estimate LONGi's cost to produce a 182mm HPBC cell at around 40c. A 430W module uses 54 of these cells. In a year from now I expect wholesale prices FOB LONGi's factories will be $70-$80.
LONGi didn't provide much in the way of technical details, so I did some research. I'm impressed with the technology, and think they will dominate the DG market once they ramp production into the 10s of GW.
The "BC" in "HPBC" stands for back contact. PERC and TOPCon cells have positive traces on one side and negative on the other, blocking some of the incoming radiation. HPBC cells use Interdigitated Back Contacts (IBC), with alternating fingers for positive and negative. One contact is aluminum, and one is silver, which reduces costs compared to TOPCon where silver is typically used for both.
The meaning of hybrid passivation took more research to figure out. The LONGi cells are a heterojunction cell (HJT), which benefit from passivation of both the positive and negative-doped areas. Passivation is done by coating hydrogenated amorphous silicon on the cell. It results in lower surface recombination and therefore more power. LONGi's HBPC cells only passivate one polarity area, not both. I'm not sure why, but I'd guess it is either for mass production efficiency, or due to chemistry (compatibility of Al or Ag contacts).
LONGi's HPBC cells use p-type mono silicon, whereas most TOPCon cells use n-type, which is about 20% more expensive. With polysilicon prices approaching $15/kg, I estimate LONGi's cost to produce a 182mm HPBC cell at around 40c. A 430W module uses 54 of these cells. In a year from now I expect wholesale prices FOB LONGi's factories will be $70-$80.
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