High solar cell efficiencies are a key motivating factor for investing in HJT. Due to the superior passivation quality, the cell technology can attain very high Voc of above 740 mV. PV producers, equipment makers and research institutes have announced different efficiency levels at various stages of the HJT process. We have listed record cell efficiencies of leading HJT players in our recent HJT Solar Technology Report (Status: Nov. 2020). But things are moving quickly in solar – also in HJT, and in mid-February GS-Solar announced a new record, so that we have updated the graph above.
The latest record from China’s GS-Solar is 25.2% for a commercial size solar cell. The company explained it was able to achieve this level of efficiency using a screen printing design and newly developed silver paste to allow for better conductivity and interconnection performance. Cost control has been achieved bringing the cost of producing a cell down by 8% to 12%, it adds, by greatly reducing silver paste consumption per cell to 120 mg. Another reason that enabled the efficiency level of 25.2% was due to the improvement achieved in transmittance of the amorphous silicon film which can ‘increase cell conversion efficiency by more than 0.2%’ (see 25.2% Efficiency For GS-Solar HJT Solar Cell).
A joint development program between the research center CEA-INES and HJT producer Enel Green Power has attained a certified efficiency of 25% on M2 wafer size. This is was the highest certified efficiency reported for a full size HJT cell among today’s active HJT players until recently.
However, that title was held by China’s Hanergy in principle, which reported an efficiency of 25.11% over a surface area of 244.45 cm2 in November 2019. In that same year, Hanergy announced two more record efficiencies of 24.85% in August and 24.3% in January. However, several of the companies’ solar subsidiaries filed for bankruptcy, ceased operations in the meantime.
Hevel has been mass producing HJT cells at its fab in Russia since 2017. Its current average and best efficiencies are 23.3% and 23.8%, respectively, for busbar-less cells compatible with SWCT module technology, whereas a 5-busbar cell has an average efficiency of 22.8%.
Jinergy has no R&D line; instead, it completely focuses on its commercial manufacturing line, which produces HJT cells with an average efficiency of 24%. The best cells coming out of this production line are about 24.4% efficient. The company is optimistic to improve the average production value to its best efficiency level by the end of this year. All these efficiencies are referring to M6 wafer format; Jinergy is the first HJT manufacturer to move to the larger M6 wafer size.
Tongwei, which stepped into the HJT arena two years ago, has already reached 24% efficiency in production. EcoSolifer says it is running the production at a 23.5% efficiency level, while the best cell produced so far is 24.4% efficient. Risen reported an average efficiency of 23.6% and the maximum value touched in the production line is at 24.2%. REC, which played an instrumental role in driving HJT technology into high volume production, is operating at a 24% efficiency level on average with M4 wafer size. CIE Power, also one of the early adopters of the technology, has two different cell types. The 5-busbar cell has an average efficiency of 23%, while the best cell in this metallization pattern reached 23.5%. The 9-busbar cell of the company has an average production efficiency of 24% and the best of this lot reached 24.3%. Panasonic, the inventor of the technology but stuck with the 5-inch wafer size, has started a pilot project to adapt the technology to 6-inch. It attained a certified efficiency of 23.9%. According to our earlier research, GS-Solar attained an average efficiency of 24.1% and best efficiency of 24.68% in production. Its new record is now 25.2%. In addition, the company has also adapted the HJT technology to multicrystalline wafers with MBB. The 158 mm cell reached a cell efficiency of 23.53%.
The efficiencies in this text (expect for the latest GS-Solar efficiency) are taken from the TaiyangNews Heterojunction Solar Technology 2020 report, which provides details on HTJ technology and can be downloaded for free here.
TaiyangNews high efficiency cell technologies conference held on Dec.3, 2020 gives detailed information about HJT and all high efficiency cell technologies. All recordings and Conference summary can be accessed for free here.